1 files changed, 33 insertions, 24 deletions

diff --git a/flang/lib/Semantics/check-omp-structure.cpp b/flang/lib/Semantics/check-omp-structure.cpp
index 8264e1d..d214d22 100644
--- a/flang/lib/Semantics/check-omp-structure.cpp
+++ b/flang/lib/Semantics/check-omp-structure.cpp
@@ -16,7 +16,6 @@
 #include "flang/Common/idioms.h"
 #include "flang/Common/indirection.h"
 #include "flang/Common/visit.h"
-#include "flang/Evaluate/shape.h"
 #include "flang/Evaluate/tools.h"
 #include "flang/Evaluate/type.h"
 #include "flang/Parser/char-block.h"
@@ -782,12 +781,15 @@ void OmpStructureChecker::CheckTargetNest(const parser::OpenMPConstruct &c) {
 
 void OmpStructureChecker::Enter(const parser::OpenMPBlockConstruct &x) {
   const auto &beginBlockDir{std::get<parser::OmpBeginBlockDirective>(x.t)};
-  const auto &endBlockDir{std::get<parser::OmpEndBlockDirective>(x.t)};
+  const auto &endBlockDir{
+      std::get<std::optional<parser::OmpEndBlockDirective>>(x.t)};
   const auto &beginDir{std::get<parser::OmpBlockDirective>(beginBlockDir.t)};
-  const auto &endDir{std::get<parser::OmpBlockDirective>(endBlockDir.t)};
   const parser::Block &block{std::get<parser::Block>(x.t)};
 
-  CheckMatching<parser::OmpBlockDirective>(beginDir, endDir);
+  if (endBlockDir) {
+    const auto &endDir{std::get<parser::OmpBlockDirective>(endBlockDir->t)};
+    CheckMatching<parser::OmpBlockDirective>(beginDir, endDir);
+  }
 
   PushContextAndClauseSets(beginDir.source, beginDir.v);
   if (llvm::omp::allTargetSet.test(GetContext().directive)) {
@@ -837,14 +839,14 @@ void OmpStructureChecker::Enter(const parser::OpenMPBlockConstruct &x) {
     bool foundNowait{false};
     parser::CharBlock NowaitSource;
 
-    auto catchCopyPrivateNowaitClauses = [&](const auto &dir, bool endDir) {
+    auto catchCopyPrivateNowaitClauses = [&](const auto &dir, bool isEnd) {
       for (auto &clause : std::get<parser::OmpClauseList>(dir.t).v) {
         if (clause.Id() == llvm::omp::Clause::OMPC_copyprivate) {
           for (const auto &ompObject : GetOmpObjectList(clause)->v) {
             const auto *name{parser::Unwrap<parser::Name>(ompObject)};
             if (Symbol * symbol{name->symbol}) {
               if (singleCopyprivateSyms.count(symbol)) {
-                if (endDir) {
+                if (isEnd) {
                   context_.Warn(common::UsageWarning::OpenMPUsage, name->source,
                       "The COPYPRIVATE clause with '%s' is already used on the SINGLE directive"_warn_en_US,
                       name->ToString());
@@ -858,7 +860,7 @@ void OmpStructureChecker::Enter(const parser::OpenMPBlockConstruct &x) {
                     "'%s' appears in more than one COPYPRIVATE clause on the END SINGLE directive"_err_en_US,
                     name->ToString());
               } else {
-                if (endDir) {
+                if (isEnd) {
                   endSingleCopyprivateSyms.insert(symbol);
                 } else {
                   singleCopyprivateSyms.insert(symbol);
@@ -871,7 +873,7 @@ void OmpStructureChecker::Enter(const parser::OpenMPBlockConstruct &x) {
             context_.Say(clause.source,
                 "At most one NOWAIT clause can appear on the SINGLE directive"_err_en_US);
           } else {
-            foundNowait = !endDir;
+            foundNowait = !isEnd;
           }
           if (!NowaitSource.ToString().size()) {
             NowaitSource = clause.source;
@@ -880,7 +882,9 @@ void OmpStructureChecker::Enter(const parser::OpenMPBlockConstruct &x) {
       }
     };
     catchCopyPrivateNowaitClauses(beginBlockDir, false);
-    catchCopyPrivateNowaitClauses(endBlockDir, true);
+    if (endBlockDir) {
+      catchCopyPrivateNowaitClauses(*endBlockDir, true);
+    }
     unsigned version{context_.langOptions().OpenMPVersion};
     if (version <= 52 && NowaitSource.ToString().size() &&
         (singleCopyprivateSyms.size() || endSingleCopyprivateSyms.size())) {
@@ -4151,21 +4155,26 @@ void OmpStructureChecker::CheckArraySection(
   // Detect this by looking for array accesses on character variables which are
   // not arrays.
   bool isSubstring{false};
-  evaluate::ExpressionAnalyzer ea{context_};
-  if (MaybeExpr expr = ea.Analyze(arrayElement.base)) {
-    std::optional<evaluate::Shape> shape = evaluate::GetShape(expr);
-    // Not an array: rank 0
-    if (shape && shape->size() == 0) {
-      if (std::optional<evaluate::DynamicType> type = expr->GetType()) {
-        if (type->category() == evaluate::TypeCategory::Character) {
-          // Substrings are explicitly denied by the standard [6.0:163:9-11].
-          // This is supported as an extension. This restriction was added in
-          // OpenMP 5.2.
-          isSubstring = true;
-          context_.Say(GetContext().clauseSource,
-              "The use of substrings in OpenMP argument lists has been disallowed since OpenMP 5.2."_port_en_US);
-        } else {
-          llvm_unreachable("Array indexing on a variable that isn't an array");
+  // Cannot analyze a base of an assumed-size array on its own. If we know
+  // this is an array (assumed-size or not) we can ignore it, since we're
+  // looking for strings.
+  if (!IsAssumedSizeArray(*name.symbol)) {
+    evaluate::ExpressionAnalyzer ea{context_};
+    if (MaybeExpr expr = ea.Analyze(arrayElement.base)) {
+      if (expr->Rank() == 0) {
+        // Not an array: rank 0
+        if (std::optional<evaluate::DynamicType> type = expr->GetType()) {
+          if (type->category() == evaluate::TypeCategory::Character) {
+            // Substrings are explicitly denied by the standard [6.0:163:9-11].
+            // This is supported as an extension. This restriction was added in
+            // OpenMP 5.2.
+            isSubstring = true;
+            context_.Say(GetContext().clauseSource,
+                "The use of substrings in OpenMP argument lists has been disallowed since OpenMP 5.2."_port_en_US);
+          } else {
+            llvm_unreachable(
+                "Array indexing on a variable that isn't an array");
+          }
         }
       }
     }