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[clang][bytecode] Fix discarding ImplitiValueInitExprs #170089

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Merged
tbaederr merged 1 commit into from
Dec 1, 2025
Merged

[clang][bytecode] Fix discarding ImplitiValueInitExprs #170089

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3 changes: 3 additions & 0 deletions clang/lib/AST/ByteCode/Compiler.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -1705,6 +1705,9 @@ bool Compiler<Emitter>::VisitFixedPointUnaryOperator(const UnaryOperator *E) {
template <class Emitter>
bool Compiler<Emitter>::VisitImplicitValueInitExpr(
const ImplicitValueInitExpr *E) {
if (DiscardResult)
return true;

QualType QT = E->getType();

if (OptPrimType T = classify(QT))
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13 changes: 13 additions & 0 deletions clang/test/AST/ByteCode/c.c
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Expand Up @@ -392,3 +392,16 @@ void plainComplex(void) {
_Complex cd; // all-warning {{_Complex double}}
cd = *(_Complex *)&(struct { double r, i; }){0.0, 0.0}; // all-warning {{_Complex double}}
}

/// This test results in an ImplicitValueInitExpr with DiscardResult set.
struct M{
char c;
};
typedef struct S64 {
struct M m;
char a[64];
} I64;

_Static_assert((((I64){}, 1)), ""); // all-warning {{left operand of comma operator has no effect}} \
// pedantic-warning {{use of an empty initializer is a C23 extension}} \
// pedantic-warning {{expression is not an integer constant expression; folding it to a constant is a GNU extension}}