[PATCH] src: add -Wno-error=stack-usage= to AM_LDFLAGS

[PATCH] src: add -Wno-error=stack-usage= to AM_LDFLAGS

[Dmitry V. Levin]

While -Wstack-usage= is already excluded from AM_CFLAGS for various
tools in src using *_no_Wstack_usage variables, this obviously does not
help when LTO is enabled, so add -Wno-error=stack-usage= to AM_LDFLAGS
for linking tools in src.

References: https://sourceware.org/bugzilla/show_bug.cgi?id=24498
Signed-off-by: Dmitry V. Levin <ldv@altlinux.org>
---
 config/ChangeLog | 4 ++++
 config/eu.am     | 2 ++
 src/ChangeLog    | 4 ++++
 src/Makefile.am  | 2 +-
 4 files changed, 11 insertions(+), 1 deletion(-)

diff --git a/config/ChangeLog b/config/ChangeLog
index 70a1e923..b2c0af8a 100644
--- a/config/ChangeLog
+++ b/config/ChangeLog
@@ -1,3 +1,7 @@
+2021-09-05  Dmitry V. Levin  <ldv@altlinux.org>
+
+	* eu.am (STACK_USAGE_NO_ERROR): New variable.
+
 2021-07-06  Alice Zhang  <alizhang@redhat.com>
 
         * debuginfod.sysconfig: Introduce default retry limit.
diff --git a/config/eu.am b/config/eu.am
index 2c3e4571..58cd3c4f 100644
--- a/config/eu.am
+++ b/config/eu.am
@@ -39,8 +39,10 @@ ARFLAGS = cr
 # Warn about stack usage of more than 256K = 262144 bytes.
 if ADD_STACK_USAGE_WARNING
 STACK_USAGE_WARNING=-Wstack-usage=262144
+STACK_USAGE_NO_ERROR=-Wno-error=stack-usage=
 else
 STACK_USAGE_WARNING=
+STACK_USAGE_NO_ERROR=
 endif
 
 if SANE_LOGICAL_OP_WARNING
diff --git a/src/ChangeLog b/src/ChangeLog
index b729eaa4..e83e0a5e 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,7 @@
+2021-09-05  Dmitry V. Levin  <ldv@altlinux.org>
+
+	* Makefile.am (AM_LDFLAGS): Add $(STACK_USAGE_NO_ERROR).
+
 2021-08-20  Saleem Abdulrasool  <abdulras@google.com>
 
 	* elfclassify.c: Remove error.h include.
diff --git a/src/Makefile.am b/src/Makefile.am
index 88d0ac8f..86d5bcf8 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -23,7 +23,7 @@ AM_CPPFLAGS += -I$(srcdir)/../libelf -I$(srcdir)/../libebl \
 	    -I$(srcdir)/../libdw -I$(srcdir)/../libdwelf \
 	    -I$(srcdir)/../libdwfl -I$(srcdir)/../libasm
 
-AM_LDFLAGS = -Wl,-rpath-link,../libelf:../libdw
+AM_LDFLAGS = -Wl,-rpath-link,../libelf:../libdw $(STACK_USAGE_NO_ERROR)
 
 bin_PROGRAMS = readelf nm size strip elflint findtextrel addr2line \
 	       elfcmp objdump ranlib strings ar unstrip stack elfcompress \
-- 
ldv

Re: [PATCH] src: add -Wno-error=stack-usage= to AM_LDFLAGS

[Mark Wielaard]

Hi Dmitry,

On Mon, Sep 06, 2021 at 03:59:05AM +0300, Dmitry V. Levin wrote:
> While -Wstack-usage= is already excluded from AM_CFLAGS for various
> tools in src using *_no_Wstack_usage variables, this obviously does not
> help when LTO is enabled, so add -Wno-error=stack-usage= to AM_LDFLAGS
> for linking tools in src.

I didn't know it worked to pass warning flags to the compiler during
linking for lto. That is really useful in this case. Of course maybe
we really should get rid of the unbounded stack allocations in the
first place. But till we do, we need this to build with lto enabled.

Please apply.

Thanks,

Mark