[gcc r9-9099] PR fortran/95342 - ICE in gfc_match_subroutine, at fortran/decl.c:7913

[Harald Anlauf <anlauf@gcc.gnu.org>]

https://gcc.gnu.org/g:34e72e050bf4e23689af7061f6381b95339eb7fa

commit r9-9099-g34e72e050bf4e23689af7061f6381b95339eb7fa
Author: Harald Anlauf <anlauf@gmx.de>
Date:   Thu Dec 3 20:33:22 2020 +0100

    PR fortran/95342 - ICE in gfc_match_subroutine, at fortran/decl.c:7913
    
    Add checks for NULL pointers before dereferencing them.
    
    gcc/fortran/ChangeLog:
    
            PR fortran/95342
            * decl.c (gfc_match_function_decl): Avoid NULL pointer dereference.
            (gfc_match_subroutine): Likewise.
    
    gcc/testsuite/ChangeLog:
    
            PR fortran/95342
            * gfortran.dg/pr95342.f90: New test.
    
    (cherry picked from commit 30b606bb9b9314010a446ea4bed3481632008f75)

Diff:
---
 gcc/fortran/decl.c                    |  2 ++
 gcc/testsuite/gfortran.dg/pr95342.f90 | 20 ++++++++++++++++++++
 2 files changed, 22 insertions(+)

diff --git a/gcc/fortran/decl.c b/gcc/fortran/decl.c
index b7987fb24ba..00321da827e 100644
--- a/gcc/fortran/decl.c
+++ b/gcc/fortran/decl.c
@@ -7310,6 +7310,7 @@ gfc_match_function_decl (void)
      procedure interface body.  */
     if (sym->attr.is_bind_c && sym->attr.module_procedure && sym->old_symbol
   	&& strcmp (sym->name, sym->old_symbol->name) == 0
+	&& sym->binding_label && sym->old_symbol->binding_label
 	&& strcmp (sym->binding_label, sym->old_symbol->binding_label) != 0)
       {
 	  const char *null = "NULL", *s1, *s2;
@@ -7825,6 +7826,7 @@ gfc_match_subroutine (void)
 	 procedure interface body.  */
       if (sym->attr.module_procedure && sym->old_symbol
   	  && strcmp (sym->name, sym->old_symbol->name) == 0
+	  && sym->binding_label && sym->old_symbol->binding_label
 	  && strcmp (sym->binding_label, sym->old_symbol->binding_label) != 0)
 	{
 	  const char *null = "NULL", *s1, *s2;
diff --git a/gcc/testsuite/gfortran.dg/pr95342.f90 b/gcc/testsuite/gfortran.dg/pr95342.f90
new file mode 100644
index 00000000000..41c987d3bbb
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/pr95342.f90
@@ -0,0 +1,20 @@
+! { dg-do compile }
+! PR fortran/95342 - ICE in gfc_match_subroutine, at fortran/decl.c:7913
+
+module m1
+  interface
+     module subroutine s()
+     end
+     subroutine s() bind(c) ! { dg-error "EXTERNAL attribute conflicts" }
+     end                    ! { dg-error "END INTERFACE" }
+  end interface
+end
+
+module m2
+  interface
+     module function f()
+     end
+     function f() bind(c)
+     end                    ! { dg-error "Duplicate EXTERNAL attribute" }
+  end interface
+end