[llvm-branch-commits] [clang] [MC/DC] Enable nested expressions (PR #125413)

[NAKAMURA Takumi via llvm-branch-commits]

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@@ -275,49 +276,57 @@ struct MapRegionCounters : public RecursiveASTVisitor<MapRegionCounters> {
   // an AST Stmt node.  MC/DC will use it to to signal when the top of a
   // logical operation (boolean expression) nest is encountered.
   bool dataTraverseStmtPost(Stmt *S) {
-    /// If MC/DC is not enabled, MCDCMaxCond will be set to 0. Do nothing.
-    if (MCDCMaxCond == 0)
+    if (DecisionStack.empty())
       return true;
 
-    if (const Expr *E = dyn_cast<Expr>(S)) {
-      const BinaryOperator *BinOp = dyn_cast<BinaryOperator>(E->IgnoreParens());
-      if (BinOp && BinOp->isLogicalOp()) {
-        assert(LogOpStack.back() == BinOp);
-        LogOpStack.pop_back();
-
-        /// At the top of logical operator nest:
-        if (LogOpStack.empty()) {
-          /// Was the "split-nested" logical operator case encountered?
-          if (SplitNestedLogicalOp) {
-            unsigned DiagID = Diag.getCustomDiagID(
-                DiagnosticsEngine::Warning,
-                "unsupported MC/DC boolean expression; "
-                "contains an operation with a nested boolean expression. "
-                "Expression will not be covered");
-            Diag.Report(S->getBeginLoc(), DiagID);
-            return true;
-          }
-
-          /// Was the maximum number of conditions encountered?
-          if (NumCond > MCDCMaxCond) {
-            unsigned DiagID = Diag.getCustomDiagID(
-                DiagnosticsEngine::Warning,
-                "unsupported MC/DC boolean expression; "
-                "number of conditions (%0) exceeds max (%1). "
-                "Expression will not be covered");
-            Diag.Report(S->getBeginLoc(), DiagID) << NumCond << MCDCMaxCond;
-            return true;
-          }
-
-          // Otherwise, allocate the Decision.
-          MCDCState.DecisionByStmt[BinOp].ID = MCDCState.DecisionByStmt.size();
-        }
-        return true;
+    /// If MC/DC is not enabled, MCDCMaxCond will be set to 0. Do nothing.
+    assert(MCDCMaxCond > 0);
+
+    auto &StackTop = DecisionStack.back();
+
+    if (StackTop.DecisionExpr != S) {
+      if (StackTop.Leaves.contains(S)) {
+        assert(StackTop.Split);
+        StackTop.Split = false;
       }
+
+      return true;
+    }
+
+    /// Allocate the entry (with Valid=false)
+    auto &DecisionEntry =
+        MCDCState
+            .DecisionByStmt[CodeGenFunction::stripCond(StackTop.DecisionExpr)];
+
+    /// Was the "split-nested" logical operator case encountered?
+    if (false && DecisionStack.size() > 1) {
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chapuni wrote:

This is the option for deprecating this warning, "warn if nested level >= n" or deprecate. @evodius96 Opinions?

https://github.com/llvm/llvm-project/pull/125413