dev-util/meson: backport patch to stop hiding vala compiler warnings

This is especially bad because it makes these packages disappear
entirely from QA checks for, say, Modern C. Although it's only a matter
of adding more warnings, and doesn't really affect the resulting
packages, we need this live in order to do proper QA.

Bug: https://bugs.gentoo.org/870412
Signed-off-by: Eli Schwartz <eschwartz93@gmail.com>
Closes: https://github.com/gentoo/gentoo/pull/34141
Signed-off-by: Sam James <sam@gentoo.org>

2 files changed, 385 insertions, 0 deletions

diff --git a/dev-util/meson/files/0001-ninja-backend-don-t-hide-all-compiler-warnings-for-t.patch b/dev-util/meson/files/0001-ninja-backend-don-t-hide-all-compiler-warnings-for-t.patch
new file mode 100644
index 000000000000..652ffd25228b
--- /dev/null
+++ b/dev-util/meson/files/0001-ninja-backend-don-t-hide-all-compiler-warnings-for-t.patch
@@ -0,0 +1,250 @@
+From 5f659af870011e74299d1455a65c2cd5f5ace51f Mon Sep 17 00:00:00 2001
+From: Eli Schwartz <eschwartz93@gmail.com>
+Date: Tue, 5 Dec 2023 14:26:54 -0500
+Subject: [PATCH] ninja backend: don't hide all compiler warnings for
+ transpiled languages
+
+This was originally added for vala only, with the rationale that vala
+generates bad code that has warnings. Unfortunately, the rationale was
+fatally flawed. The compiler warns about a number of things, which the
+user can control depending on their code (or their code generator's
+code), but some of those things are absolutely critical to warn about.
+
+In particular, GCC 14 and clang 17 are updating their defaults to warn
+-- and error by default for -- invalid C code that breaks the standard,
+but has been silently accepted for over 20 years "because lots of people
+do it". The code in question is UB, and compilers will generate faulty
+machine code that behaves erroneously and probably has a mass of CVEs
+waiting to happen.
+
+Compiler warnings are NOT safe to just... universally turn off. Compiler
+warnings could be either:
+
+- coding style lints
+
+- threatening statements that the code is factually and behaviorally wrong
+
+There is no magic bullet to ignore the former while respecting the
+latter. And the very last thing we should ever do is pass `-w`, since
+that causes ALL warnings to be disabled, even the manually added
+`-Werror=XXX`.
+
+If vala generated code creates warnings, then the vala compiler can
+decrease the log level by generating better code, or by adding warning
+suppression pragmas for *specific* issues, such as unused functions.
+---
+ mesonbuild/backend/backends.py                | 13 ++-----
+ mesonbuild/backend/ninjabackend.py            | 19 ++++------
+ .../failing build/1 vala c werror/meson.build | 10 -----
+ .../failing build/1 vala c werror/prog.vala   |  7 ----
+ .../1 vala c werror/unused-var.c              |  8 ----
+ test cases/vala/5 target glib/meson.build     |  4 --
+ unittests/linuxliketests.py                   | 37 -------------------
+ 7 files changed, 11 insertions(+), 87 deletions(-)
+ delete mode 100644 test cases/failing build/1 vala c werror/meson.build
+ delete mode 100644 test cases/failing build/1 vala c werror/prog.vala
+ delete mode 100644 test cases/failing build/1 vala c werror/unused-var.c
+
+diff --git a/mesonbuild/backend/backends.py b/mesonbuild/backend/backends.py
+index 2c24e4c31..639e07b2a 100644
+--- a/mesonbuild/backend/backends.py
++++ b/mesonbuild/backend/backends.py
+@@ -986,7 +986,7 @@ class Backend:
+             return compiler.get_no_stdinc_args()
+         return []
+ 
+-    def generate_basic_compiler_args(self, target: build.BuildTarget, compiler: 'Compiler', no_warn_args: bool = False) -> 'CompilerArgs':
++    def generate_basic_compiler_args(self, target: build.BuildTarget, compiler: 'Compiler') -> 'CompilerArgs':
+         # Create an empty commands list, and start adding arguments from
+         # various sources in the order in which they must override each other
+         # starting from hard-coded defaults followed by build options and so on.
+@@ -999,17 +999,12 @@ class Backend:
+         commands += self.get_no_stdlib_args(target, compiler)
+         # Add things like /NOLOGO or -pipe; usually can't be overridden
+         commands += compiler.get_always_args()
+-        # Only add warning-flags by default if the buildtype enables it, and if
+-        # we weren't explicitly asked to not emit warnings (for Vala, f.ex)
+-        if no_warn_args:
+-            commands += compiler.get_no_warn_args()
+-        else:
+-            # warning_level is a string, but mypy can't determine that
+-            commands += compiler.get_warn_args(T.cast('str', target.get_option(OptionKey('warning_level'))))
++        # warning_level is a string, but mypy can't determine that
++        commands += compiler.get_warn_args(T.cast('str', target.get_option(OptionKey('warning_level'))))
+         # Add -Werror if werror=true is set in the build options set on the
+         # command-line or default_options inside project(). This only sets the
+         # action to be done for warnings if/when they are emitted, so it's ok
+-        # to set it after get_no_warn_args() or get_warn_args().
++        # to set it after or get_warn_args().
+         if target.get_option(OptionKey('werror')):
+             commands += compiler.get_werror_args()
+         # Add compile args for c_* or cpp_* build options set on the
+diff --git a/mesonbuild/backend/ninjabackend.py b/mesonbuild/backend/ninjabackend.py
+index 049ae253f..cdb747d73 100644
+--- a/mesonbuild/backend/ninjabackend.py
++++ b/mesonbuild/backend/ninjabackend.py
+@@ -1939,7 +1939,7 @@ class NinjaBackend(backends.Backend):
+         if cratetype in {'bin', 'dylib'}:
+             args.extend(rustc.get_linker_always_args())
+ 
+-        args += self.generate_basic_compiler_args(target, rustc, False)
++        args += self.generate_basic_compiler_args(target, rustc)
+         # Rustc replaces - with _. spaces or dots are not allowed, so we replace them with underscores
+         args += ['--crate-name', target.name.replace('-', '_').replace(' ', '_').replace('.', '_')]
+         depfile = os.path.join(target.subdir, target.name + '.d')
+@@ -2804,10 +2804,9 @@ https://gcc.gnu.org/bugzilla/show_bug.cgi?id=47485'''))
+             bargs = []
+         return (sargs, bargs)
+ 
+-    def _generate_single_compile(self, target: build.BuildTarget, compiler: 'Compiler',
+-                                 is_generated: bool = False) -> 'CompilerArgs':
++    def _generate_single_compile(self, target: build.BuildTarget, compiler: Compiler) -> CompilerArgs:
+         commands = self._generate_single_compile_base_args(target, compiler)
+-        commands += self._generate_single_compile_target_args(target, compiler, is_generated)
++        commands += self._generate_single_compile_target_args(target, compiler)
+         return commands
+ 
+     def _generate_single_compile_base_args(self, target: build.BuildTarget, compiler: 'Compiler') -> 'CompilerArgs':
+@@ -2825,14 +2824,10 @@ https://gcc.gnu.org/bugzilla/show_bug.cgi?id=47485'''))
+         return commands
+ 
+     @lru_cache(maxsize=None)
+-    def _generate_single_compile_target_args(self, target: build.BuildTarget, compiler: 'Compiler',
+-                                             is_generated: bool = False) -> 'ImmutableListProtocol[str]':
+-        # The code generated by valac is usually crap and has tons of unused
+-        # variables and such, so disable warnings for Vala C sources.
+-        no_warn_args = is_generated == 'vala'
++    def _generate_single_compile_target_args(self, target: build.BuildTarget, compiler: Compiler) -> ImmutableListProtocol[str]:
+         # Add compiler args and include paths from several sources; defaults,
+         # build options, external dependencies, etc.
+-        commands = self.generate_basic_compiler_args(target, compiler, no_warn_args)
++        commands = self.generate_basic_compiler_args(target, compiler)
+         # Add custom target dirs as includes automatically, but before
+         # target-specific include directories.
+         if target.implicit_include_directories:
+@@ -2901,7 +2896,7 @@ https://gcc.gnu.org/bugzilla/show_bug.cgi?id=47485'''))
+             if use_pch and 'mw' not in compiler.id:
+                 commands += self.get_pch_include_args(compiler, target)
+ 
+-            commands += self._generate_single_compile_target_args(target, compiler, is_generated=False)
++            commands += self._generate_single_compile_target_args(target, compiler)
+ 
+             # Metrowerks compilers require PCH include args to come after intraprocedural analysis args
+             if use_pch and 'mw' in compiler.id:
+@@ -2935,7 +2930,7 @@ https://gcc.gnu.org/bugzilla/show_bug.cgi?id=47485'''))
+         if use_pch and 'mw' not in compiler.id:
+             commands += self.get_pch_include_args(compiler, target)
+ 
+-        commands += self._generate_single_compile_target_args(target, compiler, is_generated)
++        commands += self._generate_single_compile_target_args(target, compiler)
+ 
+         # Metrowerks compilers require PCH include args to come after intraprocedural analysis args
+         if use_pch and 'mw' in compiler.id:
+diff --git a/test cases/failing build/1 vala c werror/meson.build b/test cases/failing build/1 vala c werror/meson.build
+deleted file mode 100644
+index 736d7aa43..000000000
+--- a/test cases/failing build/1 vala c werror/meson.build	
++++ /dev/null
+@@ -1,10 +0,0 @@
+-project('valatest', 'c', default_options : 'werror=true')
+-
+-if find_program('valac', required : false).found()
+-  add_languages('vala')
+-  valadeps = [dependency('glib-2.0'), dependency('gobject-2.0')]
+-  # Must fail due to -Werror and unused variable in C file
+-  executable('valaprog', 'prog.vala', 'unused-var.c', dependencies : valadeps)
+-else
+-  executable('failprog', 'unused-var.c')
+-endif
+diff --git a/test cases/failing build/1 vala c werror/prog.vala b/test cases/failing build/1 vala c werror/prog.vala
+deleted file mode 100644
+index 638e77660..000000000
+--- a/test cases/failing build/1 vala c werror/prog.vala	
++++ /dev/null
+@@ -1,7 +0,0 @@
+-class MainProg : GLib.Object {
+-
+-    public static int main(string[] args) {
+-        stdout.printf("Vala is working.\n");
+-        return 0;
+-    }
+-}
+diff --git a/test cases/failing build/1 vala c werror/unused-var.c b/test cases/failing build/1 vala c werror/unused-var.c
+deleted file mode 100644
+index 6b85078c9..000000000
+--- a/test cases/failing build/1 vala c werror/unused-var.c	
++++ /dev/null
+@@ -1,8 +0,0 @@
+-#warning "something"
+-
+-int
+-somelib(void)
+-{
+-  int unused_var;
+-  return 33;
+-}
+diff --git a/test cases/vala/5 target glib/meson.build b/test cases/vala/5 target glib/meson.build
+index f285d9f16..089bb3c97 100644
+--- a/test cases/vala/5 target glib/meson.build	
++++ b/test cases/vala/5 target glib/meson.build	
+@@ -1,9 +1,5 @@
+ project('valatest', 'vala', 'c')
+ 
+-if not meson.is_unity()
+-  add_global_arguments('-Werror', language : 'c')
+-endif
+-
+ valadeps = [dependency('glib-2.0', version : '>=2.32'), dependency('gobject-2.0')]
+ 
+ e = executable('valaprog', 'GLib.Thread.vala', 'retcode.c', dependencies : valadeps)
+diff --git a/unittests/linuxliketests.py b/unittests/linuxliketests.py
+index 4fcf52e09..a02c99e8f 100644
+--- a/unittests/linuxliketests.py
++++ b/unittests/linuxliketests.py
+@@ -298,43 +298,6 @@ class LinuxlikeTests(BasePlatformTests):
+         self.build()
+         self._run(self.mtest_command)
+ 
+-    def test_vala_c_warnings(self):
+-        '''
+-        Test that no warnings are emitted for C code generated by Vala. This
+-        can't be an ordinary test case because we need to inspect the compiler
+-        database.
+-        https://github.com/mesonbuild/meson/issues/864
+-        '''
+-        if not shutil.which('valac'):
+-            raise SkipTest('valac not installed.')
+-        testdir = os.path.join(self.vala_test_dir, '5 target glib')
+-        self.init(testdir)
+-        compdb = self.get_compdb()
+-        vala_command = None
+-        c_command = None
+-        for each in compdb:
+-            if each['file'].endswith('GLib.Thread.c'):
+-                vala_command = each['command']
+-            elif each['file'].endswith('GLib.Thread.vala'):
+-                continue
+-            elif each['file'].endswith('retcode.c'):
+-                c_command = each['command']
+-            else:
+-                m = 'Unknown file {!r} in vala_c_warnings test'.format(each['file'])
+-                raise AssertionError(m)
+-        self.assertIsNotNone(vala_command)
+-        self.assertIsNotNone(c_command)
+-        # -w suppresses all warnings, should be there in Vala but not in C
+-        self.assertIn(" -w ", vala_command)
+-        self.assertNotIn(" -w ", c_command)
+-        # -Wall enables all warnings, should be there in C but not in Vala
+-        self.assertNotIn(" -Wall ", vala_command)
+-        self.assertIn(" -Wall ", c_command)
+-        # -Werror converts warnings to errors, should always be there since it's
+-        # injected by an unrelated piece of code and the project has werror=true
+-        self.assertIn(" -Werror ", vala_command)
+-        self.assertIn(" -Werror ", c_command)
+-
+     @skipIfNoPkgconfig
+     def test_qtdependency_pkgconfig_detection(self):
+         '''
+-- 
+2.41.0
+
diff --git a/dev-util/meson/meson-1.3.0-r2.ebuild b/dev-util/meson/meson-1.3.0-r2.ebuild
new file mode 100644
index 000000000000..af208ef34bdc
--- /dev/null
+++ b/dev-util/meson/meson-1.3.0-r2.ebuild
@@ -0,0 +1,135 @@
+# Copyright 2016-2023 Gentoo Authors
+# Distributed under the terms of the GNU General Public License v2
+
+EAPI=8
+
+PYTHON_COMPAT=( python3_{10..12} pypy3 )
+DISTUTILS_USE_PEP517=setuptools
+
+if [[ ${PV} = *9999* ]]; then
+	EGIT_REPO_URI="https://github.com/mesonbuild/meson"
+	inherit git-r3
+else
+	inherit verify-sig
+
+	MY_PV=${PV/_/}
+	MY_P=${P/_/}
+	S=${WORKDIR}/${MY_P}
+
+	SRC_URI="
+		https://github.com/mesonbuild/meson/releases/download/${MY_PV}/${MY_P}.tar.gz
+		verify-sig? ( https://github.com/mesonbuild/meson/releases/download/${MY_PV}/${MY_P}.tar.gz.asc )
+	"
+	BDEPEND="verify-sig? ( sec-keys/openpgp-keys-jpakkane )"
+	VERIFY_SIG_OPENPGP_KEY_PATH=/usr/share/openpgp-keys/jpakkane.gpg
+
+	if [[ ${PV} != *_rc* ]] ; then
+		KEYWORDS="~alpha ~amd64 ~arm ~arm64 ~hppa ~ia64 ~loong ~m68k ~mips ~ppc ~ppc64 ~riscv ~s390 ~sparc ~x86 ~amd64-linux ~x86-linux ~arm64-macos ~ppc-macos ~x64-macos ~x64-solaris"
+	fi
+fi
+
+inherit bash-completion-r1 distutils-r1 toolchain-funcs
+
+DESCRIPTION="Open source build system"
+HOMEPAGE="https://mesonbuild.com/"
+
+LICENSE="Apache-2.0"
+SLOT="0"
+IUSE="test"
+RESTRICT="!test? ( test )"
+
+DEPEND="
+	test? (
+		dev-libs/glib:2
+		dev-libs/gobject-introspection
+		dev-util/ninja
+		dev-vcs/git
+		sys-libs/zlib[static-libs(+)]
+		virtual/pkgconfig
+	)
+"
+RDEPEND="
+	virtual/pkgconfig
+"
+
+PATCHES=(
+	"${FILESDIR}"/${PN}-1.2.1-python-path.patch
+
+	# backport fix for broken configure_file()
+	"${FILESDIR}"/0001-Only-convert-boolean-values-for-cmake-formats.patch
+
+	# backport fix for hiding compiler warnings (such as Modern C) in vala and cython
+	"${FILESDIR}"/0001-ninja-backend-don-t-hide-all-compiler-warnings-for-t.patch
+)
+
+python_prepare_all() {
+	local disable_unittests=(
+		# ASAN and sandbox both want control over LD_PRELOAD
+		# https://bugs.gentoo.org/673016
+		-e 's/test_generate_gir_with_address_sanitizer/_&/'
+
+		# ASAN is unsupported on some targets
+		# https://bugs.gentoo.org/692822
+		-e 's/test_pch_with_address_sanitizer/_&/'
+
+		# https://github.com/mesonbuild/meson/issues/7203
+		-e 's/test_templates/_&/'
+
+		# Broken due to python2 wrapper
+		-e 's/test_python_module/_&/'
+	)
+
+	sed -i "${disable_unittests[@]}" unittests/*.py || die
+
+	# Broken due to python2 script created by python_wrapper_setup
+	rm -r "test cases/frameworks/1 boost" || die
+
+	distutils-r1_python_prepare_all
+}
+
+src_test() {
+	tc-export PKG_CONFIG
+	if ${PKG_CONFIG} --exists Qt5Core && ! ${PKG_CONFIG} --exists Qt5Gui; then
+		ewarn "Found Qt5Core but not Qt5Gui; skipping tests"
+	else
+		distutils-r1_src_test
+	fi
+}
+
+python_test() {
+	(
+		# test_meson_installed
+		unset PYTHONDONTWRITEBYTECODE
+
+		# https://bugs.gentoo.org/687792
+		unset PKG_CONFIG
+
+		# test_cross_file_system_paths
+		unset XDG_DATA_HOME
+
+		# 'test cases/unit/73 summary' expects 80 columns
+		export COLUMNS=80
+
+		# If JAVA_HOME is not set, meson looks for javac in PATH.
+		# If javac is in /usr/bin, meson assumes /usr/include is a valid
+		# JDK include path. Setting JAVA_HOME works around this broken
+		# autodetection. If no JDK is installed, we should end up with an empty
+		# value in JAVA_HOME, and the tests should get skipped.
+		export JAVA_HOME=$(java-config -O 2>/dev/null)
+
+		# Call python3 instead of EPYTHON to satisfy test_meson_uninstalled.
+		python3 run_tests.py
+	) || die "Testing failed with ${EPYTHON}"
+}
+
+python_install_all() {
+	distutils-r1_python_install_all
+
+	insinto /usr/share/vim/vimfiles
+	doins -r data/syntax-highlighting/vim/{ftdetect,indent,syntax}
+
+	insinto /usr/share/zsh/site-functions
+	doins data/shell-completions/zsh/_meson
+
+	dobashcomp data/shell-completions/bash/meson
+}