meson.build WARNING's returned for using "-Wall" and "-O2" instead of their Meson equivalents

[sscargal]

On Fedora 35, two warning messages are returned. These are harmless, but should be resolved.

# meson setup build
The Meson build system
Version: 0.59.4
Source dir: /downloads/ndctl
Build dir: /downloads/ndctl/build
Build type: native build
Project name: ndctl
Project version: 73
C compiler for the host machine: cc (gcc 11.2.1 "cc (GCC) 11.2.1 20220127 (Red Hat 11.2.1-9)")
C linker for the host machine: cc ld.bfd 2.37-10
Host machine cpu family: x86_64
Host machine cpu: x86_64
Compiler for C supports arguments -Wall: YES
Compiler for C supports arguments -Wchar-subscripts: YES
Compiler for C supports arguments -Wformat-security: YES
Compiler for C supports arguments -Wmissing-declarations: YES
Compiler for C supports arguments -Wmissing-prototypes: YES
Compiler for C supports arguments -Wnested-externs : NO
Compiler for C supports arguments -Wshadow: YES
Compiler for C supports arguments -Wsign-compare: YES
Compiler for C supports arguments -Wstrict-prototypes: YES
Compiler for C supports arguments -Wtype-limits: YES
Compiler for C supports arguments -Wmaybe-uninitialized: YES
Compiler for C supports arguments -Wdeclaration-after-statement: YES
Compiler for C supports arguments -Wunused-result: YES
Compiler for C supports arguments -D_FORTIFY_SOURCE=2: YES
Compiler for C supports arguments -O2: YES
meson.build:77: WARNING: Consider using the built-in warning_level option instead of using "-Wall".
meson.build:77: WARNING: Consider using the built-in optimization level instead of using "-O2".
Program git found: YES (/usr/bin/git)
Program env found: YES (/usr/bin/env)
Program /usr/bin/meson found: YES (/usr/bin/meson)
Found pkg-config: /usr/bin/pkg-config (1.8.0)
Run-time dependency libkmod found: YES 29
Run-time dependency libudev found: YES 249
Run-time dependency uuid found: YES 2.37.4
Run-time dependency json-c found: YES 0.15
Program asciidoctor found: YES (/usr/local/bin/asciidoctor)
Run-time dependency systemd found: YES 249
Run-time dependency udev found: YES 249
Library keyutils found: YES
Library iniparser found: YES
Has header "dlfcn.h" : YES
Has header "inttypes.h" : YES
Has header "keyutils.h" : YES
Has header "linux/version.h" : YES
Has header "memory.h" : YES
Has header "stdint.h" : YES
Has header "stdlib.h" : YES
Has header "strings.h" : YES
Has header "string.h" : YES
Has header "sys/stat.h" : YES
Has header "sys/types.h" : YES
Has header "unistd.h" : YES
Header <signal.h> has symbol "BUS_MCEERR_AR" : YES
Header <linux/mman.h> has symbol "MAP_SHARED_VALIDATE" : YES
Header <linux/mman.h> has symbol "MAP_SYNC" : YES
Checking for function "secure_getenv" : YES
Checking for function "__secure_getenv" : NO
Checking for function "json_object_new_uint64" with dependency json-c: YES
Configuring config.h using configuration
Program sed found: YES (/usr/bin/sed)
Program sed found: YES (/usr/bin/sed)
Program sed found: YES (/usr/bin/sed)
Program sed found: YES (/usr/bin/sed)
Program sed found: YES (/usr/bin/sed)
Program sed found: YES (/usr/bin/sed)
Program sed found: YES (/usr/bin/sed)
Program create.sh found: YES (/downloads/ndctl/test/create.sh)
Program clear.sh found: YES (/downloads/ndctl/test/clear.sh)
Program pmem-errors.sh found: YES (/downloads/ndctl/test/pmem-errors.sh)
Program daxdev-errors.sh found: YES (/downloads/ndctl/test/daxdev-errors.sh)
Program multi-dax.sh found: YES (/downloads/ndctl/test/multi-dax.sh)
Program btt-check.sh found: YES (/downloads/ndctl/test/btt-check.sh)
Program label-compat.sh found: YES (/downloads/ndctl/test/label-compat.sh)
Program sector-mode.sh found: YES (/downloads/ndctl/test/sector-mode.sh)
Program inject-error.sh found: YES (/downloads/ndctl/test/inject-error.sh)
Program btt-errors.sh found: YES (/downloads/ndctl/test/btt-errors.sh)
Program btt-pad-compat.sh found: YES (/downloads/ndctl/test/btt-pad-compat.sh)
Program firmware-update.sh found: YES (/downloads/ndctl/test/firmware-update.sh)
Program rescan-partitions.sh found: YES (/downloads/ndctl/test/rescan-partitions.sh)
Program inject-smart.sh found: YES (/downloads/ndctl/test/inject-smart.sh)
Program monitor.sh found: YES (/downloads/ndctl/test/monitor.sh)
Program max_available_extent_ns.sh found: YES (/downloads/ndctl/test/max_available_extent_ns.sh)
Program pfn-meta-errors.sh found: YES (/downloads/ndctl/test/pfn-meta-errors.sh)
Program track-uuid.sh found: YES (/downloads/ndctl/test/track-uuid.sh)
Program security.sh found: YES (/downloads/ndctl/test/security.sh)
Run-time dependency bash-completion found: YES 2.11
Program /usr/bin/meson found: YES (/usr/bin/meson)
Program sed found: YES (/usr/bin/sed)
Program /usr/bin/meson found: YES (/usr/bin/meson)
Program cat found: YES (/usr/bin/cat)
Program sed found: YES (/usr/bin/sed)
Build targets in project: 93

Found ninja-1.10.2 at /usr/bin/ninja

[djbw]

yeah, known issue, but warning_level enables even more warnings that need to be resolved first.

[eli-schwartz]

It shouldn't, Meson's default warning_level is 1 and enables -Wall. So adding -Wall yourself is redundant, but I guess if you really wanted you could set it in default_options.

Is -O2 really necessary? Could that be left to the buildtype? Under release you get -O3 and under debugoptimized you get -O2.

[djbw]

@eli-schwartz this is what was inherited from our autotools conversion. Perhaps I was tripping over trying to get those extra warnings enabled via warning-level without pulling in others. Perhaps I can just do warning_level 1 and have leave the rest in cc_flags. Yes, the manual -O2 is indeed bogus.

cc_flags = [ '-Wall', '-Wchar-subscripts', '-Wformat-security', '-Wmissing-declarations', '-Wmissing-prototypes', '-Wnested-externs ', '-Wshadow', '-Wsign-compare', '-Wstrict-prototypes', '-Wtype-limits', '-Wmaybe-uninitialized', '-Wdeclaration-after-statement', '-Wunused-result', '-D_FORTIFY_SOURCE=2', '-O2', ]

[djbw]

ok, this seems to work. Thanks for the nudges:

diff --git a/meson.build b/meson.build
index 5e97e1ce3068..a4149bb7b08c 100644
--- a/meson.build
+++ b/meson.build
@@ -57,7 +57,6 @@ sed -e s,@VERSION@,@0@,g
 '''.format(meson.project_version(), prefixdir, libdir, includedir).split()

 cc_flags = [
-  '-Wall',
   '-Wchar-subscripts',
   '-Wformat-security',
   '-Wmissing-declarations',
@@ -70,9 +69,12 @@ cc_flags = [
   '-Wmaybe-uninitialized',
   '-Wdeclaration-after-statement',
   '-Wunused-result',
-  '-D_FORTIFY_SOURCE=2',
-  '-O2',
 ]
+
+if get_option('optimization') != '0'
+  cc_flags += [ '-D_FORTIFY_SOURCE=2' ]
+endif
+
 cc = meson.get_compiler('c')
 add_project_arguments(cc.get_supported_arguments(cc_flags), language : 'c')