[clang] 19a6a28 - [clang] Fix crashes when initializing constexpr int* with floating-point (#180376)

[via cfe-commits]

Author: Samrudh Nelli
Date: 2026-02-17T15:02:20+01:00
New Revision: 19a6a2810ee35724a5967f7780242dbfd677283e

URL: https://github.com/llvm/llvm-project/commit/19a6a2810ee35724a5967f7780242dbfd677283e
DIFF: https://github.com/llvm/llvm-project/commit/19a6a2810ee35724a5967f7780242dbfd677283e.diff

LOG: [clang] Fix crashes when initializing constexpr int* with floating-point (#180376)

Call isNullPointer() only when we are sure that Rvalue is a pointer.
Fixes #180313

---------

Co-authored-by: Mariya Podchishchaeva <mariya.podchishchaeva at intel.com>

Added: 
    

Modified: 
    clang/docs/ReleaseNotes.rst
    clang/lib/Sema/SemaInit.cpp
    clang/test/AST/ByteCode/constexpr.c
    clang/test/Sema/constexpr.c

Removed: 
    


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diff  --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst
index a2cdeb7bc1744..5416b25b3927c 100644
--- a/clang/docs/ReleaseNotes.rst
+++ b/clang/docs/ReleaseNotes.rst
@@ -300,6 +300,7 @@ Miscellaneous Clang Crashes Fixed
 - Fixed a crash when using loop hint with a value dependent argument inside a
   generic lambda. (#GH172289)
 - Fixed a crash in C++ overload resolution with ``_Atomic``-qualified argument types. (#GH170433)
+- Fixed a crash when initializing a ``constexpr`` pointer with a floating-point literal in C23. (#GH180313)
 - Fixed an assertion when diagnosing address-space qualified ``new``/``delete`` in language-defined address spaces such as OpenCL ``__local``. (#GH178319)
 - Fixed an assertion failure in ObjC++ ARC when binding a rvalue reference to reference with 
diff erent lifetimes (#GH178524)
 

diff  --git a/clang/lib/Sema/SemaInit.cpp b/clang/lib/Sema/SemaInit.cpp
index 989f7cd80cbef..498ffd0887630 100644
--- a/clang/lib/Sema/SemaInit.cpp
+++ b/clang/lib/Sema/SemaInit.cpp
@@ -8512,8 +8512,9 @@ ExprResult InitializationSequence::Perform(Sema &S,
         Expr::EvalResult ER;
         if (Entity.getType()->getAs<PointerType>() &&
             CurInit.get()->EvaluateAsRValue(ER, S.Context) &&
-            !ER.Val.isNullPointer()) {
+            (ER.Val.isLValue() && !ER.Val.isNullPointer())) {
           S.Diag(Kind.getLocation(), diag::err_c23_constexpr_pointer_not_null);
+          return ExprError();
         }
       }
 

diff  --git a/clang/test/AST/ByteCode/constexpr.c b/clang/test/AST/ByteCode/constexpr.c
index af96bf3a06f37..dfe3d667f27cc 100644
--- a/clang/test/AST/ByteCode/constexpr.c
+++ b/clang/test/AST/ByteCode/constexpr.c
@@ -309,10 +309,10 @@ constexpr const int *V81 = &V80;
 constexpr int *V82 = 0;
 constexpr int *V83 = V82;
 constexpr int *V84 = 42;
-// both-error at -1 {{constexpr variable 'V84' must be initialized by a constant expression}}
-// both-note at -2 {{this conversion is not allowed in a constant expression}}
-// both-error at -3 {{constexpr pointer initializer is not null}}
+// both-error at -1 {{constexpr pointer initializer is not null}}
 constexpr int *V85 = nullptr;
+constexpr int *V91 = 0.;
+// both-error at -1 {{initializing 'int *const' with an expression of incompatible type 'double'}}
 
 // Check that constexpr variables should not be VLAs.
 void f6(const int P1) {

diff  --git a/clang/test/Sema/constexpr.c b/clang/test/Sema/constexpr.c
index ae01c71e09b06..04da0f56a741d 100644
--- a/clang/test/Sema/constexpr.c
+++ b/clang/test/Sema/constexpr.c
@@ -309,10 +309,10 @@ constexpr const int *V81 = &V80;
 constexpr int *V82 = 0;
 constexpr int *V83 = V82;
 constexpr int *V84 = 42;
-// expected-error at -1 {{constexpr variable 'V84' must be initialized by a constant expression}}
-// expected-note at -2 {{this conversion is not allowed in a constant expression}}
-// expected-error at -3 {{constexpr pointer initializer is not null}}
+// expected-error at -1 {{constexpr pointer initializer is not null}}
 constexpr int *V85 = nullptr;
+constexpr int *V91 = 0.0; 
+// expected-error at -1 {{initializing 'int *const' with an expression of incompatible type 'double'}}
 
 // Check that constexpr variables should not be VLAs.
 void f6(const int P1) {