tools: ynl: extend CFLAGS to keep options from environment

JIRA: https://issues.redhat.com/browse/RHEL-50389
Upstream Status: net.git commit 05a318b

commit 05a318b
Author: Jan Stancek <jstancek@redhat.com>
Date:   Tue Nov 12 09:21:33 2024 +0100

    tools: ynl: extend CFLAGS to keep options from environment

    Package build environments like Fedora rpmbuild introduced hardening
    options (e.g. -pie -Wl,-z,now) by passing a -spec option to CFLAGS
    and LDFLAGS.

    ynl Makefiles currently override CFLAGS but not LDFLAGS, which leads
    to a mismatch and build failure:
            CC sample devlink
      /usr/bin/ld: devlink.o: relocation R_X86_64_32 against symbol `ynl_devlink_family' can not be used when making a PIE object; recompile with -fPIE
      /usr/bin/ld: failed to set dynamic section sizes: bad value
      collect2: error: ld returned 1 exit status

    Extend CFLAGS to support hardening options set by build environment.

    Signed-off-by: Jan Stancek <jstancek@redhat.com>
    Acked-by: Jakub Kicinski <kuba@kernel.org>
    Reviewed-by: Donald Hunter <donald.hunter@gmail.com>
    Link: https://patch.msgid.link/265b2d5d3a6d4721a161219f081058ed47dc846a.1731399562.git.jstancek@redhat.com
    Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Signed-off-by: Hangbin Liu <haliu@redhat.com>

Author: Hangbin Liu

tools/net/ynl/generated/Makefile

@@ -1,7 +1,7 @@
 # SPDX-License-Identifier: GPL-2.0
 
 CC=gcc
-CFLAGS=-std=gnu11 -O2 -W -Wall -Wextra -Wno-unused-parameter -Wshadow \
+CFLAGS += -std=gnu11 -O2 -W -Wall -Wextra -Wno-unused-parameter -Wshadow \
 	-I../lib/ -idirafter $(UAPI_PATH)
 ifeq ("$(DEBUG)","1")
   CFLAGS += -g -fsanitize=address -fsanitize=leak -static-libasan

tools/net/ynl/lib/Makefile

@@ -1,7 +1,7 @@
 # SPDX-License-Identifier: GPL-2.0
 
 CC=gcc
-CFLAGS=-std=gnu11 -O2 -W -Wall -Wextra -Wno-unused-parameter -Wshadow
+CFLAGS += -std=gnu11 -O2 -W -Wall -Wextra -Wno-unused-parameter -Wshadow
 ifeq ("$(DEBUG)","1")
   CFLAGS += -g -fsanitize=address -fsanitize=leak -static-libasan
 endif

tools/net/ynl/samples/Makefile

@@ -3,7 +3,7 @@
 include ../Makefile.deps
 
 CC=gcc
-CFLAGS=-std=gnu11 -O2 -W -Wall -Wextra -Wno-unused-parameter -Wshadow \
+CFLAGS += -std=gnu11 -O2 -W -Wall -Wextra -Wno-unused-parameter -Wshadow \
 	-I../lib/ -I../generated/ -idirafter $(UAPI_PATH)
 ifeq ("$(DEBUG)","1")
   CFLAGS += -g -fsanitize=address -fsanitize=leak -static-libasan