[CIR] Upstream non-empty Try block with catch all (#165158)

Upstream support for try block and catch all block with a function call
that may throw an exception.

Issue llvm/llvm-project#154992

Author: AmrDeveloper

clang/include/clang/CIR/Dialect/Builder/CIRBaseBuilder.h

@@ -389,25 +389,6 @@ class CIRBaseBuilderTy : public mlir::OpBuilder {
     return createCallOp(loc, callee, cir::VoidType(), operands, attrs);
   }
 
-  cir::CallOp createTryCallOp(
-      mlir::Location loc, mlir::SymbolRefAttr callee = mlir::SymbolRefAttr(),
-      mlir::Type returnType = cir::VoidType(),
-      mlir::ValueRange operands = mlir::ValueRange(),
-      [[maybe_unused]] cir::SideEffect sideEffect = cir::SideEffect::All) {
-    assert(!cir::MissingFeatures::opCallCallConv());
-    assert(!cir::MissingFeatures::opCallSideEffect());
-    return createCallOp(loc, callee, returnType, operands);
-  }
-
-  cir::CallOp createTryCallOp(
-      mlir::Location loc, cir::FuncOp callee, mlir::ValueRange operands,
-      [[maybe_unused]] cir::SideEffect sideEffect = cir::SideEffect::All) {
-    assert(!cir::MissingFeatures::opCallCallConv());
-    assert(!cir::MissingFeatures::opCallSideEffect());
-    return createTryCallOp(loc, mlir::SymbolRefAttr::get(callee),
-                           callee.getFunctionType().getReturnType(), operands);
-  }
-
   //===--------------------------------------------------------------------===//
   // Cast/Conversion Operators
   //===--------------------------------------------------------------------===//

clang/include/clang/CIR/MissingFeatures.h

@@ -94,6 +94,7 @@ struct MissingFeatures {
   static bool opFuncNoReturn() { return false; }
   static bool setFunctionAttributes() { return false; }
   static bool setLLVMFunctionFEnvAttributes() { return false; }
+  static bool setFunctionPersonality() { return false; }
 
   // CallOp handling
   static bool opCallAggregateArgs() { return false; }
@@ -334,6 +335,9 @@ struct MissingFeatures {
   static bool vtableRelativeLayout() { return false; }
   static bool weakRefReference() { return false; }
   static bool writebacks() { return false; }
+  static bool msvcCXXPersonality() { return false; }
+  static bool functionUsesSEHTry() { return false; }
+  static bool nothrowAttr() { return false; }
 
   // Missing types
   static bool dataMemberType() { return false; }
@@ -349,7 +353,6 @@ struct MissingFeatures {
   static bool awaitOp() { return false; }
   static bool callOp() { return false; }
   static bool ifOp() { return false; }
-  static bool invokeOp() { return false; }
   static bool labelOp() { return false; }
   static bool ptrDiffOp() { return false; }
   static bool llvmLoweringPtrDiffConsidersPointee() { return false; }
@@ -359,6 +362,7 @@ struct MissingFeatures {
   static bool tryOp() { return false; }
   static bool vecTernaryOp() { return false; }
   static bool zextOp() { return false; }
+  static bool catchParamOp() { return false; }
 
   // Future CIR attributes
   static bool optInfoAttr() { return false; }

clang/lib/CIR/CodeGen/CIRGenCall.cpp

@@ -465,12 +465,47 @@ static cir::CIRCallOpInterface
 emitCallLikeOp(CIRGenFunction &cgf, mlir::Location callLoc,
                cir::FuncType indirectFuncTy, mlir::Value indirectFuncVal,
                cir::FuncOp directFuncOp,
-               const SmallVectorImpl<mlir::Value> &cirCallArgs,
+               const SmallVectorImpl<mlir::Value> &cirCallArgs, bool isInvoke,
                const mlir::NamedAttrList &attrs) {
   CIRGenBuilderTy &builder = cgf.getBuilder();
 
   assert(!cir::MissingFeatures::opCallSurroundingTry());
-  assert(!cir::MissingFeatures::invokeOp());
+
+  if (isInvoke) {
+    // This call may throw and requires catch and/or cleanup handling.
+    // If this call does not appear within the `try` region of an existing
+    // TryOp, we must create a synthetic TryOp to contain the call. This
+    // happens when a call that may throw appears within a cleanup
+    // scope.
+
+    // In OG, we build the landing pad for this scope. In CIR, we emit a
+    // synthetic cir.try because this didn't come from code generating from a
+    // try/catch in C++.
+    assert(cgf.curLexScope && "expected scope");
+    cir::TryOp tryOp = cgf.curLexScope->getClosestTryParent();
+    if (!tryOp) {
+      cgf.cgm.errorNYI(
+          "emitCallLikeOp: call does not have an associated cir.try");
+      return {};
+    }
+
+    if (tryOp.getSynthetic()) {
+      cgf.cgm.errorNYI("emitCallLikeOp: tryOp synthetic");
+      return {};
+    }
+
+    cir::CallOp callOpWithExceptions;
+    if (indirectFuncTy) {
+      cgf.cgm.errorNYI("emitCallLikeOp: indirect function type");
+      return {};
+    }
+
+    callOpWithExceptions =
+        builder.createCallOp(callLoc, directFuncOp, cirCallArgs);
+
+    cgf.populateCatchHandlersIfRequired(tryOp);
+    return callOpWithExceptions;
+  }
 
   assert(builder.getInsertionBlock() && "expected valid basic block");
 
@@ -601,8 +636,6 @@ RValue CIRGenFunction::emitCall(const CIRGenFunctionInfo &funcInfo,
   assert(!cir::MissingFeatures::opCallAttrs());
   cgm.constructAttributeList(callee.getAbstractInfo(), attrs);
 
-  assert(!cir::MissingFeatures::invokeOp());
-
   cir::FuncType indirectFuncTy;
   mlir::Value indirectFuncVal;
   cir::FuncOp directFuncOp;
@@ -628,10 +661,17 @@ RValue CIRGenFunction::emitCall(const CIRGenFunctionInfo &funcInfo,
     indirectFuncVal = calleePtr->getResult(0);
   }
 
+  assert(!cir::MissingFeatures::msvcCXXPersonality());
+  assert(!cir::MissingFeatures::functionUsesSEHTry());
+  assert(!cir::MissingFeatures::nothrowAttr());
+
+  bool cannotThrow = attrs.getNamed("nothrow").has_value();
+  bool isInvoke = !cannotThrow && isCatchOrCleanupRequired();
+
   mlir::Location callLoc = loc;
   cir::CIRCallOpInterface theCall =
       emitCallLikeOp(*this, loc, indirectFuncTy, indirectFuncVal, directFuncOp,
-                     cirCallArgs, attrs);
+                     cirCallArgs, isInvoke, attrs);
 
   if (callOp)
     *callOp = theCall;

clang/lib/CIR/CodeGen/CIRGenCleanup.cpp

@@ -188,9 +188,22 @@ void EHScopeStack::popCleanup() {
   }
 }
 
+bool EHScopeStack::requiresCatchOrCleanup() const {
+  for (stable_iterator si = getInnermostEHScope(); si != stable_end();) {
+    if (auto *cleanup = dyn_cast<EHCleanupScope>(&*find(si))) {
+      if (cleanup->isLifetimeMarker()) {
+        // Skip lifetime markers and continue from the enclosing EH scope
+        assert(!cir::MissingFeatures::emitLifetimeMarkers());
+        continue;
+      }
+    }
+    return true;
+  }
+  return false;
+}
+
 EHCatchScope *EHScopeStack::pushCatch(unsigned numHandlers) {
   char *buffer = allocate(EHCatchScope::getSizeForNumHandlers(numHandlers));
-  assert(!cir::MissingFeatures::innermostEHScope());
   EHCatchScope *scope =
       new (buffer) EHCatchScope(numHandlers, innermostEHScope);
   innermostEHScope = stable_begin();

clang/lib/CIR/CodeGen/CIRGenCleanup.h

@@ -18,6 +18,7 @@
 #include "CIRGenModule.h"
 #include "EHScopeStack.h"
 #include "mlir/IR/Value.h"
+#include "clang/AST/StmtCXX.h"
 
 namespace clang::CIRGen {
 
@@ -38,6 +39,8 @@ class EHScope {
   };
   enum { NumCommonBits = 3 };
 
+  bool scopeMayThrow;
+
 protected:
   class CatchBitFields {
     friend class EHCatchScope;
@@ -92,10 +95,11 @@ class EHScope {
     // Traditional LLVM codegen also checks for `!block->use_empty()`, but
     // in CIRGen the block content is not important, just used as a way to
     // signal `hasEHBranches`.
-    assert(!cir::MissingFeatures::ehstackBranches());
-    return false;
+    return scopeMayThrow;
   }
 
+  void setMayThrow(bool mayThrow) { scopeMayThrow = mayThrow; }
+
   EHScopeStack::stable_iterator getEnclosingEHScope() const {
     return enclosingEHScope;
   }
@@ -121,6 +125,9 @@ class EHCatchScope : public EHScope {
     /// The catch handler for this type.
     mlir::Region *region;
 
+    /// The catch handler stmt.
+    const CXXCatchStmt *stmt;
+
     bool isCatchAll() const { return type.rtti == nullptr; }
   };
 
@@ -147,10 +154,13 @@ class EHCatchScope : public EHScope {
 
   unsigned getNumHandlers() const { return catchBits.numHandlers; }
 
-  void setHandler(unsigned i, CatchTypeInfo type, mlir::Region *region) {
+  void setHandler(unsigned i, CatchTypeInfo type, mlir::Region *region,
+                  const CXXCatchStmt *stmt) {
     assert(i < getNumHandlers());
-    getHandlers()[i].type = type;
-    getHandlers()[i].region = region;
+    Handler *handler = &getHandlers()[i];
+    handler->type = type;
+    handler->region = region;
+    handler->stmt = stmt;
   }
 
   const Handler &getHandler(unsigned i) const {
@@ -231,6 +241,8 @@ class alignas(EHScopeStack::ScopeStackAlignment) EHCleanupScope
   bool isActive() const { return cleanupBits.isActive; }
   void setActive(bool isActive) { cleanupBits.isActive = isActive; }
 
+  bool isLifetimeMarker() const { return cleanupBits.isLifetimeMarker; }
+
   unsigned getFixupDepth() const { return fixupDepth; }
   EHScopeStack::stable_iterator getEnclosingNormalCleanup() const {
     return enclosingNormal;