compilers: Split C-Like functionality into a mixin classes

Currently C++ inherits C, which can lead to diamond problems. By pulling
the code out into a standalone mixin class that the C, C++, ObjC, and
Objc++ compilers can inherit and override as necessary we remove one
source of diamonding. I've chosen to split this out into it's own file
as the CLikeCompiler class is over 1000 lines by itself. This also
breaks the VisualStudio derived classes inheriting from each other, to
avoid the same C -> CPP inheritance problems. This is all one giant
patch because there just isn't a clean way to separate this.

I've done the same for Fortran since it effectively inherits the
CCompiler (I say effectively because was it actually did was gross
beyond explanation), it's probably not correct, but it seems to work for
now. There really is a lot of layering violation going on in the
Compilers, and a really good scrubbing would do this code a lot of good.

2 files changed, 9 insertions, 9 deletions

diff --git a/mesonbuild/backend/backends.py b/mesonbuild/backend/backends.py
index d0b4bb5..0565de3 100644
--- a/mesonbuild/backend/backends.py
+++ b/mesonbuild/backend/backends.py
@@ -23,7 +23,7 @@ import subprocess
 from ..mesonlib import MachineChoice, MesonException, OrderedSet
 from ..mesonlib import classify_unity_sources
 from ..mesonlib import File
-from ..compilers import CompilerArgs, VisualStudioCCompiler
+from ..compilers import CompilerArgs, VisualStudioLikeCompiler
 from collections import OrderedDict
 import shlex
 from functools import lru_cache
@@ -551,7 +551,7 @@ class Backend:
             return args
         extra_args = []
         # Compiler-specific escaping is needed for -D args but not for any others
-        if isinstance(compiler, VisualStudioCCompiler):
+        if isinstance(compiler, VisualStudioLikeCompiler):
             # MSVC needs escaping when a -D argument ends in \ or \"
             for arg in args:
                 if arg.startswith('-D') or arg.startswith('/D'):
diff --git a/mesonbuild/backend/ninjabackend.py b/mesonbuild/backend/ninjabackend.py
index 7eafcad..e0a6440 100644
--- a/mesonbuild/backend/ninjabackend.py
+++ b/mesonbuild/backend/ninjabackend.py
@@ -29,7 +29,7 @@ from .. import build
 from .. import mlog
 from .. import dependencies
 from .. import compilers
-from ..compilers import CompilerArgs, CCompiler, VisualStudioCCompiler, FortranCompiler
+from ..compilers import CompilerArgs, CCompiler, VisualStudioLikeCompiler, FortranCompiler
 from ..linkers import ArLinker
 from ..mesonlib import File, MachineChoice, MesonException, OrderedSet, LibType
 from ..mesonlib import get_compiler_for_source, has_path_sep
@@ -221,7 +221,7 @@ class NinjaBackend(backends.Backend):
         Detect the search prefix to use.'''
         for compiler in self.build.compilers.values():
             # Have to detect the dependency format
-            if isinstance(compiler, VisualStudioCCompiler):
+            if isinstance(compiler, VisualStudioLikeCompiler):
                 break
         else:
             # None of our compilers are MSVC, we're done.
@@ -1673,7 +1673,7 @@ https://gcc.gnu.org/bugzilla/show_bug.cgi?id=47485'''))
         command = [ninja_quote(i) for i in compiler.get_exelist()]
         args = ['$ARGS'] + quoted_depargs + compiler.get_output_args('$out') + compiler.get_compile_only_args() + ['$in']
         description = 'Compiling %s object $out.' % compiler.get_display_language()
-        if isinstance(compiler, VisualStudioCCompiler):
+        if isinstance(compiler, VisualStudioLikeCompiler):
             deps = 'msvc'
             depfile = None
         else:
@@ -1698,13 +1698,13 @@ https://gcc.gnu.org/bugzilla/show_bug.cgi?id=47485'''))
             if d != '$out' and d != '$in':
                 d = quote_func(d)
             quoted_depargs.append(d)
-        if isinstance(compiler, VisualStudioCCompiler):
+        if isinstance(compiler, VisualStudioLikeCompiler):
             output = []
         else:
             output = compiler.get_output_args('$out')
         command = compiler.get_exelist() + ['$ARGS'] + quoted_depargs + output + compiler.get_compile_only_args() + ['$in']
         description = 'Precompiling header $in.'
-        if isinstance(compiler, VisualStudioCCompiler):
+        if isinstance(compiler, VisualStudioLikeCompiler):
             deps = 'msvc'
             depfile = None
         else:
@@ -1886,7 +1886,7 @@ https://gcc.gnu.org/bugzilla/show_bug.cgi?id=47485'''))
         return compiler.get_no_stdinc_args()
 
     def get_compile_debugfile_args(self, compiler, target, objfile):
-        if not isinstance(compiler, VisualStudioCCompiler):
+        if not isinstance(compiler, VisualStudioLikeCompiler):
             return []
         # The way MSVC uses PDB files is documented exactly nowhere so
         # the following is what we have been able to decipher via
@@ -2275,7 +2275,7 @@ https://gcc.gnu.org/bugzilla/show_bug.cgi?id=47485'''))
                       ''.format(target.get_basename())
                 raise InvalidArguments(msg)
             compiler = target.compilers[lang]
-            if isinstance(compiler, VisualStudioCCompiler):
+            if isinstance(compiler, VisualStudioLikeCompiler):
                 (commands, dep, dst, objs, src) = self.generate_msvc_pch_command(target, compiler, pch)
                 extradep = os.path.join(self.build_to_src, target.get_source_subdir(), pch[0])
             elif compiler.id == 'intel':