Add functions to derive standard libs from compilation

Pass CompilerInstance directly to InitGlobals to give it access to the
entire compilation state.

No functional change.

3 files changed, 26 insertions, 15 deletions

diff --git a/iwyu.cc b/iwyu.cc
index b437553..de67fa7 100644
--- a/iwyu.cc
+++ b/iwyu.cc
@@ -4299,8 +4299,7 @@ class IwyuAction : public ASTFrontendAction {
       CompilerInstance& compiler,  // NOLINT
       llvm::StringRef /* dummy */) override {
     // Do this first thing after getting our hands on a CompilerInstance.
-    InitGlobals(&compiler.getSourceManager(),
-                &compiler.getPreprocessor().getHeaderSearchInfo());
+    InitGlobals(compiler);
 
     auto* const preprocessor_consumer = new IwyuPreprocessorInfo();
     compiler.getPreprocessor().addPPCallbacks(
diff --git a/iwyu_globals.cc b/iwyu_globals.cc
index b43a480..8f71160 100644
--- a/iwyu_globals.cc
+++ b/iwyu_globals.cc
@@ -33,7 +33,9 @@
 #include "clang/AST/PrettyPrinter.h"
 #include "clang/Basic/FileManager.h"
 #include "clang/Basic/Version.h"
+#include "clang/Frontend/CompilerInstance.h"
 #include "clang/Lex/HeaderSearch.h"
+#include "clang/Lex/Preprocessor.h"
 
 using clang::DirectoryEntry;
 using std::make_pair;
@@ -408,22 +410,30 @@ static vector<HeaderSearchPath> ComputeHeaderSearchPaths(
   return NormalizeHeaderSearchPaths(search_path_map);
 }
 
-void InitGlobals(clang::SourceManager* sm, clang::HeaderSearch* header_search) {
-  CHECK_(sm && "InitGlobals() needs a non-nullptr SourceManager");
-  source_manager = sm;
+static CStdLib DeriveCStdLib(clang::CompilerInstance&) {
+  if (GlobalFlags().no_default_mappings)
+    return CStdLib::None;
+  return CStdLib::Glibc;
+}
+
+static CXXStdLib DeriveCXXStdLib(clang::CompilerInstance&) {
+  if (GlobalFlags().no_default_mappings)
+    return CXXStdLib::None;
+  return CXXStdLib::Libstdcxx;
+}
+
+void InitGlobals(clang::CompilerInstance& compiler) {
+  source_manager = &compiler.getSourceManager();
   data_getter = new SourceManagerCharacterDataGetter(*source_manager);
-  vector<HeaderSearchPath> search_paths =
-      ComputeHeaderSearchPaths(header_search);
+  vector<HeaderSearchPath> search_paths = ComputeHeaderSearchPaths(
+      &compiler.getPreprocessor().getHeaderSearchInfo());
   SetHeaderSearchPaths(search_paths);
-  CStdLib cstdlib = CStdLib::Glibc;
-  CXXStdLib cxxstdlib = CXXStdLib::Libstdcxx;
-  if (GlobalFlags().no_default_mappings) {
-    cstdlib = CStdLib::None;
-    cxxstdlib = CXXStdLib::None;
-  }
 
-  include_picker =
-      new IncludePicker(GlobalFlags().regex_dialect, cstdlib, cxxstdlib);
+  RegexDialect regex_dialect = GlobalFlags().regex_dialect;
+  CStdLib cstdlib = DeriveCStdLib(compiler);
+  CXXStdLib cxxstdlib = DeriveCXXStdLib(compiler);
+  include_picker = new IncludePicker(regex_dialect, cstdlib, cxxstdlib);
+
   function_calls_full_use_cache = new FullUseCache;
   class_members_full_use_cache = new FullUseCache;
 
diff --git a/iwyu_globals.h b/iwyu_globals.h
index 84b613f..23b6b2f 100644
--- a/iwyu_globals.h
+++ b/iwyu_globals.h
@@ -16,6 +16,7 @@
 #include <vector>                       // for vector
 
 namespace clang {
+class CompilerInstance;
 class FileEntry;
 class HeaderSearch;
 class SourceManager;
@@ -56,6 +57,7 @@ class OptionsParser {
 };
 
 void InitGlobals(clang::SourceManager* sm, clang::HeaderSearch* header_search);
+void InitGlobals(clang::CompilerInstance& compiler);
 
 // Can be called by tests -- doesn't need a SourceManager or
 // argc/argv.  Note that GlobalSourceManager() and DefaultDataGetter()