From: Willy Tarreau <w@1wt.eu>
Date: Wed, 13 Apr 2022 15:09:45 +0000 (+0200)
Subject: BUILD: debug: mark the __start_mem_stats/__stop_mem_stats symbols as weak
X-Git-Tag: v2.6-dev6~28
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=b12966af1;p=thirdparty%2Fhaproxy.git

BUILD: debug: mark the __start_mem_stats/__stop_mem_stats symbols as weak

Building with clang and DEBUG_MEM_STATS shows the following warnings:

  warning: __start_mem_stats changed binding to STB_WEAK [-Wsource-mgr]
  warning: __stop_mem_stats changed binding to STB_WEAK [-Wsource-mgr]

The reason is that the symbols are declared using ".globl" while they
are also referenced as __attribute__((weak)) elsewhere. It turns out
that a weak symbol is implicitly a global one and that the two classes
are exclusive, thus it may confuse the linker. Better fix this.

This may be backported where the patch applies.
---

diff --git a/include/haproxy/bug.h b/include/haproxy/bug.h
index 71b37eda69..997a114600 100644
--- a/include/haproxy/bug.h
+++ b/include/haproxy/bug.h
@@ -234,8 +234,8 @@ struct mem_stats {
 		.file = __FILE__, .line = __LINE__,			\
 		.type = MEM_STATS_TYPE_CALLOC,				\
 	};								\
-	__asm__(".globl __start_mem_stats");				\
-	__asm__(".globl __stop_mem_stats");				\
+	__asm__(".weak __start_mem_stats");				\
+	__asm__(".weak __stop_mem_stats");				\
 	_HA_ATOMIC_INC(&_.calls);					\
 	_HA_ATOMIC_ADD(&_.size, __x * __y);				\
 	calloc(__x,__y);						\
@@ -251,8 +251,8 @@ struct mem_stats {
 		.file = __FILE__, .line = __LINE__,			\
 		.type = MEM_STATS_TYPE_FREE,				\
 	};								\
-	__asm__(".globl __start_mem_stats");				\
-	__asm__(".globl __stop_mem_stats");				\
+	__asm__(".weak __start_mem_stats");				\
+	__asm__(".weak __stop_mem_stats");				\
 	if (__x)							\
 		_HA_ATOMIC_INC(&_.calls);				\
 	free(__x);							\
@@ -265,8 +265,8 @@ struct mem_stats {
 		.file = __FILE__, .line = __LINE__,			\
 		.type = MEM_STATS_TYPE_FREE,				\
 	};								\
-	__asm__(".globl __start_mem_stats");				\
-	__asm__(".globl __stop_mem_stats");				\
+	__asm__(".weak __start_mem_stats");				\
+	__asm__(".weak __stop_mem_stats");				\
 	if (__builtin_constant_p((x)) || __builtin_constant_p(*(x))) {  \
 		HA_LINK_ERROR(call_to_ha_free_attempts_to_free_a_constant); \
 	}								\
@@ -283,8 +283,8 @@ struct mem_stats {
 		.file = __FILE__, .line = __LINE__,			\
 		.type = MEM_STATS_TYPE_MALLOC,				\
 	};								\
-	__asm__(".globl __start_mem_stats");				\
-	__asm__(".globl __stop_mem_stats");				\
+	__asm__(".weak __start_mem_stats");				\
+	__asm__(".weak __stop_mem_stats");				\
 	_HA_ATOMIC_INC(&_.calls);					\
 	_HA_ATOMIC_ADD(&_.size, __x);					\
 	malloc(__x);							\
@@ -297,8 +297,8 @@ struct mem_stats {
 		.file = __FILE__, .line = __LINE__,			\
 		.type = MEM_STATS_TYPE_REALLOC,				\
 	};								\
-	__asm__(".globl __start_mem_stats");				\
-	__asm__(".globl __stop_mem_stats");				\
+	__asm__(".weak __start_mem_stats");				\
+	__asm__(".weak __stop_mem_stats");				\
 	_HA_ATOMIC_INC(&_.calls);					\
 	_HA_ATOMIC_ADD(&_.size, __y);					\
 	realloc(__x,__y);						\
@@ -311,8 +311,8 @@ struct mem_stats {
 		.file = __FILE__, .line = __LINE__,			\
 		.type = MEM_STATS_TYPE_STRDUP,				\
 	};								\
-	__asm__(".globl __start_mem_stats");				\
-	__asm__(".globl __stop_mem_stats");				\
+	__asm__(".weak __start_mem_stats");				\
+	__asm__(".weak __stop_mem_stats");				\
 	_HA_ATOMIC_INC(&_.calls);					\
 	_HA_ATOMIC_ADD(&_.size, __y);					\
 	strdup(__x);							\