[OPENMP] Additional processing of 'omp atomic read' directive.
According to OpenMP standard, Section 2.12.6, atomic Construct, '#pragma omp atomic read' is allowed to be used only for expression statements of form 'v = x;', where x and v (as applicable) are both l-value expressions with scalar type. Patch adds checks for it.
llvm-svn: 222231
diff --git a/clang/lib/Sema/SemaOpenMP.cpp b/clang/lib/Sema/SemaOpenMP.cpp
index 9bdb092..e4838de 100644
--- a/clang/lib/Sema/SemaOpenMP.cpp
+++ b/clang/lib/Sema/SemaOpenMP.cpp
@@ -3223,13 +3223,94 @@
}
}
}
+
auto Body = CS->getCapturedStmt();
+ Expr *X = nullptr;
+ Expr *V = nullptr;
+ Expr *E = nullptr;
+ // OpenMP [2.12.6, atomic Construct]
+ // In the next expressions:
+ // * x and v (as applicable) are both l-value expressions with scalar type.
+ // * During the execution of an atomic region, multiple syntactic
+ // occurrences of x must designate the same storage location.
+ // * Neither of v and expr (as applicable) may access the storage location
+ // designated by x.
+ // * Neither of x and expr (as applicable) may access the storage location
+ // designated by v.
+ // * expr is an expression with scalar type.
+ // * binop is one of +, *, -, /, &, ^, |, <<, or >>.
+ // * binop, binop=, ++, and -- are not overloaded operators.
+ // * The expression x binop expr must be numerically equivalent to x binop
+ // (expr). This requirement is satisfied if the operators in expr have
+ // precedence greater than binop, or by using parentheses around expr or
+ // subexpressions of expr.
+ // * The expression expr binop x must be numerically equivalent to (expr)
+ // binop x. This requirement is satisfied if the operators in expr have
+ // precedence equal to or greater than binop, or by using parentheses around
+ // expr or subexpressions of expr.
+ // * For forms that allow multiple occurrences of x, the number of times
+ // that x is evaluated is unspecified.
if (AtomicKind == OMPC_read) {
- if (!isa<Expr>(Body)) {
- Diag(Body->getLocStart(),
- diag::err_omp_atomic_read_not_expression_statement);
- return StmtError();
+ enum {
+ NotAnExpression,
+ NotAnAssignmentOp,
+ NotAScalarType,
+ NotAnLValue,
+ NoError
+ } ErrorFound = NoError;
+ SourceLocation ErrorLoc, NoteLoc;
+ SourceRange ErrorRange, NoteRange;
+ // If clause is read:
+ // v = x;
+ if (auto AtomicBody = dyn_cast<Expr>(Body)) {
+ auto AtomicBinOp =
+ dyn_cast<BinaryOperator>(AtomicBody->IgnoreParenImpCasts());
+ if (AtomicBinOp && AtomicBinOp->getOpcode() == BO_Assign) {
+ X = AtomicBinOp->getRHS()->IgnoreParenImpCasts();
+ V = AtomicBinOp->getLHS()->IgnoreParenImpCasts();
+ if ((X->isInstantiationDependent() || X->getType()->isScalarType()) &&
+ (V->isInstantiationDependent() || V->getType()->isScalarType())) {
+ if (!X->isLValue() || !V->isLValue()) {
+ auto NotLValueExpr = X->isLValue() ? V : X;
+ ErrorFound = NotAnLValue;
+ ErrorLoc = AtomicBinOp->getExprLoc();
+ ErrorRange = AtomicBinOp->getSourceRange();
+ NoteLoc = NotLValueExpr->getExprLoc();
+ NoteRange = NotLValueExpr->getSourceRange();
+ }
+ } else if (!X->isInstantiationDependent() ||
+ !V->isInstantiationDependent()) {
+ auto NotScalarExpr =
+ (X->isInstantiationDependent() || X->getType()->isScalarType())
+ ? V
+ : X;
+ ErrorFound = NotAScalarType;
+ ErrorLoc = AtomicBinOp->getExprLoc();
+ ErrorRange = AtomicBinOp->getSourceRange();
+ NoteLoc = NotScalarExpr->getExprLoc();
+ NoteRange = NotScalarExpr->getSourceRange();
+ }
+ } else {
+ ErrorFound = NotAnAssignmentOp;
+ ErrorLoc = AtomicBody->getExprLoc();
+ ErrorRange = AtomicBody->getSourceRange();
+ NoteLoc = AtomicBinOp ? AtomicBinOp->getOperatorLoc()
+ : AtomicBody->getExprLoc();
+ NoteRange = AtomicBinOp ? AtomicBinOp->getSourceRange()
+ : AtomicBody->getSourceRange();
+ }
+ } else {
+ ErrorFound = NotAnExpression;
+ NoteLoc = ErrorLoc = Body->getLocStart();
+ NoteRange = ErrorRange = SourceRange(NoteLoc, NoteLoc);
}
+ if (ErrorFound != NoError) {
+ Diag(ErrorLoc, diag::err_omp_atomic_read_not_expression_statement)
+ << ErrorRange;
+ Diag(NoteLoc, diag::note_omp_atomic_read) << ErrorFound << NoteRange;
+ return StmtError();
+ } else if (CurContext->isDependentContext())
+ V = X = nullptr;
} else if (AtomicKind == OMPC_write) {
if (!isa<Expr>(Body)) {
Diag(Body->getLocStart(),
@@ -3257,7 +3338,8 @@
getCurFunction()->setHasBranchProtectedScope();
- return OMPAtomicDirective::Create(Context, StartLoc, EndLoc, Clauses, AStmt);
+ return OMPAtomicDirective::Create(Context, StartLoc, EndLoc, Clauses, AStmt,
+ X, V, E);
}
StmtResult Sema::ActOnOpenMPTargetDirective(ArrayRef<OMPClause *> Clauses,