[CIR][NFC] Add helpers for cir.try and do some refactoring

Author: bcardosolopes

clang/include/clang/CIR/Dialect/IR/CIROps.td

@@ -3570,6 +3570,15 @@ def TryOp : CIR_Op<"try",
     attr-dict
   }];
 
+  let extraClassDeclaration = [{
+  private:
+    mlir::Region *getCatchLastRegion();
+  public:
+    mlir::Block *getCatchAllEntryBlock();
+    mlir::Block *getCatchUnwindEntryBlock();
+    bool isCatchAllOnly();
+  }];
+
   // Everything already covered elsewhere.
   let hasVerifier = 0;
   let builders = [

clang/lib/CIR/CodeGen/CIRGenException.cpp

@@ -252,16 +252,6 @@ void CIRGenFunction::buildAnyExprToExn(const Expr *e, Address addr) {
   DeactivateCleanupBlock(cleanup, op);
 }
 
-static mlir::Block *getResumeBlockFromCatch(mlir::cir::TryOp &tryOp,
-                                            mlir::cir::GlobalOp globalParent) {
-  assert(tryOp && "cir.try expected");
-  unsigned numCatchRegions = tryOp.getCatchRegions().size();
-  assert(numCatchRegions && "expected at least one region");
-  auto &fallbackRegion = tryOp.getCatchRegions()[numCatchRegions - 1];
-  return &fallbackRegion.getBlocks().back();
-  return nullptr;
-}
-
 mlir::Block *CIRGenFunction::getEHResumeBlock(bool isCleanup,
                                               mlir::cir::TryOp tryOp) {
 
@@ -270,7 +260,8 @@ mlir::Block *CIRGenFunction::getEHResumeBlock(bool isCleanup,
   // Just like some other try/catch related logic: return the basic block
   // pointer but only use it to denote we're tracking things, but there
   // shouldn't be any changes to that block after work done in this function.
-  ehResumeBlock = getResumeBlockFromCatch(tryOp, CGM.globalOpContext);
+  assert(tryOp && "expected available cir.try");
+  ehResumeBlock = tryOp.getCatchUnwindEntryBlock();
   if (!ehResumeBlock->empty())
     return ehResumeBlock;
 

clang/lib/CIR/Dialect/IR/CIRDialect.cpp

@@ -1243,6 +1243,27 @@ void TryOp::build(
   catchBuilder(builder, result.location, result);
 }
 
+mlir::Region *TryOp::getCatchLastRegion() {
+  unsigned numCatchRegions = getCatchRegions().size();
+  assert(numCatchRegions && "expected at least one region");
+  auto &lastRegion = getCatchRegions()[numCatchRegions - 1];
+  return &lastRegion;
+}
+
+mlir::Block *TryOp::getCatchUnwindEntryBlock() {
+  return &getCatchLastRegion()->getBlocks().front();
+}
+
+mlir::Block *TryOp::getCatchAllEntryBlock() {
+  return &getCatchLastRegion()->getBlocks().front();
+}
+
+bool TryOp::isCatchAllOnly() {
+  mlir::ArrayAttr catchAttrList = getCatchTypesAttr();
+  return catchAttrList.size() == 1 &&
+         isa<mlir::cir::CatchAllAttr>(catchAttrList[0]);
+}
+
 void TryOp::getSuccessorRegions(mlir::RegionBranchPoint point,
                                 SmallVectorImpl<RegionSuccessor> &regions) {
   // If any index all the underlying regions branch back to the parent

clang/lib/CIR/Dialect/Transforms/FlattenCFG.cpp

@@ -418,8 +418,6 @@ class CIRTryOpFlattening : public mlir::OpRewritePattern<mlir::cir::TryOp> {
       // Do not update `nextDispatcher`, no more business in try/catch
     } else if (auto catchUnwind =
                    dyn_cast<mlir::cir::CatchUnwindAttr>(catchAttr)) {
-      // assert(dispatcher->empty() && "expect empty dispatcher");
-      // assert(!dispatcher->args_empty() && "expected block argument");
       assert(dispatcher->getArguments().size() == 2 &&
              "expected two block argument");
       buildUnwindCase(rewriter, catchRegion, dispatcher);
@@ -440,22 +438,18 @@ class CIRTryOpFlattening : public mlir::OpRewritePattern<mlir::cir::TryOp> {
     rewriter.setInsertionPointToEnd(beforeCatch);
     rewriter.replaceOpWithNewOp<mlir::cir::BrOp>(tryBodyYield, afterTry);
 
-    // Retrieve catch list and some properties.
-    mlir::ArrayAttr catchAttrList = tryOp.getCatchTypesAttr();
-    bool tryOnlyHasCatchAll = catchAttrList.size() == 1 &&
-                              isa<mlir::cir::CatchAllAttr>(catchAttrList[0]);
-
     // Start the landing pad by getting the inflight exception information.
     mlir::Block *nextDispatcher =
         buildLandingPads(tryOp, rewriter, beforeCatch, afterTry, callsToRewrite,
-                         landingPads, tryOnlyHasCatchAll);
+                         landingPads, tryOp.isCatchAllOnly());
 
     // Fill in dispatcher to all catch clauses.
     rewriter.setInsertionPointToEnd(nextDispatcher);
     llvm::MutableArrayRef<mlir::Region> catchRegions = tryOp.getCatchRegions();
     unsigned catchIdx = 0;
 
     // Build control-flow for all catch clauses.
+    mlir::ArrayAttr catchAttrList = tryOp.getCatchTypesAttr();
     for (mlir::Attribute catchAttr : catchAttrList) {
       mlir::Attribute nextCatchAttr;
       if (catchIdx + 1 < catchAttrList.size())