re PR fortran/77972 (ICE on broken character continuation with -Wall etc.)

2016-10-15  Jerry DeLisle  <jvdelisle@gcc.gnu.org>

	PR fortran/77972
	* scanner.c (gfc_next_char_literal): If nextc is null do not
	decrement the pointer and call the diagnostics.

	PR fortran/77972
	* gfortran.dg/unexpected_eof_4.f90: New test.

From-SVN: r241201

gcc/fortran/ChangeLog

+2016-10-15  Jerry DeLisle  <jvdelisle@gcc.gnu.org>
+
+	PR fortran/77972
+	* scanner.c (gfc_next_char_literal): If nextc is null do not
+	decrement the pointer and call the diagnostics.
+
 2016-10-14  Andre Vehreschild  <vehre@gcc.gnu.org>
 
 	* resolve.c (resolve_symbol): Add unimplemented message for

gcc/fortran/scanner.c

@@ -1414,10 +1414,9 @@ restart:
 
       if (c != '&')
 	{
-	  if (in_string)
+	  if (in_string && gfc_current_locus.nextc)
 	    {
-	      if (gfc_current_locus.nextc)
-	        gfc_current_locus.nextc--;
+	      gfc_current_locus.nextc--;
 	      if (warn_ampersand && in_string == INSTRING_WARN)
 		gfc_warning (OPT_Wampersand, 
 			     "Missing %<&%> in continued character "

gcc/testsuite/ChangeLog

+2016-10-15  Jerry DeLisle  <jvdelisle@gcc.gnu.org>
+
+	PR fortran/77972
+	* gfortran.dg/unexpected_eof_4.f90: New test.
+
 2016-10-15  Janne Blomqvist  <jb@gcc.gnu.org>
 
         PR libfortran/48587

gcc/testsuite/gfortran.dg/unexpected_eof_4.f90

+! { dg-do compile }
+! { dg-options "-Wampersand" }
+! PR77972
+program p
+   character(8) :: z
+   z = 'abc&
+! { dg-error "Unterminated character constant" "" { target *-*-* } 0  }
+! { dg-error "Unexpected end of file" "" { target *-*-* } 0 }