[clang][ExtractAPI] Add --emit-symbol-graph option

Add new --emit-symbol-graph=<DIR> option which generates ExtractAPI symbol
graph information of .c/.m files on regular compilation job and put them in
the provided "DIR" directory.

Reviewed By: dang

Differential Revision: https://reviews.llvm.org/D152356

1 files changed, 8 insertions, 0 deletions

diff --git a/clang/lib/FrontendTool/ExecuteCompilerInvocation.cpp b/clang/lib/FrontendTool/ExecuteCompilerInvocation.cpp
index 47157ca..310f677 100644
--- a/clang/lib/FrontendTool/ExecuteCompilerInvocation.cpp
+++ b/clang/lib/FrontendTool/ExecuteCompilerInvocation.cpp
@@ -178,6 +178,14 @@ CreateFrontendAction(CompilerInstance &CI) {
   }
 #endif
 
+  // Wrap the base FE action in an extract api action to generate
+  // symbol graph as a biproduct of comilation ( enabled with
+  // --emit-symbol-graph option )
+  if (!FEOpts.SymbolGraphOutputDir.empty()) {
+    CI.getCodeGenOpts().ClearASTBeforeBackend = false;
+    Act = std::make_unique<WrappingExtractAPIAction>(std::move(Act));
+  }
+
   // If there are any AST files to merge, create a frontend action
   // adaptor to perform the merge.
   if (!FEOpts.ASTMergeFiles.empty())