[gcc r15-7966] Fortran: reject SAVE of a COMMON in a BLOCK construct [PR119199]

[Harald Anlauf via Gcc-cvs]

https://gcc.gnu.org/g:5e9f71254a5276cfca1769a5d490f6416a823b8d

commit r15-7966-g5e9f71254a5276cfca1769a5d490f6416a823b8d
Author: Harald Anlauf <anl...@gmx.de>
Date:   Mon Mar 10 22:24:27 2025 +0100

    Fortran: reject SAVE of a COMMON in a BLOCK construct [PR119199]
    
            PR fortran/119199
    
    gcc/fortran/ChangeLog:
    
            * decl.cc (gfc_match_save): Reject SAVE statement of a COMMON block
            when in a BLOCK construct.
            * trans-common.cc (translate_common): Avoid NULL pointer 
dereference.
    
    gcc/testsuite/ChangeLog:
    
            * gfortran.dg/common_30.f90: New test.
            * gfortran.dg/common_31.f90: New test.

Diff:
---
 gcc/fortran/decl.cc                     |  9 +++++++++
 gcc/fortran/trans-common.cc             |  2 +-
 gcc/testsuite/gfortran.dg/common_30.f90 | 10 ++++++++++
 gcc/testsuite/gfortran.dg/common_31.f90 | 15 +++++++++++++++
 4 files changed, 35 insertions(+), 1 deletion(-)

diff --git a/gcc/fortran/decl.cc b/gcc/fortran/decl.cc
index 5a46658651aa..feb454ea5b36 100644
--- a/gcc/fortran/decl.cc
+++ b/gcc/fortran/decl.cc
@@ -9795,6 +9795,15 @@ gfc_match_save (void)
       if (m == MATCH_NO)
        goto syntax;
 
+      /* F2023:C1108: A SAVE statement in a BLOCK construct shall contain a
+        saved-entity-list that does not specify a common-block-name.  */
+      if (gfc_current_state () == COMP_BLOCK)
+       {
+         gfc_error ("SAVE of COMMON block %qs at %C is not allowed "
+                    "in a BLOCK construct", n);
+         return MATCH_ERROR;
+       }
+
       c = gfc_get_common (n, 0);
       c->saved = 1;
 
diff --git a/gcc/fortran/trans-common.cc b/gcc/fortran/trans-common.cc
index 70b45174f84a..2db50da20dd0 100644
--- a/gcc/fortran/trans-common.cc
+++ b/gcc/fortran/trans-common.cc
@@ -1218,7 +1218,7 @@ translate_common (gfc_common_head *common, gfc_symbol 
*var_list)
   align = 1;
   saw_equiv = false;
 
-  if (var_list->attr.omp_allocate)
+  if (var_list && var_list->attr.omp_allocate)
     gfc_error ("Sorry, !$OMP allocate for COMMON block variable %qs at %L "
               "not supported", common->name, &common->where);
 
diff --git a/gcc/testsuite/gfortran.dg/common_30.f90 
b/gcc/testsuite/gfortran.dg/common_30.f90
new file mode 100644
index 000000000000..77a86348f4a7
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/common_30.f90
@@ -0,0 +1,10 @@
+! { dg-do compile }
+! PR fortran/119199
+!
+! One cannot SAVE an undefined COMMON block
+!
+! Contributed by David Binderman
+
+program main
+  save /argmnt1/ ! { dg-error "does not exist" }
+end
diff --git a/gcc/testsuite/gfortran.dg/common_31.f90 
b/gcc/testsuite/gfortran.dg/common_31.f90
new file mode 100644
index 000000000000..b60f46d7d5a5
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/common_31.f90
@@ -0,0 +1,15 @@
+! { dg-do compile }
+! PR fortran/119199 - reject SAVE of a COMMON in a BLOCK construct
+!
+! F2023:C1108: A SAVE statement in a BLOCK construct shall contain a
+!              saved-entity-list that does not specify a common-block-name.
+!
+! Contributed by David Binderman
+
+program main
+  real r
+  common /argmnt2/ r
+  block
+    save /argmnt2/ ! { dg-error "not allowed in a BLOCK construct" }
+  end block
+end