Make it possible for AST plugins to enable themselves by default

Currently when an AST plugin is loaded it must then be enabled by passing
-plugin pluginname or -add-plugin pluginname to the -cc1 command line. This
patch adds a method to PluginASTAction which allows it to declare that the
action happens before, instead of, or after the main AST action, plus the
relevant changes to make the plugin action happen at that time automatically.

Differential Revision: http://reviews.llvm.org/D17959

llvm-svn: 263546

1 files changed, 15 insertions, 1 deletions

diff --git a/clang/lib/FrontendTool/ExecuteCompilerInvocation.cpp b/clang/lib/FrontendTool/ExecuteCompilerInvocation.cpp
index 116590e5375..509c326d159 100644
--- a/clang/lib/FrontendTool/ExecuteCompilerInvocation.cpp
+++ b/clang/lib/FrontendTool/ExecuteCompilerInvocation.cpp
@@ -66,7 +66,9 @@ CreateFrontendBaseAction(CompilerInstance &CI) {
          it != ie; ++it) {
       if (it->getName() == CI.getFrontendOpts().ActionName) {
         std::unique_ptr<PluginASTAction> P(it->instantiate());
-        if (!P->ParseArgs(CI, CI.getFrontendOpts().PluginArgs))
+        if ((P->getActionType() != PluginASTAction::ReplaceAction &&
+             P->getActionType() != PluginASTAction::Cmdline) ||
+            !P->ParseArgs(CI, CI.getFrontendOpts().PluginArgs[it->getName()]))
           return nullptr;
         return std::move(P);
       }
@@ -194,6 +196,18 @@ bool clang::ExecuteCompilerInvocation(CompilerInstance *Clang) {
         << Path << Error;
   }
 
+  // Check if any of the loaded plugins replaces the main AST action
+  for (FrontendPluginRegistry::iterator it = FrontendPluginRegistry::begin(),
+                                        ie = FrontendPluginRegistry::end();
+       it != ie; ++it) {
+    std::unique_ptr<PluginASTAction> P(it->instantiate());
+    if (P->getActionType() == PluginASTAction::ReplaceAction) {
+      Clang->getFrontendOpts().ProgramAction = clang::frontend::PluginAction;
+      Clang->getFrontendOpts().ActionName = it->getName();
+      break;
+    }
+  }
+
   // Honor -mllvm.
   //
   // FIXME: Remove this, one day.