Merge pull request #7609 from dcbaker/submit/2020-08/cmake-fix-apple-clang

Fix mapping of apple compilers in cmake

mesonbuild/cmake/executor.py

@@ -29,13 +29,18 @@ from .. import mlog, mesonlib
 from ..mesonlib import PerMachine, Popen_safe, version_compare, MachineChoice
 from ..environment import Environment
 from ..envconfig import get_env_var
+from ..compilers import (
+    AppleClangCCompiler, AppleClangCPPCompiler, AppleClangObjCCompiler,
+    AppleClangObjCPPCompiler
+)
 
 if T.TYPE_CHECKING:
     from ..dependencies.base import ExternalProgram
+    from ..compilers import Compiler
 
 TYPE_result = T.Tuple[int, T.Optional[str], T.Optional[str]]
 
-MESON_TO_CMAKE_MAPPING = {
+_MESON_TO_CMAKE_MAPPING = {
     'arm':          'ARMCC',
     'armclang':     'ARMClang',
     'clang':        'Clang',
@@ -51,13 +56,21 @@ MESON_TO_CMAKE_MAPPING = {
     'sun':          'SunPro',
 }
 
-def meson_compiler_to_cmake_id(cobj):
-    # cland and apple clang both map to 'clang' in meson, so we need to look at
-    # the linker that's being used
-    if cobj.linker.get_id() == 'ld64':
+def meson_compiler_to_cmake_id(cobj: 'Compiler') -> str:
+    """Translate meson compiler's into CMAKE compiler ID's.
+
+    Most of these can be handled by a simple table lookup, with a few
+    exceptions.
+
+    Clang and Apple's Clang are both identified as "clang" by meson. To make
+    things more complicated gcc and vanilla clang both use Apple's ld64 on
+    macOS. The only way to know for sure is to do an isinstance() check.
+    """
+    if isinstance(cobj, (AppleClangCCompiler, AppleClangCPPCompiler,
+                         AppleClangObjCCompiler, AppleClangObjCPPCompiler)):
         return 'AppleClang'
     # If no mapping, try GNU and hope that the build files don't care
-    return MESON_TO_CMAKE_MAPPING.get(cobj.get_id(), 'GNU')
+    return _MESON_TO_CMAKE_MAPPING.get(cobj.get_id(), 'GNU')
 
 
 class CMakeExecutor:

mesonbuild/compilers/__init__.py

@@ -36,6 +36,8 @@ __all__ = [
 
     'AppleClangCCompiler',
     'AppleClangCPPCompiler',
+    'AppleClangObjCCompiler',
+    'AppleClangObjCPPCompiler',
     'ArmCCompiler',
     'ArmCPPCompiler',
     'ArmclangCCompiler',
@@ -189,11 +191,13 @@ from .fortran import (
 from .java import JavaCompiler
 from .objc import (
     ObjCCompiler,
+    AppleClangObjCCompiler,
     ClangObjCCompiler,
     GnuObjCCompiler,
 )
 from .objcpp import (
     ObjCPPCompiler,
+    AppleClangObjCPPCompiler,
     ClangObjCPPCompiler,
     GnuObjCPPCompiler,
 )

mesonbuild/compilers/objc.py

@@ -92,3 +92,8 @@ class ClangObjCCompiler(ClangCompiler, ObjCCompiler):
                           '1': default_warn_args,
                           '2': default_warn_args + ['-Wextra'],
                           '3': default_warn_args + ['-Wextra', '-Wpedantic']}
+
+
+class AppleClangObjCCompiler(ClangObjCCompiler):
+
+    """Handle the differences between Apple's clang and vanilla clang."""

mesonbuild/compilers/objcpp.py

@@ -90,3 +90,9 @@ class ClangObjCPPCompiler(ClangCompiler, ObjCPPCompiler):
                           '1': default_warn_args,
                           '2': default_warn_args + ['-Wextra'],
                           '3': default_warn_args + ['-Wextra', '-Wpedantic']}
+
+
+
+class AppleClangObjCPPCompiler(ClangObjCPPCompiler):
+
+    """Handle the differences between Apple's clang and vanilla clang."""

mesonbuild/environment.py

@@ -76,6 +76,8 @@ from .compilers import (
     ArmclangCPPCompiler,
     AppleClangCCompiler,
     AppleClangCPPCompiler,
+    AppleClangObjCCompiler,
+    AppleClangObjCPPCompiler,
     ClangCCompiler,
     ClangCPPCompiler,
     ClangObjCCompiler,
@@ -1527,7 +1529,7 @@ class Environment:
     def detect_objcpp_compiler(self, for_machine: MachineInfo) -> 'Compiler':
         return self._detect_objc_or_objcpp_compiler(for_machine, False)
 
-    def _detect_objc_or_objcpp_compiler(self, for_machine: MachineInfo, objc: bool) -> 'Compiler':
+    def _detect_objc_or_objcpp_compiler(self, for_machine: MachineChoice, objc: bool) -> 'Compiler':
         popen_exceptions = {}
         compilers, ccache, exe_wrap = self._get_compilers('objc' if objc else 'objcpp', for_machine)
         is_cross = self.is_cross_build(for_machine)
@@ -1556,7 +1558,10 @@ class Environment:
                     exe_wrap, defines, linker=linker)
             if 'clang' in out:
                 linker = None
-                comp = ClangObjCCompiler if objc else ClangObjCPPCompiler
+                if 'Apple' in out:
+                    comp = AppleClangObjCCompiler if objc else AppleClangObjCPPCompiler
+                else:
+                    comp = ClangObjCCompiler if objc else ClangObjCPPCompiler
                 if 'windows' in out or self.machines[for_machine].is_windows():
                     # If we're in a MINGW context this actually will use a gnu style ld
                     try: