try to autodetect flags needed to build Clang plugins

Instead of having a lot of it hardcoded, which brings problems like:
- Clang-to-be-10 has switched to -std=c++14, so our hardcoded c++11
makes the build fail
- I cannot compile with my openSUSE-shipped clang, because it ships
only libclang-cpp and not the other libClangSomething libs
The possibility to explicitly set the necessary variables is still there.

Change-Id: I58d401d4584fa064f1c1351a8a06ff4e29643063
Reviewed-on: https://gerrit.libreoffice.org/80300
Tested-by: Jenkins
Reviewed-by: Luboš Luňák <l.lunak@collabora.com>

1 files changed, 8 insertions, 9 deletions

diff --git a/compilerplugins/clang/sharedvisitor/analyzer.cxx b/compilerplugins/clang/sharedvisitor/analyzer.cxx
index 5b716f407fd4..4d8e2b2bb763 100644
--- a/compilerplugins/clang/sharedvisitor/analyzer.cxx
+++ b/compilerplugins/clang/sharedvisitor/analyzer.cxx
@@ -12,6 +12,7 @@
 #include "clang/Frontend/CompilerInstance.h"
 #include "clang/Frontend/FrontendAction.h"
 #include "clang/Tooling/Tooling.h"
+#include "llvm/ADT/StringExtras.h"
 
 #include <cstddef>
 #include <cstring>
@@ -27,6 +28,7 @@
 using namespace std;
 
 using namespace clang;
+using namespace llvm;
 
 using namespace loplugin;
 
@@ -241,16 +243,13 @@ int main(int argc, char** argv)
     }
 #define STRINGIFY2(a) #a
 #define STRINGIFY(a) STRINGIFY2(a)
+    SmallVector< StringRef, 20 > clangflags;
+    SplitString( STRINGIFY(CLANGFLAGS), clangflags );
+    args.insert( args.end(), clangflags.begin(), clangflags.end());
     args.insert(
         args.end(),
         {   // These must match LO_CLANG_ANALYZER_PCH_CXXFLAGS in Makefile-clang.mk .
-            "-I" BUILDDIR "/config_host", // plugin sources use e.g. config_global.h
-            "-I" STRINGIFY(CLANGDIR) "/include", // clang's headers
-            "-I" STRINGIFY(CLANGSYSINCLUDE), // clang system headers
-            STDOPTION,
-            "-D__STDC_CONSTANT_MACROS", // Clang headers require these.
-            "-D__STDC_FORMAT_MACROS",
-            "-D__STDC_LIMIT_MACROS"
+            "-I" BUILDDIR "/config_host" // plugin sources use e.g. config_global.h
 #ifdef LO_CLANG_USE_ANALYZER_PCH
             ,
             "-include-pch", // use PCH with Clang headers to speed up parsing/analysing
@@ -264,9 +263,9 @@ int main(int argc, char** argv)
             continue;
         foundSomething = false;
 #if CLANG_VERSION >= 100000
-        if( !clang::tooling::runToolOnCodeWithArgs( std::unique_ptr<FindNamedClassAction>(new FindNamedClassAction), contents, args, argv[ i ] ))
+        if( !tooling::runToolOnCodeWithArgs( std::unique_ptr<FindNamedClassAction>(new FindNamedClassAction), contents, args, argv[ i ] ))
 #else
-        if( !clang::tooling::runToolOnCodeWithArgs( new FindNamedClassAction, contents, args, argv[ i ] ))
+        if( !tooling::runToolOnCodeWithArgs( new FindNamedClassAction, contents, args, argv[ i ] ))
 #endif
         {
             cerr << "Failed to analyze: " << argv[ i ] << endl;