Fortran: prevent NULL pointer dereferences checking do-loop contained stuff

gcc/fortran/ChangeLog:

	PR fortran/103718
	PR fortran/103719
	* frontend-passes.c (doloop_contained_procedure_code): Add several
	checks to prevent NULL pointer dereferences on valid and invalid
	code called within do-loops.

gcc/testsuite/ChangeLog:

	PR fortran/103718
	PR fortran/103719
	* gfortran.dg/do_check_18.f90: New test.

diff --git a/gcc/fortran/frontend-passes.c b/gcc/fortran/frontend-passes.c
index 57b24a1..c106ee0 100644 (file)
--- a/gcc/fortran/frontend-passes.c
+++ b/gcc/fortran/frontend-passes.c
@@ -2390,7 +2390,7 @@ doloop_contained_procedure_code (gfc_code **c,
   switch (co->op)
     {
     case EXEC_ASSIGN:
-      if (co->expr1->symtree->n.sym == do_var)
+      if (co->expr1->symtree && co->expr1->symtree->n.sym == do_var)
        gfc_error_now (errmsg, do_var->name, &co->loc, info->procedure->name,
                       &info->where_do);
       break;
@@ -2411,14 +2411,14 @@ doloop_contained_procedure_code (gfc_code **c,
       break;
 
     case EXEC_OPEN:
-      if (co->ext.open->iostat
+      if (co->ext.open && co->ext.open->iostat
          && co->ext.open->iostat->symtree->n.sym == do_var)
        gfc_error_now (errmsg, do_var->name, &co->ext.open->iostat->where,
                       info->procedure->name, &info->where_do);
       break;
 
     case EXEC_CLOSE:
-      if (co->ext.close->iostat
+      if (co->ext.close && co->ext.close->iostat
          && co->ext.close->iostat->symtree->n.sym == do_var)
        gfc_error_now (errmsg, do_var->name, &co->ext.close->iostat->where,
                       info->procedure->name, &info->where_do);
@@ -2429,7 +2429,8 @@ doloop_contained_procedure_code (gfc_code **c,
        {
 
        case EXEC_INQUIRE:
-#define CHECK_INQ(a) do { if (co->ext.inquire->a &&                    \
+#define CHECK_INQ(a) do { if (co->ext.inquire    &&                    \
+                             co->ext.inquire->a &&                     \
                              co->ext.inquire->a->symtree->n.sym == do_var) \
              gfc_error_now (errmsg, do_var->name,                      \
                             &co->ext.inquire->a->where,                \
@@ -2448,21 +2449,23 @@ doloop_contained_procedure_code (gfc_code **c,
 #undef CHECK_INQ
 
        case EXEC_READ:
-         if (co->expr1 && co->expr1->symtree->n.sym == do_var)
+         if (co->expr1 && co->expr1->symtree
+             && co->expr1->symtree->n.sym == do_var)
            gfc_error_now (errmsg, do_var->name, &co->expr1->where,
                           info->procedure->name, &info->where_do);
 
          /* Fallthrough.  */
 
        case EXEC_WRITE:
-         if (co->ext.dt->iostat
+         if (co->ext.dt && co->ext.dt->iostat && co->ext.dt->iostat->symtree
              && co->ext.dt->iostat->symtree->n.sym == do_var)
            gfc_error_now (errmsg, do_var->name, &co->ext.dt->iostat->where,
                           info->procedure->name, &info->where_do);
          break;
 
        case EXEC_IOLENGTH:
-         if (co->expr1 && co->expr1->symtree->n.sym == do_var)
+         if (co->expr1 && co->expr1->symtree
+             && co->expr1->symtree->n.sym == do_var)
            gfc_error_now (errmsg, do_var->name, &co->expr1->where,
                           info->procedure->name, &info->where_do);
          break;

diff --git a/gcc/testsuite/gfortran.dg/do_check_18.f90 b/gcc/testsuite/gfortran.dg/do_check_18.f90
new file mode 100644 (file)
index 0000000..b06112a
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/do_check_18.f90
@@ -0,0 +1,27 @@
+! { dg-do compile }
+! PR103718,
+! PR103719 - ICE in doloop_contained_procedure_code
+! Contributed by G.Steinmetz
+
+subroutine s1
+  integer :: i
+  do i = 1, 2
+     call s
+  end do
+contains
+  subroutine s
+    integer :: n
+    inquire (iolength=n) 0  ! valid
+  end
+end
+
+subroutine s2
+  integer :: i
+  do i = 1, 2
+     call s
+  end do
+contains
+  subroutine s
+    shape(1) = 0    ! { dg-error "Non-variable expression" }
+  end
+end