Better detection for libclang and its builtin header path

radio/util/find_clang.py

@@ -0,0 +1,116 @@
+#
+# Most of this code is from clang_complete:
+# https://github.com/xavierd/clang_complete/blob/master/plugin/libclang.py
+#
+import os
+import sys
+from clang.cindex import *
+
+# Check if libclang is able to find the builtin include files.
+#
+# libclang sometimes fails to correctly locate its builtin include files. This
+# happens especially if libclang is not installed at a standard location. This
+# function checks if the builtin includes are available.
+def canFindBuiltinHeaders(index, args = []):
+    flags = 0
+    currentFile = ("test.c", '#include "stddef.h"')
+    try:
+        tu = index.parse("test.c", args, [currentFile], flags)
+    except TranslationUnitLoadError as e:
+        return 0
+
+    return len(tu.diagnostics) == 0
+
+# Derive path to clang builtin headers.
+#
+# This function tries to derive a path to clang's builtin header files. We are
+# just guessing, but the guess is very educated. In fact, we should be right
+# for all manual installations (the ones where the builtin header path problem
+# is very common) as well as a set of very common distributions.
+def getBuiltinHeaderPath(library_path):
+    if os.path.isfile(library_path):
+        library_path = os.path.dirname(library_path)
+
+    knownPaths = [
+        library_path + "/../lib/clang",  # default value
+        library_path + "/../clang",      # gentoo
+        library_path + "/clang",         # opensuse
+        library_path + "/",              # Google
+        "/usr/lib64/clang",              # x86_64 (openSUSE, Fedora)
+        "/usr/lib/clang"
+    ]
+
+    for path in knownPaths:
+        try:
+            subDirs = [f for f in os.listdir(path) if os.path.isdir(path + "/" + f)]
+            subDirs = sorted(subDirs) or ['.']
+            path = path + "/" + subDirs[-1] + "/include"
+            print("searching builtins in " + path)
+            if canFindBuiltinHeaders(index, ["-I" + path]):
+                return path
+        except:
+            pass
+
+    return None
+
+def findLibClang():
+    if sys.platform == "darwin":
+        knownPaths = [
+            "/usr/local/Cellar/llvm/6.0.0/lib",
+            "/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/lib",
+            "/Library/Developer/CommandLineTools/usr/lib"
+        ]
+        libSuffix = ".dylib"
+    elif sys.platform.startswith("linux"):
+        knownPaths = [
+            "/usr/lib/llvm-7/lib",
+            "/usr/lib/llvm-6.0/lib",
+            "/usr/lib/llvm-3.8/lib",
+            "/usr/local/lib",
+            "/usr/lib"
+        ]
+        libSuffix = ".so"
+    elif sys.platform == "win32" or sys.platform == "msys":
+        knownPaths = os.environ.get("PATH").split(':')
+        libSuffix = ".dll"
+    else:
+        # Unsupported platform
+        return None
+        
+    for path in knownPaths:
+        # print("trying " + path)
+        if os.path.exists(path + "/libclang" + libSuffix):
+            return path
+
+    return None
+
+def initLibClang():
+    global index
+
+    library_path = findLibClang()
+    if library_path:
+        print("libclang found: " + library_path)
+        if os.path.isdir(library_path):
+            Config.set_library_path(library_path)
+        else:
+            Config.set_library_file(library_path)
+    else:
+        print("ERROR: libclang not found!")
+        return False
+
+    Config.set_compatibility_check(False)
+    
+    try:
+        index = Index.create()
+    except Exception as e:
+        print("ERROR: could not load libclang from '%s'." % library_path)
+        return False
+
+    global builtin_hdr_path
+    builtin_hdr_path = getBuiltinHeaderPath(library_path)
+    if not builtin_hdr_path:
+        print("ERROR: builtin header path not found")
+        return False
+
+    # Everything is OK, libclang can be used
+    return True

radio/util/generate_datacopy.py

@@ -1,5 +1,6 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
+import find_clang
 import sys
 import clang.cindex
 import time
@@ -9,25 +10,6 @@ import os
 structs = []
 extrastructs = []
 
-
-def find_libclang():
-    if sys.platform == "darwin":
-        for path in ("/usr/local/Cellar/llvm/6.0.0/lib/libclang.dylib",
-                     "/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/lib/libclang.dylib",
-                     "/Library/Developer/CommandLineTools/usr/lib/libclang.dylib"):
-            if os.path.exists(path):
-                return path
-    elif sys.platform.startswith("linux"):
-        for version in ("7", "6.0", "3.8"):
-            path = "/usr/lib/llvm-%s/lib/libclang.so" % version
-            if os.path.exists(path):
-                return path
-        for path in ("/usr/local/lib/libclang.so",
-                     "/usr/lib/libclang.so"):
-            if os.path.exists(path):
-                return path
-
-
 def build_struct(cursor, anonymousUnion=False):
     if not anonymousUnion:
         structs.append(cursor.spelling)
@@ -108,13 +90,16 @@ def print_translation_unit_diags(diags, prefix=''):
 
 
 def main():
-    libclang = find_libclang()
-    if libclang:
-        # print(libclang, file=sys.stderr)
-        clang.cindex.Config.set_library_file(libclang)
 
-    index = clang.cindex.Index.create()
-    translation_unit = index.parse(sys.argv[1], ['-x', 'c++', '-std=c++11'] + sys.argv[2:])
+    if not find_clang.initLibClang():
+        sys.exit(-1)
+
+    index = find_clang.index
+    args = ['-x', 'c++', '-std=c++11'] + sys.argv[2:]
+    if find_clang.builtin_hdr_path:
+        args.append("-I" + find_clang.builtin_hdr_path)
+
+    translation_unit = index.parse(sys.argv[1], args)
 
     if translation_unit.diagnostics:
         print_translation_unit_diags(translation_unit.diagnostics)