[Flang][OpenMP] Finalize Statement context of clauses before op creation (#71679)

Currently Statement context used during processing of clauses is
finalized after the OpenMP operation creation. This causes the
finalization to go inside the OpenMP region and this can lead to
multiple finalizations in a parallel region. This fix proposes to
finalize them before the OpenMP op creation.

Fixes #71342

Author: kiranchandramohan

flang/lib/Lower/OpenMP.cpp

@@ -561,8 +561,7 @@ class ClauseProcessor {
   bool processDepend(llvm::SmallVectorImpl<mlir::Attribute> &dependTypeOperands,
                      llvm::SmallVectorImpl<mlir::Value> &dependOperands) const;
   bool
-  processIf(Fortran::lower::StatementContext &stmtCtx,
-            Fortran::parser::OmpIfClause::DirectiveNameModifier directiveName,
+  processIf(Fortran::parser::OmpIfClause::DirectiveNameModifier directiveName,
             mlir::Value &result) const;
   bool
   processLink(llvm::SmallVectorImpl<DeclareTargetCapturePair> &result) const;
@@ -1116,7 +1115,6 @@ genDependKindAttr(fir::FirOpBuilder &firOpBuilder,
 
 static mlir::Value getIfClauseOperand(
     Fortran::lower::AbstractConverter &converter,
-    Fortran::lower::StatementContext &stmtCtx,
     const Fortran::parser::OmpClause::If *ifClause,
     Fortran::parser::OmpIfClause::DirectiveNameModifier directiveName,
     mlir::Location clauseLocation) {
@@ -1127,6 +1125,7 @@ static mlir::Value getIfClauseOperand(
   if (directive && directive.value() != directiveName)
     return nullptr;
 
+  Fortran::lower::StatementContext stmtCtx;
   fir::FirOpBuilder &firOpBuilder = converter.getFirOpBuilder();
   auto &expr = std::get<Fortran::parser::ScalarLogicalExpr>(ifClause->v.t);
   mlir::Value ifVal = fir::getBase(
@@ -1672,15 +1671,14 @@ bool ClauseProcessor::processDepend(
 }
 
 bool ClauseProcessor::processIf(
-    Fortran::lower::StatementContext &stmtCtx,
     Fortran::parser::OmpIfClause::DirectiveNameModifier directiveName,
     mlir::Value &result) const {
   bool found = false;
   findRepeatableClause<ClauseTy::If>(
       [&](const ClauseTy::If *ifClause,
           const Fortran::parser::CharBlock &source) {
         mlir::Location clauseLocation = converter.genLocation(source);
-        mlir::Value operand = getIfClauseOperand(converter, stmtCtx, ifClause,
+        mlir::Value operand = getIfClauseOperand(converter, ifClause,
                                                  directiveName, clauseLocation);
         // Assume that, at most, a single 'if' clause will be applicable to the
         // given directive.
@@ -2305,8 +2303,7 @@ genParallelOp(Fortran::lower::AbstractConverter &converter,
   llvm::SmallVector<mlir::Attribute> reductionDeclSymbols;
 
   ClauseProcessor cp(converter, clauseList);
-  cp.processIf(stmtCtx,
-               Fortran::parser::OmpIfClause::DirectiveNameModifier::Parallel,
+  cp.processIf(Fortran::parser::OmpIfClause::DirectiveNameModifier::Parallel,
                ifClauseOperand);
   cp.processNumThreads(stmtCtx, numThreadsClauseOperand);
   cp.processProcBind(procBindKindAttr);
@@ -2360,8 +2357,7 @@ genTaskOp(Fortran::lower::AbstractConverter &converter,
       dependOperands;
 
   ClauseProcessor cp(converter, clauseList);
-  cp.processIf(stmtCtx,
-               Fortran::parser::OmpIfClause::DirectiveNameModifier::Task,
+  cp.processIf(Fortran::parser::OmpIfClause::DirectiveNameModifier::Task,
                ifClauseOperand);
   cp.processAllocate(allocatorOperands, allocateOperands);
   cp.processDefault();
@@ -2418,8 +2414,7 @@ genDataOp(Fortran::lower::AbstractConverter &converter,
   llvm::SmallVector<const Fortran::semantics::Symbol *> useDeviceSymbols;
 
   ClauseProcessor cp(converter, clauseList);
-  cp.processIf(stmtCtx,
-               Fortran::parser::OmpIfClause::DirectiveNameModifier::TargetData,
+  cp.processIf(Fortran::parser::OmpIfClause::DirectiveNameModifier::TargetData,
                ifClauseOperand);
   cp.processDevice(stmtCtx, deviceOperand);
   cp.processUseDevicePtr(devicePtrOperands, useDeviceTypes, useDeviceLocs,
@@ -2464,7 +2459,7 @@ genEnterExitDataOp(Fortran::lower::AbstractConverter &converter,
   }
 
   ClauseProcessor cp(converter, clauseList);
-  cp.processIf(stmtCtx, directiveName, ifClauseOperand);
+  cp.processIf(directiveName, ifClauseOperand);
   cp.processDevice(stmtCtx, deviceOperand);
   cp.processNowait(nowaitAttr);
   cp.processMap(currentLocation, directive, semanticsContext, stmtCtx,
@@ -2588,8 +2583,7 @@ genTargetOp(Fortran::lower::AbstractConverter &converter,
   llvm::SmallVector<const Fortran::semantics::Symbol *> mapSymbols;
 
   ClauseProcessor cp(converter, clauseList);
-  cp.processIf(stmtCtx,
-               Fortran::parser::OmpIfClause::DirectiveNameModifier::Target,
+  cp.processIf(Fortran::parser::OmpIfClause::DirectiveNameModifier::Target,
                ifClauseOperand);
   cp.processDevice(stmtCtx, deviceOperand);
   cp.processThreadLimit(stmtCtx, threadLimitOperand);
@@ -2743,8 +2737,7 @@ genTeamsOp(Fortran::lower::AbstractConverter &converter,
   llvm::SmallVector<mlir::Attribute> reductionDeclSymbols;
 
   ClauseProcessor cp(converter, clauseList);
-  cp.processIf(stmtCtx,
-               Fortran::parser::OmpIfClause::DirectiveNameModifier::Teams,
+  cp.processIf(Fortran::parser::OmpIfClause::DirectiveNameModifier::Teams,
                ifClauseOperand);
   cp.processAllocate(allocatorOperands, allocateOperands);
   cp.processDefault();
@@ -3019,8 +3012,7 @@ static void genOMP(Fortran::lower::AbstractConverter &converter,
     llvm::SmallVector<mlir::Value> alignedVars, nontemporalVars;
     mlir::Value ifClauseOperand;
     mlir::IntegerAttr simdlenClauseOperand, safelenClauseOperand;
-    cp.processIf(stmtCtx,
-                 Fortran::parser::OmpIfClause::DirectiveNameModifier::Simd,
+    cp.processIf(Fortran::parser::OmpIfClause::DirectiveNameModifier::Simd,
                  ifClauseOperand);
     cp.processSimdlen(simdlenClauseOperand);
     cp.processSafelen(safelenClauseOperand);

flang/test/Lower/OpenMP/parallel-if.f90

@@ -0,0 +1,12 @@
+!RUN: %flang_fc1 -emit-hlfir -fopenmp %s -o - | FileCheck %s
+
+!CHECK-LABEL: func @_QPtest1
+subroutine test1(a)
+integer :: a(:,:)
+!CHECK: hlfir.destroy
+!CHECK: omp.parallel if
+!$omp parallel if(any(a .eq. 1))
+!CHECK-NOT: hlfir.destroy
+  print *, "Hello"
+!$omp end parallel
+end subroutine