compilers: generalize -fembed-bitcode

Produce -Cembed-bitcode for Rust, and also disable bitcode
generation when LTO is not enabled.

3 files changed, 18 insertions, 2 deletions

diff --git a/mesonbuild/compilers/compilers.py b/mesonbuild/compilers/compilers.py
index bd283ed32..8ee2c1b24 100644
--- a/mesonbuild/compilers/compilers.py
+++ b/mesonbuild/compilers/compilers.py
@@ -273,6 +273,7 @@ def are_asserts_disabled_for_subproject(subproject: str, env: 'Environment') ->
 
 def get_base_compile_args(target: 'BuildTarget', compiler: 'Compiler', env: 'Environment') -> T.List[str]:
     args: T.List[str] = []
+    lto = False
     try:
         if env.coredata.get_option_for_target(target, 'b_lto'):
             num_threads = get_option_value_for_target(env, target, OptionKey('b_lto_threads'), 0)
@@ -280,6 +281,7 @@ def get_base_compile_args(target: 'BuildTarget', compiler: 'Compiler', env: 'Env
             args.extend(compiler.get_lto_compile_args(
                 threads=num_threads,
                 mode=ltomode))
+            lto = True
     except (KeyError, AttributeError):
         pass
     try:
@@ -320,8 +322,8 @@ def get_base_compile_args(target: 'BuildTarget', compiler: 'Compiler', env: 'Env
     except KeyError:
         pass
     # This does not need a try...except
-    if option_enabled(compiler.base_options, target, env, 'b_bitcode'):
-        args.append('-fembed-bitcode')
+    bitcode = option_enabled(compiler.base_options, target, env, 'b_bitcode')
+    args.extend(compiler.get_embed_bitcode_args(bitcode, lto))
     try:
         crt_val = env.coredata.get_option_for_target(target, 'b_vscrt')
         assert isinstance(crt_val, str)
@@ -1035,6 +1037,9 @@ class Compiler(HoldableObject, metaclass=abc.ABCMeta):
             ret.append(arg)
         return ret
 
+    def get_embed_bitcode_args(self, bitcode: bool, lto: bool) -> T.List[str]:
+        return []
+
     def get_lto_compile_args(self, *, threads: int = 0, mode: str = 'default') -> T.List[str]:
         return []
 
diff --git a/mesonbuild/compilers/mixins/clang.py b/mesonbuild/compilers/mixins/clang.py
index 2c1e326bd..5c3310062 100644
--- a/mesonbuild/compilers/mixins/clang.py
+++ b/mesonbuild/compilers/mixins/clang.py
@@ -216,6 +216,9 @@ class ClangCompiler(GnuLikeCompiler):
     def get_coverage_link_args(self) -> T.List[str]:
         return ['--coverage']
 
+    def get_embed_bitcode_args(self, bitcode: bool, lto: bool) -> T.List[str]:
+        return ['-fembed-bitcode'] if bitcode else []
+
     def get_lto_compile_args(self, *, threads: int = 0, mode: str = 'default') -> T.List[str]:
         args: T.List[str] = []
         if mode == 'thin':
diff --git a/mesonbuild/compilers/rust.py b/mesonbuild/compilers/rust.py
index 54b3da91a..54b917f7a 100644
--- a/mesonbuild/compilers/rust.py
+++ b/mesonbuild/compilers/rust.py
@@ -341,6 +341,14 @@ class RustCompiler(Compiler):
             args.extend(['-C', f'link-arg={a}'])
         return args
 
+    def get_embed_bitcode_args(self, bitcode: bool, lto: bool) -> T.List[str]:
+        if bitcode:
+            return ['-C', 'embed-bitcode=yes']
+        elif lto:
+            return []
+        else:
+            return ['-C', 'embed-bitcode=no']
+
     def get_lto_compile_args(self, *, threads: int = 0, mode: str = 'default') -> T.List[str]:
         # TODO: what about -Clinker-plugin-lto?
         rustc_lto = 'lto=thin' if mode == 'thin' else 'lto'