[gcc r10-9871] PR fortran/98411 - Pointless warning for static variables

[gcc r10-9871] PR fortran/98411 - Pointless warning for static variables

[Harald Anlauf]

https://gcc.gnu.org/g:799cf16051844f80d09526f17194373902254708

commit r10-9871-g799cf16051844f80d09526f17194373902254708
Author: Harald Anlauf <anlauf@gmx.de>
Date:   Mon May 17 21:35:38 2021 +0200

    PR fortran/98411 - Pointless warning for static variables
    
    Variables with explicit SAVE attribute cannot end up on the stack.
    There is no point in checking whether they should be moved off the
    stack to static storage.
    
    gcc/fortran/ChangeLog:
    
            PR fortran/98411
            * trans-decl.c (gfc_finish_var_decl): Add check for explicit SAVE
            attribute.
    
    gcc/testsuite/ChangeLog:
    
            PR fortran/98411
            * gfortran.dg/pr98411.f90: New test.
    
    (cherry picked from commit 09867aa0ef7568012650395189b735f9a34cf9b5)

Diff:
---
 gcc/fortran/trans-decl.c              |  1 +
 gcc/testsuite/gfortran.dg/pr98411.f90 | 16 ++++++++++++++++
 2 files changed, 17 insertions(+)

diff --git a/gcc/fortran/trans-decl.c b/gcc/fortran/trans-decl.c
index 529417fa8aa..bca15a51d99 100644
--- a/gcc/fortran/trans-decl.c
+++ b/gcc/fortran/trans-decl.c
@@ -737,6 +737,7 @@ gfc_finish_var_decl (tree decl, gfc_symbol * sym)
   /* Keep variables larger than max-stack-var-size off stack.  */
   if (!(sym->ns->proc_name && sym->ns->proc_name->attr.recursive)
       && !sym->attr.automatic
+      && sym->attr.save != SAVE_EXPLICIT
       && INTEGER_CST_P (DECL_SIZE_UNIT (decl))
       && !gfc_can_put_var_on_stack (DECL_SIZE_UNIT (decl))
 	 /* Put variable length auto array pointers always into stack.  */
diff --git a/gcc/testsuite/gfortran.dg/pr98411.f90 b/gcc/testsuite/gfortran.dg/pr98411.f90
new file mode 100644
index 00000000000..249afaea419
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/pr98411.f90
@@ -0,0 +1,16 @@
+! { dg-do compile }
+! { dg-options "-Wall -fautomatic -fmax-stack-var-size=100" }
+! PR fortran/98411 - Pointless warning for static variables 
+
+module try
+  implicit none
+  integer, save :: a(1000)
+contains
+  subroutine initmodule
+    real, save :: b(1000)
+    logical    :: c(1000) ! { dg-warning "moved from stack to static storage" }
+    a(1) = 42
+    b(2) = 3.14
+    c(3) = .true.
+  end subroutine initmodule
+end module try