Add -Wswitch to --enable-gcc-warnings

Make --enable-gcc-warnings a bit pickier, by also using -Wswitch.
* configure.ac (WERROR_CFLAGS): Don’t add -Wno-switch.
* lib-src/etags.c (main, consider_token, C_entries):
* src/coding.c (encode_invocation_designation):
* src/data.c (Ftype_of):
* src/eval.c (Fdefvaralias, default_toplevel_binding)
(Fbacktrace__locals, mark_specpdl):
* src/lisp.h (record_xmalloc):
* src/syntax.c (scan_lists, scan_sexps_forward):
* src/window.c (window_relative_x_coord):
* src/xdisp.c (push_it, pop_it):
* src/xterm.c (xg_scroll_callback, x_check_fullscreen):
Error out or do nothing (as appropriate) if a switch statement
with an enum value does not cover all of the enum.
* src/dispextern.h (struct iterator_stack_entry.u.comp):
Remove unused member discovered by using -Wswitch.
* src/lisp.h (record_xmalloc): Add a ‘+ 0’ to pacify -Wswitch.
* src/vm-limit.c (check_memory_limits):
Simplify warning-diagnostic computation by using a table.

1 files changed, 40 insertions, 2 deletions

diff --git a/lib-src/etags.c b/lib-src/etags.c
index 7baff8cbfe8..791722d4b66 100644
--- a/lib-src/etags.c
+++ b/lib-src/etags.c
@@ -1268,6 +1268,8 @@ main (int argc, char **argv)
           this_file = argbuffer[i].what;
           process_file (stdin, this_file, lang);
           break;
+        default:
+          error ("internal error: arg_type");
         }
     }
 
@@ -2754,6 +2756,9 @@ consider_token (char *str, int len, int c, int *c_extp,
          case st_C_struct:
          case st_C_enum:
            typdef = ttypeseen;
+           break;
+         default:
+           break;
          }
        break;
      case ttypeseen:
@@ -2770,8 +2775,11 @@ consider_token (char *str, int len, int c, int *c_extp,
          case st_C_struct:
          case st_C_enum:
            return false;
+         default:
+           return true;
          }
-       return true;
+     default:
+       break;
      }
 
    switch (toktype)
@@ -2804,6 +2812,8 @@ consider_token (char *str, int len, int c, int *c_extp,
              fvdef = fvnone;
          }
        return false;
+     default:
+       break;
      }
 
    if (structdef == skeyseen)
@@ -2827,6 +2837,8 @@ consider_token (char *str, int len, int c, int *c_extp,
          case st_C_objimpl:
            objdef = oimplementation;
            return false;
+         default:
+           break;
          }
        break;
      case oimplementation:
@@ -2888,6 +2900,8 @@ consider_token (char *str, int len, int c, int *c_extp,
            objdef = onone;
          }
        return false;
+     default:
+       break;
      }
 
    /* A function, variable or enum constant? */
@@ -2943,6 +2957,8 @@ consider_token (char *str, int len, int c, int *c_extp,
                    return false;
                  }
                break;
+             default:
+               break;
              }
           /* FALLTHRU */
           case fvnameseen:
@@ -2959,8 +2975,12 @@ consider_token (char *str, int len, int c, int *c_extp,
           fvdef = fvnameseen;   /* function or variable */
           *is_func_or_var = true;
           return true;
+         default:
+           break;
         }
       break;
+     default:
+       break;
     }
 
   return false;
@@ -3470,6 +3490,8 @@ C_entries (int c_ext, FILE *inf)
                           fvdef = fignore;
                         }
                       break;
+                    default:
+                      break;
                     }
                   if (structdef == stagseen && !cjava)
                     {
@@ -3480,6 +3502,8 @@ C_entries (int c_ext, FILE *inf)
                 case dsharpseen:
                   savetoken = token;
                   break;
+                default:
+                  break;
                 }
               if (!yacc_rules || lp == newlb.buffer + 1)
                 {
@@ -3508,7 +3532,7 @@ C_entries (int c_ext, FILE *inf)
             break;
           switch (objdef)
             {
-            case  otagseen:
+            case otagseen:
               objdef = oignore;
               make_C_tag (true); /* an Objective C class */
               break;
@@ -3522,6 +3546,8 @@ C_entries (int c_ext, FILE *inf)
                   strcpy (token_name.buffer + toklen, ":");
                 }
               break;
+            default:
+              break;
             }
           if (structdef == stagseen)
             {
@@ -3599,6 +3625,8 @@ C_entries (int c_ext, FILE *inf)
               make_C_tag (true); /* an Objective C method */
               objdef = oinbody;
               break;
+            default:
+              break;
             }
           switch (fvdef)
             {
@@ -3672,6 +3700,8 @@ C_entries (int c_ext, FILE *inf)
                   fvdef = fvnone;
                 }
               break;
+            default:
+              break;
             }
           break;
         case '(':
@@ -3705,6 +3735,8 @@ C_entries (int c_ext, FILE *inf)
             case flistseen:
               fvdef = finlist;
               break;
+            default:
+              break;
             }
           parlev++;
           break;
@@ -3730,6 +3762,8 @@ C_entries (int c_ext, FILE *inf)
                 case finlist:
                   fvdef = flistseen;
                   break;
+                default:
+                  break;
                 }
               if (!instruct
                   && (typdef == tend
@@ -3801,6 +3835,8 @@ C_entries (int c_ext, FILE *inf)
                     bracelev = -1;
                 }
               break;
+            default:
+              break;
             }
           switch (structdef)
             {
@@ -3814,6 +3850,8 @@ C_entries (int c_ext, FILE *inf)
               structdef = snone;
               make_C_tag (false);  /* a struct or enum */
               break;
+            default:
+              break;
             }
           bracelev += 1;
           break;