Re: meson: Specify -Wformat as a common warning flag for extensions - Mailing list pgsql-hackers

Hi,

In <4707d4ed-f268-43c0-b4dd-cdbc7520f508@eisentraut.org>
  "Re: meson: Specify -Wformat as a common warning flag for extensions" on Tue, 28 May 2024 23:31:05 -0700,
  Peter Eisentraut <peter@eisentraut.org> wrote:

> On 07.04.24 18:01, Sutou Kouhei wrote:
>> +# We don't have "warning_level == 3" and "warning_level ==
>> +# 'everything'" here because we don't use these warning levels.
>> +if warning_level == '1'
>> +  common_builtin_flags += ['-Wall']
>> +elif warning_level == '2'
>> +  common_builtin_flags += ['-Wall', '-Wextra']
>> +endif
> 
> I would trim this even further and always export just '-Wall'.  The
> other options aren't really something we support.

OK. How about the v6 patch? It always uses '-Wall'.

Thanks,
-- 
kou
From 8238adba3f3fc96d4a9e50af611b1cb3566abc0e Mon Sep 17 00:00:00 2001
From: Sutou Kouhei <kou@clear-code.com>
Date: Fri, 15 Mar 2024 18:27:30 +0900
Subject: [PATCH v6] meson: Restore implicit warning/debug/optimize flags for
 extensions

Meson specifies warning/debug/optimize flags such as "-Wall", "-g" and
"-O2" automatically based on "--warnlevel" and "--buildtype"
options. And we use "--warning_level=1" and
"--buildtype=debugoptimized" by default.

We don't specify warning/debug/optimize flags explicitly to build
PostgreSQL with Meson. Because Meson does it automatically as we said.
But Meson doesn't care about flags in Makefile.global and
pg_config. So we need to care about them manually.

This changes do it. They detect debug/optimize flags based on
debug/optimization option values because Meson doesn't tell us flags
Meson guessed. We always use -Wall for warning flags.
---
 meson.build             | 27 +++++++++++++++++++++++++++
 src/include/meson.build |  4 ++--
 2 files changed, 29 insertions(+), 2 deletions(-)

diff --git a/meson.build b/meson.build
index d6401fb8e30..d7239dbb114 100644
--- a/meson.build
+++ b/meson.build
@@ -1851,6 +1851,33 @@ endif
 vectorize_cflags = cc.get_supported_arguments(['-ftree-vectorize'])
 unroll_loops_cflags = cc.get_supported_arguments(['-funroll-loops'])
 
+# They aren't used for building PostgreSQL itself because Meson does
+# everything internally. They are used by extensions via pg_config or
+# Makefile.global.
+common_builtin_flags = ['-Wall']
+
+if get_option('debug')
+  common_builtin_flags += ['-g']
+endif
+
+optimization = get_option('optimization')
+if optimization == '0'
+  common_builtin_flags += ['-O0']
+elif optimization == '1'
+  common_builtin_flags += ['-O1']
+elif optimization == '2'
+  common_builtin_flags += ['-O2']
+elif optimization == '3'
+  common_builtin_flags += ['-O3']
+elif optimization == 's'
+  common_builtin_flags += ['-Os']
+endif
+
+cflags_builtin = cc.get_supported_arguments(common_builtin_flags)
+if llvm.found()
+  cxxflags_builtin = cpp.get_supported_arguments(common_builtin_flags)
+endif
+
 common_warning_flags = [
   '-Wmissing-prototypes',
   '-Wpointer-arith',
diff --git a/src/include/meson.build b/src/include/meson.build
index a28f115d867..58b7a9c1e7e 100644
--- a/src/include/meson.build
+++ b/src/include/meson.build
@@ -44,9 +44,9 @@ config_paths_data.set_quoted('MANDIR', dir_prefix / dir_man)
 
 var_cc = ' '.join(cc.cmd_array())
 var_cpp = ' '.join(cc.cmd_array() + ['-E'])
-var_cflags = ' '.join(cflags + cflags_warn + get_option('c_args'))
+var_cflags = ' '.join(cflags + cflags_builtin + cflags_warn + get_option('c_args'))
 if llvm.found()
-  var_cxxflags = ' '.join(cxxflags + cxxflags_warn + get_option('cpp_args'))
+  var_cxxflags = ' '.join(cxxflags + cxxflags_builtin + cxxflags_warn + get_option('cpp_args'))
 else
   var_cxxflags = ''
 endif
-- 
2.43.0