[clang] d36edf8 - [clang][Interp] Bail out on value dependent variable initializers

[Timm Bäder via cfe-commits]

Author: Timm Bäder
Date: 2024-07-24T12:11:06+02:00
New Revision: d36edf8146cfea9f0407e2fb26283297eb6a6ac4

URL: https://github.com/llvm/llvm-project/commit/d36edf8146cfea9f0407e2fb26283297eb6a6ac4
DIFF: https://github.com/llvm/llvm-project/commit/d36edf8146cfea9f0407e2fb26283297eb6a6ac4.diff

LOG: [clang][Interp] Bail out on value dependent variable initializers

Added: 
    

Modified: 
    clang/lib/AST/Interp/Compiler.cpp
    clang/test/AST/Interp/literals.cpp

Removed: 
    


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diff  --git a/clang/lib/AST/Interp/Compiler.cpp b/clang/lib/AST/Interp/Compiler.cpp
index dbd2686b17f09..0455eec3f0145 100644
--- a/clang/lib/AST/Interp/Compiler.cpp
+++ b/clang/lib/AST/Interp/Compiler.cpp
@@ -3683,6 +3683,9 @@ VarCreationState Compiler<Emitter>::visitVarDecl(const VarDecl *VD, bool Topleve
   const Expr *Init = VD->getInit();
   std::optional<PrimType> VarT = classify(VD->getType());
 
+  if (Init && Init->isValueDependent())
+    return false;
+
   if (Context::shouldBeGloballyIndexed(VD)) {
     auto checkDecl = [&]() -> bool {
       bool NeedsOp = !Toplevel && VD->isLocalVarDecl() && VD->isStaticLocal();

diff  --git a/clang/test/AST/Interp/literals.cpp b/clang/test/AST/Interp/literals.cpp
index 2b8abf665b20d..815fb67b9bbfc 100644
--- a/clang/test/AST/Interp/literals.cpp
+++ b/clang/test/AST/Interp/literals.cpp
@@ -1307,3 +1307,15 @@ namespace VolatileReads {
   static_assert(b, ""); // both-error {{not an integral constant expression}} \
                         // both-note {{read of volatile-qualified type 'const volatile int' is not allowed in a constant expression}}
 }
+#if __cplusplus >= 201703L
+namespace {
+  struct C {
+    int x;
+  };
+
+  template <const C *p> void f() {
+    const auto &[c] = *p;
+    &c; // both-warning {{expression result unused}}
+  }
+}
+#endif