compilers: move get_compile_check_args() to Compiler

This is groundwork to put _build_wrapper in the base Compiler, which is
needed to make the D compilers truly type safe.

3 files changed, 47 insertions, 26 deletions

diff --git a/mesonbuild/compilers/compilers.py b/mesonbuild/compilers/compilers.py
index 0a53529..42bc251 100644
--- a/mesonbuild/compilers/compilers.py
+++ b/mesonbuild/compilers/compilers.py
@@ -14,6 +14,7 @@
 
 import abc
 import contextlib, os.path, re, tempfile
+import enum
 import itertools
 import typing as T
 from functools import lru_cache
@@ -165,6 +166,14 @@ def is_known_suffix(fname: 'mesonlib.FileOrString') -> bool:
 
     return suffix in all_suffixes
 
+
+class CompileCheckMode(enum.Enum):
+
+    PREPROCESS = 'preprocess'
+    COMPILE = 'compile'
+    LINK = 'link'
+
+
 cuda_buildtype_args = {'plain': [],
                        'debug': [],
                        'debugoptimized': [],
@@ -716,14 +725,16 @@ class Compiler(metaclass=abc.ABCMeta):
             suffix = 'obj'
         return os.path.join(dirname, 'output.' + suffix)
 
-    def get_compiler_args_for_mode(self, mode: str) -> T.List[str]:
+    def get_compiler_args_for_mode(self, mode: CompileCheckMode) -> T.List[str]:
         # TODO: mode should really be an enum
         args = []  # type: T.List[str]
         args += self.get_always_args()
-        if mode == 'compile':
+        if mode is CompileCheckMode.COMPILE:
             args += self.get_compile_only_args()
-        if mode == 'preprocess':
+        elif mode is CompileCheckMode.PREPROCESS:
             args += self.get_preprocess_only_args()
+        else:
+            assert mode is CompileCheckMode.LINK
         return args
 
     def compiler_args(self, args: T.Optional[T.Iterable[str]] = None) -> CompilerArgs:
@@ -761,7 +772,7 @@ class Compiler(metaclass=abc.ABCMeta):
                 if mode != 'preprocess':
                     output = self._get_compile_output(tmpdirname, mode)
                     commands += self.get_output_args(output)
-                commands.extend(self.get_compiler_args_for_mode(mode))
+                commands.extend(self.get_compiler_args_for_mode(CompileCheckMode(mode)))
                 # extra_args must be last because it could contain '/link' to
                 # pass args to VisualStudio's linker. In that case everything
                 # in the command line after '/link' is given to the linker.
@@ -1106,6 +1117,21 @@ class Compiler(metaclass=abc.ABCMeta):
     def module_name_to_filename(self, module_name: str) -> str:
         raise EnvironmentError('{} does not implement module_name_to_filename'.format(self.id))
 
+    def get_compiler_check_args(self, mode: CompileCheckMode) -> T.List[str]:
+        """Arguments to pass the compiler and/or linker for checks.
+
+        The default implementation turns off optimizations. mode should be
+        one of:
+
+        Examples of things that go here:
+          - extra arguments for error checking
+        """
+        return self.get_no_optimization_args()
+
+    def get_no_optimization_args(self) -> T.List[str]:
+        """Arguments to the compiler to turn off all optimizations."""
+        return []
+
 
 def get_args_from_envvars(lang: str,
                           for_machine: MachineChoice,
diff --git a/mesonbuild/compilers/cpp.py b/mesonbuild/compilers/cpp.py
index 4ef13e8..d934fa8 100644
--- a/mesonbuild/compilers/cpp.py
+++ b/mesonbuild/compilers/cpp.py
@@ -26,6 +26,7 @@ from .compilers import (
     gnu_winlibs,
     msvc_winlibs,
     Compiler,
+    CompileCheckMode,
 )
 from .c_function_attributes import CXX_FUNC_ATTRIBUTES, C_FUNC_ATTRIBUTES
 from .mixins.clike import CLikeCompiler
@@ -90,11 +91,11 @@ class CPPCompiler(CLikeCompiler, Compiler):
         code = 'class breakCCompiler;int main(void) { return 0; }\n'
         return self._sanity_check_impl(work_dir, environment, 'sanitycheckcpp.cc', code)
 
-    def get_compiler_check_args(self) -> T.List[str]:
+    def get_compiler_check_args(self, mode: CompileCheckMode) -> T.List[str]:
         # -fpermissive allows non-conforming code to compile which is necessary
         # for many C++ checks. Particularly, the has_header_symbol check is
         # too strict without this and always fails.
-        return super().get_compiler_check_args() + ['-fpermissive']
+        return super().get_compiler_check_args(mode) + ['-fpermissive']
 
     def has_header_symbol(self, hname: str, symbol: str, prefix: str,
                           env: 'Environment', *,
@@ -605,9 +606,9 @@ class VisualStudioLikeCPPCompilerMixin(CompilerMixinBase):
 
         return args
 
-    def get_compiler_check_args(self) -> T.List[str]:
+    def get_compiler_check_args(self, mode: CompileCheckMode) -> T.List[str]:
         # XXX: this is a hack because so much GnuLike stuff is in the base CPPCompiler class.
-        return CLikeCompiler.get_compiler_check_args(self)
+        return Compiler.get_compiler_check_args(self, mode)
 
 
 class CPP11AsCPP14Mixin(CompilerMixinBase):
@@ -739,7 +740,7 @@ class ArmCPPCompiler(ArmCompiler, CPPCompiler):
     def get_option_link_args(self, options: 'OptionDictType') -> T.List[str]:
         return []
 
-    def get_compiler_check_args(self) -> T.List[str]:
+    def get_compiler_check_args(self, mode: CompileCheckMode) -> T.List[str]:
         return []
 
 
@@ -768,7 +769,7 @@ class CcrxCPPCompiler(CcrxCompiler, CPPCompiler):
     def get_option_link_args(self, options: 'OptionDictType') -> T.List[str]:
         return []
 
-    def get_compiler_check_args(self) -> T.List[str]:
+    def get_compiler_check_args(self, mode: CompileCheckMode) -> T.List[str]:
         return []
 
 class C2000CPPCompiler(C2000Compiler, CPPCompiler):
@@ -802,5 +803,5 @@ class C2000CPPCompiler(C2000Compiler, CPPCompiler):
     def get_option_link_args(self, options: 'OptionDictType') -> T.List[str]:
         return []
 
-    def get_compiler_check_args(self) -> T.List[str]:
+    def get_compiler_check_args(self, mode: CompileCheckMode) -> T.List[str]:
         return []
diff --git a/mesonbuild/compilers/mixins/clike.py b/mesonbuild/compilers/mixins/clike.py
index 7cac7dc..9de715c 100644
--- a/mesonbuild/compilers/mixins/clike.py
+++ b/mesonbuild/compilers/mixins/clike.py
@@ -37,6 +37,7 @@ from ... import mlog
 from ...linkers import GnuLikeDynamicLinkerMixin, SolarisDynamicLinker, CompCertDynamicLinker
 from ...mesonlib import LibType
 from .. import compilers
+from ..compilers import CompileCheckMode
 from .visualstudio import VisualStudioLikeCompiler
 
 if T.TYPE_CHECKING:
@@ -184,13 +185,6 @@ class CLikeCompiler(Compiler):
     def get_no_optimization_args(self) -> T.List[str]:
         return ['-O0']
 
-    def get_compiler_check_args(self) -> T.List[str]:
-        '''
-        Get arguments useful for compiler checks such as being permissive in
-        the code quality and not doing any optimization.
-        '''
-        return self.get_no_optimization_args()
-
     def get_output_args(self, target: str) -> T.List[str]:
         return ['-o', target]
 
@@ -296,7 +290,7 @@ class CLikeCompiler(Compiler):
 
         source_name = os.path.join(work_dir, sname)
         binname = sname.rsplit('.', 1)[0]
-        mode = 'link'
+        mode = CompileCheckMode.LINK
         if self.is_cross:
             binname += '_cross'
             if self.exe_wrapper is None:
@@ -305,7 +299,7 @@ class CLikeCompiler(Compiler):
                 # on OSX the compiler binary is the same but you need
                 # a ton of compiler flags to differentiate between
                 # arm and x86_64. So just compile.
-                mode = 'compile'
+                mode = CompileCheckMode.COMPILE
         cargs, largs = self._get_basic_compiler_args(environment, mode)
         extra_flags = cargs + self.linker_to_compiler_args(largs)
 
@@ -432,7 +426,7 @@ class CLikeCompiler(Compiler):
     def _get_compiler_check_args(self, env: 'Environment',
                                  extra_args: T.Union[None, arglist.CompilerArgs, T.List[str]],
                                  dependencies: T.Optional[T.List['Dependency']],
-                                 mode: str = 'compile') -> arglist.CompilerArgs:
+                                 mode: CompileCheckMode = CompileCheckMode.COMPILE) -> arglist.CompilerArgs:
         # TODO: the caller should handle the listfing of these arguments
         if extra_args is None:
             extra_args = []
@@ -460,7 +454,7 @@ class CLikeCompiler(Compiler):
         cargs += ca
         largs += la
 
-        cargs += self.get_compiler_check_args()
+        cargs += self.get_compiler_check_args(mode)
 
         # on MSVC compiler and linker flags must be separated by the "/link" argument
         # at this point, the '/link' argument may already be part of extra_args, otherwise, it is added here
@@ -482,10 +476,10 @@ class CLikeCompiler(Compiler):
     def _build_wrapper(self, code: str, env: 'Environment',
                        extra_args: T.Union[None, arglist.CompilerArgs, T.List[str]] = None,
                        dependencies: T.Optional[T.List['Dependency']] = None,
-                       mode: str = 'compile', want_output: bool = False,
+                       mode: str = CompileCheckMode.COMPILE, want_output: bool = False,
                        disable_cache: bool = False,
                        temp_dir: str = None) -> T.Iterator[T.Optional[compilers.CompileResult]]:
-        args = self._get_compiler_check_args(env, extra_args, dependencies, mode)
+        args = self._get_compiler_check_args(env, extra_args, dependencies, CompileCheckMode(mode))
         if disable_cache or want_output:
             with self.compile(code, extra_args=args, mode=mode, want_output=want_output, temp_dir=env.scratch_dir) as r:
                 yield r
@@ -720,7 +714,7 @@ class CLikeCompiler(Compiler):
         #endif
         {delim}\n{define}'''
         args = self._get_compiler_check_args(env, extra_args, dependencies,
-                                             mode='preprocess').to_native()
+                                             mode=CompileCheckMode.PREPROCESS).to_native()
         func = functools.partial(self.cached_compile, code.format(**fargs), env.coredata, extra_args=args, mode='preprocess')
         if disable_cache:
             func = functools.partial(self.compile, code.format(**fargs), extra_args=args, mode='preprocess', temp_dir=env.scratch_dir)
@@ -966,7 +960,7 @@ class CLikeCompiler(Compiler):
         }
         #endif
         '''
-        args = self.get_compiler_check_args()
+        args = self.get_compiler_check_args(CompileCheckMode.COMPILE)
         n = 'symbols_have_underscore_prefix'
         with self._build_wrapper(code, env, extra_args=args, mode='compile', want_output=True, temp_dir=env.scratch_dir) as p:
             if p.returncode != 0: