[OpenMP] diagnose zero-length array section in the depend clause

The OpenMP specification disallows having zero-length array
sections in the depend clause (OpenMP 5.0 2.17.11).

Differential Revision: https://reviews.llvm.org/D71969

16 files changed, 35 insertions, 20 deletions

diff --git a/clang/include/clang/Basic/DiagnosticSemaKinds.td b/clang/include/clang/Basic/DiagnosticSemaKinds.td
index 54299a0409f..99ce42dd753 100644
--- a/clang/include/clang/Basic/DiagnosticSemaKinds.td
+++ b/clang/include/clang/Basic/DiagnosticSemaKinds.td
@@ -9640,6 +9640,8 @@ def err_omp_depend_sink_expected_plus_minus : Error<
   "expected '+' or '-' operation">;
 def err_omp_depend_sink_source_not_allowed : Error<
   "'depend(%select{source|sink:vec}0)' clause%select{|s}0 cannot be mixed with 'depend(%select{sink:vec|source}0)' clause%select{s|}0">;
+def err_omp_depend_zero_length_array_section_not_allowed : Error<
+  "zero-length array section is not allowed in 'depend' clause">;
 def err_omp_linear_ordered : Error<
   "'linear' clause cannot be specified along with 'ordered' clause with a parameter">;
 def err_omp_unexpected_schedule_modifier : Error<
diff --git a/clang/lib/Sema/SemaOpenMP.cpp b/clang/lib/Sema/SemaOpenMP.cpp
index 23cd6f04a93..5a4254f11a8 100644
--- a/clang/lib/Sema/SemaOpenMP.cpp
+++ b/clang/lib/Sema/SemaOpenMP.cpp
@@ -15020,6 +15020,22 @@ Sema::ActOnOpenMPDependClause(OpenMPDependClauseKind DepKind,
       }
       OpsOffs.emplace_back(RHS, OOK);
     } else {
+      // OpenMP 5.0 [2.17.11, Restrictions]
+      // List items used in depend clauses cannot be zero-length array sections.
+      const auto *OASE = dyn_cast<OMPArraySectionExpr>(SimpleExpr);
+      if (OASE) {
+        const Expr *Length = OASE->getLength();
+        Expr::EvalResult Result;
+        if (Length && !Length->isValueDependent() &&
+            Length->EvaluateAsInt(Result, Context) &&
+            Result.Val.getInt().isNullValue()) {
+          Diag(ELoc,
+               diag::err_omp_depend_zero_length_array_section_not_allowed)
+              << SimpleExpr->getSourceRange();
+          continue;
+        }
+      }
+
       auto *ASE = dyn_cast<ArraySubscriptExpr>(SimpleExpr);
       if (!RefExpr->IgnoreParenImpCasts()->isLValue() ||
           (ASE &&
diff --git a/clang/test/OpenMP/target_depend_messages.cpp b/clang/test/OpenMP/target_depend_messages.cpp
index a18bc5d5edc..df8723e12be 100644
--- a/clang/test/OpenMP/target_depend_messages.cpp
+++ b/clang/test/OpenMP/target_depend_messages.cpp
@@ -74,7 +74,7 @@ int main(int argc, char **argv, char *env[]) {
   foo();
   #pragma omp target depend (in : argv[0:-1]) // expected-error {{section length is evaluated to a negative value -1}}
   foo();
-  #pragma omp target depend (in : argv[-1:0])
+  #pragma omp target depend (in : argv[-1:0]) // expected-error {{zero-length array section is not allowed in 'depend' clause}}
   foo();
   #pragma omp target depend (in : argv[:]) // expected-error {{section length is unspecified and cannot be inferred because subscripted value is not an array}}
   foo();
diff --git a/clang/test/OpenMP/target_enter_data_depend_messages.cpp b/clang/test/OpenMP/target_enter_data_depend_messages.cpp
index 49dddfcc7cb..6d459e8793e 100644
--- a/clang/test/OpenMP/target_enter_data_depend_messages.cpp
+++ b/clang/test/OpenMP/target_enter_data_depend_messages.cpp
@@ -70,7 +70,7 @@ int tmain(T argc, S **argv, R *env[]) {
   foo();
   #pragma omp target enter data map(to: i) depend (in : argv[0:-1]) // expected-error {{section length is evaluated to a negative value -1}}
   foo();
-  #pragma omp target enter data map(to: i) depend (in : argv[-1:0])
+  #pragma omp target enter data map(to: i) depend (in : argv[-1:0]) // expected-error {{zero-length array section is not allowed in 'depend' clause}}
   foo();
   #pragma omp target enter data map(to: i) depend (in : argv[:]) // expected-error {{section length is unspecified and cannot be inferred because subscripted value is not an array}}
   foo();
@@ -145,7 +145,7 @@ int main(int argc, char **argv, char *env[]) {
   foo();
   #pragma omp target enter data map(to: i) depend (in : argv[0:-1]) // expected-error {{section length is evaluated to a negative value -1}}
   foo();
-  #pragma omp target enter data map(to: i) depend (in : argv[-1:0])
+  #pragma omp target enter data map(to: i) depend (in : argv[-1:0]) // expected-error {{zero-length array section is not allowed in 'depend' clause}}
   foo();
   #pragma omp target enter data map(to: i) depend (in : argv[:]) // expected-error {{section length is unspecified and cannot be inferred because subscripted value is not an array}}
   foo();
diff --git a/clang/test/OpenMP/target_exit_data_depend_messages.cpp b/clang/test/OpenMP/target_exit_data_depend_messages.cpp
index 8a2b07e55c5..e35e59090b9 100644
--- a/clang/test/OpenMP/target_exit_data_depend_messages.cpp
+++ b/clang/test/OpenMP/target_exit_data_depend_messages.cpp
@@ -70,7 +70,7 @@ int tmain(T argc, S **argv, R *env[]) {
   foo();
   #pragma omp target exit data map(from: i) depend (in : argv[0:-1]) // expected-error {{section length is evaluated to a negative value -1}}
   foo();
-  #pragma omp target exit data map(from: i) depend (in : argv[-1:0])
+  #pragma omp target exit data map(from: i) depend (in : argv[-1:0]) // expected-error {{zero-length array section is not allowed in 'depend' clause}}
   foo();
   #pragma omp target exit data map(from: i) depend (in : argv[:]) // expected-error {{section length is unspecified and cannot be inferred because subscripted value is not an array}}
   foo();
@@ -145,7 +145,7 @@ int main(int argc, char **argv, char *env[]) {
   foo();
   #pragma omp target exit data map(from: i) depend (in : argv[0:-1]) // expected-error {{section length is evaluated to a negative value -1}}
   foo();
-  #pragma omp target exit data map(from: i) depend (in : argv[-1:0])
+  #pragma omp target exit data map(from: i) depend (in : argv[-1:0]) // expected-error {{zero-length array section is not allowed in 'depend' clause}}
   foo();
   #pragma omp target exit data map(from: i) depend (in : argv[:]) // expected-error {{section length is unspecified and cannot be inferred because subscripted value is not an array}}
   foo();
diff --git a/clang/test/OpenMP/target_parallel_depend_messages.cpp b/clang/test/OpenMP/target_parallel_depend_messages.cpp
index 61557bd2aaf..1044a2b823a 100644
--- a/clang/test/OpenMP/target_parallel_depend_messages.cpp
+++ b/clang/test/OpenMP/target_parallel_depend_messages.cpp
@@ -68,7 +68,7 @@ int main(int argc, char **argv, char *env[]) {
   foo();
   #pragma omp target parallel depend (in : argv[0:-1]) // expected-error {{section length is evaluated to a negative value -1}}
   foo();
-  #pragma omp target parallel depend (in : argv[-1:0])
+  #pragma omp target parallel depend (in : argv[-1:0]) // expected-error {{zero-length array section is not allowed in 'depend' clause}}
   foo();
   #pragma omp target parallel depend (in : argv[:]) // expected-error {{section length is unspecified and cannot be inferred because subscripted value is not an array}}
   foo();
diff --git a/clang/test/OpenMP/target_parallel_for_depend_messages.cpp b/clang/test/OpenMP/target_parallel_for_depend_messages.cpp
index f6206912fe1..889c49149ce 100644
--- a/clang/test/OpenMP/target_parallel_for_depend_messages.cpp
+++ b/clang/test/OpenMP/target_parallel_for_depend_messages.cpp
@@ -69,7 +69,7 @@ int main(int argc, char **argv, char *env[]) {
   for (i = 0; i < argc; ++i) foo();
   #pragma omp target parallel for depend (in : argv[0:-1]) // expected-error {{section length is evaluated to a negative value -1}}
   for (i = 0; i < argc; ++i) foo();
-  #pragma omp target parallel for depend (in : argv[-1:0])
+  #pragma omp target parallel for depend (in : argv[-1:0]) // expected-error {{zero-length array section is not allowed in 'depend' clause}}
   for (i = 0; i < argc; ++i) foo();
   #pragma omp target parallel for depend (in : argv[:]) // expected-error {{section length is unspecified and cannot be inferred because subscripted value is not an array}}
   for (i = 0; i < argc; ++i) foo();
diff --git a/clang/test/OpenMP/target_parallel_for_simd_depend_messages.cpp b/clang/test/OpenMP/target_parallel_for_simd_depend_messages.cpp
index 01e00bf15f3..4b4c61ab2f6 100644
--- a/clang/test/OpenMP/target_parallel_for_simd_depend_messages.cpp
+++ b/clang/test/OpenMP/target_parallel_for_simd_depend_messages.cpp
@@ -69,7 +69,7 @@ int main(int argc, char **argv, char *env[]) {
   for (i = 0; i < argc; ++i) foo();
   #pragma omp target parallel for simd depend (in : argv[0:-1]) // expected-error {{section length is evaluated to a negative value -1}}
   for (i = 0; i < argc; ++i) foo();
-  #pragma omp target parallel for simd depend (in : argv[-1:0])
+  #pragma omp target parallel for simd depend (in : argv[-1:0]) // expected-error {{zero-length array section is not allowed in 'depend' clause}}
   for (i = 0; i < argc; ++i) foo();
   #pragma omp target parallel for simd depend (in : argv[:]) // expected-error {{section length is unspecified and cannot be inferred because subscripted value is not an array}}
   for (i = 0; i < argc; ++i) foo();
diff --git a/clang/test/OpenMP/target_simd_depend_messages.cpp b/clang/test/OpenMP/target_simd_depend_messages.cpp
index c02fac5a824..b8bb8daf308 100644
--- a/clang/test/OpenMP/target_simd_depend_messages.cpp
+++ b/clang/test/OpenMP/target_simd_depend_messages.cpp
@@ -69,7 +69,7 @@ int main(int argc, char **argv, char *env[]) {
   for (i = 0; i < argc; ++i) foo();
   #pragma omp target simd depend (in : argv[0:-1]) // expected-error {{section length is evaluated to a negative value -1}}
   for (i = 0; i < argc; ++i) foo();
-  #pragma omp target simd depend (in : argv[-1:0]) // OK
+  #pragma omp target simd depend (in : argv[-1:0]) // expected-error {{zero-length array section is not allowed in 'depend' clause}}
   for (i = 0; i < argc; ++i) foo();
   #pragma omp target simd depend (in : argv[:]) // expected-error {{section length is unspecified and cannot be inferred because subscripted value is not an array}}
   for (i = 0; i < argc; ++i) foo();
diff --git a/clang/test/OpenMP/target_teams_depend_messages.cpp b/clang/test/OpenMP/target_teams_depend_messages.cpp
index b8e1657d013..d83bbdcf2d8 100644
--- a/clang/test/OpenMP/target_teams_depend_messages.cpp
+++ b/clang/test/OpenMP/target_teams_depend_messages.cpp
@@ -68,7 +68,7 @@ int main(int argc, char **argv, char *env[]) {
   foo();
 #pragma omp target teams depend (in : argv[0:-1]) // expected-error {{section length is evaluated to a negative value -1}}
   foo();
-#pragma omp target teams depend (in : argv[-1:0])
+#pragma omp target teams depend (in : argv[-1:0]) // expected-error {{zero-length array section is not allowed in 'depend' clause}}
   foo();
 #pragma omp target teams depend (in : argv[:]) // expected-error {{section length is unspecified and cannot be inferred because subscripted value is not an array}}
   foo();
diff --git a/clang/test/OpenMP/target_teams_distribute_depend_messages.cpp b/clang/test/OpenMP/target_teams_distribute_depend_messages.cpp
index bb10a8f300a..38132eba3da 100644
--- a/clang/test/OpenMP/target_teams_distribute_depend_messages.cpp
+++ b/clang/test/OpenMP/target_teams_distribute_depend_messages.cpp
@@ -69,7 +69,7 @@ int main(int argc, char **argv, char *env[]) {
   for (i = 0; i < argc; ++i) foo();
 #pragma omp target teams distribute depend (in : argv[0:-1]) // expected-error {{section length is evaluated to a negative value -1}}
   for (i = 0; i < argc; ++i) foo();
-#pragma omp target teams distribute depend (in : argv[-1:0])
+#pragma omp target teams distribute depend (in : argv[-1:0]) // expected-error {{zero-length array section is not allowed in 'depend' clause}}
   for (i = 0; i < argc; ++i) foo();
 #pragma omp target teams distribute depend (in : argv[:]) // expected-error {{section length is unspecified and cannot be inferred because subscripted value is not an array}}
   for (i = 0; i < argc; ++i) foo();
diff --git a/clang/test/OpenMP/target_teams_distribute_parallel_for_depend_messages.cpp b/clang/test/OpenMP/target_teams_distribute_parallel_for_depend_messages.cpp
index 621f35808ce..0b4e6195552 100644
--- a/clang/test/OpenMP/target_teams_distribute_parallel_for_depend_messages.cpp
+++ b/clang/test/OpenMP/target_teams_distribute_parallel_for_depend_messages.cpp
@@ -69,7 +69,7 @@ int main(int argc, char **argv, char *env[]) {
   for (i = 0; i < argc; ++i) foo();
 #pragma omp target teams distribute parallel for depend (in : argv[0:-1]) // expected-error {{section length is evaluated to a negative value -1}}
   for (i = 0; i < argc; ++i) foo();
-#pragma omp target teams distribute parallel for depend (in : argv[-1:0])
+#pragma omp target teams distribute parallel for depend (in : argv[-1:0]) // expected-error {{zero-length array section is not allowed in 'depend' clause}}
   for (i = 0; i < argc; ++i) foo();
 #pragma omp target teams distribute parallel for depend (in : argv[:]) // expected-error {{section length is unspecified and cannot be inferred because subscripted value is not an array}}
   for (i = 0; i < argc; ++i) foo();
diff --git a/clang/test/OpenMP/target_teams_distribute_parallel_for_simd_depend_messages.cpp b/clang/test/OpenMP/target_teams_distribute_parallel_for_simd_depend_messages.cpp
index d0735e43500..d35a5c0579c 100644
--- a/clang/test/OpenMP/target_teams_distribute_parallel_for_simd_depend_messages.cpp
+++ b/clang/test/OpenMP/target_teams_distribute_parallel_for_simd_depend_messages.cpp
@@ -69,7 +69,7 @@ int main(int argc, char **argv, char *env[]) {
   for (i = 0; i < argc; ++i) foo();
 #pragma omp target teams distribute parallel for simd depend (in : argv[0:-1]) // expected-error {{section length is evaluated to a negative value -1}}
   for (i = 0; i < argc; ++i) foo();
-#pragma omp target teams distribute parallel for simd depend (in : argv[-1:0])
+#pragma omp target teams distribute parallel for simd depend (in : argv[-1:0]) // expected-error {{zero-length array section is not allowed in 'depend' clause}}
   for (i = 0; i < argc; ++i) foo();
 #pragma omp target teams distribute parallel for simd depend (in : argv[:]) // expected-error {{section length is unspecified and cannot be inferred because subscripted value is not an array}}
   for (i = 0; i < argc; ++i) foo();
diff --git a/clang/test/OpenMP/target_teams_distribute_simd_depend_messages.cpp b/clang/test/OpenMP/target_teams_distribute_simd_depend_messages.cpp
index 2e1be6c725b..b71e87a6d41 100644
--- a/clang/test/OpenMP/target_teams_distribute_simd_depend_messages.cpp
+++ b/clang/test/OpenMP/target_teams_distribute_simd_depend_messages.cpp
@@ -69,7 +69,7 @@ int main(int argc, char **argv, char *env[]) {
   for (i = 0; i < argc; ++i) foo();
 #pragma omp target teams distribute simd depend (in : argv[0:-1]) // expected-error {{section length is evaluated to a negative value -1}}
   for (i = 0; i < argc; ++i) foo();
-#pragma omp target teams distribute simd depend (in : argv[-1:0])
+#pragma omp target teams distribute simd depend (in : argv[-1:0]) // expected-error {{zero-length array section is not allowed in 'depend' clause}}
   for (i = 0; i < argc; ++i) foo();
 #pragma omp target teams distribute simd depend (in : argv[:]) // expected-error {{section length is unspecified and cannot be inferred because subscripted value is not an array}}
   for (i = 0; i < argc; ++i) foo();
diff --git a/clang/test/OpenMP/target_update_depend_messages.cpp b/clang/test/OpenMP/target_update_depend_messages.cpp
index e09284f7291..181078533f4 100644
--- a/clang/test/OpenMP/target_update_depend_messages.cpp
+++ b/clang/test/OpenMP/target_update_depend_messages.cpp
@@ -15,7 +15,6 @@ class vector {
   public:
     int operator[](int index) { return 0; }
 };
-
 template <class T, class S, class R>
 int tmain(T argc, S **argv, R *env[]) {
   vector vec;
@@ -52,7 +51,7 @@ int tmain(T argc, S **argv, R *env[]) {
   #pragma omp target update to(z) depend(in : argv[argc: // expected-error {{expected expression}} expected-error {{expected ']'}} expected-error {{expected ')'}} expected-note {{to match this '['}} expected-note {{to match this '('}}
   #pragma omp target update to(z) depend(in : argv[argc:argc] // expected-error {{expected ')'}} expected-note {{to match this '('}}
   #pragma omp target update to(z) depend(in : argv[0:-1]) // expected-error {{section length is evaluated to a negative value -1}}
-  #pragma omp target update to(z) depend(in : argv[-1:0])
+  #pragma omp target update to(z) depend(in : argv[-1:0]) // expected-error {{zero-length array section is not allowed in 'depend' clause}}
   #pragma omp target update to(z) depend(in : argv[:]) // expected-error {{section length is unspecified and cannot be inferred because subscripted value is not an array}}
   #pragma omp target update to(z) depend(in : argv[3:4:1]) // expected-error {{expected ']'}} expected-note {{to match this '['}}
   #pragma omp target update to(z) depend(in:a[0:1]) // expected-error {{subscripted value is not an array or pointer}}
@@ -64,7 +63,6 @@ int tmain(T argc, S **argv, R *env[]) {
 
   return 0;
 }
-
 int main(int argc, char **argv, char *env[]) {
   vector vec;
   typedef float V __attribute__((vector_size(16)));
@@ -100,7 +98,7 @@ int main(int argc, char **argv, char *env[]) {
   #pragma omp target update to(z) depend(in : argv[argc: // expected-error {{expected expression}} expected-error {{expected ']'}} expected-error {{expected ')'}} expected-note {{to match this '['}} expected-note {{to match this '('}}
   #pragma omp target update to(z) depend(in : argv[argc:argc] // expected-error {{expected ')'}} expected-note {{to match this '('}}
   #pragma omp target update to(z) depend(in : argv[0:-1]) // expected-error {{section length is evaluated to a negative value -1}}
-  #pragma omp target update to(z) depend(in : argv[-1:0])
+  #pragma omp target update to(z) depend(in : argv[-1:0]) // expected-error {{zero-length array section is not allowed in 'depend' clause}}
   #pragma omp target update to(z) depend(in : argv[:]) // expected-error {{section length is unspecified and cannot be inferred because subscripted value is not an array}}
   #pragma omp target update to(z) depend(in : argv[3:4:1]) // expected-error {{expected ']'}} expected-note {{to match this '['}}
   #pragma omp target update to(z) depend(in:a[0:1]) // expected-error {{subscripted value is not an array or pointer}}
@@ -109,6 +107,5 @@ int main(int argc, char **argv, char *env[]) {
   #pragma omp target update to(z) depend(in:env[0:][:]) // expected-error {{section length is unspecified and cannot be inferred because subscripted value is an array of unknown bound}}
   #pragma omp target update to(z) depend(in : argv[ : argc][1 : argc - 1])
   #pragma omp target update to(z) depend(in : arr[0])
-
   return tmain(argc, argv, env); // expected-note {{in instantiation of function template specialization 'tmain<int, char, char>' requested here}}
 }
diff --git a/clang/test/OpenMP/task_depend_messages.cpp b/clang/test/OpenMP/task_depend_messages.cpp
index 63ad8474817..407b8b44523 100644
--- a/clang/test/OpenMP/task_depend_messages.cpp
+++ b/clang/test/OpenMP/task_depend_messages.cpp
@@ -45,7 +45,7 @@ int main(int argc, char **argv, char *env[]) {
   #pragma omp task depend (in : argv[argc: // expected-error {{expected expression}} expected-error {{expected ']'}} expected-error {{expected ')'}} expected-note {{to match this '['}} expected-note {{to match this '('}}
   #pragma omp task depend (in : argv[argc:argc] // expected-error {{expected ')'}} expected-note {{to match this '('}}
   #pragma omp task depend (in : argv[0:-1]) // expected-error {{section length is evaluated to a negative value -1}}
-  #pragma omp task depend (in : argv[-1:0])
+  #pragma omp task depend (in : argv[-1:0]) // expected-error {{zero-length array section is not allowed in 'depend' clause}}
   #pragma omp task depend (in : argv[:]) // expected-error {{section length is unspecified and cannot be inferred because subscripted value is not an array}}
   #pragma omp task depend (in : argv[3:4:1]) // expected-error {{expected ']'}} expected-note {{to match this '['}}
   #pragma omp task depend(in:a[0:1]) // expected-error {{subscripted value is not an array or pointer}}