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author | Wentao Zhang <35722712+whentojump@users.noreply.github.com> | 2024-02-22 16:04:25 -0600 |
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committer | Tom Stellard <tstellar@redhat.com> | 2024-02-26 15:09:20 -0800 |
commit | 9274829eb689c261aecf7b100561594385816b0b (patch) | |
tree | faefbceb8104006b005694436c30277ca91c01f2 | |
parent | c8b11e93004af9aa8bd8116e5cf01946546f0283 (diff) | |
download | llvm-9274829eb689c261aecf7b100561594385816b0b.zip llvm-9274829eb689c261aecf7b100561594385816b0b.tar.gz llvm-9274829eb689c261aecf7b100561594385816b0b.tar.bz2 |
[clang][CodeGen] Keep processing the rest of AST after encountering unsupported MC/DC expressions (#82464)
Currently, upon seeing unsupported decisions (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:
{ // 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.
(cherry picked from commit d4bfca3b2e673789f7c278d46a199ae8910ddd37)
-rw-r--r-- | clang/lib/CodeGen/CodeGenPGO.cpp | 11 |
1 files changed, 7 insertions, 4 deletions
diff --git a/clang/lib/CodeGen/CodeGenPGO.cpp b/clang/lib/CodeGen/CodeGenPGO.cpp index 5d7c384..fb4e86e 100644 --- a/clang/lib/CodeGen/CodeGenPGO.cpp +++ b/clang/lib/CodeGen/CodeGenPGO.cpp @@ -240,9 +240,12 @@ 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()); @@ -293,7 +296,7 @@ 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? @@ -304,7 +307,7 @@ 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 |