compilers: Make sure to not use ccache in compiler checks

ccache was used in all command lines but disabled using CCACHE_DISABLE
in Compiler.compile() method. Wrapping invokations still has a cost,
especially on Windows.

With sccache things are even worse because CCACHE_DISABLE was not
respected at all, making configure *extremely* slow on Windows when
sccache is installed.

mesonbuild/compilers/compilers.py

@@ -503,6 +503,7 @@ class Compiler(HoldableObject, metaclass=abc.ABCMeta):
                  linker: T.Optional['DynamicLinker'] = None,
                  full_version: T.Optional[str] = None, is_cross: bool = False):
         self.exelist = ccache + exelist
+        self.exelist_no_ccache = exelist
         # In case it's been overridden by a child class already
         if not hasattr(self, 'file_suffixes'):
             self.file_suffixes = lang_suffixes[self.language]
@@ -593,8 +594,8 @@ class Compiler(HoldableObject, metaclass=abc.ABCMeta):
     def symbols_have_underscore_prefix(self, env: 'Environment') -> bool:
         raise EnvironmentException('%s does not support symbols_have_underscore_prefix ' % self.get_id())
 
-    def get_exelist(self) -> T.List[str]:
-        return self.exelist.copy()
+    def get_exelist(self, ccache: bool = True) -> T.List[str]:
+        return self.exelist.copy() if ccache else self.exelist_no_ccache.copy()
 
     def get_linker_exelist(self) -> T.List[str]:
         return self.linker.get_exelist()
@@ -815,7 +816,7 @@ class Compiler(HoldableObject, metaclass=abc.ABCMeta):
             if extra_args:
                 commands += extra_args
             # Generate full command-line with the exelist
-            command_list = self.get_exelist() + commands.to_native()
+            command_list = self.get_exelist(ccache=not no_ccache) + commands.to_native()
             mlog.debug('Running compile:')
             mlog.debug('Working directory: ', tmpdirname)
             mlog.debug('Command line: ', ' '.join(command_list), '\n')

mesonbuild/compilers/mixins/clike.py

@@ -179,9 +179,6 @@ class CLikeCompiler(Compiler):
     def get_depfile_suffix(self) -> str:
         return 'd'
 
-    def get_exelist(self) -> T.List[str]:
-        return self.exelist.copy()
-
     def get_preprocess_only_args(self) -> T.List[str]:
         return ['-E', '-P']
 
@@ -1194,7 +1191,7 @@ class CLikeCompiler(Compiler):
         if self.id != 'clang':
             raise mesonlib.MesonException('Cannot find framework path with non-clang compiler')
         # Construct the compiler command-line
-        commands = self.get_exelist() + ['-v', '-E', '-']
+        commands = self.get_exelist(ccache=False) + ['-v', '-E', '-']
         commands += self.get_always_args()
         # Add CFLAGS/CXXFLAGS/OBJCFLAGS/OBJCXXFLAGS from the env
         commands += env.coredata.get_external_args(self.for_machine, self.language)

mesonbuild/compilers/mixins/elbrus.py

@@ -48,7 +48,7 @@ class ElbrusCompiler(GnuLikeCompiler):
     def get_library_dirs(self, env: 'Environment', elf_class: T.Optional[int] = None) -> T.List[str]:
         os_env = os.environ.copy()
         os_env['LC_ALL'] = 'C'
-        stdo = Popen_safe(self.exelist + ['--print-search-dirs'], env=os_env)[1]
+        stdo = Popen_safe(self.get_exelist(ccache=False) + ['--print-search-dirs'], env=os_env)[1]
         for line in stdo.split('\n'):
             if line.startswith('libraries:'):
                 # lcc does not include '=' in --print-search-dirs output. Also it could show nonexistent dirs.
@@ -59,7 +59,7 @@ class ElbrusCompiler(GnuLikeCompiler):
     def get_program_dirs(self, env: 'Environment') -> T.List[str]:
         os_env = os.environ.copy()
         os_env['LC_ALL'] = 'C'
-        stdo = Popen_safe(self.exelist + ['--print-search-dirs'], env=os_env)[1]
+        stdo = Popen_safe(self.get_exelist(ccache=False) + ['--print-search-dirs'], env=os_env)[1]
         for line in stdo.split('\n'):
             if line.startswith('programs:'):
                 # lcc does not include '=' in --print-search-dirs output.
@@ -70,7 +70,7 @@ class ElbrusCompiler(GnuLikeCompiler):
     def get_default_include_dirs(self) -> T.List[str]:
         os_env = os.environ.copy()
         os_env['LC_ALL'] = 'C'
-        p = subprocess.Popen(self.exelist + ['-xc', '-E', '-v', '-'], env=os_env, stdin=subprocess.DEVNULL, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
+        p = subprocess.Popen(self.get_exelist(ccache=False) + ['-xc', '-E', '-v', '-'], env=os_env, stdin=subprocess.DEVNULL, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
         stderr = p.stderr.read().decode('utf-8', errors='replace')
         includes = []
         for line in stderr.split('\n'):

mesonbuild/compilers/mixins/gnu.py

@@ -184,7 +184,7 @@ class GnuLikeCompiler(Compiler, metaclass=abc.ABCMeta):
         return gnulike_instruction_set_args.get(instruction_set, None)
 
     def get_default_include_dirs(self) -> T.List[str]:
-        return gnulike_default_include_dirs(tuple(self.exelist), self.language).copy()
+        return gnulike_default_include_dirs(tuple(self.get_exelist(ccache=False)), self.language).copy()
 
     @abc.abstractmethod
     def openmp_flags(self) -> T.List[str]:

mesonbuild/compilers/rust.py

@@ -110,7 +110,7 @@ class RustCompiler(Compiler):
         return rust_buildtype_args[buildtype]
 
     def get_sysroot(self) -> str:
-        cmd = self.exelist + ['--print', 'sysroot']
+        cmd = self.get_exelist(ccache=False) + ['--print', 'sysroot']
         p, stdo, stde = Popen_safe(cmd)
         return stdo.split('\n', maxsplit=1)[0]