Add pluggable action support to clang-cc, via -plugin command line option.

- Expects the plugin has been loaded with -load.

 - Using this may require disabling TOOL_NO_EXPORTS in the clang-cc Makefile, this breaks the llvm::Registry way of working (static constructors are bad, kids). This should be replaced with a "real" plugin model that has explicit plugin interfaces.

llvm-svn: 88824

clang/include/clang/Basic/DiagnosticFrontendKinds.td

@@ -28,6 +28,8 @@ def err_fe_no_fixit_and_codegen : Error<
     "FIX-ITs cannot be applied when generating code">;
 def err_fe_unable_to_find_fixit_file : Error<
     "FIX-IT could not find file '%0'">;
+def err_fe_invalid_plugin_name : Error<
+    "unable to find plugin '%0'">;
 
 def err_verify_bogus_characters : Error<
     "bogus characters before '{{' in expected string">;

clang/include/clang/Frontend/FrontendOptions.h

@@ -39,6 +39,7 @@ namespace frontend {
     ParseNoop,              ///< Parse with noop callbacks.
     ParsePrintCallbacks,    ///< Parse and print each callback.
     ParseSyntaxOnly,        ///< Parse and perform semantic analysis.
+    PluginAction,           ///< Run a plugin action, \see ActionName.
     PrintDeclContext,       ///< Print DeclContext and their Decls.
     PrintPreprocessedInput, ///< -E mode.
     RewriteBlocks,          ///< ObjC->C Rewriter for Blocks.
@@ -109,12 +110,16 @@ public:
   /// The frontend action to perform.
   frontend::ActionKind ProgramAction;
 
+  /// The name of the action to run when using a plugin action.
+  std::string ActionName;
+
 public:
   FrontendOptions() {
     DebugCodeCompletionPrinter = 0;
     DisableFree = 0;
     EmptyInputOnly = 0;
     ProgramAction = frontend::ParseSyntaxOnly;
+    ActionName = "";
     RelocatablePCH = 0;
     ShowMacrosInCodeCompletion = 0;
     ShowStats = 0;

clang/include/clang/Frontend/FrontendPluginRegistry.h

@@ -0,0 +1,23 @@
+//===-- FrontendAction.h - Pluggable Frontend Action Interface --*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_CLANG_FRONTEND_PLUGINFRONTENDACTION_H
+#define LLVM_CLANG_FRONTEND_PLUGINFRONTENDACTION_H
+
+#include "clang/Frontend/FrontendAction.h"
+#include "llvm/Support/Registry.h"
+
+namespace clang {
+
+/// The frontend plugin registry.
+typedef llvm::Registry<FrontendAction> FrontendPluginRegistry;
+
+} // end namespace clang
+
+#endif

clang/tools/clang-cc/Options.cpp

@@ -26,6 +26,7 @@
 #include "llvm/ADT/STLExtras.h"
 #include "llvm/ADT/StringMap.h"
 #include "llvm/Support/CommandLine.h"
+#include "llvm/Support/RegistryParser.h"
 #include <stdio.h>
 
 using namespace clang;
@@ -383,6 +384,11 @@ OutputFile("o",
  llvm::cl::value_desc("path"),
  llvm::cl::desc("Specify output file"));
 
+static llvm::cl::opt<std::string>
+PluginActionName("plugin",
+                 llvm::cl::desc("Use the named plugin action "
+                                "(use \"help\" to list available options)"));
+
 static llvm::cl::opt<ActionKind>
 ProgAction(llvm::cl::desc("Choose output type:"), llvm::cl::ZeroOrMore,
            llvm::cl::init(ParseSyntaxOnly),
@@ -885,12 +891,18 @@ void clang::InitializeDiagnosticOptions(DiagnosticOptions &Opts) {
 void clang::InitializeFrontendOptions(FrontendOptions &Opts) {
   using namespace frontendoptions;
 
+  // Select program action.
+  Opts.ProgramAction = ProgAction;
+  if (PluginActionName.getPosition()) {
+    Opts.ProgramAction = frontend::PluginAction;
+    Opts.ActionName = PluginActionName;
+  }
+
   Opts.CodeCompletionAt = CodeCompletionAt;
   Opts.DebugCodeCompletionPrinter = CodeCompletionDebugPrinter;
   Opts.DisableFree = DisableFree;
   Opts.EmptyInputOnly = EmptyInputOnly;
   Opts.FixItLocations = FixItAtLocations;
-  Opts.ProgramAction = ProgAction;
   Opts.OutputFile = OutputFile;
   Opts.RelocatablePCH = RelocatablePCH;
   Opts.ShowMacrosInCodeCompletion = CodeCompletionWantsMacros;

clang/tools/clang-cc/clang-cc.cpp

@@ -24,6 +24,7 @@
 #include "clang/Frontend/CompilerInvocation.h"
 #include "clang/Frontend/FrontendActions.h"
 #include "clang/Frontend/FrontendDiagnostic.h"
+#include "clang/Frontend/FrontendPluginRegistry.h"
 #include "clang/Frontend/PathDiagnosticClients.h"
 #include "clang/Frontend/PreprocessorOptions.h"
 #include "clang/Frontend/PreprocessorOutputOptions.h"
@@ -36,6 +37,7 @@
 #include "llvm/Support/ManagedStatic.h"
 #include "llvm/Support/PluginLoader.h"
 #include "llvm/Support/PrettyStackTrace.h"
+#include "llvm/Support/Registry.h"
 #include "llvm/Support/Timer.h"
 #include "llvm/Support/raw_ostream.h"
 #include "llvm/System/Host.h"
@@ -81,11 +83,13 @@ std::string GetBuiltinIncludePath(const char *Argv0) {
 /// anything.
 llvm::Timer *ClangFrontendTimer = 0;
 
-static FrontendAction *CreateFrontendAction(frontend::ActionKind AK) {
+static FrontendAction *CreateFrontendAction(CompilerInstance &CI) {
   using namespace clang::frontend;
 
-  switch (AK) {
-  default:                     return 0;
+  switch (CI.getFrontendOpts().ProgramAction) {
+  default:
+    llvm::llvm_unreachable("Invalid program action!");
+
   case ASTDump:                return new ASTDumpAction();
   case ASTPrint:               return new ASTPrintAction();
   case ASTPrintXML:            return new ASTPrintXMLAction();
@@ -105,6 +109,30 @@ static FrontendAction *CreateFrontendAction(frontend::ActionKind AK) {
   case ParseNoop:              return new ParseOnlyAction();
   case ParsePrintCallbacks:    return new PrintParseAction();
   case ParseSyntaxOnly:        return new SyntaxOnlyAction();
+
+  case PluginAction: {
+    if (CI.getFrontendOpts().ActionName == "help") {
+      llvm::errs() << "clang-cc plugins:\n";
+      for (FrontendPluginRegistry::iterator it =
+             FrontendPluginRegistry::begin(),
+             ie = FrontendPluginRegistry::end();
+           it != ie; ++it)
+        llvm::errs() << "  " << it->getName() << " - " << it->getDesc() << "\n";
+      exit(1);
+    }
+
+    for (FrontendPluginRegistry::iterator it =
+           FrontendPluginRegistry::begin(), ie = FrontendPluginRegistry::end();
+         it != ie; ++it) {
+      if (it->getName() == CI.getFrontendOpts().ActionName)
+        return it->instantiate();
+    }
+
+    CI.getDiagnostics().Report(diag::err_fe_invalid_plugin_name)
+      << CI.getFrontendOpts().ActionName;
+    return 0;
+  }
+
   case PrintDeclContext:       return new DeclContextPrintAction();
   case PrintPreprocessedInput: return new PrintPreprocessedAction();
   case RewriteBlocks:          return new RewriteBlocksAction();
@@ -279,9 +307,10 @@ int main(int argc, char **argv) {
       Clang.createPreprocessor();
     }
 
-    llvm::OwningPtr<FrontendAction> Act(
-      CreateFrontendAction(Clang.getFrontendOpts().ProgramAction));
-    assert(Act && "Invalid program action!");
+    llvm::OwningPtr<FrontendAction> Act(CreateFrontendAction(Clang));
+    if (!Act)
+      break;
+
     Act->setCurrentTimer(ClangFrontendTimer);
     if (Act->BeginSourceFile(Clang, InFile, IsAST)) {
       Act->Execute();
@@ -315,3 +344,4 @@ int main(int argc, char **argv) {
 
   return (Clang.getDiagnostics().getNumErrors() != 0);
 }
+