Clang: tune include paths used by clang

Do not search the standard system directories for include files, but do
search compiler builtin include directories. To make sure that the
include files for intrinsics are the ones clang can parse, put that
path first on the command-line.

Change-Id: I2ada992b58203d1c3dbd55851c5f195c12572943
Reviewed-by: Eike Ziller <eike.ziller@digia.com>

src/plugins/clangcodemodel/clang_installation.pri

@@ -1,4 +1,5 @@
 isEmpty(LLVM_INSTALL_DIR):LLVM_INSTALL_DIR=$$(LLVM_INSTALL_DIR)
+LLVM_INSTALL_DIR ~= s,\\\\,/,g
 
 DEFINES += CLANG_COMPLETION
 DEFINES += CLANG_HIGHLIGHTING
@@ -50,16 +51,22 @@ win32 {
             error("Cannot find Clang shared library!")
         }
     }
+    LLVM_LIBDIR = $$LLVM_INSTALL_DIR/lib
     LLVM_LIBS = \
         -L$$LLVM_INSTALL_DIR/bin \
-        -L$$LLVM_INSTALL_DIR/lib \
+        -L$$LLVM_LIBDIR \
         -l$${CLANG_LIB}
     LLVM_LIBS += -ladvapi32 -lshell32
+    LLVM_VERSION = 3.4
 }
 
 unix {
     LLVM_CONFIG = $$findLLVMConfig()
 
+    LLVM_VERSION = $$system($$LLVM_CONFIG --version)
+    LLVM_VERSION = $$replace(LLVM_VERSION, ^(\\d+\\.\\d+).*$, \\1)
+    message("... version $$LLVM_VERSION");
+
     LLVM_INCLUDEPATH = $$system($$LLVM_CONFIG --includedir)
     isEmpty(LLVM_INCLUDEPATH):LLVM_INCLUDEPATH=$$LLVM_INSTALL_DIR/include
     LLVM_LIBDIR = $$system($$LLVM_CONFIG --libdir)
@@ -87,3 +94,6 @@ unix {
     LLVM_LIBS = -L$${LLVM_LIBDIR}
     LLVM_LIBS += -l$${CLANG_LIB}
 }
+
+DEFINES += CLANG_VERSION=\\\"$${LLVM_VERSION}\\\"
+DEFINES += "\"CLANG_RESOURCE_DIR=\\\"$${LLVM_LIBDIR}/clang/$${LLVM_VERSION}/include\\\"\""

src/plugins/clangcodemodel/clangutils.cpp

@@ -35,6 +35,7 @@
 #include <coreplugin/icore.h>
 #include <coreplugin/idocument.h>
 
+#include <QDir>
 #include <QFile>
 #include <QSet>
 #include <QString>
@@ -44,6 +45,8 @@ using namespace ClangCodeModel::Internal;
 using namespace Core;
 using namespace CppTools;
 
+static const bool BeVerbose = !qgetenv("QTC_CLANG_VERBOSE").isEmpty();
+
 namespace ClangCodeModel {
 namespace Utils {
 
@@ -110,6 +113,7 @@ static QStringList buildDefines(const QByteArray &defines, bool toolchainDefines
         if (def.isEmpty())
             continue;
 
+        // TODO: verify if we can pass compiler-defined macros when also passing -undef.
         if (toolchainDefines) {
             //### FIXME: the next 3 check shouldn't be needed: we probably don't want to get the compiler-defined defines in.
             if (!def.startsWith("#define "))
@@ -137,6 +141,15 @@ static QStringList buildDefines(const QByteArray &defines, bool toolchainDefines
     return result;
 }
 
+static QString getResourceDir()
+{
+    QDir dir(Core::ICore::instance()->resourcePath() + QLatin1String("/cplusplus/clang/") +
+             QLatin1String(CLANG_VERSION) + QLatin1String("/include"));
+    if (!dir.exists() || !QFileInfo(dir, QLatin1String("stdint.h")).exists())
+        dir = QDir(QLatin1String(CLANG_RESOURCE_DIR));
+    return dir.canonicalPath();
+}
+
 /**
  * @brief Creates list of command-line arguments required for correct parsing
  * @param pPart Null if file isn't part of any project
@@ -169,9 +182,23 @@ QStringList createClangOptions(const ProjectPart::Ptr &pPart, ProjectFile::Kind
     if (pPart.isNull())
         return result;
 
-    result << QLatin1String("-nostdinc");
+    static const QString resourceDir = getResourceDir();
 
-    result << buildDefines(pPart->toolchainDefines, true);
+    if (BeVerbose)
+        result << QLatin1String("-v");
+
+    if (!resourceDir.isEmpty()) {
+        result << QLatin1String("-nostdlibinc");
+        result << (QLatin1String("-I") + resourceDir);
+        result << QLatin1String("-undef");
+    }
+
+    result << QLatin1String("-fmessage-length=0");
+    result << QLatin1String("-fdiagnostics-show-note-include-stack");
+    result << QLatin1String("-fmacro-backtrace-limit=0");
+    result << QLatin1String("-fretain-comments-from-system-headers");
+
+    result << buildDefines(pPart->toolchainDefines, false);
     result << buildDefines(pPart->projectDefines, false);
 
     foreach (const QString &frameworkPath, pPart->frameworkPaths)