From be0e2e9b2ada51be66afb6b44330acb44e0261f2 Mon Sep 17 00:00:00 2001
From: Carl Worth <cworth@cworth.org>
Date: Wed, 19 May 2010 07:29:22 -0700
Subject: [PATCH] Fix bug (and add tests) for a function-like macro defined as
 itself.

This case worked previously, but broke in the recent rewrite of
function- like macro expansion. The recursion was still terminated
correctly, but any parenthesized expression after the macro name was
still being swallowed even though the identifier was not being
expanded as a macro.

The fix is to notice earlier that the identifier is an
already-expanding macro. We let the lexer know this through the
classify_token function so that an already-expanding macro is lexed as
an identifier, not a FUNC_MACRO.
---
 glcpp-parse.y                        | 59 ++++++++++++----------------
 tests/032-define-func-self-recurse.c |  2 +
 tests/033-define-func-self-compose.c |  2 +
 3 files changed, 30 insertions(+), 33 deletions(-)
 create mode 100644 tests/032-define-func-self-recurse.c
 create mode 100644 tests/033-define-func-self-compose.c

diff --git a/glcpp-parse.y b/glcpp-parse.y
index 9f1075aa50a..8dc07483c18 100644
--- a/glcpp-parse.y
+++ b/glcpp-parse.y
@@ -427,6 +427,22 @@ glcpp_parser_destroy (glcpp_parser_t *parser)
 	talloc_free (parser);
 }
 
+static int
+glcpp_parser_is_expanding (glcpp_parser_t *parser, const char *member)
+{
+	expansion_node_t *node;
+
+	for (node = parser->expansions; node; node = node->next) {
+		if (node->macro &&
+		    strcmp (node->macro->identifier, member) == 0)
+		{
+			return 1;
+		}
+	}
+
+	return 0;
+}
+
 token_class_t
 glcpp_parser_classify_token (glcpp_parser_t *parser,
 			     const char *identifier,
@@ -457,6 +473,12 @@ glcpp_parser_classify_token (glcpp_parser_t *parser,
 	if (macro == NULL)
 		return TOKEN_CLASS_IDENTIFIER;
 
+	/* Don't consider this a macro if we are already actively
+	 * expanding this macro. */
+	if (glcpp_parser_is_expanding (parser, identifier))
+		return TOKEN_CLASS_IDENTIFIER;
+
+	/* Definitely a macro. Just need to check if it's function-like. */
 	if (macro->is_function)
 		return TOKEN_CLASS_FUNC_MACRO;
 	else
@@ -580,37 +602,6 @@ glcpp_parser_pop_expansion (glcpp_parser_t *parser)
 	talloc_free (node);
 }
 
-int
-glcpp_parser_is_expanding (glcpp_parser_t *parser, const char *member)
-{
-	expansion_node_t *node;
-
-	for (node = parser->expansions; node; node = node->next) {
-		if (node->macro &&
-		    strcmp (node->macro->identifier, member) == 0)
-		{
-			return 1;
-		}
-	}
-
-	return 0;
-}
-
-static void
-_expand_macro (glcpp_parser_t *parser,
-	       const char *token,
-	       macro_t *macro,
-	       argument_list_t *arguments)
-{
-	/* Don't recurse if we're already actively expanding this token. */
-	if (glcpp_parser_is_expanding (parser, token)) {
-		printf ("%s", token);
-		return;
-	}
-
-	glcpp_parser_push_expansion_macro (parser, macro, arguments);
-}
-
 void
 _expand_object_macro (glcpp_parser_t *parser, const char *identifier)
 {
@@ -618,8 +609,9 @@ _expand_object_macro (glcpp_parser_t *parser, const char *identifier)
 
 	macro = hash_table_find (parser->defines, identifier);
 	assert (! macro->is_function);
+	assert (! glcpp_parser_is_expanding (parser, identifier));
 
-	_expand_macro (parser, identifier, macro, NULL);
+	glcpp_parser_push_expansion_macro (parser, macro, NULL);
 }
 
 void
@@ -631,6 +623,7 @@ _expand_function_macro (glcpp_parser_t *parser,
 
 	macro = hash_table_find (parser->defines, identifier);
 	assert (macro->is_function);
+	assert (! glcpp_parser_is_expanding (parser, identifier));
 
 	if (_argument_list_length (arguments) !=
 	    _string_list_length (macro->parameters))
@@ -643,5 +636,5 @@ _expand_function_macro (glcpp_parser_t *parser,
 		return;
 	}
 
-	_expand_macro (parser, identifier, macro, arguments);
+	glcpp_parser_push_expansion_macro (parser, macro, arguments);
 }
diff --git a/tests/032-define-func-self-recurse.c b/tests/032-define-func-self-recurse.c
new file mode 100644
index 00000000000..60d8526c0aa
--- /dev/null
+++ b/tests/032-define-func-self-recurse.c
@@ -0,0 +1,2 @@
+#define foo(a) foo(2 * (a))
+foo(3)
diff --git a/tests/033-define-func-self-compose.c b/tests/033-define-func-self-compose.c
new file mode 100644
index 00000000000..8abaaf6be95
--- /dev/null
+++ b/tests/033-define-func-self-compose.c
@@ -0,0 +1,2 @@
+#define foo(a) foo(2 * (a))
+foo(foo(3))
-- 
2.30.2