Add thinlto support. Closes #7493.thinlto

3 files changed, 16 insertions, 6 deletions

diff --git a/mesonbuild/compilers/compilers.py b/mesonbuild/compilers/compilers.py
index 0f074bb..f6912f1 100644
--- a/mesonbuild/compilers/compilers.py
+++ b/mesonbuild/compilers/compilers.py
@@ -266,7 +266,9 @@ clike_debug_args = {False: [],
                     True: ['-g']}  # type: T.Dict[bool, T.List[str]]
 
 base_options = {'b_pch': coredata.UserBooleanOption('Use precompiled headers', True),
-                'b_lto': coredata.UserBooleanOption('Use link time optimization', False),
+                'b_lto': coredata.UserComboOption('Use link time optimization',
+                                                  ['false', 'true', 'thin'],
+                                                  'false'),
                 'b_sanitize': coredata.UserComboOption('Code sanitizer to use',
                                                        ['none', 'address', 'thread', 'undefined', 'memory', 'address,undefined'],
                                                        'none'),
@@ -307,8 +309,7 @@ def option_enabled(boptions: T.List[str], options: 'OptionDictType',
 def get_base_compile_args(options: 'OptionDictType', compiler: 'Compiler') -> T.List[str]:
     args = []  # type T.List[str]
     try:
-        if options['b_lto'].value:
-            args.extend(compiler.get_lto_compile_args())
+        args.extend(compiler.get_lto_compile_args(options['b_lto'].value))
     except KeyError:
         pass
     try:
@@ -940,7 +941,7 @@ class Compiler(metaclass=abc.ABCMeta):
             ret.append(arg)
         return ret
 
-    def get_lto_compile_args(self) -> T.List[str]:
+    def get_lto_compile_args(self, lto_type: str) -> T.List[str]:
         return []
 
     def get_lto_link_args(self) -> T.List[str]:
diff --git a/mesonbuild/compilers/mixins/clang.py b/mesonbuild/compilers/mixins/clang.py
index acdb352..773d9dc 100644
--- a/mesonbuild/compilers/mixins/clang.py
+++ b/mesonbuild/compilers/mixins/clang.py
@@ -77,6 +77,13 @@ class ClangCompiler(GnuLikeCompiler):
         # so it might change semantics at any time.
         return ['-include-pch', os.path.join(pch_dir, self.get_pch_name(header))]
 
+    def get_lto_compile_args(self, lto_type: str) -> T.List[str]:
+        if lto_type == 'thin':
+            return ['-flto=thin']
+        if lto_type == 'true':
+            return ['-flto']
+        return []
+
     def get_compiler_check_args(self, mode: CompileCheckMode) -> T.List[str]:
         myargs = []  # type: T.List[str]
         if mode is CompileCheckMode.COMPILE:
diff --git a/mesonbuild/compilers/mixins/gnu.py b/mesonbuild/compilers/mixins/gnu.py
index bb1fc66..5771ad8 100644
--- a/mesonbuild/compilers/mixins/gnu.py
+++ b/mesonbuild/compilers/mixins/gnu.py
@@ -295,8 +295,10 @@ class GnuLikeCompiler(Compiler, metaclass=abc.ABCMeta):
                 return self._split_fetch_real_dirs(line.split('=', 1)[1])
         return []
 
-    def get_lto_compile_args(self) -> T.List[str]:
-        return ['-flto']
+    def get_lto_compile_args(self, lto_type: str) -> T.List[str]:
+        if lto_type != 'false':
+            return ['-flto']
+        return []
 
     def sanitizer_compile_args(self, value: str) -> T.List[str]:
         if value == 'none':