Changeset 224171 in webkit for trunk/Source/JavaScriptCore/offlineasm/arm64.rb

Timestamp:

Oct 30, 2017, 1:16:44 AM (8 years ago)

Author:

[email protected]

Message:

[ARM64][Linux] Re-enable Gigacage
​https://bugs.webkit.org/show_bug.cgi?id=178130

Reviewed by Michael Catanzaro.

Source/bmalloc:

• bmalloc/Gigacage.h: Re-enable Gigacage on ARM64 Linux.

Source/JavaScriptCore:

Guard the current globaladdr opcode implementation for ARM64 with
OS(DARWIN) as it's only usable for Mach-O.

For OS(LINUX), ELF-supported :got: and :got_lo12: relocation specifiers
have to be used. The .loh directive can't be used as it's not supported
in GCC or the ld linker.

On every other OS target, a compilation error is thrown.

• offlineasm/arm64.rb:

File:

• trunk/Source/JavaScriptCore/offlineasm/arm64.rb (modified) (1 diff)

trunk/Source/JavaScriptCore/offlineasm/arm64.rb

@@ -933 +933 @@
         when "globaladdr"
             uid = $asm.newUID
+
+            # On Darwin, use Macho-O GOT relocation specifiers, along with
+            # the labels required for the .loh directive.
+            $asm.putStr("#if OS(DARWIN)")
             $asm.puts "L_offlineasm_loh_adrp_#{uid}:"
             $asm.puts "adrp #{operands[1].arm64Operand(:ptr)}, #{operands[0].asmLabel}@GOTPAGE"
             $asm.puts "L_offlineasm_loh_ldr_#{uid}:"
             $asm.puts "ldr #{operands[1].arm64Operand(:ptr)}, [#{operands[1].arm64Operand(:ptr)}, #{operands[0].asmLabel}@GOTPAGEOFF]"
+
+            # On Linux, use ELF GOT relocation specifiers.
+            $asm.putStr("#elif OS(LINUX)")
+            $asm.puts "adrp #{operands[1].arm64Operand(:ptr)}, :got:#{operands[0].asmLabel}"
+            $asm.puts "ldr #{operands[1].arm64Operand(:ptr)}, [#{operands[1].arm64Operand(:ptr)}, :got_lo12:#{operands[0].asmLabel}]"
+
+            # Throw a compiler error everywhere else.
+            $asm.putStr("#else")
+            $asm.putStr("#error Missing globaladdr implementation")
+            $asm.putStr("#endif")
+
             $asm.deferAction {
+                # On Darwin, also include the .loh directive using the generated labels.
+                $asm.putStr("#if OS(DARWIN)")
                 $asm.puts ".loh AdrpLdrGot L_offlineasm_loh_adrp_#{uid}, L_offlineasm_loh_ldr_#{uid}"
+                $asm.putStr("#endif")
             }
         else