llvmbot wrote:
<!--LLVM PR SUMMARY COMMENT--> @llvm/pr-subscribers-clang-codegen Author: Wentao Zhang (whentojump) <details> <summary>Changes</summary> Currently, upon seeing [unsupported decisions](https://clang.llvm.org/docs/SourceBasedCodeCoverage.html#mc-dc-instrumentation) (more than 6 conditions, or split nesting), the post-visitor hook `dataTraverseStmtPost()` returns a `false`. As a result, in the rest of tree even supported decisions will be skipped as well. Like in the below code: ```c { // CompoundStmt a && b; // 1: BinaryOperator (supported) a && foo(b && c); // 2: BinaryOperator (not yet supported due to split nesting) a && b; // 3: BinaryOperator (supported) } ``` Decision 3 will not be processed at all. And only one "Decision" region will be emitted. Compiler explorer example: https://godbolt.org/z/Px61sesoo We hope to process such cases and emit two "Decision" regions (1 and 3) in the above example. --- Full diff: https://github.com/llvm/llvm-project/pull/82464.diff 1 Files Affected: - (modified) clang/lib/CodeGen/CodeGenPGO.cpp (+7-4) ``````````diff diff --git a/clang/lib/CodeGen/CodeGenPGO.cpp b/clang/lib/CodeGen/CodeGenPGO.cpp index 48c5e68a3b7ba4..1ef7be3c72593d 100644 --- a/clang/lib/CodeGen/CodeGenPGO.cpp +++ b/clang/lib/CodeGen/CodeGenPGO.cpp @@ -239,9 +239,12 @@ struct MapRegionCounters : public RecursiveASTVisitor<MapRegionCounters> { if (MCDCMaxCond == 0) return true; - /// At the top of the logical operator nest, reset the number of conditions. - if (LogOpStack.empty()) + /// At the top of the logical operator nest, reset the number of conditions, + /// also forget previously seen split nesting cases. + if (LogOpStack.empty()) { NumCond = 0; + SplitNestedLogicalOp = false; + } if (const Expr *E = dyn_cast<Expr>(S)) { const BinaryOperator *BinOp = dyn_cast<BinaryOperator>(E->IgnoreParens()); @@ -292,7 +295,7 @@ struct MapRegionCounters : public RecursiveASTVisitor<MapRegionCounters> { "contains an operation with a nested boolean expression. " "Expression will not be covered"); Diag.Report(S->getBeginLoc(), DiagID); - return false; + return true; } /// Was the maximum number of conditions encountered? @@ -303,7 +306,7 @@ struct MapRegionCounters : public RecursiveASTVisitor<MapRegionCounters> { "number of conditions (%0) exceeds max (%1). " "Expression will not be covered"); Diag.Report(S->getBeginLoc(), DiagID) << NumCond << MCDCMaxCond; - return false; + return true; } // Otherwise, allocate the number of bytes required for the bitmap `````````` </details> https://github.com/llvm/llvm-project/pull/82464 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
