diff --git a/flang/include/flang/ISO_Fortran_binding_wrapper.h b/flang/include/flang/Common/ISO_Fortran_binding_wrapper.h
similarity index 72%
rename from flang/include/flang/ISO_Fortran_binding_wrapper.h
rename to flang/include/flang/Common/ISO_Fortran_binding_wrapper.h
index 37289bdbabd03..890522953efe0 100644
--- a/flang/include/flang/ISO_Fortran_binding_wrapper.h
+++ b/flang/include/flang/Common/ISO_Fortran_binding_wrapper.h
@@ -1,14 +1,13 @@
-/*===-- include/flang/ISO_Fortran_binding_wrapper.h ---------------*- C++ -*-===
+/*===-- include/flang/Common/ISO_Fortran_binding_wrapper.h --------*- C++ -*-===
  *
  * Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
  * See https://llvm.org/LICENSE.txt for license information.
  * SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
  *
- * ===-----------------------------------------------------------------------===
- */
+ *===----------------------------------------------------------------------===*/
 
-#ifndef FORTRAN_ISO_FORTRAN_BINDING_WRAPPER_H_
-#define FORTRAN_ISO_FORTRAN_BINDING_WRAPPER_H_
+#ifndef FORTRAN_COMMON_ISO_FORTRAN_BINDING_WRAPPER_H_
+#define FORTRAN_COMMON_ISO_FORTRAN_BINDING_WRAPPER_H_
 
 /* A thin wrapper around flang/include/ISO_Fortran_binding.h
  * This header file must be included when ISO_Fortran_binding.h
@@ -23,17 +22,17 @@
 
 /* clang-format off */
 #include <stddef.h>
-#include "Common/api-attrs.h"
+#include "api-attrs.h"
 #ifdef __cplusplus
 namespace Fortran {
 namespace ISO {
 #define FORTRAN_ISO_NAMESPACE_ ::Fortran::ISO
 #endif /* __cplusplus */
-#include "ISO_Fortran_binding.h"
+#include "flang/ISO_Fortran_binding.h"
 #ifdef __cplusplus
 } // namespace ISO
 } // namespace Fortran
 #endif /* __cplusplus */
 /* clang-format on */
 
-#endif /* FORTRAN_ISO_FORTRAN_BINDING_WRAPPER_H_ */
+#endif /* FORTRAN_COMMON_ISO_FORTRAN_BINDING_WRAPPER_H_ */
diff --git a/flang/include/flang/Common/erfc-scaled.h b/flang/include/flang/Common/erfc-scaled.h
index a1bf3ea0f0925..88e2183c15d03 100644
--- a/flang/include/flang/Common/erfc-scaled.h
+++ b/flang/include/flang/Common/erfc-scaled.h
@@ -9,6 +9,9 @@
 #ifndef FORTRAN_COMMON_ERFC_SCALED_H_
 #define FORTRAN_COMMON_ERFC_SCALED_H_
 
+#include <cmath>
+#include <limits>
+
 namespace Fortran::common {
 template <typename T> inline T ErfcScaled(T arg) {
   // Coefficients for approximation to erfc in the first interval.
diff --git a/flang/include/flang/Common/fast-int-set.h b/flang/include/flang/Common/fast-int-set.h
index d1c9c756a44a6..1214bac75a4bf 100644
--- a/flang/include/flang/Common/fast-int-set.h
+++ b/flang/include/flang/Common/fast-int-set.h
@@ -24,7 +24,7 @@
 #ifndef FORTRAN_COMMON_FAST_INT_SET_H_
 #define FORTRAN_COMMON_FAST_INT_SET_H_
 
-#include <optional>
+#include "optional.h"
 
 namespace Fortran::common {
 
@@ -83,9 +83,9 @@ template <int N> class FastIntSet {
     }
   }
 
-  std::optional<int> PopValue() {
+  optional<int> PopValue() {
     if (IsEmpty()) {
-      return std::nullopt;
+      return nullopt;
     } else {
       return value_[--size_];
     }
diff --git a/flang/include/flang/Common/format.h b/flang/include/flang/Common/format.h
index c5e9fb06e260f..da416506ffb5d 100644
--- a/flang/include/flang/Common/format.h
+++ b/flang/include/flang/Common/format.h
@@ -9,8 +9,8 @@
 #ifndef FORTRAN_COMMON_FORMAT_H_
 #define FORTRAN_COMMON_FORMAT_H_
 
+#include "Fortran-consts.h"
 #include "enum-set.h"
-#include "flang/Common/Fortran-consts.h"
 #include <cstring>
 
 // Define a FormatValidator class template to validate a format expression
diff --git a/flang/include/flang/Common/optional.h b/flang/include/flang/Common/optional.h
index c0f4278009f40..c7c81f40cc8c8 100644
--- a/flang/include/flang/Common/optional.h
+++ b/flang/include/flang/Common/optional.h
@@ -26,7 +26,7 @@
 #ifndef FORTRAN_COMMON_OPTIONAL_H
 #define FORTRAN_COMMON_OPTIONAL_H
 
-#include "flang/Common/api-attrs.h"
+#include "api-attrs.h"
 #include <optional>
 #include <type_traits>
 
diff --git a/flang/include/flang/Common/real.h b/flang/include/flang/Common/real.h
index b527deda0e3b4..b47ba46581db6 100644
--- a/flang/include/flang/Common/real.h
+++ b/flang/include/flang/Common/real.h
@@ -13,7 +13,7 @@
 // The various representations are distinguished by their binary precisions
 // (number of explicit significand bits and any implicit MSB in the fraction).
 
-#include "flang/Common/api-attrs.h"
+#include "api-attrs.h"
 #include <cinttypes>
 
 namespace Fortran::common {
diff --git a/flang/include/flang/Common/reference-wrapper.h b/flang/include/flang/Common/reference-wrapper.h
index 2983754108f95..85b2c6d5abce3 100644
--- a/flang/include/flang/Common/reference-wrapper.h
+++ b/flang/include/flang/Common/reference-wrapper.h
@@ -25,7 +25,7 @@
 #ifndef FORTRAN_COMMON_REFERENCE_WRAPPER_H
 #define FORTRAN_COMMON_REFERENCE_WRAPPER_H
 
-#include "flang/Common/api-attrs.h"
+#include "api-attrs.h"
 #include <functional>
 #include <type_traits>
 
diff --git a/flang/include/flang/Common/restorer.h b/flang/include/flang/Common/restorer.h
index 0f1bc48620d37..c18c13e351c76 100644
--- a/flang/include/flang/Common/restorer.h
+++ b/flang/include/flang/Common/restorer.h
@@ -18,8 +18,8 @@
 
 #ifndef FORTRAN_COMMON_RESTORER_H_
 #define FORTRAN_COMMON_RESTORER_H_
+#include "api-attrs.h"
 #include "idioms.h"
-#include "flang/Common/api-attrs.h"
 namespace Fortran::common {
 template <typename A> class Restorer {
 public:
diff --git a/flang/include/flang/Common/target-rounding.h b/flang/include/flang/Common/target-rounding.h
index c0c9f6c49b26a..f503b22930ed4 100644
--- a/flang/include/flang/Common/target-rounding.h
+++ b/flang/include/flang/Common/target-rounding.h
@@ -9,8 +9,8 @@
 #ifndef FORTRAN_COMMON_TARGET_ROUNDING_H_
 #define FORTRAN_COMMON_TARGET_ROUNDING_H_
 
-#include "flang/Common/Fortran-consts.h"
-#include "flang/Common/enum-set.h"
+#include "Fortran-consts.h"
+#include "enum-set.h"
 
 namespace Fortran::common {
 
diff --git a/flang/include/flang/Common/template.h b/flang/include/flang/Common/template.h
index 51d09fb42ce36..6501994133759 100644
--- a/flang/include/flang/Common/template.h
+++ b/flang/include/flang/Common/template.h
@@ -9,8 +9,8 @@
 #ifndef FORTRAN_COMMON_TEMPLATE_H_
 #define FORTRAN_COMMON_TEMPLATE_H_
 
+#include "idioms.h"
 #include "variant.h"
-#include "flang/Common/idioms.h"
 #include <functional>
 #include <optional>
 #include <tuple>
diff --git a/flang/include/flang/Common/uint128.h b/flang/include/flang/Common/uint128.h
index 821c8c3b08a52..faecb88737a0b 100644
--- a/flang/include/flang/Common/uint128.h
+++ b/flang/include/flang/Common/uint128.h
@@ -19,8 +19,8 @@
 #define AVOID_NATIVE_UINT128_T 0
 #endif
 
+#include "api-attrs.h"
 #include "leading-zero-bit-count.h"
-#include "flang/Common/api-attrs.h"
 #include <cstdint>
 #include <type_traits>
 
diff --git a/flang/include/flang/Common/visit.h b/flang/include/flang/Common/visit.h
index ad66297650b09..1a84102b56642 100644
--- a/flang/include/flang/Common/visit.h
+++ b/flang/include/flang/Common/visit.h
@@ -21,8 +21,8 @@
 #ifndef FORTRAN_COMMON_VISIT_H_
 #define FORTRAN_COMMON_VISIT_H_
 
+#include "api-attrs.h"
 #include "variant.h"
-#include "flang/Common/api-attrs.h"
 #include <type_traits>
 
 namespace Fortran::common {
diff --git a/flang/include/flang/Evaluate/call.h b/flang/include/flang/Evaluate/call.h
index 63277438128eb..2a5929b873d74 100644
--- a/flang/include/flang/Evaluate/call.h
+++ b/flang/include/flang/Evaluate/call.h
@@ -13,11 +13,11 @@
 #include "constant.h"
 #include "formatting.h"
 #include "type.h"
-#include "flang/Common/Fortran.h"
 #include "flang/Common/indirection.h"
 #include "flang/Common/reference.h"
 #include "flang/Parser/char-block.h"
 #include "flang/Semantics/attr.h"
+#include "flang/Support/Fortran.h"
 #include <optional>
 #include <vector>
 
diff --git a/flang/include/flang/Evaluate/characteristics.h b/flang/include/flang/Evaluate/characteristics.h
index 5cae8a68f599b..3aa980db5d931 100644
--- a/flang/include/flang/Evaluate/characteristics.h
+++ b/flang/include/flang/Evaluate/characteristics.h
@@ -18,13 +18,13 @@
 #include "shape.h"
 #include "tools.h"
 #include "type.h"
-#include "flang/Common/Fortran-features.h"
-#include "flang/Common/Fortran.h"
 #include "flang/Common/enum-set.h"
 #include "flang/Common/idioms.h"
 #include "flang/Common/indirection.h"
 #include "flang/Parser/char-block.h"
 #include "flang/Semantics/symbol.h"
+#include "flang/Support/Fortran-features.h"
+#include "flang/Support/Fortran.h"
 #include <optional>
 #include <string>
 #include <variant>
diff --git a/flang/include/flang/Evaluate/common.h b/flang/include/flang/Evaluate/common.h
index 915e95169c7f8..993540aebca57 100644
--- a/flang/include/flang/Evaluate/common.h
+++ b/flang/include/flang/Evaluate/common.h
@@ -9,9 +9,6 @@
 #ifndef FORTRAN_EVALUATE_COMMON_H_
 #define FORTRAN_EVALUATE_COMMON_H_
 
-#include "flang/Common/Fortran-features.h"
-#include "flang/Common/Fortran.h"
-#include "flang/Common/default-kinds.h"
 #include "flang/Common/enum-set.h"
 #include "flang/Common/idioms.h"
 #include "flang/Common/indirection.h"
@@ -19,6 +16,9 @@
 #include "flang/Common/target-rounding.h"
 #include "flang/Parser/char-block.h"
 #include "flang/Parser/message.h"
+#include "flang/Support/Fortran-features.h"
+#include "flang/Support/Fortran.h"
+#include "flang/Support/default-kinds.h"
 #include <cinttypes>
 #include <map>
 #include <set>
diff --git a/flang/include/flang/Evaluate/constant.h b/flang/include/flang/Evaluate/constant.h
index 61a814446bbfd..6fc22e3b86aa2 100644
--- a/flang/include/flang/Evaluate/constant.h
+++ b/flang/include/flang/Evaluate/constant.h
@@ -11,8 +11,8 @@
 
 #include "formatting.h"
 #include "type.h"
-#include "flang/Common/default-kinds.h"
 #include "flang/Common/reference.h"
+#include "flang/Support/default-kinds.h"
 #include <map>
 #include <vector>
 
diff --git a/flang/include/flang/Evaluate/expression.h b/flang/include/flang/Evaluate/expression.h
index 04f4406fc8a2c..1203fca8640a6 100644
--- a/flang/include/flang/Evaluate/expression.h
+++ b/flang/include/flang/Evaluate/expression.h
@@ -21,11 +21,11 @@
 #include "formatting.h"
 #include "type.h"
 #include "variable.h"
-#include "flang/Common/Fortran.h"
 #include "flang/Common/idioms.h"
 #include "flang/Common/indirection.h"
 #include "flang/Common/template.h"
 #include "flang/Parser/char-block.h"
+#include "flang/Support/Fortran.h"
 #include <algorithm>
 #include <list>
 #include <tuple>
diff --git a/flang/include/flang/Evaluate/intrinsics.h b/flang/include/flang/Evaluate/intrinsics.h
index 15afb772ae767..dbe1ba7fe7ec1 100644
--- a/flang/include/flang/Evaluate/intrinsics.h
+++ b/flang/include/flang/Evaluate/intrinsics.h
@@ -12,9 +12,9 @@
 #include "call.h"
 #include "characteristics.h"
 #include "type.h"
-#include "flang/Common/default-kinds.h"
 #include "flang/Parser/char-block.h"
 #include "flang/Parser/message.h"
+#include "flang/Support/default-kinds.h"
 #include <memory>
 #include <optional>
 #include <string>
diff --git a/flang/include/flang/Evaluate/target.h b/flang/include/flang/Evaluate/target.h
index e07f916b875e0..f4595dfe4e433 100644
--- a/flang/include/flang/Evaluate/target.h
+++ b/flang/include/flang/Evaluate/target.h
@@ -12,11 +12,11 @@
 #ifndef FORTRAN_EVALUATE_TARGET_H_
 #define FORTRAN_EVALUATE_TARGET_H_
 
-#include "flang/Common/Fortran.h"
 #include "flang/Common/enum-class.h"
 #include "flang/Common/enum-set.h"
 #include "flang/Common/target-rounding.h"
 #include "flang/Evaluate/common.h"
+#include "flang/Support/Fortran.h"
 #include <cstdint>
 
 namespace Fortran::evaluate {
diff --git a/flang/include/flang/Evaluate/type.h b/flang/include/flang/Evaluate/type.h
index a4afe49d6077a..cfb162f040e8a 100644
--- a/flang/include/flang/Evaluate/type.h
+++ b/flang/include/flang/Evaluate/type.h
@@ -22,11 +22,11 @@
 #include "integer.h"
 #include "logical.h"
 #include "real.h"
-#include "flang/Common/Fortran-features.h"
-#include "flang/Common/Fortran.h"
 #include "flang/Common/idioms.h"
 #include "flang/Common/real.h"
 #include "flang/Common/template.h"
+#include "flang/Support/Fortran-features.h"
+#include "flang/Support/Fortran.h"
 #include <cinttypes>
 #include <optional>
 #include <string>
diff --git a/flang/include/flang/Frontend/CompilerInvocation.h b/flang/include/flang/Frontend/CompilerInvocation.h
index 7d3f0bdf2e510..9e6724be33033 100644
--- a/flang/include/flang/Frontend/CompilerInvocation.h
+++ b/flang/include/flang/Frontend/CompilerInvocation.h
@@ -13,7 +13,6 @@
 #ifndef FORTRAN_FRONTEND_COMPILERINVOCATION_H
 #define FORTRAN_FRONTEND_COMPILERINVOCATION_H
 
-#include "flang/Common/LangOptions.h"
 #include "flang/Frontend/CodeGenOptions.h"
 #include "flang/Frontend/FrontendOptions.h"
 #include "flang/Frontend/PreprocessorOptions.h"
@@ -21,6 +20,7 @@
 #include "flang/Lower/LoweringOptions.h"
 #include "flang/Parser/parsing.h"
 #include "flang/Semantics/semantics.h"
+#include "flang/Support/LangOptions.h"
 #include "mlir/Support/Timing.h"
 #include "clang/Basic/Diagnostic.h"
 #include "clang/Basic/DiagnosticOptions.h"
diff --git a/flang/include/flang/Frontend/FrontendOptions.h b/flang/include/flang/Frontend/FrontendOptions.h
index a4cb021e309d4..0bd2e621813ca 100644
--- a/flang/include/flang/Frontend/FrontendOptions.h
+++ b/flang/include/flang/Frontend/FrontendOptions.h
@@ -13,10 +13,10 @@
 #ifndef FORTRAN_FRONTEND_FRONTENDOPTIONS_H
 #define FORTRAN_FRONTEND_FRONTENDOPTIONS_H
 
-#include "flang/Common/Fortran-features.h"
 #include "flang/Lower/EnvironmentDefault.h"
 #include "flang/Parser/characters.h"
 #include "flang/Parser/unparse.h"
+#include "flang/Support/Fortran-features.h"
 #include "llvm/ADT/StringRef.h"
 #include "llvm/Support/MemoryBuffer.h"
 #include <cstdint>
diff --git a/flang/include/flang/ISO_Fortran_binding.h b/flang/include/flang/ISO_Fortran_binding.h
index 945f8fef89f0b..f5b8d0d2ea610 100644
--- a/flang/include/flang/ISO_Fortran_binding.h
+++ b/flang/include/flang/ISO_Fortran_binding.h
@@ -14,7 +14,7 @@
  * it does so by means of a wrapper header that establishes namespaces and
  * a macro for extra function attributes (RT_API_ATTRS).
  */
-#ifndef FORTRAN_ISO_FORTRAN_BINDING_WRAPPER_H_
+#ifndef FORTRAN_COMMON_ISO_FORTRAN_BINDING_WRAPPER_H_
 #include <stddef.h>
 #define FORTRAN_ISO_NAMESPACE_
 #endif
diff --git a/flang/include/flang/Lower/AbstractConverter.h b/flang/include/flang/Lower/AbstractConverter.h
index c24f43737df50..3d2b805da6f47 100644
--- a/flang/include/flang/Lower/AbstractConverter.h
+++ b/flang/include/flang/Lower/AbstractConverter.h
@@ -13,12 +13,12 @@
 #ifndef FORTRAN_LOWER_ABSTRACTCONVERTER_H
 #define FORTRAN_LOWER_ABSTRACTCONVERTER_H
 
-#include "flang/Common/Fortran.h"
 #include "flang/Lower/LoweringOptions.h"
 #include "flang/Lower/PFTDefs.h"
 #include "flang/Optimizer/Builder/BoxValue.h"
 #include "flang/Optimizer/Dialect/FIRAttr.h"
 #include "flang/Semantics/symbol.h"
+#include "flang/Support/Fortran.h"
 #include "mlir/IR/Builders.h"
 #include "mlir/IR/BuiltinOps.h"
 #include "mlir/IR/Operation.h"
diff --git a/flang/include/flang/Lower/Bridge.h b/flang/include/flang/Lower/Bridge.h
index 6404a16f7785a..a8c2bcfda31c1 100644
--- a/flang/include/flang/Lower/Bridge.h
+++ b/flang/include/flang/Lower/Bridge.h
@@ -13,7 +13,6 @@
 #ifndef FORTRAN_LOWER_BRIDGE_H
 #define FORTRAN_LOWER_BRIDGE_H
 
-#include "flang/Common/Fortran.h"
 #include "flang/Frontend/CodeGenOptions.h"
 #include "flang/Frontend/TargetOptions.h"
 #include "flang/Lower/AbstractConverter.h"
@@ -22,6 +21,7 @@
 #include "flang/Lower/StatementContext.h"
 #include "flang/Optimizer/Builder/FIRBuilder.h"
 #include "flang/Optimizer/Dialect/Support/KindMapping.h"
+#include "flang/Support/Fortran.h"
 #include "mlir/IR/BuiltinOps.h"
 #include "mlir/IR/OwningOpRef.h"
 #include <set>
diff --git a/flang/include/flang/Lower/ConvertType.h b/flang/include/flang/Lower/ConvertType.h
index 7a3f92649a4e4..179a682584046 100644
--- a/flang/include/flang/Lower/ConvertType.h
+++ b/flang/include/flang/Lower/ConvertType.h
@@ -21,8 +21,8 @@
 #ifndef FORTRAN_LOWER_CONVERT_TYPE_H
 #define FORTRAN_LOWER_CONVERT_TYPE_H
 
-#include "flang/Common/Fortran.h"
 #include "flang/Evaluate/type.h"
+#include "flang/Support/Fortran.h"
 #include "mlir/IR/BuiltinTypes.h"
 
 namespace mlir {
diff --git a/flang/include/flang/Lower/LoweringOptions.h b/flang/include/flang/Lower/LoweringOptions.h
index 8105ccd7ef6b1..171510393b816 100644
--- a/flang/include/flang/Lower/LoweringOptions.h
+++ b/flang/include/flang/Lower/LoweringOptions.h
@@ -15,7 +15,7 @@
 #ifndef FLANG_LOWER_LOWERINGOPTIONS_H
 #define FLANG_LOWER_LOWERINGOPTIONS_H
 
-#include "flang/Common/MathOptionsBase.h"
+#include "flang/Support/MathOptionsBase.h"
 
 namespace Fortran::lower {
 
diff --git a/flang/include/flang/Optimizer/Builder/FIRBuilder.h b/flang/include/flang/Optimizer/Builder/FIRBuilder.h
index f2252d04079cf..c8acdac6cafbe 100644
--- a/flang/include/flang/Optimizer/Builder/FIRBuilder.h
+++ b/flang/include/flang/Optimizer/Builder/FIRBuilder.h
@@ -16,12 +16,12 @@
 #ifndef FORTRAN_OPTIMIZER_BUILDER_FIRBUILDER_H
 #define FORTRAN_OPTIMIZER_BUILDER_FIRBUILDER_H
 
-#include "flang/Common/MathOptionsBase.h"
 #include "flang/Optimizer/Dialect/FIROps.h"
 #include "flang/Optimizer/Dialect/FIROpsSupport.h"
 #include "flang/Optimizer/Dialect/FIRType.h"
 #include "flang/Optimizer/Dialect/Support/FIRContext.h"
 #include "flang/Optimizer/Dialect/Support/KindMapping.h"
+#include "flang/Support/MathOptionsBase.h"
 #include "mlir/IR/Builders.h"
 #include "mlir/IR/BuiltinOps.h"
 #include "llvm/ADT/DenseMap.h"
diff --git a/flang/include/flang/Optimizer/Builder/Runtime/RTBuilder.h b/flang/include/flang/Optimizer/Builder/Runtime/RTBuilder.h
index 116b927a86a7a..1ffc354d6b80f 100644
--- a/flang/include/flang/Optimizer/Builder/Runtime/RTBuilder.h
+++ b/flang/include/flang/Optimizer/Builder/Runtime/RTBuilder.h
@@ -17,12 +17,12 @@
 #ifndef FORTRAN_OPTIMIZER_BUILDER_RUNTIME_RTBUILDER_H
 #define FORTRAN_OPTIMIZER_BUILDER_RUNTIME_RTBUILDER_H
 
-#include "flang/Common/Fortran.h"
 #include "flang/Common/uint128.h"
 #include "flang/Optimizer/Builder/FIRBuilder.h"
 #include "flang/Optimizer/Dialect/FIRDialect.h"
 #include "flang/Optimizer/Dialect/FIRType.h"
 #include "flang/Runtime/reduce.h"
+#include "flang/Support/Fortran.h"
 #include "mlir/IR/BuiltinTypes.h"
 #include "mlir/IR/MLIRContext.h"
 #include "llvm/ADT/SmallVector.h"
diff --git a/flang/include/flang/Optimizer/CodeGen/DescriptorModel.h b/flang/include/flang/Optimizer/CodeGen/DescriptorModel.h
index 9cccf8db87270..b9a8a670d0793 100644
--- a/flang/include/flang/Optimizer/CodeGen/DescriptorModel.h
+++ b/flang/include/flang/Optimizer/CodeGen/DescriptorModel.h
@@ -22,7 +22,7 @@
 #ifndef OPTIMIZER_DESCRIPTOR_MODEL_H
 #define OPTIMIZER_DESCRIPTOR_MODEL_H
 
-#include "flang/ISO_Fortran_binding_wrapper.h"
+#include "flang/Common/ISO_Fortran_binding_wrapper.h"
 #include "flang/Runtime/descriptor-consts.h"
 #include "mlir/Dialect/LLVMIR/LLVMTypes.h"
 #include "mlir/IR/BuiltinTypes.h"
diff --git a/flang/include/flang/Optimizer/Dialect/CUF/Attributes/CUFAttr.h b/flang/include/flang/Optimizer/Dialect/CUF/Attributes/CUFAttr.h
index f32e39b543e3f..85615a4d69157 100644
--- a/flang/include/flang/Optimizer/Dialect/CUF/Attributes/CUFAttr.h
+++ b/flang/include/flang/Optimizer/Dialect/CUF/Attributes/CUFAttr.h
@@ -13,7 +13,7 @@
 #ifndef FORTRAN_OPTIMIZER_DIALECT_CUF_CUFATTR_H
 #define FORTRAN_OPTIMIZER_DIALECT_CUF_CUFATTR_H
 
-#include "flang/Common/Fortran.h"
+#include "flang/Support/Fortran.h"
 #include "mlir/IR/BuiltinAttributes.h"
 
 namespace llvm {
diff --git a/flang/include/flang/Optimizer/Support/TypeCode.h b/flang/include/flang/Optimizer/Support/TypeCode.h
index 308c82118d502..ec21d672287e6 100644
--- a/flang/include/flang/Optimizer/Support/TypeCode.h
+++ b/flang/include/flang/Optimizer/Support/TypeCode.h
@@ -13,7 +13,7 @@
 #ifndef FORTRAN_OPTIMIZER_SUPPORT_TYPECODE_H
 #define FORTRAN_OPTIMIZER_SUPPORT_TYPECODE_H
 
-#include "flang/ISO_Fortran_binding_wrapper.h"
+#include "flang/Common/ISO_Fortran_binding_wrapper.h"
 #include "llvm/Support/ErrorHandling.h"
 
 namespace fir {
diff --git a/flang/include/flang/Optimizer/Support/Utils.h b/flang/include/flang/Optimizer/Support/Utils.h
index d507f4116efb7..ec73af6ec72e9 100644
--- a/flang/include/flang/Optimizer/Support/Utils.h
+++ b/flang/include/flang/Optimizer/Support/Utils.h
@@ -13,13 +13,13 @@
 #ifndef FORTRAN_OPTIMIZER_SUPPORT_UTILS_H
 #define FORTRAN_OPTIMIZER_SUPPORT_UTILS_H
 
-#include "flang/Common/default-kinds.h"
 #include "flang/Optimizer/Builder/FIRBuilder.h"
 #include "flang/Optimizer/Builder/Todo.h"
 #include "flang/Optimizer/Dialect/CUF/Attributes/CUFAttr.h"
 #include "flang/Optimizer/Dialect/FIROps.h"
 #include "flang/Optimizer/Dialect/FIRType.h"
 #include "flang/Optimizer/Support/FatalError.h"
+#include "flang/Support/default-kinds.h"
 #include "mlir/Dialect/Arith/IR/Arith.h"
 #include "mlir/Dialect/Func/IR/FuncOps.h"
 #include "mlir/IR/BuiltinAttributes.h"
diff --git a/flang/include/flang/Parser/dump-parse-tree.h b/flang/include/flang/Parser/dump-parse-tree.h
index 3e4e909cdec9a..21ee1d0517840 100644
--- a/flang/include/flang/Parser/dump-parse-tree.h
+++ b/flang/include/flang/Parser/dump-parse-tree.h
@@ -14,9 +14,9 @@
 #include "parse-tree.h"
 #include "tools.h"
 #include "unparse.h"
-#include "flang/Common/Fortran.h"
 #include "flang/Common/idioms.h"
 #include "flang/Common/indirection.h"
+#include "flang/Support/Fortran.h"
 #include "llvm/Support/raw_ostream.h"
 #include <string>
 #include <type_traits>
diff --git a/flang/include/flang/Parser/message.h b/flang/include/flang/Parser/message.h
index bc38f571ca3df..e19b16c23b82b 100644
--- a/flang/include/flang/Parser/message.h
+++ b/flang/include/flang/Parser/message.h
@@ -15,10 +15,10 @@
 #include "char-block.h"
 #include "char-set.h"
 #include "provenance.h"
-#include "flang/Common/Fortran-features.h"
 #include "flang/Common/idioms.h"
 #include "flang/Common/reference-counted.h"
 #include "flang/Common/restorer.h"
+#include "flang/Support/Fortran-features.h"
 #include <cstddef>
 #include <cstring>
 #include <forward_list>
diff --git a/flang/include/flang/Parser/parse-state.h b/flang/include/flang/Parser/parse-state.h
index 76cbb3470dc08..36d70b81b7923 100644
--- a/flang/include/flang/Parser/parse-state.h
+++ b/flang/include/flang/Parser/parse-state.h
@@ -16,11 +16,11 @@
 // and recovery during parsing!
 
 #include "user-state.h"
-#include "flang/Common/Fortran-features.h"
 #include "flang/Common/idioms.h"
 #include "flang/Parser/characters.h"
 #include "flang/Parser/message.h"
 #include "flang/Parser/provenance.h"
+#include "flang/Support/Fortran-features.h"
 #include <cstddef>
 #include <cstring>
 #include <list>
diff --git a/flang/include/flang/Parser/parse-tree.h b/flang/include/flang/Parser/parse-tree.h
index d7b1ae9893c03..c3a02fca5ade8 100644
--- a/flang/include/flang/Parser/parse-tree.h
+++ b/flang/include/flang/Parser/parse-tree.h
@@ -22,9 +22,9 @@
 #include "format-specification.h"
 #include "message.h"
 #include "provenance.h"
-#include "flang/Common/Fortran.h"
 #include "flang/Common/idioms.h"
 #include "flang/Common/indirection.h"
+#include "flang/Support/Fortran.h"
 #include "llvm/Frontend/OpenACC/ACC.h.inc"
 #include "llvm/Frontend/OpenMP/OMP.h"
 #include "llvm/Frontend/OpenMP/OMPConstants.h"
diff --git a/flang/include/flang/Parser/parsing.h b/flang/include/flang/Parser/parsing.h
index 0c774decb16d3..116b6bd6f191f 100644
--- a/flang/include/flang/Parser/parsing.h
+++ b/flang/include/flang/Parser/parsing.h
@@ -14,8 +14,8 @@
 #include "message.h"
 #include "parse-tree.h"
 #include "provenance.h"
-#include "flang/Common/Fortran-features.h"
 #include "flang/Parser/preprocessor.h"
+#include "flang/Support/Fortran-features.h"
 #include "llvm/Support/raw_ostream.h"
 #include <optional>
 #include <string>
diff --git a/flang/include/flang/Parser/user-state.h b/flang/include/flang/Parser/user-state.h
index 61745a833c715..129f9fb8fee05 100644
--- a/flang/include/flang/Parser/user-state.h
+++ b/flang/include/flang/Parser/user-state.h
@@ -14,10 +14,10 @@
 // parse tree construction so as to avoid any need for representing
 // state in static data.
 
-#include "flang/Common/Fortran-features.h"
 #include "flang/Common/idioms.h"
 #include "flang/Parser/char-block.h"
 #include "flang/Parser/parse-tree.h"
+#include "flang/Support/Fortran-features.h"
 #include "llvm/Support/raw_ostream.h"
 #include <cinttypes>
 #include <optional>
diff --git a/flang/include/flang/Runtime/descriptor-consts.h b/flang/include/flang/Runtime/descriptor-consts.h
index 3b2537579d586..abcdbc4a12002 100644
--- a/flang/include/flang/Runtime/descriptor-consts.h
+++ b/flang/include/flang/Runtime/descriptor-consts.h
@@ -9,8 +9,8 @@
 #ifndef FORTRAN_RUNTIME_DESCRIPTOR_CONSTS_H_
 #define FORTRAN_RUNTIME_DESCRIPTOR_CONSTS_H_
 
+#include "flang/Common/ISO_Fortran_binding_wrapper.h"
 #include "flang/Common/api-attrs.h"
-#include "flang/ISO_Fortran_binding_wrapper.h"
 #include <cstddef>
 #include <cstdint>
 
diff --git a/flang/include/flang/Runtime/descriptor.h b/flang/include/flang/Runtime/descriptor.h
index dd36fba157ca9..628ac8c927a51 100644
--- a/flang/include/flang/Runtime/descriptor.h
+++ b/flang/include/flang/Runtime/descriptor.h
@@ -18,7 +18,7 @@
 // User C code is welcome to depend on that ISO_Fortran_binding.h file,
 // but should never reference this internal header.
 
-#include "flang/ISO_Fortran_binding_wrapper.h"
+#include "flang/Common/ISO_Fortran_binding_wrapper.h"
 #include "flang/Runtime/descriptor-consts.h"
 #include "flang/Runtime/memory.h"
 #include "flang/Runtime/type-code.h"
diff --git a/flang/include/flang/Runtime/random.h b/flang/include/flang/Runtime/random.h
index 269297dff47db..1f01be1aa9ffa 100644
--- a/flang/include/flang/Runtime/random.h
+++ b/flang/include/flang/Runtime/random.h
@@ -8,6 +8,9 @@
 
 // Intrinsic subroutines RANDOM_INIT, RANDOM_NUMBER, and RANDOM_SEED.
 
+#ifndef FORTRAN_RUNTIME_RANDOM_H_
+#define FORTRAN_RUNTIME_RANDOM_H_
+
 #include "flang/Runtime/entry-names.h"
 #include <cstdint>
 
@@ -35,3 +38,5 @@ void RTNAME(RandomSeed)(const Descriptor *size, const Descriptor *put,
 
 } // extern "C"
 } // namespace Fortran::runtime
+
+#endif // FORTRAN_RUNTIME_RANDOM_H_
diff --git a/flang/include/flang/Runtime/support.h b/flang/include/flang/Runtime/support.h
index ba9c2598bb0dd..4a6d4357e8710 100644
--- a/flang/include/flang/Runtime/support.h
+++ b/flang/include/flang/Runtime/support.h
@@ -10,7 +10,7 @@
 #ifndef FORTRAN_RUNTIME_SUPPORT_H_
 #define FORTRAN_RUNTIME_SUPPORT_H_
 
-#include "flang/ISO_Fortran_binding_wrapper.h"
+#include "flang/Common/ISO_Fortran_binding_wrapper.h"
 #include "flang/Runtime/entry-names.h"
 #include <cstddef>
 #include <cstdint>
diff --git a/flang/include/flang/Runtime/type-code.h b/flang/include/flang/Runtime/type-code.h
index dd3a9f2690ee7..ae854ed2145e4 100644
--- a/flang/include/flang/Runtime/type-code.h
+++ b/flang/include/flang/Runtime/type-code.h
@@ -10,8 +10,8 @@
 #define FORTRAN_RUNTIME_TYPE_CODE_H_
 
 #include "flang/Common/Fortran-consts.h"
+#include "flang/Common/ISO_Fortran_binding_wrapper.h"
 #include "flang/Common/optional.h"
-#include "flang/ISO_Fortran_binding_wrapper.h"
 #include <utility>
 
 namespace Fortran::runtime {
diff --git a/flang/include/flang/Semantics/expression.h b/flang/include/flang/Semantics/expression.h
index b95ceebc5e8e4..ce253e6f52e8f 100644
--- a/flang/include/flang/Semantics/expression.h
+++ b/flang/include/flang/Semantics/expression.h
@@ -10,7 +10,6 @@
 #define FORTRAN_SEMANTICS_EXPRESSION_H_
 
 #include "semantics.h"
-#include "flang/Common/Fortran.h"
 #include "flang/Common/indirection.h"
 #include "flang/Common/restorer.h"
 #include "flang/Common/visit.h"
@@ -24,6 +23,7 @@
 #include "flang/Parser/parse-tree-visitor.h"
 #include "flang/Parser/parse-tree.h"
 #include "flang/Parser/tools.h"
+#include "flang/Support/Fortran.h"
 #include <map>
 #include <optional>
 #include <type_traits>
diff --git a/flang/include/flang/Semantics/scope.h b/flang/include/flang/Semantics/scope.h
index b3b033a5a3ae3..b4046830522b8 100644
--- a/flang/include/flang/Semantics/scope.h
+++ b/flang/include/flang/Semantics/scope.h
@@ -11,11 +11,11 @@
 
 #include "attr.h"
 #include "symbol.h"
-#include "flang/Common/Fortran.h"
 #include "flang/Common/idioms.h"
 #include "flang/Common/reference.h"
 #include "flang/Parser/message.h"
 #include "flang/Parser/provenance.h"
+#include "flang/Support/Fortran.h"
 #include <list>
 #include <map>
 #include <optional>
diff --git a/flang/include/flang/Semantics/semantics.h b/flang/include/flang/Semantics/semantics.h
index 821ce021b3226..730513dbe3232 100644
--- a/flang/include/flang/Semantics/semantics.h
+++ b/flang/include/flang/Semantics/semantics.h
@@ -13,12 +13,12 @@
 #include "program-tree.h"
 #include "scope.h"
 #include "symbol.h"
-#include "flang/Common/Fortran-features.h"
-#include "flang/Common/LangOptions.h"
 #include "flang/Evaluate/common.h"
 #include "flang/Evaluate/intrinsics.h"
 #include "flang/Evaluate/target.h"
 #include "flang/Parser/message.h"
+#include "flang/Support/Fortran-features.h"
+#include "flang/Support/LangOptions.h"
 #include <iosfwd>
 #include <set>
 #include <string>
diff --git a/flang/include/flang/Semantics/symbol.h b/flang/include/flang/Semantics/symbol.h
index 235fade1ed937..4ae2775c0f849 100644
--- a/flang/include/flang/Semantics/symbol.h
+++ b/flang/include/flang/Semantics/symbol.h
@@ -10,11 +10,11 @@
 #define FORTRAN_SEMANTICS_SYMBOL_H_
 
 #include "type.h"
-#include "flang/Common/Fortran.h"
 #include "flang/Common/enum-set.h"
 #include "flang/Common/reference.h"
 #include "flang/Common/visit.h"
 #include "flang/Semantics/module-dependences.h"
+#include "flang/Support/Fortran.h"
 #include "llvm/ADT/DenseMapInfo.h"
 
 #include <array>
diff --git a/flang/include/flang/Semantics/tools.h b/flang/include/flang/Semantics/tools.h
index 87ddd38e5ae65..e82446a2ba884 100644
--- a/flang/include/flang/Semantics/tools.h
+++ b/flang/include/flang/Semantics/tools.h
@@ -12,7 +12,6 @@
 // Simple predicates and look-up functions that are best defined
 // canonically for use in semantic checking.
 
-#include "flang/Common/Fortran.h"
 #include "flang/Common/visit.h"
 #include "flang/Evaluate/expression.h"
 #include "flang/Evaluate/shape.h"
@@ -23,6 +22,7 @@
 #include "flang/Semantics/attr.h"
 #include "flang/Semantics/expression.h"
 #include "flang/Semantics/semantics.h"
+#include "flang/Support/Fortran.h"
 #include <functional>
 
 namespace Fortran::semantics {
diff --git a/flang/include/flang/Semantics/type.h b/flang/include/flang/Semantics/type.h
index 3522191502059..5d96f1e89bf52 100644
--- a/flang/include/flang/Semantics/type.h
+++ b/flang/include/flang/Semantics/type.h
@@ -9,10 +9,10 @@
 #ifndef FORTRAN_SEMANTICS_TYPE_H_
 #define FORTRAN_SEMANTICS_TYPE_H_
 
-#include "flang/Common/Fortran.h"
 #include "flang/Common/idioms.h"
 #include "flang/Evaluate/expression.h"
 #include "flang/Parser/char-block.h"
+#include "flang/Support/Fortran.h"
 #include <algorithm>
 #include <iosfwd>
 #include <map>
diff --git a/flang/include/flang/Common/Fortran-features.h b/flang/include/flang/Support/Fortran-features.h
similarity index 96%
rename from flang/include/flang/Common/Fortran-features.h
rename to flang/include/flang/Support/Fortran-features.h
index e2a420ae826bc..44ba6428e6c93 100644
--- a/flang/include/flang/Common/Fortran-features.h
+++ b/flang/include/flang/Support/Fortran-features.h
@@ -1,4 +1,4 @@
-//===-- include/flang/Common/Fortran-features.h -----------------*- C++ -*-===//
+//===-- include/flang/Support/Fortran-features.h ----------------*- C++ -*-===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
@@ -6,10 +6,10 @@
 //
 //===----------------------------------------------------------------------===//
 
-#ifndef FORTRAN_COMMON_FORTRAN_FEATURES_H_
-#define FORTRAN_COMMON_FORTRAN_FEATURES_H_
+#ifndef FORTRAN_SUPPORT_FORTRAN_FEATURES_H_
+#define FORTRAN_SUPPORT_FORTRAN_FEATURES_H_
 
-#include "flang/Common/Fortran.h"
+#include "Fortran.h"
 #include "flang/Common/enum-set.h"
 #include "flang/Common/idioms.h"
 #include <optional>
@@ -126,4 +126,4 @@ class LanguageFeatureControl {
   bool warnAllUsage_{false};
 };
 } // namespace Fortran::common
-#endif // FORTRAN_COMMON_FORTRAN_FEATURES_H_
+#endif // FORTRAN_SUPPORT_FORTRAN_FEATURES_H_
diff --git a/flang/include/flang/Common/Fortran.h b/flang/include/flang/Support/Fortran.h
similarity index 94%
rename from flang/include/flang/Common/Fortran.h
rename to flang/include/flang/Support/Fortran.h
index e1922f7654bb1..6e6e37ba594be 100644
--- a/flang/include/flang/Common/Fortran.h
+++ b/flang/include/flang/Support/Fortran.h
@@ -1,4 +1,4 @@
-//===-- include/flang/Common/Fortran.h --------------------------*- C++ -*-===//
+//===-- include/flang/Support/Fortran.h -------------------------*- C++ -*-===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
@@ -6,15 +6,15 @@
 //
 //===----------------------------------------------------------------------===//
 
-#ifndef FORTRAN_COMMON_FORTRAN_H_
-#define FORTRAN_COMMON_FORTRAN_H_
+#ifndef FORTRAN_SUPPORT_FORTRAN_H_
+#define FORTRAN_SUPPORT_FORTRAN_H_
 
 // Fortran language concepts that are used in many phases are defined
 // once here to avoid redundancy and needless translation.
 
-#include "enum-set.h"
-#include "idioms.h"
 #include "flang/Common/Fortran-consts.h"
+#include "flang/Common/enum-set.h"
+#include "flang/Common/idioms.h"
 #include <cinttypes>
 #include <optional>
 #include <string>
@@ -109,4 +109,4 @@ inline std::string GetExternalAssemblyName(
 }
 
 } // namespace Fortran::common
-#endif // FORTRAN_COMMON_FORTRAN_H_
+#endif // FORTRAN_SUPPORT_FORTRAN_H_
diff --git a/flang/include/flang/Common/LangOptions.def b/flang/include/flang/Support/LangOptions.def
similarity index 100%
rename from flang/include/flang/Common/LangOptions.def
rename to flang/include/flang/Support/LangOptions.def
diff --git a/flang/include/flang/Common/LangOptions.h b/flang/include/flang/Support/LangOptions.h
similarity index 87%
rename from flang/include/flang/Common/LangOptions.h
rename to flang/include/flang/Support/LangOptions.h
index 83f25cfbe2614..fac6fb92df85a 100644
--- a/flang/include/flang/Common/LangOptions.h
+++ b/flang/include/flang/Support/LangOptions.h
@@ -1,4 +1,4 @@
-//===------ LangOptions.h ---------------------------------------*- C++ -*-===//
+//===-- include/flang/Support/LangOptions.h ---------------------*- C++ -*-===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
@@ -12,8 +12,8 @@
 //
 //===----------------------------------------------------------------------===//
 
-#ifndef FORTRAN_COMMON_LANGOPTIONS_H
-#define FORTRAN_COMMON_LANGOPTIONS_H
+#ifndef FORTRAN_SUPPORT_LANGOPTIONS_H_
+#define FORTRAN_SUPPORT_LANGOPTIONS_H_
 
 #include <string>
 #include <vector>
@@ -45,12 +45,12 @@ class LangOptionsBase {
 
 #define LANGOPT(Name, Bits, Default) unsigned Name : Bits;
 #define ENUM_LANGOPT(Name, Type, Bits, Default)
-#include "flang/Common/LangOptions.def"
+#include "LangOptions.def"
 
 protected:
 #define LANGOPT(Name, Bits, Default)
 #define ENUM_LANGOPT(Name, Type, Bits, Default) unsigned Name : Bits;
-#include "flang/Common/LangOptions.def"
+#include "LangOptions.def"
 };
 
 /// Tracks various options which control the dialect of Fortran that is
@@ -63,7 +63,7 @@ class LangOptions : public LangOptionsBase {
 #define ENUM_LANGOPT(Name, Type, Bits, Default) \
   Type get##Name() const { return static_cast<Type>(Name); } \
   void set##Name(Type Value) { Name = static_cast<unsigned>(Value); }
-#include "flang/Common/LangOptions.def"
+#include "LangOptions.def"
 
   /// Name of the IR file that contains the result of the OpenMP target
   /// host code generation.
@@ -77,4 +77,4 @@ class LangOptions : public LangOptionsBase {
 
 } // end namespace Fortran::common
 
-#endif // FORTRAN_COMMON_LANGOPTIONS_H
+#endif // FORTRAN_SUPPORT_LANGOPTIONS_H_
diff --git a/flang/include/flang/Common/MathOptionsBase.def b/flang/include/flang/Support/MathOptionsBase.def
similarity index 100%
rename from flang/include/flang/Common/MathOptionsBase.def
rename to flang/include/flang/Support/MathOptionsBase.def
diff --git a/flang/include/flang/Common/MathOptionsBase.h b/flang/include/flang/Support/MathOptionsBase.h
similarity index 77%
rename from flang/include/flang/Common/MathOptionsBase.h
rename to flang/include/flang/Support/MathOptionsBase.h
index 7f8ebdbee1987..a2bea3c598a8c 100644
--- a/flang/include/flang/Common/MathOptionsBase.h
+++ b/flang/include/flang/Support/MathOptionsBase.h
@@ -1,4 +1,4 @@
-//===- MathOptionsBase.h - Math options config ------------------*- C++ -*-===//
+//===-- include/flang/Support/MathOptionsBase.h -----------------*- C++ -*-===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
@@ -14,8 +14,8 @@
 ///
 //===----------------------------------------------------------------------===//
 
-#ifndef FORTRAN_COMMON_MATHOPTIONSBASE_H
-#define FORTRAN_COMMON_MATHOPTIONSBASE_H
+#ifndef FORTRAN_SUPPORT_MATHOPTIONSBASE_H_
+#define FORTRAN_SUPPORT_MATHOPTIONSBASE_H_
 
 namespace Fortran::common {
 
@@ -27,18 +27,18 @@ class MathOptionsBase {
     Name = static_cast<unsigned>(Value); \
     return *this; \
   }
-#include "flang/Common/MathOptionsBase.def"
+#include "MathOptionsBase.def"
 
   MathOptionsBase() {
 #define ENUM_MATHOPT(Name, Type, Bits, Default) set##Name(Default);
-#include "flang/Common/MathOptionsBase.def"
+#include "MathOptionsBase.def"
   }
 
 private:
 #define ENUM_MATHOPT(Name, Type, Bits, Default) unsigned Name : Bits;
-#include "flang/Common/MathOptionsBase.def"
+#include "MathOptionsBase.def"
 };
 
 } // namespace Fortran::common
 
-#endif // FORTRAN_COMMON_MATHOPTIONSBASE_H
+#endif // FORTRAN_SUPPORT_MATHOPTIONSBASE_H_
diff --git a/flang/include/flang/Common/OpenMP-features.h b/flang/include/flang/Support/OpenMP-features.h
similarity index 86%
rename from flang/include/flang/Common/OpenMP-features.h
rename to flang/include/flang/Support/OpenMP-features.h
index 480c8b4c1013f..1dd7ea560cc96 100644
--- a/flang/include/flang/Common/OpenMP-features.h
+++ b/flang/include/flang/Support/OpenMP-features.h
@@ -1,4 +1,4 @@
-//===-- include/flang/Common/OpenMP-features.h -----------------*- C++ -*-====//
+//===-- include/flang/Support/OpenMP-features.h -----------------*- C++ -*-===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
@@ -6,8 +6,8 @@
 //
 //===----------------------------------------------------------------------===//
 
-#ifndef FORTRAN_COMMON_OPENMP_FEATURES_H_
-#define FORTRAN_COMMON_OPENMP_FEATURES_H_
+#ifndef FORTRAN_SUPPORT_OPENMP_FEATURES_H_
+#define FORTRAN_SUPPORT_OPENMP_FEATURES_H_
 
 namespace Fortran::common {
 
@@ -49,4 +49,4 @@ void setOpenMPMacro(int version, FortranPredefinitions &predefinitions) {
   }
 }
 } // namespace Fortran::common
-#endif // FORTRAN_COMMON_OPENMP_FEATURES_H_
+#endif // FORTRAN_SUPPORT_OPENMP_FEATURES_H_
diff --git a/flang/include/flang/Common/OpenMP-utils.h b/flang/include/flang/Support/OpenMP-utils.h
similarity index 92%
rename from flang/include/flang/Common/OpenMP-utils.h
rename to flang/include/flang/Support/OpenMP-utils.h
index 827f13bc4758e..d8f82e1cf94f1 100644
--- a/flang/include/flang/Common/OpenMP-utils.h
+++ b/flang/include/flang/Support/OpenMP-utils.h
@@ -1,4 +1,4 @@
-//===-- include/flang/Common/OpenMP-utils.h --------------------*- C++ -*-====//
+//===-- include/flang/Support/OpenMP-utils.h --------------------*- C++ -*-===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
@@ -6,8 +6,8 @@
 //
 //===----------------------------------------------------------------------===//
 
-#ifndef FORTRAN_COMMON_OPENMP_UTILS_H_
-#define FORTRAN_COMMON_OPENMP_UTILS_H_
+#ifndef FORTRAN_SUPPORT_OPENMP_UTILS_H_
+#define FORTRAN_SUPPORT_OPENMP_UTILS_H_
 
 #include "flang/Semantics/symbol.h"
 
@@ -73,4 +73,4 @@ mlir::Block *genEntryBlock(
     mlir::OpBuilder &builder, const EntryBlockArgs &args, mlir::Region &region);
 } // namespace Fortran::common::openmp
 
-#endif // FORTRAN_COMMON_OPENMP_UTILS_H_
+#endif // FORTRAN_SUPPORT_OPENMP_UTILS_H_
diff --git a/flang/include/flang/Common/Version.h b/flang/include/flang/Support/Version.h
similarity index 90%
rename from flang/include/flang/Common/Version.h
rename to flang/include/flang/Support/Version.h
index 3257d4a4f6459..fe7f7395e1eba 100644
--- a/flang/include/flang/Common/Version.h
+++ b/flang/include/flang/Support/Version.h
@@ -1,4 +1,4 @@
-//===- Version.h - Flang Version Number ---------------------*- Fortran -*-===//
+//===-- include/flang/Support/Version.h -------------------------*- C++ -*-===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
@@ -12,8 +12,8 @@
 ///
 //===----------------------------------------------------------------------===//
 
-#ifndef FORTRAN_COMMON_VERSION_H
-#define FORTRAN_COMMON_VERSION_H
+#ifndef FORTRAN_SUPPORT_VERSION_H_
+#define FORTRAN_SUPPORT_VERSION_H_
 
 #include "flang/Version.inc"
 #include "llvm/ADT/StringRef.h"
@@ -53,4 +53,4 @@ std::string getFlangFullVersion();
 std::string getFlangToolFullVersion(llvm::StringRef ToolName);
 } // namespace Fortran::common
 
-#endif // FORTRAN_COMMON_VERSION_H
+#endif // FORTRAN_SUPPORT_VERSION_H_
diff --git a/flang/include/flang/Common/default-kinds.h b/flang/include/flang/Support/default-kinds.h
similarity index 91%
rename from flang/include/flang/Common/default-kinds.h
rename to flang/include/flang/Support/default-kinds.h
index 6c66b98e98a05..ab1422d63af30 100644
--- a/flang/include/flang/Common/default-kinds.h
+++ b/flang/include/flang/Support/default-kinds.h
@@ -1,4 +1,4 @@
-//===-- include/flang/Common/default-kinds.h --------------------*- C++ -*-===//
+//===-- include/flang/Support/default-kinds.h -------------------*- C++ -*-===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
@@ -6,10 +6,10 @@
 //
 //===----------------------------------------------------------------------===//
 
-#ifndef FORTRAN_COMMON_DEFAULT_KINDS_H_
-#define FORTRAN_COMMON_DEFAULT_KINDS_H_
+#ifndef FORTRAN_SUPPORT_DEFAULT_KINDS_H_
+#define FORTRAN_SUPPORT_DEFAULT_KINDS_H_
 
-#include "flang/Common/Fortran.h"
+#include "Fortran.h"
 #include <cstdint>
 
 namespace Fortran::common {
@@ -58,4 +58,4 @@ class IntrinsicTypeDefaultKinds {
   int defaultLogicalKind_{defaultIntegerKind_};
 };
 } // namespace Fortran::common
-#endif // FORTRAN_COMMON_DEFAULT_KINDS_H_
+#endif // FORTRAN_SUPPORT_DEFAULT_KINDS_H_
diff --git a/flang/include/flang/Tools/CrossToolHelpers.h b/flang/include/flang/Tools/CrossToolHelpers.h
index 0286f2aa14519..d9401e753fb79 100644
--- a/flang/include/flang/Tools/CrossToolHelpers.h
+++ b/flang/include/flang/Tools/CrossToolHelpers.h
@@ -13,9 +13,9 @@
 #ifndef FORTRAN_TOOLS_CROSS_TOOL_HELPERS_H
 #define FORTRAN_TOOLS_CROSS_TOOL_HELPERS_H
 
-#include "flang/Common/LangOptions.h"
-#include "flang/Common/MathOptionsBase.h"
 #include "flang/Frontend/CodeGenOptions.h"
+#include "flang/Support/LangOptions.h"
+#include "flang/Support/MathOptionsBase.h"
 #include <cstdint>
 
 #include "mlir/Dialect/OpenMP/OpenMPDialect.h"
diff --git a/flang/lib/CMakeLists.txt b/flang/lib/CMakeLists.txt
index 2182e845b6a79..05c3535b09b3d 100644
--- a/flang/lib/CMakeLists.txt
+++ b/flang/lib/CMakeLists.txt
@@ -1,4 +1,3 @@
-add_subdirectory(Common)
 add_subdirectory(Evaluate)
 add_subdirectory(Decimal)
 add_subdirectory(Lower)
diff --git a/flang/lib/Common/CMakeLists.txt b/flang/lib/Common/CMakeLists.txt
deleted file mode 100644
index 4b5df0a49f403..0000000000000
--- a/flang/lib/Common/CMakeLists.txt
+++ /dev/null
@@ -1,52 +0,0 @@
-find_first_existing_vc_file("${LLVM_MAIN_SRC_DIR}" llvm_vc)
-find_first_existing_vc_file("${FLANG_SOURCE_DIR}" flang_vc)
-
-# The VC revision include that we want to generate.
-set(version_inc "${CMAKE_CURRENT_BINARY_DIR}/VCSVersion.inc")
-
-set(generate_vcs_version_script "${LLVM_CMAKE_DIR}/GenerateVersionFromVCS.cmake")
-
-if(llvm_vc AND LLVM_APPEND_VC_REV)
-  set(llvm_source_dir ${LLVM_MAIN_SRC_DIR})
-endif()
-if(flang_vc AND LLVM_APPEND_VC_REV)
-  set(flang_source_dir ${FLANG_SOURCE_DIR})
-endif()
-
-# Create custom target to generate the VC revision include.
-add_custom_command(OUTPUT "${version_inc}"
-  DEPENDS "${llvm_vc}" "${flang_vc}" "${generate_vcs_version_script}"
-  COMMAND ${CMAKE_COMMAND} "-DNAMES=\"LLVM;FLANG\""
-                           "-DLLVM_SOURCE_DIR=${llvm_source_dir}"
-                           "-DFLANG_SOURCE_DIR=${flang_source_dir}"
-                           "-DHEADER_FILE=${version_inc}"
-                           "-DLLVM_FORCE_VC_REVISION=${LLVM_FORCE_VC_REVISION}"
-                           "-DLLVM_FORCE_VC_REPOSITORY=${LLVM_FORCE_VC_REPOSITORY}"
-                           -P "${generate_vcs_version_script}")
-
-# Mark the generated header as being generated.
-set_source_files_properties("${version_inc}"
-  PROPERTIES GENERATED TRUE
-             HEADER_FILE_ONLY TRUE)
-
-if(FLANG_VENDOR)
-  set_source_files_properties(Version.cpp
-    PROPERTIES COMPILE_DEFINITIONS "FLANG_VENDOR=\"${FLANG_VENDOR} \"")
-endif()
-
-add_flang_library(FortranCommon
-  Fortran.cpp
-  Fortran-features.cpp
-  default-kinds.cpp
-  idioms.cpp
-  LangOptions.cpp
-  OpenMP-utils.cpp
-  Version.cpp
-  ${version_inc}
-
-  LINK_COMPONENTS
-  Support
-
-  MLIR_LIBS
-  MLIRIR
-)
diff --git a/flang/lib/Decimal/CMakeLists.txt b/flang/lib/Decimal/CMakeLists.txt
index 880b190f1c581..2fd2a429d7c22 100644
--- a/flang/lib/Decimal/CMakeLists.txt
+++ b/flang/lib/Decimal/CMakeLists.txt
@@ -1,3 +1,11 @@
+#===-- lib/Decimal/CMakeLists.txt ------------------------------------------===#
+#
+# Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+# See https://llvm.org/LICENSE.txt for license information.
+# SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+#
+#===------------------------------------------------------------------------===#
+
 if (CMAKE_SOURCE_DIR STREQUAL CMAKE_CURRENT_SOURCE_DIR)
   cmake_minimum_required(VERSION 3.20.0)
 
diff --git a/flang/lib/Evaluate/CMakeLists.txt b/flang/lib/Evaluate/CMakeLists.txt
index b38f450d746ea..e0bdb6b2d24d8 100644
--- a/flang/lib/Evaluate/CMakeLists.txt
+++ b/flang/lib/Evaluate/CMakeLists.txt
@@ -60,7 +60,7 @@ add_flang_library(FortranEvaluate
   variable.cpp
 
   LINK_LIBS
-  FortranCommon
+  FortranSupport
   FortranDecimal
   FortranParser
   ${LIBPGMATH}
diff --git a/flang/lib/Evaluate/call.cpp b/flang/lib/Evaluate/call.cpp
index c5b50e806d249..f77df92a7597a 100644
--- a/flang/lib/Evaluate/call.cpp
+++ b/flang/lib/Evaluate/call.cpp
@@ -7,13 +7,13 @@
 //===----------------------------------------------------------------------===//
 
 #include "flang/Evaluate/call.h"
-#include "flang/Common/Fortran.h"
 #include "flang/Common/idioms.h"
 #include "flang/Evaluate/characteristics.h"
 #include "flang/Evaluate/check-expression.h"
 #include "flang/Evaluate/expression.h"
 #include "flang/Evaluate/tools.h"
 #include "flang/Semantics/symbol.h"
+#include "flang/Support/Fortran.h"
 
 namespace Fortran::evaluate {
 
diff --git a/flang/lib/Evaluate/formatting.cpp b/flang/lib/Evaluate/formatting.cpp
index f3a53c1f983df..c4c3998257830 100644
--- a/flang/lib/Evaluate/formatting.cpp
+++ b/flang/lib/Evaluate/formatting.cpp
@@ -7,7 +7,6 @@
 //===----------------------------------------------------------------------===//
 
 #include "flang/Evaluate/formatting.h"
-#include "flang/Common/Fortran.h"
 #include "flang/Evaluate/call.h"
 #include "flang/Evaluate/constant.h"
 #include "flang/Evaluate/expression.h"
@@ -16,6 +15,7 @@
 #include "flang/Parser/characters.h"
 #include "flang/Semantics/semantics.h"
 #include "flang/Semantics/symbol.h"
+#include "flang/Support/Fortran.h"
 #include "llvm/Support/raw_ostream.h"
 
 namespace Fortran::evaluate {
diff --git a/flang/lib/Evaluate/intrinsics.cpp b/flang/lib/Evaluate/intrinsics.cpp
index 69ae69bb35fc0..5c9527cec2f69 100644
--- a/flang/lib/Evaluate/intrinsics.cpp
+++ b/flang/lib/Evaluate/intrinsics.cpp
@@ -7,7 +7,6 @@
 //===----------------------------------------------------------------------===//
 
 #include "flang/Evaluate/intrinsics.h"
-#include "flang/Common/Fortran.h"
 #include "flang/Common/enum-set.h"
 #include "flang/Common/idioms.h"
 #include "flang/Evaluate/check-expression.h"
@@ -19,6 +18,7 @@
 #include "flang/Evaluate/type.h"
 #include "flang/Semantics/scope.h"
 #include "flang/Semantics/tools.h"
+#include "flang/Support/Fortran.h"
 #include "llvm/Support/raw_ostream.h"
 #include <algorithm>
 #include <cmath>
diff --git a/flang/lib/Frontend/CMakeLists.txt b/flang/lib/Frontend/CMakeLists.txt
index d063ed36d00b4..81eef2d468d8c 100644
--- a/flang/lib/Frontend/CMakeLists.txt
+++ b/flang/lib/Frontend/CMakeLists.txt
@@ -27,7 +27,7 @@ add_flang_library(flangFrontend
   FortranParser
   FortranSemantics
   FortranEvaluate
-  FortranCommon
+  FortranSupport
   FortranLower
   FortranSupport
   FIRDialect
diff --git a/flang/lib/Frontend/CompilerInstance.cpp b/flang/lib/Frontend/CompilerInstance.cpp
index dfd15b9c3c39d..b1fa32ecb4cfc 100644
--- a/flang/lib/Frontend/CompilerInstance.cpp
+++ b/flang/lib/Frontend/CompilerInstance.cpp
@@ -11,12 +11,12 @@
 //===----------------------------------------------------------------------===//
 
 #include "flang/Frontend/CompilerInstance.h"
-#include "flang/Common/Fortran-features.h"
 #include "flang/Frontend/CompilerInvocation.h"
 #include "flang/Frontend/TextDiagnosticPrinter.h"
 #include "flang/Parser/parsing.h"
 #include "flang/Parser/provenance.h"
 #include "flang/Semantics/semantics.h"
+#include "flang/Support/Fortran-features.h"
 #include "flang/Support/Timing.h"
 #include "mlir/Support/RawOstreamExtras.h"
 #include "clang/Basic/DiagnosticFrontend.h"
diff --git a/flang/lib/Frontend/CompilerInvocation.cpp b/flang/lib/Frontend/CompilerInvocation.cpp
index a2c1d3efef6cf..3eb413e8a62a9 100644
--- a/flang/lib/Frontend/CompilerInvocation.cpp
+++ b/flang/lib/Frontend/CompilerInvocation.cpp
@@ -11,13 +11,13 @@
 //===----------------------------------------------------------------------===//
 
 #include "flang/Frontend/CompilerInvocation.h"
-#include "flang/Common/Fortran-features.h"
-#include "flang/Common/OpenMP-features.h"
-#include "flang/Common/Version.h"
 #include "flang/Frontend/CodeGenOptions.h"
 #include "flang/Frontend/PreprocessorOptions.h"
 #include "flang/Frontend/TargetOptions.h"
 #include "flang/Semantics/semantics.h"
+#include "flang/Support/Fortran-features.h"
+#include "flang/Support/OpenMP-features.h"
+#include "flang/Support/Version.h"
 #include "flang/Tools/TargetSetup.h"
 #include "flang/Version.inc"
 #include "clang/Basic/AllDiagnostics.h"
diff --git a/flang/lib/Frontend/FrontendActions.cpp b/flang/lib/Frontend/FrontendActions.cpp
index b0545a7ac2f99..b7674bd093f68 100644
--- a/flang/lib/Frontend/FrontendActions.cpp
+++ b/flang/lib/Frontend/FrontendActions.cpp
@@ -11,7 +11,6 @@
 //===----------------------------------------------------------------------===//
 
 #include "flang/Frontend/FrontendActions.h"
-#include "flang/Common/default-kinds.h"
 #include "flang/Frontend/CompilerInstance.h"
 #include "flang/Frontend/CompilerInvocation.h"
 #include "flang/Frontend/FrontendOptions.h"
@@ -34,6 +33,7 @@
 #include "flang/Semantics/runtime-type-info.h"
 #include "flang/Semantics/semantics.h"
 #include "flang/Semantics/unparse-with-symbols.h"
+#include "flang/Support/default-kinds.h"
 #include "flang/Tools/CrossToolHelpers.h"
 
 #include "mlir/IR/Dialect.h"
diff --git a/flang/lib/Lower/Bridge.cpp b/flang/lib/Lower/Bridge.cpp
index d6bde8ecbbb25..a31629b17cf29 100644
--- a/flang/lib/Lower/Bridge.cpp
+++ b/flang/lib/Lower/Bridge.cpp
@@ -12,7 +12,6 @@
 
 #include "flang/Lower/Bridge.h"
 
-#include "flang/Common/Version.h"
 #include "flang/Lower/Allocatable.h"
 #include "flang/Lower/CallInterface.h"
 #include "flang/Lower/Coarray.h"
@@ -62,6 +61,7 @@
 #include "flang/Semantics/runtime-type-info.h"
 #include "flang/Semantics/symbol.h"
 #include "flang/Semantics/tools.h"
+#include "flang/Support/Version.h"
 #include "mlir/Dialect/ControlFlow/IR/ControlFlowOps.h"
 #include "mlir/IR/Matchers.h"
 #include "mlir/IR/PatternMatch.h"
diff --git a/flang/lib/Lower/CMakeLists.txt b/flang/lib/Lower/CMakeLists.txt
index 8a4ed1c067cb2..c9b249781552e 100644
--- a/flang/lib/Lower/CMakeLists.txt
+++ b/flang/lib/Lower/CMakeLists.txt
@@ -56,7 +56,7 @@ add_flang_library(FortranLower
   FIRSupport
   FIRTransforms
   HLFIRDialect
-  FortranCommon
+  FortranSupport
   FortranParser
   FortranEvaluate
   FortranSemantics
diff --git a/flang/lib/Lower/CallInterface.cpp b/flang/lib/Lower/CallInterface.cpp
index ab421d81141f2..226ba1e52c968 100644
--- a/flang/lib/Lower/CallInterface.cpp
+++ b/flang/lib/Lower/CallInterface.cpp
@@ -7,7 +7,6 @@
 //===----------------------------------------------------------------------===//
 
 #include "flang/Lower/CallInterface.h"
-#include "flang/Common/Fortran.h"
 #include "flang/Evaluate/fold.h"
 #include "flang/Lower/Bridge.h"
 #include "flang/Lower/Mangler.h"
@@ -23,6 +22,7 @@
 #include "flang/Optimizer/Support/Utils.h"
 #include "flang/Semantics/symbol.h"
 #include "flang/Semantics/tools.h"
+#include "flang/Support/Fortran.h"
 #include <optional>
 
 static mlir::FunctionType
diff --git a/flang/lib/Lower/ConvertExpr.cpp b/flang/lib/Lower/ConvertExpr.cpp
index d9ae502edbafa..b33baf90582b8 100644
--- a/flang/lib/Lower/ConvertExpr.cpp
+++ b/flang/lib/Lower/ConvertExpr.cpp
@@ -11,7 +11,6 @@
 //===----------------------------------------------------------------------===//
 
 #include "flang/Lower/ConvertExpr.h"
-#include "flang/Common/default-kinds.h"
 #include "flang/Common/unwrap.h"
 #include "flang/Evaluate/fold.h"
 #include "flang/Evaluate/real.h"
@@ -52,6 +51,7 @@
 #include "flang/Semantics/symbol.h"
 #include "flang/Semantics/tools.h"
 #include "flang/Semantics/type.h"
+#include "flang/Support/default-kinds.h"
 #include "mlir/Dialect/Func/IR/FuncOps.h"
 #include "llvm/ADT/TypeSwitch.h"
 #include "llvm/Support/CommandLine.h"
diff --git a/flang/lib/Lower/OpenMP/OpenMP.cpp b/flang/lib/Lower/OpenMP/OpenMP.cpp
index 5e1f3b0208869..0173298b5f742 100644
--- a/flang/lib/Lower/OpenMP/OpenMP.cpp
+++ b/flang/lib/Lower/OpenMP/OpenMP.cpp
@@ -18,7 +18,6 @@
 #include "Decomposer.h"
 #include "ReductionProcessor.h"
 #include "Utils.h"
-#include "flang/Common/OpenMP-utils.h"
 #include "flang/Common/idioms.h"
 #include "flang/Lower/Bridge.h"
 #include "flang/Lower/ConvertExpr.h"
@@ -35,6 +34,7 @@
 #include "flang/Parser/parse-tree.h"
 #include "flang/Semantics/openmp-directive-sets.h"
 #include "flang/Semantics/tools.h"
+#include "flang/Support/OpenMP-utils.h"
 #include "mlir/Dialect/ControlFlow/IR/ControlFlowOps.h"
 #include "mlir/Dialect/OpenMP/OpenMPDialect.h"
 #include "mlir/Transforms/RegionUtils.h"
diff --git a/flang/lib/Optimizer/CodeGen/TypeConverter.cpp b/flang/lib/Optimizer/CodeGen/TypeConverter.cpp
index 0eace903720f0..89f498433806e 100644
--- a/flang/lib/Optimizer/CodeGen/TypeConverter.cpp
+++ b/flang/lib/Optimizer/CodeGen/TypeConverter.cpp
@@ -13,7 +13,6 @@
 #define DEBUG_TYPE "flang-type-conversion"
 
 #include "flang/Optimizer/CodeGen/TypeConverter.h"
-#include "flang/Common/Fortran.h"
 #include "flang/Optimizer/Builder/Todo.h" // remove when TODO's are done
 #include "flang/Optimizer/CodeGen/DescriptorModel.h"
 #include "flang/Optimizer/CodeGen/TBAABuilder.h"
@@ -22,6 +21,7 @@
 #include "flang/Optimizer/Dialect/Support/FIRContext.h"
 #include "flang/Optimizer/Dialect/Support/KindMapping.h"
 #include "flang/Optimizer/Support/InternalNames.h"
+#include "flang/Support/Fortran.h"
 #include "mlir/Conversion/LLVMCommon/TypeConverter.h"
 #include "llvm/ADT/ScopeExit.h"
 #include "llvm/Support/Debug.h"
diff --git a/flang/lib/Optimizer/Dialect/FIRType.cpp b/flang/lib/Optimizer/Dialect/FIRType.cpp
index 0b57a10a6c493..67d918cc0f41c 100644
--- a/flang/lib/Optimizer/Dialect/FIRType.cpp
+++ b/flang/lib/Optimizer/Dialect/FIRType.cpp
@@ -11,7 +11,7 @@
 //===----------------------------------------------------------------------===//
 
 #include "flang/Optimizer/Dialect/FIRType.h"
-#include "flang/ISO_Fortran_binding_wrapper.h"
+#include "flang/Common/ISO_Fortran_binding_wrapper.h"
 #include "flang/Optimizer/Builder/Todo.h"
 #include "flang/Optimizer/Dialect/FIRDialect.h"
 #include "flang/Optimizer/Dialect/Support/KindMapping.h"
diff --git a/flang/lib/Optimizer/OpenMP/CMakeLists.txt b/flang/lib/Optimizer/OpenMP/CMakeLists.txt
index c8509ccc7fea5..86ae93f3207cc 100644
--- a/flang/lib/Optimizer/OpenMP/CMakeLists.txt
+++ b/flang/lib/Optimizer/OpenMP/CMakeLists.txt
@@ -21,7 +21,7 @@ add_flang_library(FlangOpenMPTransforms
   FIRDialect
   FIRDialectSupport
   FIRSupport
-  FortranCommon
+  FortranSupport
   HLFIRDialect
 
   MLIR_LIBS
diff --git a/flang/lib/Optimizer/OpenMP/GenericLoopConversion.cpp b/flang/lib/Optimizer/OpenMP/GenericLoopConversion.cpp
index 3e742f7d60a9c..3512a537d38c3 100644
--- a/flang/lib/Optimizer/OpenMP/GenericLoopConversion.cpp
+++ b/flang/lib/Optimizer/OpenMP/GenericLoopConversion.cpp
@@ -6,7 +6,7 @@
 //
 //===----------------------------------------------------------------------===//
 
-#include "flang/Common/OpenMP-utils.h"
+#include "flang/Support/OpenMP-utils.h"
 
 #include "mlir/Dialect/Func/IR/FuncOps.h"
 #include "mlir/Dialect/OpenMP/OpenMPDialect.h"
diff --git a/flang/lib/Optimizer/Passes/CMakeLists.txt b/flang/lib/Optimizer/Passes/CMakeLists.txt
index eb25beba309bf..1c19a5765aff1 100644
--- a/flang/lib/Optimizer/Passes/CMakeLists.txt
+++ b/flang/lib/Optimizer/Passes/CMakeLists.txt
@@ -5,14 +5,11 @@ add_flang_library(flangPasses
   CommandLineOpts.cpp
   Pipelines.cpp
 
-  DEPENDS
-  FortranCommon
-
   LINK_LIBS
   FIRCodeGen
   FIRTransforms
   FlangOpenMPTransforms
-  FortranCommon
+  FortranSupport
   HLFIRTransforms
 
   LINK_COMPONENTS
diff --git a/flang/lib/Optimizer/Transforms/AddDebugInfo.cpp b/flang/lib/Optimizer/Transforms/AddDebugInfo.cpp
index 69915741a88f6..49c9a737b2c59 100644
--- a/flang/lib/Optimizer/Transforms/AddDebugInfo.cpp
+++ b/flang/lib/Optimizer/Transforms/AddDebugInfo.cpp
@@ -12,7 +12,6 @@
 //===----------------------------------------------------------------------===//
 
 #include "DebugTypeGenerator.h"
-#include "flang/Common/Version.h"
 #include "flang/Optimizer/Builder/FIRBuilder.h"
 #include "flang/Optimizer/Builder/Todo.h"
 #include "flang/Optimizer/CodeGen/CGOps.h"
@@ -23,6 +22,7 @@
 #include "flang/Optimizer/Dialect/Support/FIRContext.h"
 #include "flang/Optimizer/Support/InternalNames.h"
 #include "flang/Optimizer/Transforms/Passes.h"
+#include "flang/Support/Version.h"
 #include "mlir/Dialect/Func/IR/FuncOps.h"
 #include "mlir/Dialect/LLVMIR/LLVMDialect.h"
 #include "mlir/IR/Matchers.h"
diff --git a/flang/lib/Optimizer/Transforms/AssumedRankOpConversion.cpp b/flang/lib/Optimizer/Transforms/AssumedRankOpConversion.cpp
index eb59045a5fde7..d0bd67a236419 100644
--- a/flang/lib/Optimizer/Transforms/AssumedRankOpConversion.cpp
+++ b/flang/lib/Optimizer/Transforms/AssumedRankOpConversion.cpp
@@ -6,7 +6,6 @@
 //
 //===----------------------------------------------------------------------===//
 
-#include "flang/Common/Fortran.h"
 #include "flang/Lower/BuiltinModules.h"
 #include "flang/Optimizer/Builder/FIRBuilder.h"
 #include "flang/Optimizer/Builder/Runtime/Support.h"
@@ -17,6 +16,7 @@
 #include "flang/Optimizer/Support/Utils.h"
 #include "flang/Optimizer/Transforms/Passes.h"
 #include "flang/Runtime/support.h"
+#include "flang/Support/Fortran.h"
 #include "mlir/Dialect/Func/IR/FuncOps.h"
 #include "mlir/Pass/Pass.h"
 #include "mlir/Transforms/DialectConversion.h"
diff --git a/flang/lib/Optimizer/Transforms/CMakeLists.txt b/flang/lib/Optimizer/Transforms/CMakeLists.txt
index 9c550f983434a..50994fbb21700 100644
--- a/flang/lib/Optimizer/Transforms/CMakeLists.txt
+++ b/flang/lib/Optimizer/Transforms/CMakeLists.txt
@@ -46,7 +46,7 @@ add_flang_library(FIRTransforms
   FIRDialect
   FIRDialectSupport
   FIRSupport
-  FortranCommon
+  FortranSupport
   HLFIRDialect
 
   MLIR_LIBS
diff --git a/flang/lib/Optimizer/Transforms/CUFDeviceGlobal.cpp b/flang/lib/Optimizer/Transforms/CUFDeviceGlobal.cpp
index 7486dde0e281e..3f13a182ad0c3 100644
--- a/flang/lib/Optimizer/Transforms/CUFDeviceGlobal.cpp
+++ b/flang/lib/Optimizer/Transforms/CUFDeviceGlobal.cpp
@@ -6,7 +6,6 @@
 //
 //===----------------------------------------------------------------------===//
 
-#include "flang/Common/Fortran.h"
 #include "flang/Optimizer/Builder/CUFCommon.h"
 #include "flang/Optimizer/Dialect/CUF/CUFOps.h"
 #include "flang/Optimizer/Dialect/FIRDialect.h"
@@ -15,6 +14,7 @@
 #include "flang/Optimizer/Support/InternalNames.h"
 #include "flang/Runtime/CUDA/common.h"
 #include "flang/Runtime/allocatable.h"
+#include "flang/Support/Fortran.h"
 #include "mlir/Dialect/LLVMIR/NVVMDialect.h"
 #include "mlir/IR/SymbolTable.h"
 #include "mlir/Pass/Pass.h"
diff --git a/flang/lib/Optimizer/Transforms/CUFGPUToLLVMConversion.cpp b/flang/lib/Optimizer/Transforms/CUFGPUToLLVMConversion.cpp
index 4611a18a541bc..2a95e41944f3f 100644
--- a/flang/lib/Optimizer/Transforms/CUFGPUToLLVMConversion.cpp
+++ b/flang/lib/Optimizer/Transforms/CUFGPUToLLVMConversion.cpp
@@ -7,10 +7,10 @@
 //===----------------------------------------------------------------------===//
 
 #include "flang/Optimizer/Transforms/CUFGPUToLLVMConversion.h"
-#include "flang/Common/Fortran.h"
 #include "flang/Optimizer/CodeGen/TypeConverter.h"
 #include "flang/Optimizer/Support/DataLayout.h"
 #include "flang/Runtime/CUDA/common.h"
+#include "flang/Support/Fortran.h"
 #include "mlir/Conversion/LLVMCommon/Pattern.h"
 #include "mlir/Dialect/GPU/IR/GPUDialect.h"
 #include "mlir/Pass/Pass.h"
diff --git a/flang/lib/Optimizer/Transforms/CUFOpConversion.cpp b/flang/lib/Optimizer/Transforms/CUFOpConversion.cpp
index 549498f5585a6..1f0576aa82f83 100644
--- a/flang/lib/Optimizer/Transforms/CUFOpConversion.cpp
+++ b/flang/lib/Optimizer/Transforms/CUFOpConversion.cpp
@@ -7,7 +7,6 @@
 //===----------------------------------------------------------------------===//
 
 #include "flang/Optimizer/Transforms/CUFOpConversion.h"
-#include "flang/Common/Fortran.h"
 #include "flang/Optimizer/Builder/CUFCommon.h"
 #include "flang/Optimizer/Builder/Runtime/RTBuilder.h"
 #include "flang/Optimizer/CodeGen/TypeConverter.h"
@@ -22,6 +21,7 @@
 #include "flang/Runtime/CUDA/memory.h"
 #include "flang/Runtime/CUDA/pointer.h"
 #include "flang/Runtime/allocatable.h"
+#include "flang/Support/Fortran.h"
 #include "mlir/Conversion/LLVMCommon/Pattern.h"
 #include "mlir/Dialect/GPU/IR/GPUDialect.h"
 #include "mlir/IR/Matchers.h"
diff --git a/flang/lib/Optimizer/Transforms/ExternalNameConversion.cpp b/flang/lib/Optimizer/Transforms/ExternalNameConversion.cpp
index 4f6974ee52695..3d84eaa4c1595 100644
--- a/flang/lib/Optimizer/Transforms/ExternalNameConversion.cpp
+++ b/flang/lib/Optimizer/Transforms/ExternalNameConversion.cpp
@@ -6,12 +6,12 @@
 //
 //===----------------------------------------------------------------------===//
 
-#include "flang/Common/Fortran.h"
 #include "flang/Optimizer/Dialect/FIRDialect.h"
 #include "flang/Optimizer/Dialect/FIROps.h"
 #include "flang/Optimizer/Dialect/FIROpsSupport.h"
 #include "flang/Optimizer/Support/InternalNames.h"
 #include "flang/Optimizer/Transforms/Passes.h"
+#include "flang/Support/Fortran.h"
 #include "mlir/Dialect/GPU/IR/GPUDialect.h"
 #include "mlir/IR/Attributes.h"
 #include "mlir/IR/SymbolTable.h"
diff --git a/flang/lib/Optimizer/Transforms/LoopVersioning.cpp b/flang/lib/Optimizer/Transforms/LoopVersioning.cpp
index 0aa89f1f5471e..1f3495569c9dd 100644
--- a/flang/lib/Optimizer/Transforms/LoopVersioning.cpp
+++ b/flang/lib/Optimizer/Transforms/LoopVersioning.cpp
@@ -40,7 +40,7 @@
 ///       could be part of the cost analysis above.
 //===----------------------------------------------------------------------===//
 
-#include "flang/ISO_Fortran_binding_wrapper.h"
+#include "flang/Common/ISO_Fortran_binding_wrapper.h"
 #include "flang/Optimizer/Builder/BoxValue.h"
 #include "flang/Optimizer/Builder/FIRBuilder.h"
 #include "flang/Optimizer/Builder/Runtime/Inquiry.h"
diff --git a/flang/lib/Optimizer/Transforms/SimplifyIntrinsics.cpp b/flang/lib/Optimizer/Transforms/SimplifyIntrinsics.cpp
index fa6a7b23624e8..df2887ff1422e 100644
--- a/flang/lib/Optimizer/Transforms/SimplifyIntrinsics.cpp
+++ b/flang/lib/Optimizer/Transforms/SimplifyIntrinsics.cpp
@@ -22,7 +22,6 @@
 /// and small in size.
 //===----------------------------------------------------------------------===//
 
-#include "flang/Common/Fortran.h"
 #include "flang/Optimizer/Builder/BoxValue.h"
 #include "flang/Optimizer/Builder/CUFCommon.h"
 #include "flang/Optimizer/Builder/FIRBuilder.h"
@@ -35,6 +34,7 @@
 #include "flang/Optimizer/Transforms/Passes.h"
 #include "flang/Optimizer/Transforms/Utils.h"
 #include "flang/Runtime/entry-names.h"
+#include "flang/Support/Fortran.h"
 #include "mlir/Dialect/LLVMIR/LLVMDialect.h"
 #include "mlir/IR/Matchers.h"
 #include "mlir/IR/Operation.h"
diff --git a/flang/lib/Optimizer/Transforms/StackReclaim.cpp b/flang/lib/Optimizer/Transforms/StackReclaim.cpp
index bd3e49a47bc39..acb685850d173 100644
--- a/flang/lib/Optimizer/Transforms/StackReclaim.cpp
+++ b/flang/lib/Optimizer/Transforms/StackReclaim.cpp
@@ -6,11 +6,11 @@
 //
 //===----------------------------------------------------------------------===//
 
-#include "flang/Common/Fortran.h"
 #include "flang/Optimizer/Builder/FIRBuilder.h"
 #include "flang/Optimizer/Dialect/FIRDialect.h"
 #include "flang/Optimizer/Dialect/FIROps.h"
 #include "flang/Optimizer/Transforms/Passes.h"
+#include "flang/Support/Fortran.h"
 #include "mlir/Dialect/LLVMIR/LLVMDialect.h"
 #include "mlir/IR/Matchers.h"
 #include "mlir/Pass/Pass.h"
diff --git a/flang/lib/Optimizer/Transforms/VScaleAttr.cpp b/flang/lib/Optimizer/Transforms/VScaleAttr.cpp
index d311167c58b4d..54a2456e77366 100644
--- a/flang/lib/Optimizer/Transforms/VScaleAttr.cpp
+++ b/flang/lib/Optimizer/Transforms/VScaleAttr.cpp
@@ -14,7 +14,7 @@
 /// likely harmless to run it on something else, but it is also not valuable].
 //===----------------------------------------------------------------------===//
 
-#include "flang/ISO_Fortran_binding_wrapper.h"
+#include "flang/Common/ISO_Fortran_binding_wrapper.h"
 #include "flang/Optimizer/Builder/BoxValue.h"
 #include "flang/Optimizer/Builder/FIRBuilder.h"
 #include "flang/Optimizer/Builder/Runtime/Inquiry.h"
diff --git a/flang/lib/Parser/CMakeLists.txt b/flang/lib/Parser/CMakeLists.txt
index d364671d7a322..76fe3d7ce6ba4 100644
--- a/flang/lib/Parser/CMakeLists.txt
+++ b/flang/lib/Parser/CMakeLists.txt
@@ -25,7 +25,7 @@ add_flang_library(FortranParser
   user-state.cpp
 
   LINK_LIBS
-  FortranCommon
+  FortranSupport
 
   LINK_COMPONENTS
   Support
diff --git a/flang/lib/Parser/basic-parsers.h b/flang/lib/Parser/basic-parsers.h
index 1a8c14e7048f6..7e69d41debfcd 100644
--- a/flang/lib/Parser/basic-parsers.h
+++ b/flang/lib/Parser/basic-parsers.h
@@ -22,7 +22,6 @@
 // This header defines the fundamental parser class templates and helper
 // template functions.  See parser-combinators.txt for documentation.
 
-#include "flang/Common/Fortran-features.h"
 #include "flang/Common/idioms.h"
 #include "flang/Common/indirection.h"
 #include "flang/Parser/char-block.h"
@@ -30,6 +29,7 @@
 #include "flang/Parser/parse-state.h"
 #include "flang/Parser/provenance.h"
 #include "flang/Parser/user-state.h"
+#include "flang/Support/Fortran-features.h"
 #include <cstring>
 #include <functional>
 #include <list>
diff --git a/flang/lib/Parser/prescan.h b/flang/lib/Parser/prescan.h
index 08041f93b14b6..e2440ad6fbc42 100644
--- a/flang/lib/Parser/prescan.h
+++ b/flang/lib/Parser/prescan.h
@@ -16,11 +16,11 @@
 // fixed form character literals on truncated card images, file
 // inclusion, and driving the Fortran source preprocessor.
 
-#include "flang/Common/Fortran-features.h"
 #include "flang/Parser/characters.h"
 #include "flang/Parser/message.h"
 #include "flang/Parser/provenance.h"
 #include "flang/Parser/token-sequence.h"
+#include "flang/Support/Fortran-features.h"
 #include <bitset>
 #include <optional>
 #include <string>
diff --git a/flang/lib/Parser/unparse.cpp b/flang/lib/Parser/unparse.cpp
index 243f586b3ca4f..cd91fbe4ea5eb 100644
--- a/flang/lib/Parser/unparse.cpp
+++ b/flang/lib/Parser/unparse.cpp
@@ -10,13 +10,13 @@
 // traversal templates in parse-tree-visitor.h.
 
 #include "flang/Parser/unparse.h"
-#include "flang/Common/Fortran.h"
 #include "flang/Common/idioms.h"
 #include "flang/Common/indirection.h"
 #include "flang/Parser/characters.h"
 #include "flang/Parser/parse-tree-visitor.h"
 #include "flang/Parser/parse-tree.h"
 #include "flang/Parser/tools.h"
+#include "flang/Support/Fortran.h"
 #include "llvm/Support/raw_ostream.h"
 #include <algorithm>
 #include <cinttypes>
diff --git a/flang/lib/Semantics/CMakeLists.txt b/flang/lib/Semantics/CMakeLists.txt
index 7855ae7eed138..00108dde49dbd 100644
--- a/flang/lib/Semantics/CMakeLists.txt
+++ b/flang/lib/Semantics/CMakeLists.txt
@@ -53,7 +53,7 @@ add_flang_library(FortranSemantics
   omp_gen
 
   LINK_LIBS
-  FortranCommon
+  FortranSupport
   FortranParser
   FortranEvaluate
 
diff --git a/flang/lib/Semantics/check-return.cpp b/flang/lib/Semantics/check-return.cpp
index 22729f659ed5b..52220a566bbdc 100644
--- a/flang/lib/Semantics/check-return.cpp
+++ b/flang/lib/Semantics/check-return.cpp
@@ -7,11 +7,11 @@
 //===----------------------------------------------------------------------===//
 
 #include "check-return.h"
-#include "flang/Common/Fortran-features.h"
 #include "flang/Parser/message.h"
 #include "flang/Parser/parse-tree.h"
 #include "flang/Semantics/semantics.h"
 #include "flang/Semantics/tools.h"
+#include "flang/Support/Fortran-features.h"
 
 namespace Fortran::semantics {
 
diff --git a/flang/lib/Semantics/check-select-rank.cpp b/flang/lib/Semantics/check-select-rank.cpp
index 2e602d307013c..b227bbaaef4ba 100644
--- a/flang/lib/Semantics/check-select-rank.cpp
+++ b/flang/lib/Semantics/check-select-rank.cpp
@@ -7,11 +7,11 @@
 //===----------------------------------------------------------------------===//
 
 #include "check-select-rank.h"
-#include "flang/Common/Fortran.h"
 #include "flang/Common/idioms.h"
 #include "flang/Parser/message.h"
 #include "flang/Parser/tools.h"
 #include "flang/Semantics/tools.h"
+#include "flang/Support/Fortran.h"
 #include <list>
 #include <optional>
 #include <set>
diff --git a/flang/lib/Semantics/check-stop.cpp b/flang/lib/Semantics/check-stop.cpp
index 43535b07f029e..aabd52098e63b 100644
--- a/flang/lib/Semantics/check-stop.cpp
+++ b/flang/lib/Semantics/check-stop.cpp
@@ -7,11 +7,11 @@
 //===----------------------------------------------------------------------===//
 
 #include "check-stop.h"
-#include "flang/Common/Fortran.h"
 #include "flang/Evaluate/expression.h"
 #include "flang/Parser/parse-tree.h"
 #include "flang/Semantics/semantics.h"
 #include "flang/Semantics/tools.h"
+#include "flang/Support/Fortran.h"
 #include <optional>
 
 namespace Fortran::semantics {
diff --git a/flang/lib/Semantics/data-to-inits.h b/flang/lib/Semantics/data-to-inits.h
index d8cc4601de26f..7486ac8113e90 100644
--- a/flang/lib/Semantics/data-to-inits.h
+++ b/flang/lib/Semantics/data-to-inits.h
@@ -9,10 +9,10 @@
 #ifndef FORTRAN_SEMANTICS_DATA_TO_INITS_H_
 #define FORTRAN_SEMANTICS_DATA_TO_INITS_H_
 
-#include "flang/Common/default-kinds.h"
 #include "flang/Common/interval.h"
 #include "flang/Evaluate/fold-designator.h"
 #include "flang/Evaluate/initial-image.h"
+#include "flang/Support/default-kinds.h"
 #include <list>
 #include <map>
 
diff --git a/flang/lib/Semantics/expression.cpp b/flang/lib/Semantics/expression.cpp
index f9fa4a554a62a..6949e5693d08f 100644
--- a/flang/lib/Semantics/expression.cpp
+++ b/flang/lib/Semantics/expression.cpp
@@ -11,7 +11,6 @@
 #include "pointer-assignment.h"
 #include "resolve-names-utils.h"
 #include "resolve-names.h"
-#include "flang/Common/Fortran.h"
 #include "flang/Common/idioms.h"
 #include "flang/Evaluate/common.h"
 #include "flang/Evaluate/fold.h"
@@ -24,6 +23,7 @@
 #include "flang/Semantics/semantics.h"
 #include "flang/Semantics/symbol.h"
 #include "flang/Semantics/tools.h"
+#include "flang/Support/Fortran.h"
 #include "llvm/Support/raw_ostream.h"
 #include <algorithm>
 #include <functional>
diff --git a/flang/lib/Semantics/resolve-names-utils.cpp b/flang/lib/Semantics/resolve-names-utils.cpp
index 347f54e064070..742bb748b7ff3 100644
--- a/flang/lib/Semantics/resolve-names-utils.cpp
+++ b/flang/lib/Semantics/resolve-names-utils.cpp
@@ -7,8 +7,6 @@
 //===----------------------------------------------------------------------===//
 
 #include "resolve-names-utils.h"
-#include "flang/Common/Fortran-features.h"
-#include "flang/Common/Fortran.h"
 #include "flang/Common/idioms.h"
 #include "flang/Common/indirection.h"
 #include "flang/Evaluate/fold.h"
@@ -20,6 +18,8 @@
 #include "flang/Semantics/expression.h"
 #include "flang/Semantics/semantics.h"
 #include "flang/Semantics/tools.h"
+#include "flang/Support/Fortran-features.h"
+#include "flang/Support/Fortran.h"
 #include <initializer_list>
 #include <variant>
 
diff --git a/flang/lib/Semantics/resolve-names.cpp b/flang/lib/Semantics/resolve-names.cpp
index fbf43d4744335..e64abe6b50e78 100644
--- a/flang/lib/Semantics/resolve-names.cpp
+++ b/flang/lib/Semantics/resolve-names.cpp
@@ -13,8 +13,6 @@
 #include "resolve-directives.h"
 #include "resolve-names-utils.h"
 #include "rewrite-parse-tree.h"
-#include "flang/Common/Fortran.h"
-#include "flang/Common/default-kinds.h"
 #include "flang/Common/indirection.h"
 #include "flang/Common/restorer.h"
 #include "flang/Common/visit.h"
@@ -38,6 +36,8 @@
 #include "flang/Semantics/symbol.h"
 #include "flang/Semantics/tools.h"
 #include "flang/Semantics/type.h"
+#include "flang/Support/Fortran.h"
+#include "flang/Support/default-kinds.h"
 #include "llvm/Support/raw_ostream.h"
 #include <list>
 #include <map>
diff --git a/flang/lib/Semantics/semantics.cpp b/flang/lib/Semantics/semantics.cpp
index 58dc1f218b56f..10a01039ea0ae 100644
--- a/flang/lib/Semantics/semantics.cpp
+++ b/flang/lib/Semantics/semantics.cpp
@@ -37,12 +37,12 @@
 #include "resolve-labels.h"
 #include "resolve-names.h"
 #include "rewrite-parse-tree.h"
-#include "flang/Common/default-kinds.h"
 #include "flang/Parser/parse-tree-visitor.h"
 #include "flang/Parser/tools.h"
 #include "flang/Semantics/expression.h"
 #include "flang/Semantics/scope.h"
 #include "flang/Semantics/symbol.h"
+#include "flang/Support/default-kinds.h"
 #include "llvm/Support/raw_ostream.h"
 #include "llvm/TargetParser/Host.h"
 #include "llvm/TargetParser/Triple.h"
diff --git a/flang/lib/Semantics/tools.cpp b/flang/lib/Semantics/tools.cpp
index 9ebfbbb5317b6..7544731a682ec 100644
--- a/flang/lib/Semantics/tools.cpp
+++ b/flang/lib/Semantics/tools.cpp
@@ -7,7 +7,6 @@
 //===----------------------------------------------------------------------===//
 
 #include "flang/Parser/tools.h"
-#include "flang/Common/Fortran.h"
 #include "flang/Common/indirection.h"
 #include "flang/Parser/dump-parse-tree.h"
 #include "flang/Parser/message.h"
@@ -17,6 +16,7 @@
 #include "flang/Semantics/symbol.h"
 #include "flang/Semantics/tools.h"
 #include "flang/Semantics/type.h"
+#include "flang/Support/Fortran.h"
 #include "llvm/Support/raw_ostream.h"
 #include <algorithm>
 #include <set>
diff --git a/flang/lib/Support/CMakeLists.txt b/flang/lib/Support/CMakeLists.txt
index 12183f590316d..4ee381589a208 100644
--- a/flang/lib/Support/CMakeLists.txt
+++ b/flang/lib/Support/CMakeLists.txt
@@ -1,9 +1,62 @@
+#===-- lib/Support/CMakeLists.txt ------------------------------------------===#
+#
+# Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+# See https://llvm.org/LICENSE.txt for license information.
+# SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+#
+#===------------------------------------------------------------------------===#
+
+find_first_existing_vc_file("${LLVM_MAIN_SRC_DIR}" llvm_vc)
+find_first_existing_vc_file("${FLANG_SOURCE_DIR}" flang_vc)
+
+# The VC revision include that we want to generate.
+set(version_inc "${CMAKE_CURRENT_BINARY_DIR}/VCSVersion.inc")
+
+set(generate_vcs_version_script "${LLVM_CMAKE_DIR}/GenerateVersionFromVCS.cmake")
+
+if(llvm_vc AND LLVM_APPEND_VC_REV)
+  set(llvm_source_dir ${LLVM_MAIN_SRC_DIR})
+endif()
+if(flang_vc AND LLVM_APPEND_VC_REV)
+  set(flang_source_dir ${FLANG_SOURCE_DIR})
+endif()
+
+# Create custom target to generate the VC revision include.
+add_custom_command(OUTPUT "${version_inc}"
+  DEPENDS "${llvm_vc}" "${flang_vc}" "${generate_vcs_version_script}"
+  COMMAND ${CMAKE_COMMAND} "-DNAMES=\"LLVM;FLANG\""
+                           "-DLLVM_SOURCE_DIR=${llvm_source_dir}"
+                           "-DFLANG_SOURCE_DIR=${flang_source_dir}"
+                           "-DHEADER_FILE=${version_inc}"
+                           "-DLLVM_FORCE_VC_REVISION=${LLVM_FORCE_VC_REVISION}"
+                           "-DLLVM_FORCE_VC_REPOSITORY=${LLVM_FORCE_VC_REPOSITORY}"
+                           -P "${generate_vcs_version_script}")
+
+# Mark the generated header as being generated.
+set_source_files_properties("${version_inc}"
+  PROPERTIES GENERATED TRUE
+             HEADER_FILE_ONLY TRUE)
+
+if(FLANG_VENDOR)
+  set_source_files_properties(Version.cpp
+    PROPERTIES COMPILE_DEFINITIONS "FLANG_VENDOR=\"${FLANG_VENDOR} \"")
+endif()
+
 add_flang_library(FortranSupport
+  default-kinds.cpp
+  Fortran.cpp
+  Fortran-features.cpp
+  idioms.cpp
+  LangOptions.cpp
+  OpenMP-utils.cpp
   Timing.cpp
+  Version.cpp
+  ${version_inc}
 
   LINK_COMPONENTS
   Support
 
   MLIR_LIBS
+  MLIRIR
   MLIRSupport
 )
diff --git a/flang/lib/Common/Fortran-features.cpp b/flang/lib/Support/Fortran-features.cpp
similarity index 97%
rename from flang/lib/Common/Fortran-features.cpp
rename to flang/lib/Support/Fortran-features.cpp
index e2601e1af3a2f..bbeb4b15a0486 100644
--- a/flang/lib/Common/Fortran-features.cpp
+++ b/flang/lib/Support/Fortran-features.cpp
@@ -1,4 +1,4 @@
-//===-- lib/Common/Fortran-features.cpp -----------------------------------===//
+//===-- lib/Support/Fortran-features.cpp ------------------------*- C++ -*-===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
@@ -6,9 +6,9 @@
 //
 //===----------------------------------------------------------------------===//
 
-#include "flang/Common/Fortran-features.h"
-#include "flang/Common/Fortran.h"
+#include "flang/Support/Fortran-features.h"
 #include "flang/Common/idioms.h"
+#include "flang/Support/Fortran.h"
 
 namespace Fortran::common {
 
diff --git a/flang/lib/Common/Fortran.cpp b/flang/lib/Support/Fortran.cpp
similarity index 96%
rename from flang/lib/Common/Fortran.cpp
rename to flang/lib/Support/Fortran.cpp
index eec83419f9eb2..746b7c9740728 100644
--- a/flang/lib/Common/Fortran.cpp
+++ b/flang/lib/Support/Fortran.cpp
@@ -1,4 +1,4 @@
-//===-- lib/Common/Fortran.cpp --------------------------------------------===//
+//===-- lib/Support/Fortran.cpp ---------------------------------*- C++ -*-===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
@@ -6,8 +6,8 @@
 //
 //===----------------------------------------------------------------------===//
 
-#include "flang/Common/Fortran.h"
-#include "flang/Common/Fortran-features.h"
+#include "flang/Support/Fortran.h"
+#include "flang/Support/Fortran-features.h"
 
 namespace Fortran::common {
 
diff --git a/flang/lib/Common/LangOptions.cpp b/flang/lib/Support/LangOptions.cpp
similarity index 80%
rename from flang/lib/Common/LangOptions.cpp
rename to flang/lib/Support/LangOptions.cpp
index 415c715156e7b..273274fc07215 100644
--- a/flang/lib/Common/LangOptions.cpp
+++ b/flang/lib/Support/LangOptions.cpp
@@ -1,4 +1,4 @@
-//===------ LangOptions.cpp -----------------------------------------------===//
+//===-- lib/Support/LangOptions.cpp -----------------------------*- C++ -*-===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
@@ -10,7 +10,7 @@
 //
 //===----------------------------------------------------------------------===//
 
-#include "flang/Common/LangOptions.h"
+#include "flang/Support/LangOptions.h"
 #include <string.h>
 
 namespace Fortran::common {
@@ -18,7 +18,7 @@ namespace Fortran::common {
 LangOptions::LangOptions() {
 #define LANGOPT(Name, Bits, Default) Name = Default;
 #define ENUM_LANGOPT(Name, Type, Bits, Default) set##Name(Default);
-#include "flang/Common/LangOptions.def"
+#include "flang/Support/LangOptions.def"
 }
 
 } // end namespace Fortran::common
diff --git a/flang/lib/Common/OpenMP-utils.cpp b/flang/lib/Support/OpenMP-utils.cpp
similarity index 93%
rename from flang/lib/Common/OpenMP-utils.cpp
rename to flang/lib/Support/OpenMP-utils.cpp
index 47e89fe6dd1ee..178a6e38dc0f2 100644
--- a/flang/lib/Common/OpenMP-utils.cpp
+++ b/flang/lib/Support/OpenMP-utils.cpp
@@ -1,4 +1,4 @@
-//===-- include/flang/Common/OpenMP-utils.cpp ------------------*- C++ -*-====//
+//===-- lib/Support/OpenMP-utils.cpp ----------------------------*- C++ -*-===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
@@ -6,7 +6,7 @@
 //
 //===----------------------------------------------------------------------===//
 
-#include "flang/Common/OpenMP-utils.h"
+#include "flang/Support/OpenMP-utils.h"
 
 #include "mlir/IR/OpDefinition.h"
 
diff --git a/flang/lib/Common/Version.cpp b/flang/lib/Support/Version.cpp
similarity index 95%
rename from flang/lib/Common/Version.cpp
rename to flang/lib/Support/Version.cpp
index d67255f353dfd..8ee4908f28f62 100644
--- a/flang/lib/Common/Version.cpp
+++ b/flang/lib/Support/Version.cpp
@@ -1,4 +1,4 @@
-//===- Version.cpp - Flang Version Number -------------------*- Fortran -*-===//
+//===-- lib/Support/Version.cpp ---------------------------------*- C++ -*-===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
@@ -10,7 +10,7 @@
 //
 //===----------------------------------------------------------------------===//
 
-#include "flang/Common/Version.h"
+#include "flang/Support/Version.h"
 #include "llvm/Support/raw_ostream.h"
 #include <cstdlib>
 #include <cstring>
diff --git a/flang/lib/Common/default-kinds.cpp b/flang/lib/Support/default-kinds.cpp
similarity index 94%
rename from flang/lib/Common/default-kinds.cpp
rename to flang/lib/Support/default-kinds.cpp
index d2ca910351361..b763f8ec19418 100644
--- a/flang/lib/Common/default-kinds.cpp
+++ b/flang/lib/Support/default-kinds.cpp
@@ -1,4 +1,4 @@
-//===-- lib/Common/default-kinds.cpp --------------------------------------===//
+//===-- lib/Support/default-kinds.cpp ---------------------------*- C++ -*-===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
@@ -6,7 +6,7 @@
 //
 //===----------------------------------------------------------------------===//
 
-#include "flang/Common/default-kinds.h"
+#include "flang/Support/default-kinds.h"
 #include "flang/Common/idioms.h"
 
 namespace Fortran::common {
diff --git a/flang/lib/Common/idioms.cpp b/flang/lib/Support/idioms.cpp
similarity index 89%
rename from flang/lib/Common/idioms.cpp
rename to flang/lib/Support/idioms.cpp
index 536a5c2e5479d..906a4c1bcd9b0 100644
--- a/flang/lib/Common/idioms.cpp
+++ b/flang/lib/Support/idioms.cpp
@@ -1,4 +1,4 @@
-//===-- lib/Common/idioms.cpp ---------------------------------------------===//
+//===-- lib/Support/idioms.cpp ----------------------------------*- C++ -*-===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
diff --git a/flang/runtime/CUDA/allocator.cpp b/flang/runtime/CUDA/allocator.cpp
index 85b3daf65a8ba..368c1124ef70a 100644
--- a/flang/runtime/CUDA/allocator.cpp
+++ b/flang/runtime/CUDA/allocator.cpp
@@ -11,10 +11,10 @@
 #include "../stat.h"
 #include "../terminator.h"
 #include "../type-info.h"
-#include "flang/Common/Fortran.h"
-#include "flang/ISO_Fortran_binding_wrapper.h"
+#include "flang/Common/ISO_Fortran_binding_wrapper.h"
 #include "flang/Runtime/CUDA/common.h"
 #include "flang/Runtime/allocator-registry.h"
+#include "flang/Support/Fortran.h"
 
 #include "cuda_runtime.h"
 
diff --git a/flang/runtime/ISO_Fortran_binding.cpp b/flang/runtime/ISO_Fortran_binding.cpp
index fe22026f31f55..64e239f498230 100644
--- a/flang/runtime/ISO_Fortran_binding.cpp
+++ b/flang/runtime/ISO_Fortran_binding.cpp
@@ -11,7 +11,7 @@
 
 #include "ISO_Fortran_util.h"
 #include "terminator.h"
-#include "flang/ISO_Fortran_binding_wrapper.h"
+#include "flang/Common/ISO_Fortran_binding_wrapper.h"
 #include "flang/Runtime/descriptor.h"
 #include "flang/Runtime/pointer.h"
 #include "flang/Runtime/type-code.h"
diff --git a/flang/runtime/ISO_Fortran_util.h b/flang/runtime/ISO_Fortran_util.h
index dd0eeef80bb89..aca9aee8c5718 100644
--- a/flang/runtime/ISO_Fortran_util.h
+++ b/flang/runtime/ISO_Fortran_util.h
@@ -12,7 +12,7 @@
 // Internal utils for establishing CFI_cdesc_t descriptors.
 
 #include "terminator.h"
-#include "flang/ISO_Fortran_binding_wrapper.h"
+#include "flang/Common/ISO_Fortran_binding_wrapper.h"
 #include "flang/Runtime/descriptor.h"
 #include "flang/Runtime/type-code.h"
 #include <cstdlib>
diff --git a/flang/runtime/allocatable.cpp b/flang/runtime/allocatable.cpp
index 5e065f47636a8..686114bf86eaf 100644
--- a/flang/runtime/allocatable.cpp
+++ b/flang/runtime/allocatable.cpp
@@ -12,7 +12,7 @@
 #include "stat.h"
 #include "terminator.h"
 #include "type-info.h"
-#include "flang/ISO_Fortran_binding_wrapper.h"
+#include "flang/Common/ISO_Fortran_binding_wrapper.h"
 #include "flang/Runtime/assign.h"
 #include "flang/Runtime/descriptor.h"
 
diff --git a/flang/runtime/stat.h b/flang/runtime/stat.h
index 71faeb027d908..572cb6d10b489 100644
--- a/flang/runtime/stat.h
+++ b/flang/runtime/stat.h
@@ -11,8 +11,8 @@
 
 #ifndef FORTRAN_RUNTIME_STAT_H_
 #define FORTRAN_RUNTIME_STAT_H_
+#include "flang/Common/ISO_Fortran_binding_wrapper.h"
 #include "flang/Common/api-attrs.h"
-#include "flang/ISO_Fortran_binding_wrapper.h"
 #include "flang/Runtime/magic-numbers.h"
 namespace Fortran::runtime {
 
diff --git a/flang/runtime/temporary-stack.cpp b/flang/runtime/temporary-stack.cpp
index 667b10e04dbd2..93340266b1b44 100644
--- a/flang/runtime/temporary-stack.cpp
+++ b/flang/runtime/temporary-stack.cpp
@@ -11,7 +11,7 @@
 
 #include "flang/Runtime/temporary-stack.h"
 #include "terminator.h"
-#include "flang/ISO_Fortran_binding_wrapper.h"
+#include "flang/Common/ISO_Fortran_binding_wrapper.h"
 #include "flang/Runtime/assign.h"
 #include "flang/Runtime/descriptor.h"
 #include "flang/Runtime/memory.h"
diff --git a/flang/tools/bbc/CMakeLists.txt b/flang/tools/bbc/CMakeLists.txt
index 97462be83ea43..f950f03920d3f 100644
--- a/flang/tools/bbc/CMakeLists.txt
+++ b/flang/tools/bbc/CMakeLists.txt
@@ -29,11 +29,6 @@ target_link_libraries(bbc PRIVATE
   flangFrontend
   flangPasses
   FlangOpenMPTransforms
-  FortranCommon
-  FortranParser
-  FortranEvaluate
-  FortranSemantics
-  FortranLower
 )
 
 mlir_target_link_libraries(bbc PRIVATE
@@ -41,4 +36,9 @@ mlir_target_link_libraries(bbc PRIVATE
   ${extension_libs}
   MLIRAffineToStandard
   MLIRSCFToControlFlow
+  FortranSupport
+  FortranParser
+  FortranEvaluate
+  FortranSemantics
+  FortranLower
 )
diff --git a/flang/tools/bbc/bbc.cpp b/flang/tools/bbc/bbc.cpp
index dafbcd856389a..3b19a1c2a78d9 100644
--- a/flang/tools/bbc/bbc.cpp
+++ b/flang/tools/bbc/bbc.cpp
@@ -14,11 +14,6 @@
 ///
 //===----------------------------------------------------------------------===//
 
-#include "flang/Common/Fortran-features.h"
-#include "flang/Common/LangOptions.h"
-#include "flang/Common/OpenMP-features.h"
-#include "flang/Common/Version.h"
-#include "flang/Common/default-kinds.h"
 #include "flang/Frontend/CodeGenOptions.h"
 #include "flang/Frontend/TargetOptions.h"
 #include "flang/Lower/Bridge.h"
@@ -42,6 +37,11 @@
 #include "flang/Semantics/runtime-type-info.h"
 #include "flang/Semantics/semantics.h"
 #include "flang/Semantics/unparse-with-symbols.h"
+#include "flang/Support/Fortran-features.h"
+#include "flang/Support/LangOptions.h"
+#include "flang/Support/OpenMP-features.h"
+#include "flang/Support/Version.h"
+#include "flang/Support/default-kinds.h"
 #include "flang/Tools/CrossToolHelpers.h"
 #include "flang/Tools/TargetSetup.h"
 #include "flang/Version.inc"
diff --git a/flang/tools/f18-parse-demo/CMakeLists.txt b/flang/tools/f18-parse-demo/CMakeLists.txt
index df1f1d24a55e5..743a44017e8a5 100644
--- a/flang/tools/f18-parse-demo/CMakeLists.txt
+++ b/flang/tools/f18-parse-demo/CMakeLists.txt
@@ -11,6 +11,6 @@ add_flang_tool(f18-parse-demo
 
 target_link_libraries(f18-parse-demo
   PRIVATE
-  FortranCommon
+  FortranSupport
   FortranParser
   )
diff --git a/flang/tools/f18-parse-demo/f18-parse-demo.cpp b/flang/tools/f18-parse-demo/f18-parse-demo.cpp
index 3025dbd4dca4a..a50c88dc84064 100644
--- a/flang/tools/f18-parse-demo/f18-parse-demo.cpp
+++ b/flang/tools/f18-parse-demo/f18-parse-demo.cpp
@@ -21,8 +21,6 @@
 // scaffolding compiler driver that can test some semantic passes of the
 // F18 compiler under development.
 
-#include "flang/Common/Fortran-features.h"
-#include "flang/Common/default-kinds.h"
 #include "flang/Parser/characters.h"
 #include "flang/Parser/dump-parse-tree.h"
 #include "flang/Parser/message.h"
@@ -31,6 +29,8 @@
 #include "flang/Parser/parsing.h"
 #include "flang/Parser/provenance.h"
 #include "flang/Parser/unparse.h"
+#include "flang/Support/Fortran-features.h"
+#include "flang/Support/default-kinds.h"
 #include "llvm/Support/Errno.h"
 #include "llvm/Support/FileSystem.h"
 #include "llvm/Support/Program.h"
diff --git a/flang/tools/tco/CMakeLists.txt b/flang/tools/tco/CMakeLists.txt
index 220f908d2f108..c277cdbf167b6 100644
--- a/flang/tools/tco/CMakeLists.txt
+++ b/flang/tools/tco/CMakeLists.txt
@@ -20,7 +20,7 @@ target_link_libraries(tco PRIVATE
   flangPasses
   FIROpenACCSupport
   FlangOpenMPTransforms
-  FortranCommon
+  FortranSupport
 )
 
 mlir_target_link_libraries(tco PRIVATE
diff --git a/flang/unittests/Evaluate/CMakeLists.txt b/flang/unittests/Evaluate/CMakeLists.txt
index 52eb385f4763f..0ea02ad7f7115 100644
--- a/flang/unittests/Evaluate/CMakeLists.txt
+++ b/flang/unittests/Evaluate/CMakeLists.txt
@@ -26,7 +26,7 @@ add_flang_nongtest_unittest(uint128
 )
 
 add_flang_nongtest_unittest(expression
-  FortranCommon
+  FortranSupport
   FortranEvaluateTesting
   FortranEvaluate
   FortranSemantics
@@ -40,7 +40,7 @@ add_flang_nongtest_unittest(integer
 )
 
 add_flang_nongtest_unittest(intrinsics
-  FortranCommon
+  FortranSupport
   FortranEvaluateTesting
   FortranEvaluate
   FortranDecimal
@@ -84,7 +84,7 @@ add_flang_nongtest_unittest(ISO-Fortran-binding
 )
 
 add_flang_nongtest_unittest(folding
-  FortranCommon
+  FortranSupport
   FortranEvaluateTesting
   FortranEvaluate
   FortranSemantics
diff --git a/flang/unittests/Evaluate/ISO-Fortran-binding.cpp b/flang/unittests/Evaluate/ISO-Fortran-binding.cpp
index 3c98363f90046..38688b404876f 100644
--- a/flang/unittests/Evaluate/ISO-Fortran-binding.cpp
+++ b/flang/unittests/Evaluate/ISO-Fortran-binding.cpp
@@ -1,5 +1,5 @@
 #include "testing.h"
-#include "flang/ISO_Fortran_binding_wrapper.h"
+#include "flang/Common/ISO_Fortran_binding_wrapper.h"
 #include "flang/Runtime/descriptor.h"
 #include "llvm/Support/raw_ostream.h"
 #include <type_traits>
diff --git a/flang/unittests/Frontend/CMakeLists.txt b/flang/unittests/Frontend/CMakeLists.txt
index 9177997f41f53..3cbc2cf148511 100644
--- a/flang/unittests/Frontend/CMakeLists.txt
+++ b/flang/unittests/Frontend/CMakeLists.txt
@@ -18,7 +18,7 @@ target_link_libraries(FlangFrontendTests
   FortranLower
   FortranParser
   FortranSemantics
-  FortranCommon
+  FortranSupport
   FortranEvaluate
 )
 
diff --git a/flang/unittests/Runtime/CUDA/Allocatable.cpp b/flang/unittests/Runtime/CUDA/Allocatable.cpp
index 0f7eb27789316..bdfa8f5cc3213 100644
--- a/flang/unittests/Runtime/CUDA/Allocatable.cpp
+++ b/flang/unittests/Runtime/CUDA/Allocatable.cpp
@@ -9,11 +9,11 @@
 #include "flang/Runtime/allocatable.h"
 #include "gtest/gtest.h"
 #include "../../../runtime/terminator.h"
-#include "flang/Common/Fortran.h"
 #include "flang/Runtime/CUDA/allocator.h"
 #include "flang/Runtime/CUDA/common.h"
 #include "flang/Runtime/CUDA/descriptor.h"
 #include "flang/Runtime/allocator-registry.h"
+#include "flang/Support/Fortran.h"
 
 #include "cuda_runtime.h"
 
diff --git a/flang/unittests/Runtime/CUDA/AllocatorCUF.cpp b/flang/unittests/Runtime/CUDA/AllocatorCUF.cpp
index 7cb25787e7797..5ec122e4c5777 100644
--- a/flang/unittests/Runtime/CUDA/AllocatorCUF.cpp
+++ b/flang/unittests/Runtime/CUDA/AllocatorCUF.cpp
@@ -8,11 +8,11 @@
 
 #include "gtest/gtest.h"
 #include "../../../runtime/terminator.h"
-#include "flang/Common/Fortran.h"
 #include "flang/Runtime/CUDA/allocator.h"
 #include "flang/Runtime/CUDA/descriptor.h"
 #include "flang/Runtime/allocatable.h"
 #include "flang/Runtime/allocator-registry.h"
+#include "flang/Support/Fortran.h"
 
 #include "cuda_runtime.h"
 
diff --git a/flang/unittests/Runtime/CUDA/Memory.cpp b/flang/unittests/Runtime/CUDA/Memory.cpp
index 7c8b7aa5a4d78..61c9d1131ee56 100644
--- a/flang/unittests/Runtime/CUDA/Memory.cpp
+++ b/flang/unittests/Runtime/CUDA/Memory.cpp
@@ -10,12 +10,12 @@
 #include "gtest/gtest.h"
 #include "../../../runtime/terminator.h"
 #include "../tools.h"
-#include "flang/Common/Fortran.h"
 #include "flang/Runtime/CUDA/allocator.h"
 #include "flang/Runtime/CUDA/common.h"
 #include "flang/Runtime/CUDA/descriptor.h"
 #include "flang/Runtime/allocatable.h"
 #include "flang/Runtime/allocator-registry.h"
+#include "flang/Support/Fortran.h"
 
 #include "cuda_runtime.h"
 
diff --git a/flang/unittests/Runtime/TemporaryStack.cpp b/flang/unittests/Runtime/TemporaryStack.cpp
index 0a9344969ca6b..4f701e09b2945 100644
--- a/flang/unittests/Runtime/TemporaryStack.cpp
+++ b/flang/unittests/Runtime/TemporaryStack.cpp
@@ -8,7 +8,7 @@
 
 #include "gtest/gtest.h"
 #include "tools.h"
-#include "flang/ISO_Fortran_binding_wrapper.h"
+#include "flang/Common/ISO_Fortran_binding_wrapper.h"
 #include "flang/Runtime/allocatable.h"
 #include "flang/Runtime/cpp-type.h"
 #include "flang/Runtime/descriptor.h"