move Gnu-specific feature '--print-search-dirs' to GnuLikeCompiler

1 files changed, 60 insertions, 0 deletions

diff --git a/mesonbuild/compilers/compilers.py b/mesonbuild/compilers/compilers.py
index 50225c0..8800923 100644
--- a/mesonbuild/compilers/compilers.py
+++ b/mesonbuild/compilers/compilers.py
@@ -13,8 +13,10 @@
 # limitations under the License.
 
 import abc, contextlib, enum, os.path, re, tempfile, shlex
+import functools
 import subprocess
 from typing import List, Optional, Tuple
+from pathlib import Path
 
 from ..linkers import StaticLinker
 from .. import coredata
@@ -2005,6 +2007,64 @@ class GnuLikeCompiler(abc.ABC):
 
         return parameter_list
 
+    @functools.lru_cache()
+    def _get_search_dirs(self, env):
+        extra_args = ['--print-search-dirs']
+        stdo = None
+        with self._build_wrapper('', env, extra_args=extra_args,
+                                 dependencies=None, mode='compile',
+                                 want_output=True) as p:
+            stdo = p.stdo
+        return stdo
+
+    def _split_fetch_real_dirs(self, pathstr):
+        # We need to use the path separator used by the compiler for printing
+        # lists of paths ("gcc --print-search-dirs"). By default
+        # we assume it uses the platform native separator.
+        pathsep = os.pathsep
+
+        # clang uses ':' instead of ';' on Windows https://reviews.llvm.org/D61121
+        # so we need to repair things like 'C:\foo:C:\bar'
+        if pathsep == ';':
+            pathstr = re.sub(r':([^/\\])', r';\1', pathstr)
+
+        # pathlib treats empty paths as '.', so filter those out
+        paths = [p for p in pathstr.split(pathsep) if p]
+
+        result = []
+        for p in paths:
+            # GCC returns paths like this:
+            # /usr/lib/gcc/x86_64-linux-gnu/8/../../../../x86_64-linux-gnu/lib
+            # It would make sense to normalize them to get rid of the .. parts
+            # Sadly when you are on a merged /usr fs it also kills these:
+            # /lib/x86_64-linux-gnu
+            # since /lib is a symlink to /usr/lib. This would mean
+            # paths under /lib would be considered not a "system path",
+            # which is wrong and breaks things. Store everything, just to be sure.
+            pobj = Path(p)
+            unresolved = pobj.as_posix()
+            if pobj.exists():
+                if unresolved not in result:
+                    result.append(unresolved)
+                try:
+                    resolved = Path(p).resolve().as_posix()
+                    if resolved not in result:
+                        result.append(resolved)
+                except FileNotFoundError:
+                    pass
+        return tuple(result)
+
+    def get_compiler_dirs(self, env, name):
+        '''
+        Get dirs from the compiler, either `libraries:` or `programs:`
+        '''
+        stdo = self._get_search_dirs(env)
+        for line in stdo.split('\n'):
+            if line.startswith(name + ':'):
+                return self._split_fetch_real_dirs(line.split('=', 1)[1])
+        return ()
+
+
 class GnuCompiler(GnuLikeCompiler):
     """
     GnuCompiler represents an actual GCC in its many incarnations.