[committed] openmp, fortran: Improve !$omp atomic checks [PR104328]

[committed] openmp, fortran: Improve !$omp atomic checks [PR104328]

[Jakub Jelinek]

Hi!

The testcase shows some cases that weren't verified and we ICE on
invalid because of that.
One problem is that unlike before, we weren't checking if some expression
is EXPR_VARIABLE with non-NULL symtree in the case where there was
a conversion around it.
The other two issues is that we check that in an IF ->block is non-NULL
and then immediately dereference ->block->next->op, but on invalid
code with no statements in the then clause ->block->next might be NULL.

Bootstrapped/regtested on x86_64-linux and i686-linux, committed to
trunk.

2022-02-02  Jakub Jelinek  <jakub@redhat.com>

	PR fortran/104328
	* openmp.cc (is_scalar_intrinsic_expr): If must_be_var && conv_ok
	and expr is conversion, verify it is a conversion from EXPR_VARIABLE
	with non-NULL symtree.  Check ->block->next before dereferencing it.

	* gfortran.dg/gomp/atomic-27.f90: New test.

--- gcc/fortran/openmp.cc.jj	2022-01-21 11:01:12.458449420 +0100
+++ gcc/fortran/openmp.cc	2022-02-02 20:20:22.020000000 +0100
@@ -7660,9 +7660,16 @@ static bool
 is_scalar_intrinsic_expr (gfc_expr *expr, bool must_be_var, bool conv_ok)
 {
   if (must_be_var
-      && (expr->expr_type != EXPR_VARIABLE || !expr->symtree)
-      && (!conv_ok || !is_conversion (expr, true, true)))
-    return false;
+      && (expr->expr_type != EXPR_VARIABLE || !expr->symtree))
+    {
+      if (!conv_ok)
+	return false;
+      gfc_expr *conv = is_conversion (expr, true, true);
+      if (!conv)
+	return false;
+      if (conv->expr_type != EXPR_VARIABLE || !conv->symtree)
+	return false;
+    }
   return (expr->rank == 0
 	  && !gfc_is_coindexed (expr)
 	  && (expr->ts.type == BT_INTEGER
@@ -7705,6 +7712,7 @@ resolve_omp_atomic (gfc_code *code)
       if (next->op == EXEC_IF
 	  && next->block
 	  && next->block->op == EXEC_IF
+	  && next->block->next
 	  && next->block->next->op == EXEC_ASSIGN)
 	{
 	  comp_cond = next->block->expr1;
@@ -7757,6 +7765,7 @@ resolve_omp_atomic (gfc_code *code)
       if (code->op == EXEC_IF
 	  && code->block
 	  && code->block->op == EXEC_IF
+	  && code->block->next
 	  && code->block->next->op == EXEC_ASSIGN)
 	{
 	  comp_cond = code->block->expr1;
--- gcc/testsuite/gfortran.dg/gomp/atomic-27.f90.jj	2022-02-02 20:30:44.101437198 +0100
+++ gcc/testsuite/gfortran.dg/gomp/atomic-27.f90	2022-02-02 20:29:50.651217307 +0100
@@ -0,0 +1,34 @@
+! PR fortran/104328
+! { dg-do compile }
+
+subroutine foo
+  integer :: k = 1
+  !$omp atomic compare
+  if ( k == 2 ) then	! { dg-error "unexpected !.OMP ATOMIC expression" }
+  end if
+end
+subroutine bar
+  real :: x = 1
+  !$omp atomic compare
+  if ( x == 2 ) then	! { dg-error "unexpected !.OMP ATOMIC expression" }
+  end if
+end
+subroutine baz
+  integer :: i
+  !$omp atomic capture
+  i = 1
+  i = i + 1.		! { dg-error "!.OMP ATOMIC capture-statement requires a scalar variable of intrinsic type" }
+end
+subroutine qux
+  integer :: i = 0
+  !$omp atomic capture
+  i = i + 1.0
+  i = i + 1.0		! { dg-error "!.OMP ATOMIC capture-statement requires a scalar variable of intrinsic type" }
+end
+subroutine garply
+  logical :: k = .true.
+  !$omp atomic capture compare
+  if ( k ) then		! { dg-error "unexpected !.OMP ATOMIC expression" }
+  else
+  end if
+end


	Jakub