Sema: Improve diagnostics a bit in shaping exprs.

Author: mikaoP

clang/include/clang/Basic/DiagnosticSemaKinds.td

@@ -9737,6 +9737,8 @@ def err_oss_section_incomplete_type : Error<
   "section of pointer to incomplete type %0">;
 def err_oss_typecheck_section_not_integer : Error<
   "array section %select{lower bound|length}0 is not an integer">;
+def err_oss_typecheck_shape_not_integer : Error<
+  "array shape is not an integer">;
 def err_oss_section_not_subset_of_array : Error<
   "array section must be a subset of the original array">;
 def err_oss_section_length_negative : Error<
@@ -9745,6 +9747,8 @@ def err_oss_section_length_undefined : Error<
   "section length is unspecified and cannot be inferred because subscripted value is %select{not an array|an array of unknown bound}0">;
 def err_oss_typecheck_shaping_base_no_ptr_or_array: Error<
   "shaping expression base is not a pointer or array">;
+def err_oss_shape_incomplete_type : Error<
+  "shape of pointer to incomplete type %0">;
 def warn_oss_section_is_char : Warning<"array section %select{lower bound|length}0 is of type 'char'">,
   InGroup<CharSubscript>, DefaultIgnore;
 } // end of OmpSs component.

clang/lib/Sema/SemaExpr.cpp

@@ -4648,6 +4648,9 @@ ExprResult Sema::ActOnOSSArraySectionExpr(Expr *Base, SourceLocation LBLoc,
     auto Res = PerformOmpSsImplicitIntegerConversion(LowerBound->getExprLoc(),
                                                      LowerBound);
     if (Res.isInvalid())
+      // FIXME: PerformContextualImplicitConversion doesn't always tell us if it
+      // failed and produced a diagnostic.
+      // From commit ef6c43dc
       return ExprError(Diag(LowerBound->getExprLoc(),
                             diag::err_oss_typecheck_section_not_integer)
                        << 0 << LowerBound->getSourceRange());
@@ -4662,6 +4665,9 @@ ExprResult Sema::ActOnOSSArraySectionExpr(Expr *Base, SourceLocation LBLoc,
     auto Res =
         PerformOmpSsImplicitIntegerConversion(Length->getExprLoc(), Length);
     if (Res.isInvalid())
+      // FIXME: PerformContextualImplicitConversion doesn't always tell us if it
+      // failed and produced a diagnostic.
+      // From commit ef6c43dc
       return ExprError(Diag(Length->getExprLoc(),
                             diag::err_oss_typecheck_section_not_integer)
                        << 1 << Length->getSourceRange());
@@ -4792,12 +4798,23 @@ ExprResult Sema::ActOnOSSArrayShapingExpr(Expr *Base, ArrayRef<Expr *> Shapes,
   else if (Type->isArrayType())
     Type = Type->getAsArrayTypeUnsafe()->getElementType();
 
+  // Handle the case
+  // struct S *p; incomplete type
+  // [10]p
+  if (RequireCompleteType(Base->getExprLoc(), Type,
+                diag::err_oss_shape_incomplete_type, Base)) {
+    ErrorFound = true;
+  }
+
   for (int i = Shapes.size() - 1 ; i >= 0; --i) {
     auto Res = PerformOmpSsImplicitIntegerConversion(Shapes[i]->getExprLoc(),
                                                      Shapes[i]);
     if (Res.isInvalid()) {
       ErrorFound = true;
-      Diag(Shapes[i]->getExprLoc(), diag::err_oss_typecheck_section_not_integer)
+      // FIXME: PerformContextualImplicitConversion doesn't always tell us if it
+      // failed and produced a diagnostic.
+      // From commit ef6c43dc
+      Diag(Shapes[i]->getExprLoc(), diag::err_oss_typecheck_shape_not_integer)
                        << 0 << Shapes[i]->getSourceRange();
       continue;
     }

clang/test/OmpSs/Sema/task_depend_shaping_expr.c

@@ -0,0 +1,10 @@
+// RUN: %clang_cc1 -verify -fompss-2 -ferror-limit 100 -o - %s
+
+
+void foo(int *p) {
+    struct S *s; // expected-note 2 {{forward declaration of 'struct S'}}
+    #pragma oss task depend(in : [4]p[3]) // expected-error {{shaping expression base is not a pointer or array}}
+    {}
+    #pragma oss task depend(in : [4]s) // expected-error {{shape of pointer to incomplete type 'struct S'}} expected-error {{array has incomplete element type 'struct S'}}
+    {}
+}