CppTools: Make code model on "cl" mode more robust

Unknown command line options starting with / are now transformed
into commands starting with -, which will cause unknown commands
warnings in libclang.

The / commands cause errors because they are treated as missing
files.

Fixes: QTCREATORBUG-22871
Change-Id: I75f7878ab6a7951df24c954ccff1c298ea65f839
Reviewed-by: Nikolai Kosjar <nikolai.kosjar@qt.io>

1 files changed, 9 insertions, 0 deletions

diff --git a/src/plugins/cpptools/compileroptionsbuilder.cpp b/src/plugins/cpptools/compileroptionsbuilder.cpp
index 109613d2c0..7fde0b3a57 100644
--- a/src/plugins/cpptools/compileroptionsbuilder.cpp
+++ b/src/plugins/cpptools/compileroptionsbuilder.cpp
@@ -792,6 +792,15 @@ void CompilerOptionsBuilder::evaluateCompilerFlags()
             containsDriverMode = true;
         }
 
+        // Transfrom the "/" starting commands into "-" commands, which if
+        // unknown will not cause clang to fail because it thinks
+        // it's a missing file.
+        if (theOption.startsWith("/") &&
+            (toolChain == ProjectExplorer::Constants::MSVC_TOOLCHAIN_TYPEID ||
+             toolChain == ProjectExplorer::Constants::CLANG_CL_TOOLCHAIN_TYPEID)) {
+            theOption[0] = '-';
+        }
+
         m_compilerFlags.flags.append(theOption);
     }