[PATCH bpf-next 4/4] bpftool: treat compilation warnings as errors

[Andrii Nakryiko <andrii@kernel.org>]

Make bpftool compilation stricter and treat all compilation warnigs as errors.

Depending on libbfd version on the system, jit_disasm.c might trigger the
following compilation warning-turned-error:

jit_disasm.c: In function ‘disasm_print_insn’:
jit_disasm.c:121:29: error: assignment discards ‘const’ qualifier from pointer
target type [-Werror=discarded-qualifiers]
   info.disassembler_options = disassembler_options;
                                ^

This was fixed in libbfd, but older versions of the library are still widely
used. So disable -Wdiscarded-qualifiers for that particular line of code.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
---
 tools/bpf/bpftool/Makefile     | 3 ++-
 tools/bpf/bpftool/jit_disasm.c | 3 +++
 2 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/tools/bpf/bpftool/Makefile b/tools/bpf/bpftool/Makefile
index b3073ae84018..59de954faaf5 100644
--- a/tools/bpf/bpftool/Makefile
+++ b/tools/bpf/bpftool/Makefile
@@ -56,7 +56,8 @@ prefix ?= /usr/local
 bash_compdir ?= /usr/share/bash-completion/completions
 
 CFLAGS += -O2
-CFLAGS += -W -Wall -Wextra -Wno-unused-parameter -Wno-missing-field-initializers
+CFLAGS += -W -Wall -Wextra -Werror
+CFLAGS += -Wno-unused-parameter -Wno-missing-field-initializers
 CFLAGS += $(filter-out -Wswitch-enum -Wnested-externs,$(EXTRA_WARNINGS))
 CFLAGS += -DPACKAGE='"bpftool"' -D__EXPORTED_HEADERS__ \
 	-I$(if $(OUTPUT),$(OUTPUT),.) \
diff --git a/tools/bpf/bpftool/jit_disasm.c b/tools/bpf/bpftool/jit_disasm.c
index e7e7eee9f172..48bc7f7a542f 100644
--- a/tools/bpf/bpftool/jit_disasm.c
+++ b/tools/bpf/bpftool/jit_disasm.c
@@ -118,7 +118,10 @@ void disasm_print_insn(unsigned char *image, ssize_t len, int opcodes,
 	info.arch = bfd_get_arch(bfdf);
 	info.mach = bfd_get_mach(bfdf);
 	if (disassembler_options)
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wdiscarded-qualifiers"
 		info.disassembler_options = disassembler_options;
+#pragma GCC diagnostic push
 	info.buffer = image;
 	info.buffer_length = len;
 
-- 
2.30.2