Fix shadowed variable in watchman/Options.cpp

Summary:
Our upcoming compiler upgrade will require us not to have shadowed variables. Such variables have a _high_ bug rate and reduce readability, so we would like to avoid them even if the compiler was not forcing us to do so.

This codemod attempts to fix an instance of a shadowed variable. Please review with care: if it's failed the result will be a silent bug.

**What's a shadowed variable?**

Shadowed variables are variables in an inner scope with the same name as another variable in an outer scope. Having the same name for both variables might be semantically correct, but it can make the code confusing to read! It can also hide subtle bugs.

This diff fixes such an issue by renaming the variable.

 - If you approve of this diff, please use the "Accept & Ship" button :-)

Reviewed By: kmancini

Differential Revision: D64398753

fbshipit-source-id: 42ae08573947b6f6f6a5180b40809b3d67985111

watchman/Options.cpp

@@ -225,27 +225,27 @@ void print_command_list_for_help(FILE* where) {
 
 /* One does not simply use getopt_long() */
 
-[[noreturn]] void usage(const OptDesc* opts, FILE* where) {
+[[noreturn]] void usage(const OptDesc* opts_2, FILE* where) {
   int i;
   size_t len;
   size_t longest = 0;
   const char* label;
 
-  fprintf(where, "Usage: watchman [opts] command\n");
+  fprintf(where, "Usage: watchman [opts_2] command\n");
 
   /* measure up option names so we can format nicely */
-  for (i = 0; opts[i].optname; i++) {
-    label = opts[i].arglabel ? opts[i].arglabel : "ARG";
+  for (i = 0; opts_2[i].optname; i++) {
+    label = opts_2[i].arglabel ? opts_2[i].arglabel : "ARG";
 
-    len = strlen(opts[i].optname);
-    switch (opts[i].argtype) {
+    len = strlen(opts_2[i].optname);
+    switch (opts_2[i].argtype) {
       case REQ_STRING:
         len += strlen(label) + strlen("=");
         break;
       default:;
     }
 
-    if (opts[i].shortopt) {
+    if (opts_2[i].shortopt) {
       len += strlen("-X, ");
     }
 
@@ -257,34 +257,34 @@ void print_command_list_for_help(FILE* where) {
   /* space between option definition and help text */
   longest += 3;
 
-  for (i = 0; opts[i].optname; i++) {
+  for (i = 0; opts_2[i].optname; i++) {
     char buf[80];
 
-    if (!opts[i].helptext) {
+    if (!opts_2[i].helptext) {
       // This is a signal that this option shouldn't be printed out.
       continue;
     }
 
-    label = opts[i].arglabel ? opts[i].arglabel : "ARG";
+    label = opts_2[i].arglabel ? opts_2[i].arglabel : "ARG";
 
     fprintf(where, "\n ");
-    if (opts[i].shortopt) {
-      fprintf(where, "-%c, ", opts[i].shortopt);
+    if (opts_2[i].shortopt) {
+      fprintf(where, "-%c, ", opts_2[i].shortopt);
     } else {
       fprintf(where, "    ");
     }
-    switch (opts[i].argtype) {
+    switch (opts_2[i].argtype) {
       case REQ_STRING:
-        snprintf(buf, sizeof(buf), "--%s=%s", opts[i].optname, label);
+        snprintf(buf, sizeof(buf), "--%s=%s", opts_2[i].optname, label);
         break;
       default:
-        snprintf(buf, sizeof(buf), "--%s", opts[i].optname);
+        snprintf(buf, sizeof(buf), "--%s", opts_2[i].optname);
         break;
     }
 
     fprintf(where, "%-*s ", (unsigned int)longest, buf);
 
-    fprintf(where, "%s", opts[i].helptext);
+    fprintf(where, "%s", opts_2[i].helptext);
     fprintf(where, "\n");
   }
 
@@ -302,7 +302,7 @@ void print_command_list_for_help(FILE* where) {
 }
 
 std::vector<std::string>
-w_getopt(const OptDesc* opts, int* argcp, char*** argvp) {
+w_getopt(const OptDesc* opts_2, int* argcp, char*** argvp) {
   int num_opts, i;
   char* nextshort;
   int argc = *argcp;
@@ -311,7 +311,7 @@ w_getopt(const OptDesc* opts, int* argcp, char*** argvp) {
   int res;
 
   /* first build up the getopt_long bits that we need */
-  for (num_opts = 0; opts[num_opts].optname; num_opts++) {
+  for (num_opts = 0; opts_2[num_opts].optname; num_opts++) {
     ;
   }
 
@@ -335,9 +335,9 @@ w_getopt(const OptDesc* opts, int* argcp, char*** argvp) {
 
   /* now transfer information into the space we made */
   for (i = 0; i < num_opts; i++) {
-    long_opts[i].name = (char*)opts[i].optname;
-    long_opts[i].val = opts[i].shortopt;
-    switch (opts[i].argtype) {
+    long_opts[i].name = (char*)opts_2[i].optname;
+    long_opts[i].val = opts_2[i].shortopt;
+    switch (opts_2[i].argtype) {
       case OPT_NONE:
         long_opts[i].has_arg = no_argument;
         break;
@@ -347,8 +347,8 @@ w_getopt(const OptDesc* opts, int* argcp, char*** argvp) {
         break;
     }
 
-    if (opts[i].shortopt) {
-      nextshort[0] = (char)opts[i].shortopt;
+    if (opts_2[i].shortopt) {
+      nextshort[0] = (char)opts_2[i].shortopt;
       nextshort++;
 
       if (long_opts[i].has_arg != no_argument) {
@@ -369,13 +369,13 @@ w_getopt(const OptDesc* opts, int* argcp, char*** argvp) {
         /* missing option argument.
          * Check to see if it was actually optional */
         for (long_pos = 0; long_pos < num_opts; long_pos++) {
-          if (opts[long_pos].shortopt == optopt) {
-            if (IS_REQUIRED(opts[long_pos].argtype)) {
+          if (opts_2[long_pos].shortopt == optopt) {
+            if (IS_REQUIRED(opts_2[long_pos].argtype)) {
               fprintf(
                   stderr,
                   "--%s (-%c) requires an argument",
-                  opts[long_pos].optname,
-                  opts[long_pos].shortopt);
+                  opts_2[long_pos].optname,
+                  opts_2[long_pos].shortopt);
               return daemon_argv;
             }
           }
@@ -385,19 +385,19 @@ w_getopt(const OptDesc* opts, int* argcp, char*** argvp) {
       case '?':
         /* unknown option */
         fprintf(stderr, "Unknown or invalid option! %s\n", argv[optind - 1]);
-        usage(opts, stderr);
+        usage(opts_2, stderr);
         return daemon_argv;
 
       default:
         if (res == 0) {
           /* we got a long option */
-          o = &opts[long_pos];
+          o = &opts_2[long_pos];
         } else {
           /* map short option to the real thing */
           o = NULL;
           for (long_pos = 0; long_pos < num_opts; long_pos++) {
-            if (opts[long_pos].shortopt == res) {
-              o = &opts[long_pos];
+            if (opts_2[long_pos].shortopt == res) {
+              o = &opts_2[long_pos];
               break;
             }
           }