strvec: rename files from argv-array to strvec

This requires updating #include lines across the code-base, but that's
all fairly mechanical, and was done with:

  git ls-files '*.c' '*.h' |
  xargs perl -i -pe 's/argv-array.h/strvec.h/'

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

strvec.h

@@ -0,0 +1,102 @@
+#ifndef STRVEC_H
+#define STRVEC_H
+
+/**
+ * The argv-array API allows one to dynamically build and store
+ * NULL-terminated lists.  An argv-array maintains the invariant that the
+ * `argv` member always points to a non-NULL array, and that the array is
+ * always NULL-terminated at the element pointed to by `argv[argc]`. This
+ * makes the result suitable for passing to functions expecting to receive
+ * argv from main().
+ *
+ * The string-list API (documented in string-list.h) is similar, but cannot be
+ * used for these purposes; instead of storing a straight string pointer,
+ * it contains an item structure with a `util` field that is not compatible
+ * with the traditional argv interface.
+ *
+ * Each `strvec` manages its own memory. Any strings pushed into the
+ * array are duplicated, and all memory is freed by strvec_clear().
+ */
+
+extern const char *empty_strvec[];
+
+/**
+ * A single array. This should be initialized by assignment from
+ * `STRVEC_INIT`, or by calling `strvec_init`. The `argv`
+ * member contains the actual array; the `argc` member contains the
+ * number of elements in the array, not including the terminating
+ * NULL.
+ */
+struct strvec {
+	const char **argv;
+	size_t argc;
+	size_t alloc;
+};
+
+#define STRVEC_INIT { empty_strvec, 0, 0 }
+
+/**
+ * Initialize an array. This is no different than assigning from
+ * `STRVEC_INIT`.
+ */
+void strvec_init(struct strvec *);
+
+/* Push a copy of a string onto the end of the array. */
+const char *strvec_push(struct strvec *, const char *);
+
+/**
+ * Format a string and push it onto the end of the array. This is a
+ * convenience wrapper combining `strbuf_addf` and `strvec_push`.
+ */
+__attribute__((format (printf,2,3)))
+const char *strvec_pushf(struct strvec *, const char *fmt, ...);
+
+/**
+ * Push a list of strings onto the end of the array. The arguments
+ * should be a list of `const char *` strings, terminated by a NULL
+ * argument.
+ */
+LAST_ARG_MUST_BE_NULL
+void strvec_pushl(struct strvec *, ...);
+
+/* Push a null-terminated array of strings onto the end of the array. */
+void strvec_pushv(struct strvec *, const char **);
+
+/**
+ * Remove the final element from the array. If there are no
+ * elements in the array, do nothing.
+ */
+void strvec_pop(struct strvec *);
+
+/* Splits by whitespace; does not handle quoted arguments! */
+void strvec_split(struct strvec *, const char *);
+
+/**
+ * Free all memory associated with the array and return it to the
+ * initial, empty state.
+ */
+void strvec_clear(struct strvec *);
+
+/**
+ * Disconnect the `argv` member from the `strvec` struct and
+ * return it. The caller is responsible for freeing the memory used
+ * by the array, and by the strings it references. After detaching,
+ * the `strvec` is in a reinitialized state and can be pushed
+ * into again.
+ */
+const char **strvec_detach(struct strvec *);
+
+/* compatibility for historic argv_array interface */
+#define argv_array strvec
+#define ARGV_ARRAY_INIT STRVEC_INIT
+#define argv_array_init strvec_init
+#define argv_array_push strvec_push
+#define argv_array_pushf strvec_pushf
+#define argv_array_pushl strvec_pushl
+#define argv_array_pushv strvec_pushv
+#define argv_array_pop strvec_pop
+#define argv_array_split strvec_split
+#define argv_array_clear strvec_clear
+#define argv_array_detach strvec_detach
+
+#endif /* STRVEC_H */