[PATCH] D148206: [clang] Do not crash after suggesting typo correction to constexpr if condition

[Mariya Podchishchaeva via Phabricator via cfe-commits]

Fznamznon created this revision.
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In some cases non-null non-constant yet valid expression may reach point where
`ConditionResult` is created. For example, typo correction mechanism can return
such expression, so double check before evaluating it.

Fixes https://github.com/llvm/llvm-project/issues/61885


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D148206

Files:
  clang/docs/ReleaseNotes.rst
  clang/include/clang/Sema/Sema.h
  clang/test/SemaCXX/invalid-if-constexpr.cpp


Index: clang/test/SemaCXX/invalid-if-constexpr.cpp
===================================================================
--- /dev/null
+++ clang/test/SemaCXX/invalid-if-constexpr.cpp
@@ -0,0 +1,14 @@
+// RUN: %clang_cc1 -verify -std=c++20 %s
+
+namespace GH61885 {
+void similar() { // expected-note {{'similar' declared here}}
+  if constexpr (similer<>) {} // expected-error {{use of undeclared identifier 'similer'; did you mean 'similar'?}}
+}
+void a() { if constexpr (__adl_swap<>) {}} // expected-error{{use of undeclared identifier '__adl_swap'; did you mean '__sync_swap'?}} \
+                                           // expected-note {{'__sync_swap' declared here}}
+
+int AA() { return true;} // expected-note {{'AA' declared here}}
+
+void b() { if constexpr (AAA<>) {}} // expected-error {{use of undeclared identifier 'AAA'; did you mean 'AA'?}}
+}
+
Index: clang/include/clang/Sema/Sema.h
===================================================================
--- clang/include/clang/Sema/Sema.h
+++ clang/include/clang/Sema/Sema.h
@@ -12851,7 +12851,8 @@
                     bool IsConstexpr)
         : ConditionVar(ConditionVar), Condition(Condition), Invalid(false),
           HasKnownValue(IsConstexpr && Condition.get() &&
-                        !Condition.get()->isValueDependent()),
+                        !Condition.get()->isValueDependent() &&
+                        Condition.get()->isIntegerConstantExpr(S.Context)),
           KnownValue(HasKnownValue &&
                      !!Condition.get()->EvaluateKnownConstInt(S.Context)) {}
     explicit ConditionResult(bool Invalid)
Index: clang/docs/ReleaseNotes.rst
===================================================================
--- clang/docs/ReleaseNotes.rst
+++ clang/docs/ReleaseNotes.rst
@@ -294,6 +294,8 @@
   not a type concept.
 - Fix crash when a doc comment contains a line splicing.
   (`#62054 <https://github.com/llvm/llvm-project/issues/62054>`_)
+- Fix crash after suggesting typo correction to constexpr if condition.
+  (`#61885 <https://github.com/llvm/llvm-project/issues/61885>`_)
 
 Bug Fixes to Compiler Builtins
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^


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