Add support for commas within parenthesized groups in function arguments.

The specification says that commas within a parenthesized group,
(that's not a function-like macro invocation), are passed through
literally and not considered argument separators in any outer macro
invocation.

Add support and a test for this case. This support makes a third
occurrence of the same "FUNC_MACRO (" shift/reduce conflict appear, so
expect that.

This change does introduce a fairly large copy/paste block in the
grammar which is unfortunate. Perhaps if I were more clever I'd find a
way to share the common pieces between argument and argument_or_comma.

diff --git a/glcpp-parse.y b/glcpp-parse.y
index 28e79ebf9f781db648c2614c44e34fb33c97e08d..c9edc5c3040e7ee6eaf8bcdd2b1dc34060237cb0 100644 (file)
--- a/glcpp-parse.y
+++ b/glcpp-parse.y
@@ -119,8 +119,8 @@ glcpp_parser_lex (glcpp_parser_t *parser);
 %type <str> FUNC_MACRO IDENTIFIER IDENTIFIER_FINALIZED OBJ_MACRO
 %type <argument_list> argument_list
 %type <string_list> macro parameter_list
-%type <token> TOKEN argument_word
-%type <token_list> argument replacement_list pp_tokens
+%type <token> TOKEN argument_word argument_word_or_comma
+%type <token_list> argument argument_or_comma replacement_list pp_tokens
 
 /* Hard to remove shift/reduce conflicts documented as follows:
  *
@@ -131,8 +131,10 @@ glcpp_parser_lex (glcpp_parser_t *parser);
  * 2. Similarly, '(' after FUNC_MACRO which is correctly resolved to
  *    shift to form macro invocation rather than reducing directly to
  *    argument.
+ *
+ * 3. Similarly again now that we added argument_or_comma as well.
  */
-%expect 2
+%expect 3
 
 %%
 
@@ -202,7 +204,7 @@ argument:
                talloc_free ($2.value);
                $$ = $1;
        }
-|      argument '(' argument ')' {
+|      argument '(' argument_or_comma ')' {
                _token_list_append ($1, '(', "(");
                _token_list_append_list ($1, $3);
                _token_list_append ($1, ')', ")");
@@ -218,6 +220,40 @@ argument_word:
 |      macro { $$.type = TOKEN; $$.value = xtalloc_strdup (parser, ""); }
 ;
 
+       /* XXX: The body of argument_or_comma is the same as the body
+        * of argument, but with "argument" and "argument_word"
+        * changed to "argument_or_comma" and
+        * "argument_word_or_comma". It would be nice to have less
+        * redundancy here, but I'm not sure how.
+        *
+        * It would also be nice to have a less ugly grammar to have
+        * to implement, but such is the C preprocessor.
+        */
+argument_or_comma:
+       argument_word_or_comma {
+               $$ = _token_list_create (parser);
+               _token_list_append ($$, $1.type, $1.value);
+       }
+|      argument_or_comma argument_word_or_comma {
+               _token_list_append ($1, $2.type, $2.value);
+               $$ = $1;
+       }
+|      argument_or_comma '(' argument_or_comma ')' {
+               _token_list_append ($1, '(', "(");
+               _token_list_append_list ($1, $3);
+               _token_list_append ($1, ')', ")");
+               $$ = $1;
+       }
+;
+
+argument_word_or_comma:
+       IDENTIFIER { $$.type = IDENTIFIER; $$.value = $1; }
+|      IDENTIFIER_FINALIZED { $$.type = IDENTIFIER_FINALIZED; $$.value = $1; }
+|      TOKEN { $$ = $1; }
+|      FUNC_MACRO { $$.type = FUNC_MACRO; $$.value = $1; }
+|      macro { $$.type = TOKEN; $$.value = xtalloc_strdup (parser, ""); }
+|      ',' { $$.type = ','; $$.value = xtalloc_strdup (parser, ","); }
+;
 
 directive:
        DEFINE IDENTIFIER NEWLINE {

diff --git a/tests/038-func-arg-with-commas.c b/tests/038-func-arg-with-commas.c
new file mode 100644 (file)
index 0000000..1407c7d
--- /dev/null
+++ b/tests/038-func-arg-with-commas.c
@@ -0,0 +1,2 @@
+#define foo(x) success
+foo(argument (with,embedded , commas) -- tricky)