50 lines
2.2 KiB
Diff
50 lines
2.2 KiB
Diff
From 0d391dbcb808755a65fcc9a8a0ceaf3aa53d153f Mon Sep 17 00:00:00 2001
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From: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
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Date: Mon, 19 Aug 2024 00:08:40 +0200
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Subject: [PATCH] configure.ac: use AX_CHECK_LINK_FLAG() to test gcc flags
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ledmon's configure.ac defines an AX_AM_CFLAGS_ADD() macro that allows
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to test if a flag is supported by gcc, and if so add it to
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AM_CFLAGS. In order to test if the flag works, it uses
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AX_CHECK_COMPILE_FLAG(), which only does a *compile* test, but not
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a *link* test. However, some flags such as -fstack-protector might
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appear to work at compile time, but not link time. Therefore
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-fstack-protector is considered functional:
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checking whether C compiler accepts -fstack-protector-strong... yes
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but the build later fails:
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/home/buildroot/autobuild/instance-0/output-1/host/lib/gcc/m68k-buildroot-linux-uclibc/13.3.0/../../../../m68k-buildroot-linux-uclibc/bin/ld: cannot find -lssp_nonshared: No such file or directory
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/home/buildroot/autobuild/instance-0/output-1/host/lib/gcc/m68k-buildroot-linux-uclibc/13.3.0/../../../../m68k-buildroot-linux-uclibc/bin/ld: cannot find -lssp: No such file or directory
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collect2: error: ld returned 1 exit status
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In order to fix this, we test all flags with AX_CHECK_LINK_FLAG()
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which does a full *link* of the test program. This allows to make sure
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that the flag is fully functional. In our test case,
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-fstack-protector-strong will be determined as being non-functional,
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and therefore won't be used.
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Upstream: https://github.com/intel/ledmon/pull/244
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Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
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---
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configure.ac | 2 +-
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1 file changed, 1 insertion(+), 1 deletion(-)
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diff --git a/configure.ac b/configure.ac
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index d3fada5..747b168 100644
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--- a/configure.ac
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+++ b/configure.ac
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@@ -52,7 +52,7 @@ AC_CONFIG_HEADERS([config_ac.h])
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AM_CFLAGS='-Wall -I../config'
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AM_CPPFLAGS='-D_DEBUG -D_GNU_SOURCE -D_DEFAULT_SOURCE -DDMALLOC_DISABLE -DBUILD_LABEL=\""$(BUILD_LABEL)"\"'
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-AC_DEFUN([AX_AM_CFLAGS_ADD],[AX_CHECK_COMPILE_FLAG($1, AM_CFLAGS="$AM_CFLAGS $1")])
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+AC_DEFUN([AX_AM_CFLAGS_ADD],[AX_CHECK_LINK_FLAG($1, AM_CFLAGS="$AM_CFLAGS $1")])
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AX_AM_CFLAGS_ADD([-Wformat -Wformat-security])
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AX_AM_CFLAGS_ADD([-Wformat-overflow=2])
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AX_AM_CFLAGS_ADD([-Wno-strict-overflow])
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--
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2.46.0
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