[Cscope-devel] [PATCH 1/2] cscope: correct the erroneous brace count caused by the unbalanced \{|\}

[Oleg N. <ol...@re...>]

cscope can't parse kernel/trace/trace_events.c (and some other files)
in the linux kernel tree because this file has

	#define do_for_each_event_file(tr, file)			\
		list_for_each_entry(tr, &ftrace_trace_arrays, list) {	\
			list_for_each_entry(file, &tr->events, list)

	#define do_for_each_event_file_safe(tr, file)			\
		list_for_each_entry(tr, &ftrace_trace_arrays, list) {	\
			struct trace_event_file *___n;				\
			list_for_each_entry_safe(file, ___n, &tr->events, list)

	#define while_for_each_event_file()		\
		}

at the top and thus the 2nd '{' in do_for_each_event_file_safe() above
is not balanced.

Simple example:

	$ cat -n test.c
	     1	#define open1 {
	     2	#define open2 {
	     3	#define close }
	     4	
	     5	void func(void)
	     6	{
	     7	}

Without this patch:

	$ ./src/cscope -bu test.c
	$ ./src/cscope -dL -1 func

With this patch:

	$ ./src/cscope -bu test.c
	$ ./src/cscope -dL -1 func
	test.c func 5 void func(void )

Signed-off-by: Oleg Nesterov <ol...@re...>
---
 src/fscanner.l | 70 ++++++++++++++++++++++++++------------------------
 1 file changed, 37 insertions(+), 33 deletions(-)

diff --git a/src/fscanner.l b/src/fscanner.l
index 43880bf..46734ea 100644
--- a/src/fscanner.l
+++ b/src/fscanner.l
@@ -178,19 +178,21 @@ wsnl		[ \t\r\v\f\n]|{comment}
 		}
 
 \{		{	/* count unmatched left braces for fcn def detection */
-			++braces;
-			
-			/* mark an untagged enum/struct/union so its beginning
-			   can be found */
-			if (tagdef) {
-				if (braces == 1) {
-					esudef = YES;
+			if (ppdefine == NO) {
+				++braces;
+
+				/* mark an untagged enum/struct/union so its beginning
+				   can be found */
+				if (tagdef) {
+					if (braces == 1) {
+						esudef = YES;
+					}
+					token = tagdef;
+					tagdef = '\0';
+					last = first;
+					my_yymore();
+					return(token);
 				}
-				token = tagdef;
-				tagdef = '\0';
-				last = first;
-				my_yymore();
-				return(token);
 			}
 			goto more;
 			/* NOTREACHED */
@@ -326,28 +328,30 @@ wsnl		[ \t\r\v\f\n]|{comment}
 		}
 
 \}		{
-			/* could be the last enum member initializer */
-			if (braces == initializerbraces) {
-				initializerbraces = -1;
-				initializer = NO;
-			}
-			if (--braces <= 0) {
-		endstate:
-				braces = 0;
-				classdef = NO;
-			}
-			if (braces == 0 || (braces == 1 && classdef == YES)) {
-
-				/* if the end of an enum/struct/union definition */
-				if (esudef == YES) {
-					esudef = NO;
+			if (ppdefine == NO) {
+				/* could be the last enum member initializer */
+				if (braces == initializerbraces) {
+					initializerbraces = -1;
+					initializer = NO;
 				}
-				/* if the end of the function */
-				else if (fcndef == YES) {
-					fcndef = NO;
-					last = first;
-					my_yymore();
-					return(FCNEND);
+				if (--braces <= 0) {
+			endstate:
+					braces = 0;
+					classdef = NO;
+				}
+				if (braces == 0 || (braces == 1 && classdef == YES)) {
+
+					/* if the end of an enum/struct/union definition */
+					if (esudef == YES) {
+						esudef = NO;
+					}
+					/* if the end of the function */
+					else if (fcndef == YES) {
+						fcndef = NO;
+						last = first;
+						my_yymore();
+						return(FCNEND);
+					}
 				}
 			}
 			goto more;
-- 
2.25.1.362.g51ebf55