CppTools: Do not use PCH when build PCH artifacts exist closeby

Clang cannot handle gcc pch files which are close to the forced
include header.

Fixes: QTCREATORBUG-22888
Change-Id: I0d678a889d1fb62bf3c6850277e13271efb91eea
Reviewed-by: Nikolai Kosjar <nikolai.kosjar@qt.io>

2 files changed, 21 insertions, 4 deletions

diff --git a/src/plugins/cpptools/compileroptionsbuilder.cpp b/src/plugins/cpptools/compileroptionsbuilder.cpp
index e2858fb368..109613d2c0 100644
--- a/src/plugins/cpptools/compileroptionsbuilder.cpp
+++ b/src/plugins/cpptools/compileroptionsbuilder.cpp
@@ -172,6 +172,14 @@ void CompilerOptionsBuilder::addSyntaxOnly()
     isClStyle() ? add("/Zs") : add("-fsyntax-only");
 }
 
+void CompilerOptionsBuilder::remove(const QStringList &args)
+{
+    auto foundPos = std::search(m_options.begin(), m_options.end(),
+                                args.begin(), args.end());
+    if (foundPos != m_options.end())
+        m_options.erase(foundPos, std::next(foundPos, args.size()));
+}
+
 QStringList createLanguageOptionGcc(ProjectFile::Kind fileKind, bool objcExt)
 {
     QStringList options;
@@ -320,11 +328,18 @@ void CompilerOptionsBuilder::addHeaderPathOptions()
 
 void CompilerOptionsBuilder::addPrecompiledHeaderOptions(UsePrecompiledHeaders usePrecompiledHeaders)
 {
-    if (usePrecompiledHeaders == UsePrecompiledHeaders::No)
-        return;
-
     for (const QString &pchFile : m_projectPart.precompiledHeaders) {
-        if (QFile::exists(pchFile)) {
+        // Bail if build system precomiple header artifacts exists
+        // Clang cannot handle foreign PCH files.
+        if (QFile::exists(pchFile + ".gch") || QFile::exists(pchFile + ".pch"))
+            usePrecompiledHeaders = UsePrecompiledHeaders::No;
+
+        if (usePrecompiledHeaders == UsePrecompiledHeaders::No) {
+            // CMake PCH will already have force included the header file in
+            // command line options, remove it if exists.
+            remove({isClStyle() ? QLatin1String(includeFileOptionCl)
+                                : QLatin1String(includeFileOptionGcc), pchFile});
+        } else if (QFile::exists(pchFile)) {
             add({isClStyle() ? QLatin1String(includeFileOptionCl)
                              : QLatin1String(includeFileOptionGcc),
                  QDir::toNativeSeparators(pchFile)});
diff --git a/src/plugins/cpptools/compileroptionsbuilder.h b/src/plugins/cpptools/compileroptionsbuilder.h
index 349279710a..5b7c682407 100644
--- a/src/plugins/cpptools/compileroptionsbuilder.h
+++ b/src/plugins/cpptools/compileroptionsbuilder.h
@@ -85,6 +85,8 @@ public:
     void add(const QStringList &args, bool gccOnlyOptions = false);
     virtual void addExtraOptions() {}
 
+    void remove(const QStringList &args);
+
     static UseToolchainMacros useToolChainMacros();
     void reset();