Index: gcc-4.3/gcc/fortran/match.c
===================================================================
--- gcc-4.3/gcc/fortran/match.c	(revision 120338)
+++ gcc-4.3/gcc/fortran/match.c	(working copy)
@@ -396,6 +396,8 @@ gfc_match_name (char *buffer)
   c = gfc_next_char ();
   if (!ISALPHA (c))
     {
+      if (gfc_error_flag_test() == 0)
+        gfc_error ("Invalid character in name at %C");
       gfc_current_locus = old_loc;
       return MATCH_NO;
     }
Index: gcc-4.3/gcc/testsuite/gfortran.dg/invalid_name.f90
===================================================================
--- gcc-4.3/gcc/testsuite/gfortran.dg/invalid_name.f90	(revision 0)
+++ gcc-4.3/gcc/testsuite/gfortran.dg/invalid_name.f90	(revision 0)
@@ -0,0 +1,6 @@
+! { dg-do compile }
+! Tests the fix for PR27698, where names not starting with a letter were
+! rejected but not diagnosed with a proper message.
+SUBROUTINE _foo ! { dg-error "Invalid character in name" }
+END
+
Index: gcc-4.3/gcc/testsuite/gfortran.dg/do_iterator.f90
===================================================================
--- gcc-4.3/gcc/testsuite/gfortran.dg/do_iterator.f90	(revision 120338)
+++ gcc-4.3/gcc/testsuite/gfortran.dg/do_iterator.f90	(working copy)
@@ -10,4 +10,4 @@ DO I=1,5       ! { dg-error "cannot be r
    READ(5,*,iostat=i) j ! { dg-error "cannot be redefined" "changing do-iterator 3" }
 ENDDO
 END
-
+! { dg-error "Invalid character" "character" { target *-*-* } 7 }
Index: gcc-4.3/gcc/testsuite/gfortran.dg/gomp/pr29759.f90
===================================================================
--- gcc-4.3/gcc/testsuite/gfortran.dg/gomp/pr29759.f90	(revision 120338)
+++ gcc-4.3/gcc/testsuite/gfortran.dg/gomp/pr29759.f90	(working copy)
@@ -22,21 +22,21 @@ PROGRAM test_omp
 
 
 !$OMP PARALLEL &		! { dg-error "Unclassifiable OpenMP" }
-!$    NUM_THREADS(2)		! { dg-error "Unclassifiable" }
+!$    NUM_THREADS(2)		! { dg-error "Unclassifiable|Invalid character" }
 !$OMP END PARALLEL		! { dg-error "Unexpected" }
 
 !$OMP PARALLEL &		! { dg-error "Unclassifiable OpenMP" }
-!$    & NUM_THREADS(2)		! { dg-error "Unclassifiable" }
+!$    & NUM_THREADS(2)		! { dg-error "Unclassifiable|Invalid character" }
 !$OMP END PARALLEL		! { dg-error "Unexpected" }
 
 !$OMP PARALLEL &		! { dg-error "Unclassifiable OpenMP" }
 !
-!$    NUM_THREADS(2)		! { dg-error "Unclassifiable" }
+!$    NUM_THREADS(2)		! { dg-error "Unclassifiable|Invalid character" }
 !$OMP END PARALLEL		! { dg-error "Unexpected" }
 
 !$OMP PARALLEL &		! { dg-error "Unclassifiable OpenMP" }
 !
-!$    & NUM_THREADS(2)		! { dg-error "Unclassifiable" }
+!$    & NUM_THREADS(2)		! { dg-error "Unclassifiable|Invalid character" }
 !$OMP END PARALLEL		! { dg-error "Unexpected" }
 
 END PROGRAM