CppTools: Fix code model for Clang builds

If you build Qt Creator with CMake version 3.16, you will have
precompile headers which will break code model.

Change-Id: I679936faed39ecfedb9ebb5fb553449a9f5ea29d
Reviewed-by: Nikolai Kosjar <nikolai.kosjar@qt.io>

1 files changed, 6 insertions, 1 deletions

diff --git a/src/plugins/cpptools/compileroptionsbuilder.cpp b/src/plugins/cpptools/compileroptionsbuilder.cpp
index aafcd35b37..ee534757ea 100644
--- a/src/plugins/cpptools/compileroptionsbuilder.cpp
+++ b/src/plugins/cpptools/compileroptionsbuilder.cpp
@@ -329,9 +329,14 @@ void CompilerOptionsBuilder::addPrecompiledHeaderOptions(UsePrecompiledHeaders u
     for (const QString &pchFile : m_projectPart.precompiledHeaders) {
         // Bail if build system precomiple header artifacts exists
         // Clang cannot handle foreign PCH files.
-        if (QFile::exists(pchFile + ".gch") || QFile::exists(pchFile + ".pch"))
+        if (QFile::exists(pchFile + ".gch") || QFile::exists(pchFile + ".pch")) {
             usePrecompiledHeaders = UsePrecompiledHeaders::No;
 
+            // In case of Clang compilers, remove the pch-inclusion arguments
+            remove({"-Xclang", "-include-pch", "-Xclang", pchFile + ".gch"});
+            remove({"-Xclang", "-include-pch", "-Xclang", pchFile + ".pch"});
+        }
+
         if (usePrecompiledHeaders == UsePrecompiledHeaders::No) {
             // CMake PCH will already have force included the header file in
             // command line options, remove it if exists.