Add yasm as fallback for nasm language

docs/markdown/snippets/asm.md

@@ -2,10 +2,7 @@
 
 When the `nasm` language is added to the project, `.asm` files are
 automatically compiled with NASM. This is only supported for x86 and x86_64 CPU
-family.
+family. `yasm` is used as fallback if `nasm` command is not found.
-
-Support for other compilers compatible with NASM language, such as YASM, could
-be added in the future.
 
 Note that GNU Assembly files usually have `.s` extension and were already built
 using C compiler such as GCC or CLANG.

mesonbuild/compilers/asm.py

@@ -1,7 +1,7 @@
 import os
 import typing as T
 
-from ..mesonlib import EnvironmentException
+from ..mesonlib import EnvironmentException, get_meson_command
 from .compilers import Compiler
 
 if T.TYPE_CHECKING:
@@ -75,3 +75,21 @@ class NasmCompiler(Compiler):
             if i[:2] == '-I':
                 parameter_list[idx] = i[:2] + os.path.normpath(os.path.join(build_dir, i[2:]))
         return parameter_list
+
+class YasmCompiler(NasmCompiler):
+    id = 'yasm'
+
+    def get_exelist(self) -> T.List[str]:
+        # Wrap yasm executable with an internal script that will write depfile.
+        exelist = super().get_exelist()
+        return get_meson_command() + ['--internal', 'yasm'] + exelist
+
+    def get_debug_args(self, is_debug: bool) -> T.List[str]:
+        if is_debug:
+            if self.info.is_windows():
+                return ['-g', 'null']
+            return ['-g', 'dwarf2']
+        return []
+
+    def get_dependency_gen_args(self, outtarget: str, outfile: str) -> T.List[str]:
+        return ['--depfile', outfile]

mesonbuild/compilers/detect.py

@@ -88,7 +88,7 @@ defaults['clang_cl_static_linker'] = ['llvm-lib']
 defaults['cuda_static_linker'] = ['nvlink']
 defaults['gcc_static_linker'] = ['gcc-ar']
 defaults['clang_static_linker'] = ['llvm-ar']
-defaults['nasm'] = ['nasm']
+defaults['nasm'] = ['nasm', 'yasm']
 
 
 def compiler_from_language(env: 'Environment', lang: str, for_machine: MachineChoice) -> T.Optional[Compiler]:
@@ -1137,7 +1137,7 @@ def detect_swift_compiler(env: 'Environment', for_machine: MachineChoice) -> Com
     raise EnvironmentException('Unknown compiler: ' + join_args(exelist))
 
 def detect_nasm_compiler(env: 'Environment', for_machine: MachineChoice) -> Compiler:
-    from .asm import NasmCompiler
+    from .asm import NasmCompiler, YasmCompiler
     compilers, _, _ = _get_compilers(env, 'nasm', for_machine)
     is_cross = env.is_cross_build(for_machine)
 
@@ -1162,6 +1162,10 @@ def detect_nasm_compiler(env: 'Environment', for_machine: MachineChoice) -> Comp
             comp_class = NasmCompiler
             env.coredata.add_lang_args(comp_class.language, comp_class, for_machine, env)
             return comp_class(comp, version, for_machine, info, cc.linker, is_cross=is_cross)
+        elif 'yasm' in output:
+            comp_class = YasmCompiler
+            env.coredata.add_lang_args(comp_class.language, comp_class, for_machine, env)
+            return comp_class(comp, version, for_machine, info, cc.linker, is_cross=is_cross)
     _handle_exceptions(popen_exceptions, compilers)
     raise EnvironmentException('Unreachable code (exception to make mypy happy)')
 

mesonbuild/scripts/yasm.py

@@ -0,0 +1,22 @@
+import argparse
+import subprocess
+import typing as T
+
+def run(args: T.List[str]) -> int:
+    parser = argparse.ArgumentParser()
+    parser.add_argument('--depfile')
+    options, yasm_cmd = parser.parse_known_args(args)
+
+    # Compile
+    returncode = subprocess.call(yasm_cmd)
+    if returncode != 0:
+        return returncode
+
+    # Capture and write depfile
+    ret = subprocess.run(yasm_cmd + ['-M'], capture_output=True)
+    if ret.returncode != 0:
+        return ret.returncode
+    with open(options.depfile, 'wb') as f:
+        f.write(ret.stdout)
+
+    return 0

test cases/nasm/2 asm language/meson.build

@@ -1,7 +1,8 @@
 project('test', 'c')
 
 nasm = find_program('nasm', required: false)
-if not nasm.found()
+yasm = find_program('yasm', required: false)
+if not nasm.found() and not yasm.found()
   assert(not add_languages('nasm', required: false))
   error('MESON_SKIP_TEST: nasm not available')
 endif