[flang] Add check for constraints on event-stmts

In the CoarrayChecker, add checks for the constraints C1177 and
C1178 for event-wait-stmt. Add event-post-stmt to the check
for the constraints for sync-stat-list. Add a check for the
constraint C1176 on event-variable.

Reviewed By: PeteSteinfeld

Differential Revision: https://reviews.llvm.org/D137204

9 files changed, 181 insertions, 22 deletions

diff --git a/flang/include/flang/Evaluate/tools.h b/flang/include/flang/Evaluate/tools.h
index dfc811fa2856..716c4a972694 100644
--- a/flang/include/flang/Evaluate/tools.h
+++ b/flang/include/flang/Evaluate/tools.h
@@ -1201,6 +1201,8 @@ bool IsLenTypeParameter(const Symbol &);
 bool IsExtensibleType(const DerivedTypeSpec *);
 bool IsBuiltinDerivedType(const DerivedTypeSpec *derived, const char *name);
 bool IsBuiltinCPtr(const Symbol &);
+bool IsEventType(const DerivedTypeSpec *);
+bool IsLockType(const DerivedTypeSpec *);
 // Is this derived type TEAM_TYPE from module ISO_FORTRAN_ENV?
 bool IsTeamType(const DerivedTypeSpec *);
 // Is this derived type TEAM_TYPE, C_PTR, or C_FUNPTR?
diff --git a/flang/lib/Evaluate/tools.cpp b/flang/lib/Evaluate/tools.cpp
index b9fb511b47cb..befe28605055 100644
--- a/flang/lib/Evaluate/tools.cpp
+++ b/flang/lib/Evaluate/tools.cpp
@@ -1568,6 +1568,14 @@ bool IsIsoCType(const DerivedTypeSpec *derived) {
       IsBuiltinDerivedType(derived, "c_funptr");
 }
 
+bool IsEventType(const DerivedTypeSpec *derived) {
+  return IsBuiltinDerivedType(derived, "event_type");
+}
+
+bool IsLockType(const DerivedTypeSpec *derived) {
+  return IsBuiltinDerivedType(derived, "lock_type");
+}
+
 bool IsTeamType(const DerivedTypeSpec *derived) {
   return IsBuiltinDerivedType(derived, "team_type");
 }
@@ -1577,8 +1585,7 @@ bool IsBadCoarrayType(const DerivedTypeSpec *derived) {
 }
 
 bool IsEventTypeOrLockType(const DerivedTypeSpec *derivedTypeSpec) {
-  return IsBuiltinDerivedType(derivedTypeSpec, "event_type") ||
-      IsBuiltinDerivedType(derivedTypeSpec, "lock_type");
+  return IsEventType(derivedTypeSpec) || IsLockType(derivedTypeSpec);
 }
 
 int CountLenParameters(const DerivedTypeSpec &type) {
diff --git a/flang/lib/Semantics/check-coarray.cpp b/flang/lib/Semantics/check-coarray.cpp
index f291a80a7033..688c3a7c92ad 100644
--- a/flang/lib/Semantics/check-coarray.cpp
+++ b/flang/lib/Semantics/check-coarray.cpp
@@ -124,6 +124,19 @@ static void CheckSyncStatList(
   }
 }
 
+static void CheckEventVariable(
+    SemanticsContext &context, const parser::EventVariable &eventVar) {
+  if (const auto *expr{GetExpr(context, eventVar)}) {
+    if (!IsEventType(evaluate::GetDerivedTypeSpec(expr->GetType()))) { // C1176
+      context.Say(parser::FindSourceLocation(eventVar),
+          "The event-variable must be of type EVENT_TYPE from module ISO_FORTRAN_ENV"_err_en_US);
+    } else if (!evaluate::IsCoarray(*expr)) { // C1604
+      context.Say(parser::FindSourceLocation(eventVar),
+          "The event-variable must be a coarray"_err_en_US);
+    }
+  }
+}
+
 void CoarrayChecker::Leave(const parser::ChangeTeamStmt &x) {
   CheckNamesAreDistinct(std::get<std::list<parser::CoarrayAssociation>>(x.t));
   CheckTeamType(context_, std::get<parser::TeamValue>(x.t));
@@ -156,6 +169,64 @@ void CoarrayChecker::Leave(const parser::SyncTeamStmt &x) {
   CheckSyncStatList(context_, std::get<std::list<parser::StatOrErrmsg>>(x.t));
 }
 
+void CoarrayChecker::Leave(const parser::EventPostStmt &x) {
+  CheckSyncStatList(context_, std::get<std::list<parser::StatOrErrmsg>>(x.t));
+  CheckEventVariable(context_, std::get<parser::EventVariable>(x.t));
+}
+
+void CoarrayChecker::Leave(const parser::EventWaitStmt &x) {
+  const auto &eventVar{std::get<parser::EventVariable>(x.t)};
+
+  if (const auto *expr{GetExpr(context_, eventVar)}) {
+    if (ExtractCoarrayRef(expr)) {
+      context_.Say(parser::FindSourceLocation(eventVar), // C1177
+          "A event-variable in a EVENT WAIT statement may not be a coindexed object"_err_en_US);
+    } else {
+      CheckEventVariable(context_, eventVar);
+    }
+  }
+
+  bool gotStat{false}, gotMsg{false}, gotUntil{false};
+  using EventWaitSpec = parser::EventWaitStmt::EventWaitSpec;
+  for (const EventWaitSpec &eventWaitSpec :
+      std::get<std::list<EventWaitSpec>>(x.t)) {
+    common::visit(
+        common::visitors{
+            [&](const parser::ScalarIntExpr &untilCount) {
+              if (gotUntil) {
+                context_.Say( // C1178
+                    "Until-spec in a event-wait-spec-list may not be repeated"_err_en_US);
+              }
+              gotUntil = true;
+            },
+            [&](const parser::StatOrErrmsg &statOrErrmsg) {
+              common::visit(
+                  common::visitors{
+                      [&](const parser::StatVariable &stat) {
+                        if (gotStat) {
+                          context_.Say( // C1178
+                              "A stat-variable in a event-wait-spec-list may not be repeated"_err_en_US);
+                        }
+                        gotStat = true;
+                      },
+                      [&](const parser::MsgVariable &errmsg) {
+                        if (gotMsg) {
+                          context_.Say( // C1178
+                              "A errmsg-variable in a event-wait-spec-list may not be repeated"_err_en_US);
+                        }
+                        gotMsg = true;
+                      },
+                  },
+                  statOrErrmsg.u);
+              CheckCoindexedStatOrErrmsg(
+                  context_, statOrErrmsg, "event-wait-spec-list");
+            },
+
+        },
+        eventWaitSpec.u);
+  }
+}
+
 void CoarrayChecker::Leave(const parser::ImageSelector &imageSelector) {
   haveStat_ = false;
   haveTeam_ = false;
diff --git a/flang/lib/Semantics/check-coarray.h b/flang/lib/Semantics/check-coarray.h
index b4ce5b42ad6f..51d030cbf771 100644
--- a/flang/lib/Semantics/check-coarray.h
+++ b/flang/lib/Semantics/check-coarray.h
@@ -17,6 +17,8 @@ class CharBlock;
 class MessageFixedText;
 struct ChangeTeamStmt;
 struct CoarrayAssociation;
+struct EventPostStmt;
+struct EventWaitStmt;
 struct FormTeamStmt;
 struct ImageSelector;
 struct SyncAllStmt;
@@ -35,6 +37,8 @@ public:
   void Leave(const parser::SyncImagesStmt &);
   void Leave(const parser::SyncMemoryStmt &);
   void Leave(const parser::SyncTeamStmt &);
+  void Leave(const parser::EventPostStmt &);
+  void Leave(const parser::EventWaitStmt &);
   void Leave(const parser::ImageSelector &);
   void Leave(const parser::FormTeamStmt &);
 
diff --git a/flang/test/Lower/pre-fir-tree04.f90 b/flang/test/Lower/pre-fir-tree04.f90
index 8188bfd54b40..e5f804245854 100644
--- a/flang/test/Lower/pre-fir-tree04.f90
+++ b/flang/test/Lower/pre-fir-tree04.f90
@@ -6,8 +6,8 @@
 Subroutine test_coarray
   use iso_fortran_env, only: team_type, event_type, lock_type
   type(team_type) :: t
-  type(event_type) :: done
-  type(lock_type) :: alock
+  type(event_type) :: done[*]
+  type(lock_type) :: alock[*]
   real :: y[10,*]
   integer :: counter[*]
   logical :: is_square
diff --git a/flang/test/Semantics/critical02.f90 b/flang/test/Semantics/critical02.f90
index 10581f9fd805..e1c9bb3e0ff1 100644
--- a/flang/test/Semantics/critical02.f90
+++ b/flang/test/Semantics/critical02.f90
@@ -61,7 +61,7 @@ end subroutine test6
 
 subroutine test7()
   use iso_fortran_env
-  type(event_type) :: x, y
+  type(event_type) :: x[*], y[*]
   critical
     !ERROR: An image control statement is not allowed in a CRITICAL construct
     event post (x)
diff --git a/flang/test/Semantics/doconcurrent01.f90 b/flang/test/Semantics/doconcurrent01.f90
index 0f4e13da2290..36595df5a62f 100644
--- a/flang/test/Semantics/doconcurrent01.f90
+++ b/flang/test/Semantics/doconcurrent01.f90
@@ -66,7 +66,7 @@ end subroutine do_concurrent_test2
 
 subroutine s1()
   use iso_fortran_env
-  type(event_type) :: x
+  type(event_type) :: x[*]
   do concurrent (i = 1:n)
 !ERROR: An image control statement is not allowed in DO CONCURRENT
     event post (x)
@@ -75,7 +75,7 @@ end subroutine s1
 
 subroutine s2()
   use iso_fortran_env
-  type(event_type) :: x
+  type(event_type) :: x[*]
   do concurrent (i = 1:n)
 !ERROR: An image control statement is not allowed in DO CONCURRENT
     event wait (x)
diff --git a/flang/test/Semantics/event01b.f90 b/flang/test/Semantics/event01b.f90
index 7cf374fbcc84..6a207427f6d4 100644
--- a/flang/test/Semantics/event01b.f90
+++ b/flang/test/Semantics/event01b.f90
@@ -22,9 +22,11 @@ program test_event_post
   !______ invalid event-variable ____________________________
 
   ! event-variable must be event_type
+  !ERROR: The event-variable must be of type EVENT_TYPE from module ISO_FORTRAN_ENV
   event post(non_event)
 
   ! event-variable must be a coarray
+  !ERROR: The event-variable must be a coarray
   event post(non_coarray)
 
   !ERROR: Must be a scalar value, but is a rank-1 array
@@ -48,18 +50,50 @@ program test_event_post
 
   !______ invalid sync-stat-lists: redundant sync-stat-list ____________
 
-  ! No specifier shall appear more than once in a given sync-stat-list
+  !ERROR: The stat-variable in a sync-stat-list may not be repeated
   event post(concert, stat=sync_status, stat=superfluous_stat)
 
-  ! No specifier shall appear more than once in a given sync-stat-list
+  !ERROR: The stat-variable in a sync-stat-list may not be repeated
+  event post(concert, errmsg=error_message, stat=sync_status, stat=superfluous_stat)
+
+  !ERROR: The stat-variable in a sync-stat-list may not be repeated
+  event post(concert, stat=sync_status, errmsg=error_message, stat=superfluous_stat)
+
+  !ERROR: The stat-variable in a sync-stat-list may not be repeated
+  event post(concert, stat=sync_status, stat=superfluous_stat, errmsg=error_message)
+
+  !ERROR: The errmsg-variable in a sync-stat-list may not be repeated
   event post(concert, errmsg=error_message, errmsg=superfluous_errmsg)
 
-  !______ invalid sync-stat-lists: coindexed stat-variable ____________
+  !ERROR: The errmsg-variable in a sync-stat-list may not be repeated
+  event post(concert, stat=sync_status, errmsg=error_message, errmsg=superfluous_errmsg)
+
+  !ERROR: The errmsg-variable in a sync-stat-list may not be repeated
+  event post(concert, errmsg=error_message, stat=sync_status, errmsg=superfluous_errmsg)
+
+  !ERROR: The errmsg-variable in a sync-stat-list may not be repeated
+  event post(concert, errmsg=error_message, errmsg=superfluous_errmsg, stat=sync_status)
 
-  ! Check constraint C1173 from the Fortran 2018 standard
+  !______ invalid sync-stat-lists: coindexed stat-variable - C1173____________
+
+  !ERROR: The stat-variable or errmsg-variable in a sync-stat-list may not be a coindexed object
   event post(concert, stat=co_indexed_integer[1])
 
-  ! Check constraint C1173 from the Fortran 2018 standard
+  !ERROR: The stat-variable or errmsg-variable in a sync-stat-list may not be a coindexed object
   event post(concert, errmsg=co_indexed_character[1])
 
+  !ERROR: The stat-variable or errmsg-variable in a sync-stat-list may not be a coindexed object
+  event post(concert, stat=co_indexed_integer[1], errmsg=error_message)
+
+  !ERROR: The stat-variable or errmsg-variable in a sync-stat-list may not be a coindexed object
+  event post(concert, stat=sync_status, errmsg=co_indexed_character[1])
+
+  !ERROR: The stat-variable or errmsg-variable in a sync-stat-list may not be a coindexed object
+  !ERROR: The stat-variable or errmsg-variable in a sync-stat-list may not be a coindexed object
+  event post(concert, stat=co_indexed_integer[1], errmsg=co_indexed_character[1])
+
+  !ERROR: The stat-variable or errmsg-variable in a sync-stat-list may not be a coindexed object
+  !ERROR: The stat-variable or errmsg-variable in a sync-stat-list may not be a coindexed object
+  event post(concert, errmsg=co_indexed_character[1], stat=co_indexed_integer[1])
+
 end program test_event_post
diff --git a/flang/test/Semantics/event02b.f90 b/flang/test/Semantics/event02b.f90
index 8aa53bd96213..20ee4047a1fe 100644
--- a/flang/test/Semantics/event02b.f90
+++ b/flang/test/Semantics/event02b.f90
@@ -21,16 +21,16 @@ program test_event_wait
 
   !_________________________ invalid event-variable ________________________________
 
-  ! event-variable must be event_type
+  !ERROR: The event-variable must be of type EVENT_TYPE from module ISO_FORTRAN_ENV
   event wait(non_event)
 
-  ! event-variable must be a coarray
+  !ERROR: The event-variable must be a coarray
   event wait(non_coarray)
 
-  ! event-variable must not be coindexed
+  !ERROR: A event-variable in a EVENT WAIT statement may not be a coindexed object
   event wait(concert[1])
 
-  ! event-variable must not be coindexed
+  !ERROR: A event-variable in a EVENT WAIT statement may not be a coindexed object
   event wait(occurrences(1)[1])
 
   !ERROR: Must be a scalar value, but is a rank-1 array
@@ -62,21 +62,62 @@ program test_event_wait
 
   !______ invalid event-wait-spec-lists: redundant event-wait-spec-list ____________
 
-  ! No specifier shall appear more than once in a given event-wait-spec-list
+  !ERROR: Until-spec in a event-wait-spec-list may not be repeated
   event wait(concert, until_count=threshold, until_count=indexed(1))
 
-  ! No specifier shall appear more than once in a given event-wait-spec-list
+  !ERROR: Until-spec in a event-wait-spec-list may not be repeated
+  event wait(concert, until_count=threshold, stat=sync_status, until_count=indexed(1))
+
+  !ERROR: Until-spec in a event-wait-spec-list may not be repeated
+  event wait(concert, until_count=threshold, errmsg=error_message, until_count=indexed(1))
+
+  !ERROR: Until-spec in a event-wait-spec-list may not be repeated
+  event wait(concert, until_count=threshold, stat=sync_status, errmsg=error_message, until_count=indexed(1))
+
+  !ERROR: A stat-variable in a event-wait-spec-list may not be repeated
   event wait(concert, stat=sync_status, stat=superfluous_stat)
 
-  ! No specifier shall appear more than once in a given event-wait-spec-list
+  !ERROR: A stat-variable in a event-wait-spec-list may not be repeated
+  event wait(concert, stat=sync_status, until_count=threshold, stat=superfluous_stat)
+
+  !ERROR: A stat-variable in a event-wait-spec-list may not be repeated
+  event wait(concert, stat=sync_status, errmsg=error_message, stat=superfluous_stat)
+
+  !ERROR: A stat-variable in a event-wait-spec-list may not be repeated
+  event wait(concert, stat=sync_status, until_count=threshold, errmsg=error_message, stat=superfluous_stat)
+
+  !ERROR: A errmsg-variable in a event-wait-spec-list may not be repeated
   event wait(concert, errmsg=error_message, errmsg=superfluous_errmsg)
 
-  !_____________ invalid sync-stat-lists: coindexed stat-variable __________________
+  !ERROR: A errmsg-variable in a event-wait-spec-list may not be repeated
+  event wait(concert, errmsg=error_message, until_count=threshold, errmsg=superfluous_errmsg)
+
+  !ERROR: A errmsg-variable in a event-wait-spec-list may not be repeated
+  event wait(concert, errmsg=error_message, stat=superfluous_stat, errmsg=superfluous_errmsg)
 
-  ! Check constraint C1173 from the Fortran 2018 standard
+  !ERROR: A errmsg-variable in a event-wait-spec-list may not be repeated
+  event wait(concert, errmsg=error_message, until_count=threshold, stat=superfluous_stat, errmsg=superfluous_errmsg)
+
+  !_____________ invalid sync-stat-lists: coindexed stat-variable - C1173 __________________
+
+  !ERROR: The stat-variable or errmsg-variable in a event-wait-spec-list may not be a coindexed object
   event wait(concert, stat=co_indexed_integer[1])
 
-  ! Check constraint C1173 from the Fortran 2018 standard
+  !ERROR: The stat-variable or errmsg-variable in a event-wait-spec-list may not be a coindexed object
   event wait(concert, errmsg=co_indexed_character[1])
 
+  !ERROR: The stat-variable or errmsg-variable in a event-wait-spec-list may not be a coindexed object
+  event wait(concert, stat=co_indexed_integer[1], errmsg=error_message)
+
+  !ERROR: The stat-variable or errmsg-variable in a event-wait-spec-list may not be a coindexed object
+  event wait(concert, stat=sync_status, errmsg=co_indexed_character[1])
+
+  !ERROR: The stat-variable or errmsg-variable in a event-wait-spec-list may not be a coindexed object
+  !ERROR: The stat-variable or errmsg-variable in a event-wait-spec-list may not be a coindexed object
+  event wait(concert, stat=co_indexed_integer[1], errmsg=co_indexed_character[1])
+
+  !ERROR: The stat-variable or errmsg-variable in a event-wait-spec-list may not be a coindexed object
+  !ERROR: The stat-variable or errmsg-variable in a event-wait-spec-list may not be a coindexed object
+  event wait(concert, errmsg=co_indexed_character[1], stat=co_indexed_integer[1])
+
 end program test_event_wait