[llvm-branch-commits] [clang] [llvm] [RFC][LLVM][Clang] Add LLVM plugin hook for back-ends (PR #170846)

[Stefan Gränitz via llvm-branch-commits]

================
@@ -49,7 +53,14 @@ struct PassPluginLibraryInfo {
 
   /// The callback for registering plugin passes with a \c PassBuilder
   /// instance
-  void (*RegisterPassBuilderCallbacks)(PassBuilder &);
+  void (*RegisterPassBuilderCallbacks)(PassBuilder &) = nullptr;
+
+  /// Callback called before running the back-end passes on the module. The
+  /// callback can generate code itself by writing the expected output to OS and
+  /// returning true to prevent the default pipeline and further plugin
+  /// callbacks from running.
+  bool (*PreCodeGenCallback)(Module &, TargetMachine &, CodeGenFileType,
----------------
weliveindetail wrote:

I like the idea to have pre/post opt/codegen callbacks. If we ever get the new pass manager in the Codegen pipeline, that would help plugins to handle the pipeline change. Could we generalize this into something like `registerPipelinePhaseCallbacks()`?

https://github.com/llvm/llvm-project/pull/170846