As implied in
gcc.gnu.org/legacy-ml/gcc-patches/2008-09/msg00076.html,
gcc provides -Wno-builtin-macro-redefined to suppress warning when
redefining builtin macro. However, at that time, there was no
scenario for __LINE__ macro.
But, when we try to build a live-patch, we compare sections by using
-ffunction-sections. Some same functions are considered changed because
of __LINE__ macro.
At present, to detect such a changed caused by __LINE__ macro, we
have to analyse code and maintain a function list. For example,
in kpatch, check this commit
github.com/dynup/kpatch/commit/0e1b95edeafa36edb7bcf11da6d1c00f76d7e03d.
So, in this scenario, when we try to compared sections, it would
be better to support suppress builtin macro redefined warnings for
__LINE__ macro.
Signed-off-by: Longjun Luo <luolongj...@gmail.com>
---
gcc/testsuite/gcc.dg/builtin-redefine.c | 1 -
libcpp/init.cc | 2 +-
2 files changed, 1 insertion(+), 2 deletions(-)
diff --git a/gcc/testsuite/gcc.dg/builtin-redefine.c
b/gcc/testsuite/gcc.dg/builtin-redefine.c
index 882b2210992..9d5b42252ee 100644
--- a/gcc/testsuite/gcc.dg/builtin-redefine.c
+++ b/gcc/testsuite/gcc.dg/builtin-redefine.c
@@ -71,7 +71,6 @@
/* { dg-bogus "Expected built-in is not defined" "" { target *-*-* } .-1 } */
#endif
-#define __LINE__ 0 /* { dg-warning "-:\"__LINE__\" redef" } */
#define __INCLUDE_LEVEL__ 0 /* { dg-warning "-:\"__INCLUDE_LEVEL__\" redef" }
*/
#define __COUNTER__ 0 /* { dg-warning "-:\"__COUNTER__\" redef" } */
diff --git a/libcpp/init.cc b/libcpp/init.cc
index 5f34e3515d2..2765b9838b7 100644
--- a/libcpp/init.cc
+++ b/libcpp/init.cc
@@ -421,7 +421,7 @@ static const struct builtin_macro builtin_array[] =
B("__FILE__", BT_FILE, false),
B("__FILE_NAME__", BT_FILE_NAME, false),
B("__BASE_FILE__", BT_BASE_FILE, false),
- B("__LINE__", BT_SPECLINE, true),
+ B("__LINE__", BT_SPECLINE, false),
B("__INCLUDE_LEVEL__", BT_INCLUDE_LEVEL, true),
B("__COUNTER__", BT_COUNTER, true),
/* Make sure to update the list of built-in
--
2.38.1
