C/C++: Get default include dirs from compilers

mesonbuild/compilers/c.py

@@ -172,6 +172,9 @@ class CCompiler(Compiler):
     def get_linker_search_args(self, dirname):
         return ['-L' + dirname]
 
+    def get_default_include_dirs(self):
+        return []
+
     def gen_import_library_args(self, implibname):
         """
         The name of the outputted import library
@@ -1082,3 +1085,8 @@ class VisualStudioCCompiler(CCompiler):
         elif version < 1920:
             return '14.1' # (Visual Studio 2017)
         return None
+
+    def get_default_include_dirs(self):
+        if 'INCLUDE' not in os.environ:
+            return []
+        return os.environ['INCLUDE'].split(os.pathsep)

mesonbuild/compilers/compilers.py

@@ -13,6 +13,7 @@
 # limitations under the License.
 
 import contextlib, os.path, re, tempfile
+import subprocess
 
 from ..linkers import StaticLinker
 from .. import coredata
@@ -917,6 +918,35 @@ def get_largefile_args(compiler):
         # those features explicitly.
     return []
 
+# TODO: The result from calling compiler should be cached. So that calling this
+# function multiple times don't add latency.
+def gnulike_default_include_dirs(compiler, lang):
+    if lang == 'cpp':
+        lang = 'c++'
+    p = subprocess.Popen(
+        compiler + ['-x{}'.format(lang), '-E', '-v', '-'],
+        stdin=subprocess.DEVNULL,
+        stderr=subprocess.PIPE,
+        stdout=subprocess.PIPE
+    )
+    stderr = p.stderr.read().decode('utf-8')
+    parse_state = 0
+    paths = []
+    for line in stderr.split('\n'):
+        if parse_state == 0:
+            if line == '#include "..." search starts here:':
+                parse_state = 1
+        elif parse_state == 1:
+            if line == '#include <...> search starts here:':
+                parse_state = 2
+            else:
+                paths.append(line[1:])
+        elif parse_state == 2:
+            if line == 'End of search list.':
+                break
+            else:
+                paths.append(line[1:])
+    return paths
 
 class GnuCompiler:
     # Functionality that is common to all GNU family compilers.
@@ -998,6 +1028,9 @@ class GnuCompiler:
     def get_instruction_set_args(self, instruction_set):
         return gnulike_instruction_set_args.get(instruction_set, None)
 
+    def get_default_include_dirs(self):
+        return gnulike_default_include_dirs(self.exelist, self.language)
+
 
 class ClangCompiler:
     def __init__(self, clang_type):
@@ -1082,6 +1115,9 @@ class ClangCompiler:
     def get_instruction_set_args(self, instruction_set):
         return gnulike_instruction_set_args.get(instruction_set, None)
 
+    def get_default_include_dirs(self):
+        return gnulike_default_include_dirs(self.exelist, self.language)
+
 
 # Tested on linux for ICC 14.0.3, 15.0.6, 16.0.4, 17.0.1
 class IntelCompiler:
@@ -1132,3 +1168,6 @@ class IntelCompiler:
         # if self.icc_type == ICC_OSX:
         #     return ['-bundle']
         return ['-shared']
+
+    def get_default_include_dirs(self):
+        return gnulike_default_include_dirs(self.exelist, self.language)

mesonbuild/dependencies/misc.py

@@ -116,18 +116,7 @@ class BoostDependency(ExternalDependency):
         # and http://stackoverflow.com/questions/37218953/isystem-on-a-system-include-directory-causes-errors
         # for more details
 
-        # TODO: The correct solution would probably be to ask the
-        # compiler for it's default include paths (ie: "gcc -xc++ -E
-        # -v -") and avoid including those with -isystem
-
-        # For now, use -isystem for all includes except for some
-        # typical defaults (which don't need to be included at all
-        # since they are in the default include paths). These typical
-        # defaults include the usual directories at the root of the
-        # filesystem, but also any path that ends with those directory
-        # names in order to handle cases like cross-compiling where we
-        # might have a different sysroot.
-        if not include_dir.endswith(('/usr/include', '/usr/local/include')):
+        if include_dir and include_dir not in self.compiler.get_default_include_dirs():
             args.append("".join(self.compiler.get_include_args(include_dir, True)))
         return args