<rdar://problem/13509689> Introduce -module-file-info option that provides information about a particular module file.

This option can be useful for end users who want to know why they
ended up with a ton of different variants of the "std" module in their
module cache. This problem should go away over time, as we reduce the
need for module variants, but it will never go away entirely.

llvm-svn: 178148

1 files changed, 125 insertions, 0 deletions

diff --git a/clang/lib/Frontend/FrontendActions.cpp b/clang/lib/Frontend/FrontendActions.cpp
index f3466f02342..5c7567fa8c0 100644
--- a/clang/lib/Frontend/FrontendActions.cpp
+++ b/clang/lib/Frontend/FrontendActions.cpp
@@ -19,6 +19,7 @@
 #include "clang/Lex/Pragma.h"
 #include "clang/Lex/Preprocessor.h"
 #include "clang/Parse/Parser.h"
+#include "clang/Serialization/ASTReader.h"
 #include "clang/Serialization/ASTWriter.h"
 #include "llvm/ADT/OwningPtr.h"
 #include "llvm/Support/FileSystem.h"
@@ -316,6 +317,130 @@ ASTConsumer *SyntaxOnlyAction::CreateASTConsumer(CompilerInstance &CI,
   return new ASTConsumer();
 }
 
+ASTConsumer *DumpModuleInfoAction::CreateASTConsumer(CompilerInstance &CI,
+                                                     StringRef InFile) {
+  return new ASTConsumer();
+}
+
+namespace {
+  /// \brief AST reader listener that dumps module information for a module
+  /// file.
+  class DumpModuleInfoListener : public ASTReaderListener {
+    llvm::raw_ostream &Out;
+
+  public:
+    DumpModuleInfoListener(llvm::raw_ostream &Out) : Out(Out) { }
+
+#define DUMP_BOOLEAN(Value, Text)                       \
+    Out.indent(4) << Text << ": " << (Value? "Yes" : "No") << "\n"
+
+    virtual bool ReadFullVersionInformation(StringRef FullVersion) {
+      Out.indent(2)
+        << "Generated by "
+        << (FullVersion == getClangFullRepositoryVersion()? "this"
+                                                          : "a different")
+        << " Clang: " << FullVersion << "\n";
+      return ASTReaderListener::ReadFullVersionInformation(FullVersion);
+    }
+
+    virtual bool ReadLanguageOptions(const LangOptions &LangOpts,
+                                     bool Complain) {
+      Out.indent(2) << "Language options:\n";
+#define LANGOPT(Name, Bits, Default, Description) \
+      DUMP_BOOLEAN(LangOpts.Name, Description);
+#define ENUM_LANGOPT(Name, Type, Bits, Default, Description) \
+      Out.indent(4) << Description << ": "                   \
+                    << static_cast<unsigned>(LangOpts.get##Name()) << "\n";
+#define VALUE_LANGOPT(Name, Bits, Default, Description) \
+      Out.indent(4) << Description << ": " << LangOpts.Name << "\n";
+#define BENIGN_LANGOPT(Name, Bits, Default, Description)
+#define BENIGN_ENUM_LANGOPT(Name, Type, Bits, Default, Description)
+#include "clang/Basic/LangOptions.def"
+      return false;
+    }
+
+    virtual bool ReadTargetOptions(const TargetOptions &TargetOpts,
+                                   bool Complain) {
+      Out.indent(2) << "Target options:\n";
+      Out.indent(4) << "  Triple: " << TargetOpts.Triple << "\n";
+      Out.indent(4) << "  CPU: " << TargetOpts.CPU << "\n";
+      Out.indent(4) << "  ABI: " << TargetOpts.ABI << "\n";
+      Out.indent(4) << "  C++ ABI: " << TargetOpts.CXXABI << "\n";
+      Out.indent(4) << "  Linker version: " << TargetOpts.LinkerVersion << "\n";
+
+      if (!TargetOpts.FeaturesAsWritten.empty()) {
+        Out.indent(4) << "Target features:\n";
+        for (unsigned I = 0, N = TargetOpts.FeaturesAsWritten.size();
+             I != N; ++I) {
+          Out.indent(6) << TargetOpts.FeaturesAsWritten[I] << "\n";
+        }
+      }
+
+      return false;
+    }
+
+    virtual bool ReadHeaderSearchOptions(const HeaderSearchOptions &HSOpts,
+                                         bool Complain) {
+      Out.indent(2) << "Header search options:\n";
+      Out.indent(4) << "System root [-isysroot=]: '" << HSOpts.Sysroot << "'\n";
+      DUMP_BOOLEAN(HSOpts.UseBuiltinIncludes,
+                   "Use builtin include directories [-nobuiltininc]");
+      DUMP_BOOLEAN(HSOpts.UseStandardSystemIncludes,
+                   "Use standard system include directories [-nostdinc]");
+      DUMP_BOOLEAN(HSOpts.UseStandardCXXIncludes,
+                   "Use standard C++ include directories [-nostdinc++]");
+      DUMP_BOOLEAN(HSOpts.UseLibcxx,
+                   "Use libc++ (rather than libstdc++) [-stdlib=]");
+      return false;
+    }
+
+    virtual bool ReadPreprocessorOptions(const PreprocessorOptions &PPOpts,
+                                         bool Complain,
+                                         std::string &SuggestedPredefines) {
+      Out.indent(2) << "Preprocessor options:\n";
+      DUMP_BOOLEAN(PPOpts.UsePredefines,
+                   "Uses compiler/target-specific predefines [-undef]");
+      DUMP_BOOLEAN(PPOpts.DetailedRecord,
+                   "Uses detailed preprocessing record (for indexing)");
+
+      if (!PPOpts.Macros.empty()) {
+        Out.indent(4) << "Predefined macros:\n";
+      }
+
+      for (std::vector<std::pair<std::string, bool/*isUndef*/> >::const_iterator
+             I = PPOpts.Macros.begin(), IEnd = PPOpts.Macros.end();
+           I != IEnd; ++I) {
+        Out.indent(6);
+        if (I->second)
+          Out << "-U";
+        else
+          Out << "-D";
+        Out << I->first << "\n";
+      }
+      return false;
+    }
+#undef DUMP_BOOLEAN
+  };
+}
+
+void DumpModuleInfoAction::ExecuteAction() {
+  // Set up the output file.
+  llvm::OwningPtr<llvm::raw_fd_ostream> OutFile;
+  StringRef OutputFileName = getCompilerInstance().getFrontendOpts().OutputFile;
+  if (!OutputFileName.empty() && OutputFileName != "-") {
+    std::string ErrorInfo;
+    OutFile.reset(new llvm::raw_fd_ostream(OutputFileName.str().c_str(),
+                                           ErrorInfo));
+  }
+  llvm::raw_ostream &Out = OutFile.get()? *OutFile.get() : llvm::outs();
+
+  Out << "Information for module file '" << getCurrentFile() << "':\n";
+  DumpModuleInfoListener Listener(Out);
+  ASTReader::readASTFileControlBlock(getCurrentFile(),
+                                     getCompilerInstance().getFileManager(),
+                                     Listener);
+}
+
 //===----------------------------------------------------------------------===//
 // Preprocessor Actions
 //===----------------------------------------------------------------------===//