Roll getopt_port to latest version

The new implementation corresponds to
https://github.com/kimgr/getopt_port/commit/6ad8cc105b55ad9f83136129fd0c6c2a209da43e.

This fixes the ambiguity issue raised in PR #1260.

2 files changed, 25 insertions, 11 deletions

diff --git a/iwyu_getopt.cc b/iwyu_getopt.cc
index 77323d1..67c756b 100644
--- a/iwyu_getopt.cc
+++ b/iwyu_getopt.cc
@@ -17,10 +17,6 @@
 #include <stddef.h>
 #include <string.h>
 
-const int no_argument = 0;
-const int required_argument = 1;
-const int optional_argument = 2;
-
 char* optarg;
 int optopt;
 /* The variable optind [...] shall be initialized to 1 by the system. */
@@ -98,7 +94,7 @@ int getopt(int argc, char* const argv[], const char* optstring) {
         if (optdecl[2] != ':') {
           /* If the option was the last character in the string pointed to by
              an element of argv, then optarg shall contain the next element
-             of argv, and optind shall be incremented by 2.  If the resulting
+             of argv, and optind shall be incremented by 2. If the resulting
              value of optind is greater than argc, this indicates a missing
              option-argument, and getopt() shall return an error indication.
 
@@ -144,11 +140,12 @@ no_more_optchars:
 [1] http://www.kernel.org/doc/man-pages/online/pages/man3/getopt.3.html
 */
 int getopt_long(int argc, char* const argv[], const char* optstring,
-    const struct option* longopts, int* longindex) {
+                const struct option* longopts, int* longindex) {
   const struct option* o = longopts;
   const struct option* match = NULL;
   int num_matches = 0;
   size_t argument_name_length = 0;
+  size_t option_length = 0;
   const char* current_argument = NULL;
   int retval = -1;
 
@@ -165,6 +162,16 @@ int getopt_long(int argc, char* const argv[], const char* optstring,
   current_argument = argv[optind] + 2;
   argument_name_length = strcspn(current_argument, "=");
   for (; o->name; ++o) {
+    /* Check for exact match first. */
+    option_length = strlen(o->name);
+    if (option_length == argument_name_length &&
+        strncmp(o->name, current_argument, option_length) == 0) {
+      match = o;
+      num_matches = 1;
+      break;
+    }
+
+    /* If not exact, count the number of abbreviated matches. */
     if (strncmp(o->name, current_argument, argument_name_length) == 0) {
       match = o;
       ++num_matches;
@@ -192,7 +199,7 @@ int getopt_long(int argc, char* const argv[], const char* optstring,
         ++optarg;
 
       if (match->has_arg == required_argument) {
-        /* Only scan the next argv for required arguments.  Behavior is not
+        /* Only scan the next argv for required arguments. Behavior is not
            specified, but has been observed with Ubuntu and Mac OSX. */
         if (optarg == NULL && ++optind < argc) {
           optarg = argv[optind];
diff --git a/iwyu_getopt.h b/iwyu_getopt.h
index 1a0c697..41ea82b 100644
--- a/iwyu_getopt.h
+++ b/iwyu_getopt.h
@@ -12,10 +12,13 @@
 
 #if defined(_MSC_VER)
 
-// Hand-rolled implementation of getopt/getopt_long for Visual C++.
-extern const int no_argument;
-extern const int required_argument;
-extern const int optional_argument;
+#if defined(__cplusplus)
+extern "C" {
+#endif
+
+#define no_argument 1
+#define required_argument 2
+#define optional_argument 3
 
 extern char* optarg;
 extern int optind, opterr, optopt;
@@ -32,6 +35,10 @@ int getopt(int argc, char* const argv[], const char* optstring);
 int getopt_long(int argc, char* const argv[],
   const char* optstring, const struct option* longopts, int* longindex);
 
+#if defined(__cplusplus)
+}
+#endif
+
 #else  // #if defined(_MSC_VER)
 
 #include <getopt.h>   // IWYU pragma: export