[clang][OpenMP] Add error for large expr in SIMD collapse

Author: AmrDeveloper

clang/docs/ReleaseNotes.rst

@@ -503,6 +503,8 @@ Improvements to Clang's diagnostics
 - ``-Wreserved-identifier`` now fires on reserved parameter names in a function
   declaration which is not a definition.
 
+- An error is now emitted when OpenMP SIMD ``collapse`` clause has expression larger than 64 bit.
+
 Improvements to Clang's time-trace
 ----------------------------------
 

clang/include/clang/Basic/DiagnosticSemaKinds.td

@@ -11519,6 +11519,8 @@ def note_omp_collapse_ordered_expr : Note<
   "as specified in %select{'collapse'|'ordered'|'collapse' and 'ordered'}0 clause%select{||s}0">;
 def err_omp_negative_expression_in_clause : Error<
   "argument to '%0' clause must be a %select{non-negative|strictly positive}1 integer value">;
+def err_omp_large_expression_in_clause : Error<
+  "argument to '%0' clause cannot have more than 64 bits size">;
 def err_omp_not_integral : Error<
   "expression must have integral or unscoped enumeration "
   "type, not %0">;

clang/lib/Sema/SemaOpenMP.cpp

@@ -15901,6 +15901,13 @@ ExprResult SemaOpenMP::VerifyPositiveIntegerConstantInClause(
         << E->getSourceRange();
     return ExprError();
   }
+
+  if (!Result.isRepresentableByInt64()) {
+    Diag(E->getExprLoc(), diag::err_omp_large_expression_in_clause)
+        << getOpenMPClauseNameForDiag(CKind) << E->getSourceRange();
+    return ExprError();
+  }
+
   if (CKind == OMPC_collapse && DSAStack->getAssociatedLoops() == 1)
     DSAStack->setAssociatedLoops(Result.getExtValue());
   else if (CKind == OMPC_ordered)

clang/test/OpenMP/simd_collapse_messages.cpp

@@ -43,6 +43,8 @@ T tmain(T argc, S **argv) {
   for (int i = ST; i < N; i++) argv[0][i] = argv[0][i] - argv[0][i-ST];
   #pragma omp simd collapse (S) // expected-error {{'S' does not refer to a value}}
   for (int i = ST; i < N; i++) argv[0][i] = argv[0][i] - argv[0][i-ST];
+  #pragma omp simd collapse (0xFFFFFFFFFFFFFFFF) // expected-error {{argument to 'collapse' clause cannot have more than 64 bits size}}
+  for (int i = ST; i < N; i++) argv[0][i] = argv[0][i] - argv[0][i-ST];
 #if __cplusplus <= 199711L
   // expected-error@+4 2 {{integral constant expression}} expected-note@+4 0+{{constant expression}}
 #else