From 8f38aff9b5dd42ef963532fe5fc618e8bafa218a Mon Sep 17 00:00:00 2001
From: Carl Worth <cworth@cworth.org>
Date: Wed, 19 May 2010 10:01:29 -0700
Subject: [PATCH] Add a wrapper function around the lexer.

We rename the generated lexer from yylex to glcpp_lex. Then we
implement our own yylex function in glcpp-parse.y that calls
glcpp_lex. This doesn't change the behavior at all yet, but gives us a
place where we can do implement alternate lexing in the future.

(We want this because instead of re-lexing from strings for macro
expansion, we want to lex from pre-parsed token lists. We need this so
that when we terminate recursion due to an already active macro
expansion, we can ensure that that symbol never gets expanded again
later.)
---
 Makefile      |  2 +-
 glcpp-parse.y | 13 +++++++++++--
 glcpp.h       |  6 +++---
 3 files changed, 15 insertions(+), 6 deletions(-)

diff --git a/Makefile b/Makefile
index 3fa863c49b9..88116128f85 100644
--- a/Makefile
+++ b/Makefile
@@ -13,7 +13,7 @@ glcpp: glcpp.o glcpp-lex.o glcpp-parse.o hash_table.o xtalloc.o
 	bison --debug --defines=$*.h --output=$*.c $^
 
 %.c: %.l
-	flex --outfile=$@ $<
+	flex --prefix=glcpp_ --outfile=$@ $<
 
 glcpp-lex.c: glcpp-parse.h
 
diff --git a/glcpp-parse.y b/glcpp-parse.y
index 647532f209d..6ef1cae0eca 100644
--- a/glcpp-parse.y
+++ b/glcpp-parse.y
@@ -82,6 +82,9 @@ _argument_list_length (argument_list_t *list);
 string_list_t *
 _argument_list_member_at (argument_list_t *list, int index);
 
+static int
+yylex (yyscan_t scanner);
+
 %}
 
 %union {
@@ -405,7 +408,7 @@ glcpp_parser_create (void)
 
 	parser = xtalloc (NULL, glcpp_parser_t);
 
-	yylex_init_extra (parser, &parser->scanner);
+	glcpp_lex_init_extra (parser, &parser->scanner);
 	parser->defines = hash_table_ctor (32, hash_table_string_hash,
 					   hash_table_string_compare);
 	parser->expansions = NULL;
@@ -426,7 +429,7 @@ glcpp_parser_parse (glcpp_parser_t *parser)
 void
 glcpp_parser_destroy (glcpp_parser_t *parser)
 {
-	yylex_destroy (parser->scanner);
+	glcpp_lex_destroy (parser->scanner);
 	hash_table_dtor (parser->defines);
 	talloc_free (parser);
 }
@@ -642,3 +645,9 @@ _expand_function_macro (glcpp_parser_t *parser,
 
 	glcpp_parser_push_expansion_macro (parser, macro, arguments);
 }
+
+static int
+yylex (yyscan_t scanner)
+{
+	return glcpp_lex (scanner);
+}
diff --git a/glcpp.h b/glcpp.h
index 81f7d14c5ba..6aabf6f1823 100644
--- a/glcpp.h
+++ b/glcpp.h
@@ -128,13 +128,13 @@ glcpp_parser_pop_expansion (glcpp_parser_t *parser);
 /* Generated by glcpp-lex.l to glcpp-lex.c */
 
 int
-yylex_init_extra (glcpp_parser_t *parser, yyscan_t* scanner);
+glcpp_lex_init_extra (glcpp_parser_t *parser, yyscan_t* scanner);
 
 int
-yylex (yyscan_t scanner);
+glcpp_lex (yyscan_t scanner);
 
 int
-yylex_destroy (yyscan_t scanner);
+glcpp_lex_destroy (yyscan_t scanner);
 
 /* Generated by glcpp-parse.y to glcpp-parse.c */
 
-- 
2.30.2