[gcc r15-8040] Fortran: improve checking of substring bounds [PR119118]

[Harald Anlauf via Gcc-cvs]

https://gcc.gnu.org/g:a5d56278d145d439092adf6f65c865c85623f881

commit r15-8040-ga5d56278d145d439092adf6f65c865c85623f881
Author: Harald Anlauf <anl...@gmx.de>
Date:   Thu Mar 13 18:46:54 2025 +0100

    Fortran: improve checking of substring bounds [PR119118]
    
    Commit r15-7873 copy-pasted erroneous code containing a non-terminating
    loop that did not progress its control variable, and a switch statement
    with an unhandled case leading to a gcc_unreachable () with suitable input.
    
            PR fortran/119118
    
    gcc/fortran/ChangeLog:
    
            * dependency.cc (contains_forall_index_p): Let loop over elements
            of a constructor update its control variable.  Handle REF_INQUIRY
            in switch statement.
            (gfc_contains_implied_index_p): Likewise.
    
    gcc/testsuite/ChangeLog:
    
            * gfortran.dg/bounds_check_26.f90: Update test.

Diff:
---
 gcc/fortran/dependency.cc                     | 6 ++++--
 gcc/testsuite/gfortran.dg/bounds_check_26.f90 | 4 +++-
 2 files changed, 7 insertions(+), 3 deletions(-)

diff --git a/gcc/fortran/dependency.cc b/gcc/fortran/dependency.cc
index 28b872f66382..57c0c49391bd 100644
--- a/gcc/fortran/dependency.cc
+++ b/gcc/fortran/dependency.cc
@@ -1853,7 +1853,7 @@ contains_forall_index_p (gfc_expr *expr)
     case EXPR_STRUCTURE:
     case EXPR_ARRAY:
       for (c = gfc_constructor_first (expr->value.constructor);
-          c; gfc_constructor_next (c))
+          c; c = gfc_constructor_next (c))
        if (contains_forall_index_p (c->expr))
          return true;
       break;
@@ -1874,6 +1874,7 @@ contains_forall_index_p (gfc_expr *expr)
        break;
 
       case REF_COMPONENT:
+      case REF_INQUIRY:
        break;
 
       case REF_SUBSTRING:
@@ -1933,7 +1934,7 @@ gfc_contains_implied_index_p (gfc_expr *expr)
     case EXPR_STRUCTURE:
     case EXPR_ARRAY:
       for (c = gfc_constructor_first (expr->value.constructor);
-          c; gfc_constructor_next (c))
+          c; c = gfc_constructor_next (c))
        if (gfc_contains_implied_index_p (c->expr))
          return true;
       break;
@@ -1954,6 +1955,7 @@ gfc_contains_implied_index_p (gfc_expr *expr)
        break;
 
       case REF_COMPONENT:
+      case REF_INQUIRY:
        break;
 
       case REF_SUBSTRING:
diff --git a/gcc/testsuite/gfortran.dg/bounds_check_26.f90 
b/gcc/testsuite/gfortran.dg/bounds_check_26.f90
index 69ac9fbe2f22..ddfcbd07f3c0 100644
--- a/gcc/testsuite/gfortran.dg/bounds_check_26.f90
+++ b/gcc/testsuite/gfortran.dg/bounds_check_26.f90
@@ -19,6 +19,8 @@ program main
   print *,      str(-n:11)  ! 2 checked bounds
   print *, len (str(-n:11)) ! 2 checked bounds
 
+  print *,      str(-n*n%kind:sum(n-[0,n%kind])) ! 2 checked bounds
+
 end program main
 
-! { dg-final { scan-tree-dump-times "Substring out of bounds:" 10 "original" } 
}
+! { dg-final { scan-tree-dump-times "Substring out of bounds:" 12 "original" } 
}