[clang] Fix accsessing "PresentModifierLocs" array beyond its end. (PR #73579)

[via cfe-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-clang

Author: None (jyu2-git)

<details>
<summary>Changes</summary>

Currently PresentModifierLocs defined with size DefaultmapKindNum; where DefaultmapKindNum = OMPC_DEFAULTMAP_pointer + 1

Before 5.0 variable-category can not be omitted. For the test like \#pragma omp target map(tofrom: errors) defaultmap(present)

error would be mitted.

After 5.0 that is allowd.

When try to:
PresentModifierLocs[DMC->getDefaultmapKind()] =
              DMC->getDefaultmapModifierLoc();
It is accessed beyound array end.

---
Full diff: https://github.com/llvm/llvm-project/pull/73579.diff


2 Files Affected:

- (modified) clang/lib/Sema/SemaOpenMP.cpp (+3-3) 
- (modified) clang/test/OpenMP/target_ast_print.cpp (+4) 


``````````diff
diff --git a/clang/lib/Sema/SemaOpenMP.cpp b/clang/lib/Sema/SemaOpenMP.cpp
index 3a5f4b12ce29621..e400f248d15aa34 100644
--- a/clang/lib/Sema/SemaOpenMP.cpp
+++ b/clang/lib/Sema/SemaOpenMP.cpp
@@ -161,7 +161,7 @@ class DSAStackTy {
     LoopControlVariablesMapTy LCVMap;
     DefaultDataSharingAttributes DefaultAttr = DSA_unspecified;
     SourceLocation DefaultAttrLoc;
-    DefaultmapInfo DefaultmapMap[OMPC_DEFAULTMAP_unknown];
+    DefaultmapInfo DefaultmapMap[OMPC_DEFAULTMAP_unknown + 1];
     OpenMPDirectiveKind Directive = OMPD_unknown;
     /// GenericLoopDirective with bind clause is mapped to other directives,
     /// like for, distribute and simd. Presently, set MappedDirective to
@@ -3689,7 +3689,7 @@ class DSAAttrChecker final : public StmtVisitor<DSAAttrChecker, void> {
   bool ErrorFound = false;
   bool TryCaptureCXXThisMembers = false;
   CapturedStmt *CS = nullptr;
-  const static unsigned DefaultmapKindNum = OMPC_DEFAULTMAP_pointer + 1;
+  const static unsigned DefaultmapKindNum = OMPC_DEFAULTMAP_unknown + 1;
   llvm::SmallVector<Expr *, 4> ImplicitFirstprivate;
   llvm::SmallVector<Expr *, 4> ImplicitPrivate;
   llvm::SmallVector<Expr *, 4> ImplicitMap[DefaultmapKindNum][OMPC_MAP_delete];
@@ -6276,7 +6276,7 @@ StmtResult Sema::ActOnOpenMPExecutableDirective(
     SmallVector<Expr *, 4> ImplicitPrivates(
         DSAChecker.getImplicitPrivate().begin(),
         DSAChecker.getImplicitPrivate().end());
-    const unsigned DefaultmapKindNum = OMPC_DEFAULTMAP_pointer + 1;
+    const unsigned DefaultmapKindNum = OMPC_DEFAULTMAP_unknown + 1;
     SmallVector<Expr *, 4> ImplicitMaps[DefaultmapKindNum][OMPC_MAP_delete];
     SmallVector<OpenMPMapModifierKind, NumberOfOMPMapClauseModifiers>
         ImplicitMapModifiers[DefaultmapKindNum];
diff --git a/clang/test/OpenMP/target_ast_print.cpp b/clang/test/OpenMP/target_ast_print.cpp
index d3daed053cc2ea5..45907e93321a824 100644
--- a/clang/test/OpenMP/target_ast_print.cpp
+++ b/clang/test/OpenMP/target_ast_print.cpp
@@ -1110,6 +1110,8 @@ T tmain(T argc, T *argv) {
   foo();
   #pragma omp target thread_limit(C)
   foo();
+  #pragma omp target defaultmap(present)
+  foo();
 
   return 0;
 }
@@ -1123,6 +1125,8 @@ T tmain(T argc, T *argv) {
 // OMP51-NEXT: foo()
 // OMP51-NEXT: #pragma omp target thread_limit(C)
 // OMP51-NEXT: foo()
+// OMP51-NEXT: #pragma omp target defaultmap(present)
+// OMP51-NEXT: foo()
 
 // OMP51-LABEL: int main(int argc, char **argv) {
 int main (int argc, char **argv) {

``````````

</details>


https://github.com/llvm/llvm-project/pull/73579