[clang] Use the materialized temporary's type while creating the APValue

[zyn0217]

See #72025 for the bug and its diagnosis.

[llvmbot]

@llvm/pr-subscribers-clang

Author: Younan Zhang (zyn0217)

Changes

See #72025 for the bug and its diagnosis.

---

Full diff: https://github.com/llvm/llvm-project/pull/73355.diff

3 Files Affected:

• (modified) clang/docs/ReleaseNotes.rst (+3)
• (modified) clang/lib/AST/ExprConstant.cpp (+1-1)
• (added) clang/test/SemaCXX/pr72025.cpp (+9)

diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst
index 74358219ba9fb22..d434d016907f815 100644
--- a/clang/docs/ReleaseNotes.rst
+++ b/clang/docs/ReleaseNotes.rst
@@ -691,6 +691,9 @@ Bug Fixes to C++ Support
   Fixes:
   (`#68769 <https://github.com/llvm/llvm-project/issues/68769>`_)
 
+- Fixed a crash for C++98/03 while checking an ill-formed ``_Static_assert`` expression.
+  Fixes: (`#72025 <https://github.com/llvm/llvm-project/issues/72025>`_)
+
 - Clang now defers the instantiation of explicit specifier until constraint checking
   completes (except deduction guides). Fixes:
   (`#59827 <https://github.com/llvm/llvm-project/issues/59827>`_)
diff --git a/clang/lib/AST/ExprConstant.cpp b/clang/lib/AST/ExprConstant.cpp
index e16fec6109e744e..6c6ad12119d13c3 100644
--- a/clang/lib/AST/ExprConstant.cpp
+++ b/clang/lib/AST/ExprConstant.cpp
@@ -8607,7 +8607,7 @@ bool LValueExprEvaluator::VisitMaterializeTemporaryExpr(
     Result.set(E);
   } else {
     Value = &Info.CurrentCall->createTemporary(
-        E, E->getType(),
+        E, Inner->getType(),
         E->getStorageDuration() == SD_FullExpression ? ScopeKind::FullExpression
                                                      : ScopeKind::Block,
         Result);
diff --git a/clang/test/SemaCXX/pr72025.cpp b/clang/test/SemaCXX/pr72025.cpp
new file mode 100644
index 000000000000000..9f0a4b0f43630c5
--- /dev/null
+++ b/clang/test/SemaCXX/pr72025.cpp
@@ -0,0 +1,9 @@
+// RUN: %clang_cc1 -verify -std=c++03 -fsyntax-only %s
+struct V {
+  char c[2];
+  banana V() : c("i") {} // expected-error {{unknown type name}}
+                         // expected-error@-1 {{constructor cannot have a return type}}
+};
+
+_Static_assert(V().c[0], ""); // expected-error {{is not an integral constant expression}}
+

[github-actions]

⚠️ C/C++ code formatter, clang-format found issues in your code. ⚠️

You can test this locally with the following command:

git-clang-format --diff d896b1f5a614daef1c3aa65cb3521ec82bc728d5 3ff1b189cf55d3705b2823dc39eaaf710fa26541 -- clang/test/SemaCXX/pr72025.cpp clang/lib/AST/ExprConstant.cpp

View the diff from clang-format here.

diff --git a/clang/lib/AST/ExprConstant.cpp b/clang/lib/AST/ExprConstant.cpp
index 6c6ad12119..0650c91a8f 100644
--- a/clang/lib/AST/ExprConstant.cpp
+++ b/clang/lib/AST/ExprConstant.cpp
@@ -3185,8 +3185,8 @@ static bool HandleLValueIndirectMember(EvalInfo &Info, const Expr *E,
 }
 
 /// Get the size of the given type in char units.
-static bool HandleSizeof(EvalInfo &Info, SourceLocation Loc,
-                         QualType Type, CharUnits &Size) {
+static bool HandleSizeof(EvalInfo &Info, SourceLocation Loc, QualType Type,
+                         CharUnits &Size) {
   // sizeof(void), __alignof__(void), sizeof(function) = 1 as a gcc
   // extension.
   if (Type->isVoidType() || Type->isFunctionType()) {
@@ -11516,8 +11516,8 @@ enum class GCCTypeClass {
 
 /// EvaluateBuiltinClassifyType - Evaluate __builtin_classify_type the same way
 /// as GCC.
-static GCCTypeClass
-EvaluateBuiltinClassifyType(QualType T, const LangOptions &LangOpts) {
+static GCCTypeClass EvaluateBuiltinClassifyType(QualType T,
+                                                const LangOptions &LangOpts) {
   assert(!T->isDependentType() && "unexpected dependent type");
 
   QualType CanTy = T.getCanonicalType();

[zyn0217]

Ping. And invited @cor3ntin to kindly take a look at this.

[zyn0217]

The code-formatter failed on other unrelated lines, so I think I'd better not to touch them.

[AaronBallman]

LGTM -- thank you for the detailed analysis in the issue and fix!