Make STRING an unreserved_keyword.

Commit 1a36bc9db (SQL/JSON query functions) introduced STRING as a
type_func_name_keyword, thereby breaking applications that use
"string" as a table name, column name, function parameter name, etc.
That seems like a pretty bad thing, not least because the SQL spec
says that STRING is an unreserved keyword.

This is easy enough to fix so far as the core grammar is concerned.
However, doing so causes some ECPG test cases to fail, specifically
those that use "string" as a typedef name.  It turns out this is
because portions of the ECPG grammar allow type_func_name_keywords
but not unreserved_keywords as typedef names.  That's pretty horrid,
and it's mildly astonishing that we've not heard complaints about it
before.  We can fix two of those uses trivially, but the ones in the
var_type production are less easy.  As a stopgap, hard-code STRING as
an allowed alternative in var_type.

Per report from Alastair McKinley.

Discussion: https://postgr.es/m/3661437.1653855582@sss.pgh.pa.us

diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index 989db0dbecec84282be3965b6d406bd4ad23af39..969c9c158f63830b6075910b7d2377f2016b4d3c 100644 (file)
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -17940,6 +17940,7 @@ unreserved_keyword:
            | STORAGE
            | STORED
            | STRICT_P
+           | STRING
            | STRIP_P
            | SUBSCRIPTION
            | SUPPORT
@@ -18098,7 +18099,6 @@ type_func_name_keyword:
            | OVERLAPS
            | RIGHT
            | SIMILAR
-           | STRING
            | TABLESAMPLE
            | VERBOSE
        ;

diff --git a/src/include/parser/kwlist.h b/src/include/parser/kwlist.h
index 8a2ab405a28e086efeb8ced1af78abd7db13c1f8..ae35f03251384b5dd5c6ce1eb65177f2d80e780f 100644 (file)
--- a/src/include/parser/kwlist.h
+++ b/src/include/parser/kwlist.h
@@ -426,7 +426,7 @@ PG_KEYWORD("stdout", STDOUT, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("storage", STORAGE, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("stored", STORED, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("strict", STRICT_P, UNRESERVED_KEYWORD, BARE_LABEL)
-PG_KEYWORD("string", STRING, TYPE_FUNC_NAME_KEYWORD, BARE_LABEL)
+PG_KEYWORD("string", STRING, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("strip", STRIP_P, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("subscription", SUBSCRIPTION, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("substring", SUBSTRING, COL_NAME_KEYWORD, BARE_LABEL)

diff --git a/src/interfaces/ecpg/preproc/ecpg.trailer b/src/interfaces/ecpg/preproc/ecpg.trailer
index daf979a8e8259a5f2a013b99cea575f70273eff7..b95fc44314d767d40a30dab0c250ba0703f65be2 100644 (file)
--- a/src/interfaces/ecpg/preproc/ecpg.trailer
+++ b/src/interfaces/ecpg/preproc/ecpg.trailer
@@ -467,7 +467,7 @@ type_declaration: S_TYPEDEF
        /* an initializer specified */
        initializer = 0;
    }
-   var_type opt_pointer ECPGColLabelCommon opt_array_bounds ';'
+   var_type opt_pointer ECPGColLabel opt_array_bounds ';'
    {
        add_typedef($5, $6.index1, $6.index2, $3.type_enum, $3.type_dimension, $3.type_index, initializer, *$4 ? 1 : 0);
 
@@ -701,6 +701,43 @@ var_type:  simple_type
                struct_member_list[struct_level] = ECPGstruct_member_dup(this->struct_member_list);
            }
        }
+       | STRING
+       {
+           /*
+            * It's quite horrid that ECPGColLabelCommon excludes
+            * unreserved_keyword, meaning that unreserved keywords can't be
+            * used as type names in var_type.  However, this is hard to avoid
+            * since what follows ecpgstart can be either a random SQL
+            * statement or an ECPGVarDeclaration (beginning with var_type).
+            * Pending a bright idea about how to fix that, we must
+            * special-case STRING (and any other unreserved keywords that are
+            * likely to be needed here).
+            */
+           if (INFORMIX_MODE)
+           {
+               $$.type_enum = ECPGt_string;
+               $$.type_str = mm_strdup("char");
+               $$.type_dimension = mm_strdup("-1");
+               $$.type_index = mm_strdup("-1");
+               $$.type_sizeof = NULL;
+           }
+           else
+           {
+               /* this is for typedef'ed types */
+               struct typedefs *this = get_typedef("string");
+
+               $$.type_str = (this->type->type_enum == ECPGt_varchar || this->type->type_enum == ECPGt_bytea) ? EMPTY : mm_strdup(this->name);
+               $$.type_enum = this->type->type_enum;
+               $$.type_dimension = this->type->type_dimension;
+               $$.type_index = this->type->type_index;
+               if (this->type->type_sizeof && strlen(this->type->type_sizeof) != 0)
+                   $$.type_sizeof = this->type->type_sizeof;
+               else
+                   $$.type_sizeof = cat_str(3, mm_strdup("sizeof("), mm_strdup(this->name), mm_strdup(")"));
+
+               struct_member_list[struct_level] = ECPGstruct_member_dup(this->struct_member_list);
+           }
+       }
        | s_struct_union_symbol
        {
            /* this is for named structs/unions */
@@ -1342,7 +1379,7 @@ ECPGTypedef: TYPE_P
            /* an initializer specified */
            initializer = 0;
        }
-       ECPGColLabelCommon IS var_type opt_array_bounds opt_reference
+       ECPGColLabel IS var_type opt_array_bounds opt_reference
        {
            add_typedef($3, $6.index1, $6.index2, $5.type_enum, $5.type_dimension, $5.type_index, initializer, *$7 ? 1 : 0);