Add Semantic check for Flang OpenMP 4.5 - 2.7.1 Do Loop restrictions on single directive and firstprivate clause.maste

Semantic checks added to check the worksharing 'single' region closely nested inside a worksharing 'do' region. And also to check whether the DO iteration variable is a variable in Firstprivate clause.

Files:
check-directive-structure.h
check-omp-structure.h
check-omp-structure.cpp

Testcases:
omp-do01-positivecase.f90
omp-do01.f90
omp-do05-positivecase.f90
omp-do05.f90

Reviewed by: Kiran Chandramohan @kiranchandramohan , Valentin Clement @clementval

Differential Revision: https://reviews.llvm.org/D93205

1 files changed, 4 insertions, 0 deletions

diff --git a/flang/lib/Semantics/check-directive-structure.h b/flang/lib/Semantics/check-directive-structure.h
index 1075087feb4f..b93287e8c8dd 100644
--- a/flang/lib/Semantics/check-directive-structure.h
+++ b/flang/lib/Semantics/check-directive-structure.h
@@ -139,8 +139,11 @@ protected:
     const PC *clause{nullptr};
     std::multimap<C, const PC *> clauseInfo;
     std::list<C> actualClauses;
+    Symbol *loopIV{nullptr};
   };
 
+  void SetLoopIv(Symbol *symbol) { GetContext().loopIV = symbol; }
+
   // back() is the top of the stack
   DirectiveContext &GetContext() {
     CHECK(!dirContext_.empty());
@@ -160,6 +163,7 @@ protected:
     GetContext().allowedExclusiveClauses = {};
     GetContext().requiredClauses = {};
     GetContext().clauseInfo = {};
+    GetContext().loopIV = {nullptr};
   }
 
   void SetContextDirectiveSource(const parser::CharBlock &directive) {