[Clang] prevent assertion failure when converting vectors to int/float with invalid expressions

[a-tarasyuk]

Fixes #105486

[llvmbot]

@llvm/pr-subscribers-clang

Author: Oleksandr T. (a-tarasyuk)

Changes

Fixes #105486

---

Full diff: https://github.com/llvm/llvm-project/pull/105727.diff

3 Files Affected:

• (modified) clang/docs/ReleaseNotes.rst (+1)
• (modified) clang/lib/Sema/SemaExpr.cpp (+6)
• (modified) clang/test/SemaCXX/vector.cpp (+14)

diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst
index 12a924acc14331..27aac987011dea 100644
--- a/clang/docs/ReleaseNotes.rst
+++ b/clang/docs/ReleaseNotes.rst
@@ -296,6 +296,7 @@ Bug Fixes to C++ Support
   template depth than the friend function template. (#GH98258)
 - Clang now rebuilds the template parameters of out-of-line declarations and specializations in the context
   of the current instantiation in all cases.
+- Fixed an assertion failure when converting vectors to int/float with invalid expressions. (#GH105486)
 
 Bug Fixes to AST Handling
 ^^^^^^^^^^^^^^^^^^^^^^^^^
diff --git a/clang/lib/Sema/SemaExpr.cpp b/clang/lib/Sema/SemaExpr.cpp
index c67183df335dd5..58825ef89213d2 100644
--- a/clang/lib/Sema/SemaExpr.cpp
+++ b/clang/lib/Sema/SemaExpr.cpp
@@ -9889,6 +9889,9 @@ static ExprResult convertVector(Expr *E, QualType ElementType, Sema &S) {
 /// IntTy without losing precision.
 static bool canConvertIntToOtherIntTy(Sema &S, ExprResult *Int,
                                       QualType OtherIntTy) {
+  if (Int->get()->isValueDependent())
+    return false;
+
   QualType IntTy = Int->get()->getType().getUnqualifiedType();
 
   // Reject cases where the value of the Int is unknown as that would
@@ -9927,6 +9930,9 @@ static bool canConvertIntToOtherIntTy(Sema &S, ExprResult *Int,
 /// FloatTy without losing precision.
 static bool canConvertIntTyToFloatTy(Sema &S, ExprResult *Int,
                                      QualType FloatTy) {
+  if (Int->get()->isValueDependent())
+    return false;
+
   QualType IntTy = Int->get()->getType().getUnqualifiedType();
 
   // Determine if the integer constant can be expressed as a floating point
diff --git a/clang/test/SemaCXX/vector.cpp b/clang/test/SemaCXX/vector.cpp
index 7c8ee89814e578..808bdb679b09cd 100644
--- a/clang/test/SemaCXX/vector.cpp
+++ b/clang/test/SemaCXX/vector.cpp
@@ -772,3 +772,17 @@ void test_scoped_enum_vector(EnumClass ea, v2u v2ua) {
 }
 #endif
 }
+
+namespace GH105486 {
+__attribute__((__vector_size__(sizeof(double)))) double a;
+double b = a - (long)(*0); // expected-error {{indirection requires pointer operand ('int' invalid)}} \
+                           // expected-error {{cannot initialize a variable of type 'double' with an rvalue of type '__attribute__((__vector_size__(1 * sizeof(double)))) double' (vector of 1 'double' value)}}
+
+__attribute__((__vector_size__(sizeof(long)))) long c;
+long d = c - (long)(*0); // expected-error {{indirection requires pointer operand ('int' invalid)}} \
+                         // expected-error {{cannot initialize a variable of type 'long' with an rvalue of type '__attribute__((__vector_size__(1 * sizeof(long)))) long' (vector of 1 'long' value)}}
+
+const long long e = *0; // expected-error {{indirection requires pointer operand ('int' invalid)}}
+double f = a - e;       // expected-error {{cannot initialize a variable of type 'double' with an rvalue of type '__attribute__((__vector_size__(1 * sizeof(double)))) double' (vector of 1 'double' value)}}
+int h = c - e;          // expected-error {{cannot initialize a variable of type 'int' with an rvalue of type '__attribute__((__vector_size__(1 * sizeof(long)))) long' (vector of 1 'long' value)}}
+}

[shafik]

Thank you for the fix, can you add more details to the summary, in this case some details on the fix and why it works would be helpful.

[AaronBallman]

LGTM!