Improve docs, examples, warnings

This improves docs in some of the public header files, cleans
up and improves some of the example code, and fixes a couple
of pedantic warnings in places.

3 files changed, 63 insertions, 48 deletions

diff --git a/examples/Makefile b/examples/Makefile
index fe99c75cb..da4df5240 100644
--- a/examples/Makefile
+++ b/examples/Makefile
@@ -1,7 +1,7 @@
 .PHONY: all
 
 CC = gcc
-CFLAGS = -g -I../include -I../src
+CFLAGS = -g -I../include -I../src -Wall -Wextra -Wmissing-prototypes
 LFLAGS = -L../build -lgit2 -lz
 APPS = general showindex diff
 
diff --git a/examples/diff.c b/examples/diff.c
index b72a75e1c..31ebf6bfb 100644
--- a/examples/diff.c
+++ b/examples/diff.c
@@ -3,7 +3,7 @@
 #include <stdlib.h>
 #include <string.h>
 
-void check(int error, const char *message)
+static void check(int error, const char *message)
 {
 	if (error) {
 		fprintf(stderr, "%s (%d)\n", message, error);
@@ -11,7 +11,8 @@ void check(int error, const char *message)
 	}
 }
 
-int resolve_to_tree(git_repository *repo, const char *identifier, git_tree **tree)
+static int resolve_to_tree(
+	git_repository *repo, const char *identifier, git_tree **tree)
 {
 	int err = 0;
 	size_t len = strlen(identifier);
@@ -61,16 +62,18 @@ char *colors[] = {
 	"\033[36m" /* cyan */
 };
 
-int printer(
+static int printer(
 	void *data,
-	git_diff_delta *delta,
-	git_diff_range *range,
+	const git_diff_delta *delta,
+	const git_diff_range *range,
 	char usage,
 	const char *line,
 	size_t line_len)
 {
 	int *last_color = data, color = 0;
 
+	(void)delta; (void)range; (void)line_len;
+
 	if (*last_color >= 0) {
 		switch (usage) {
 		case GIT_DIFF_LINE_ADDITION: color = 3; break;
@@ -93,7 +96,7 @@ int printer(
 	return 0;
 }
 
-int check_uint16_param(const char *arg, const char *pattern, uint16_t *val)
+static int check_uint16_param(const char *arg, const char *pattern, uint16_t *val)
 {
 	size_t len = strlen(pattern);
 	uint16_t strval;
@@ -107,7 +110,7 @@ int check_uint16_param(const char *arg, const char *pattern, uint16_t *val)
 	return 1;
 }
 
-int check_str_param(const char *arg, const char *pattern, char **val)
+static int check_str_param(const char *arg, const char *pattern, char **val)
 {
 	size_t len = strlen(pattern);
 	if (strncmp(arg, pattern, len))
@@ -116,7 +119,7 @@ int check_str_param(const char *arg, const char *pattern, char **val)
 	return 1;
 }
 
-void usage(const char *message, const char *arg)
+static void usage(const char *message, const char *arg)
 {
 	if (message && arg)
 		fprintf(stderr, "%s: %s\n", message, arg);
@@ -128,14 +131,15 @@ void usage(const char *message, const char *arg)
 
 int main(int argc, char *argv[])
 {
-	char path[GIT_PATH_MAX];
 	git_repository *repo = NULL;
 	git_tree *t1 = NULL, *t2 = NULL;
-	git_diff_options opts = {0};
+	git_diff_options opts;
 	git_diff_list *diff;
 	int i, color = -1, compact = 0, cached = 0;
 	char *a, *dir = ".", *treeish1 = NULL, *treeish2 = NULL;
 
+	memset(&opts, 0, sizeof(opts));
+
 	/* parse arguments as copied from git-diff */
 
 	for (i = 1; i < argc; ++i) {
diff --git a/examples/showindex.c b/examples/showindex.c
index d26fbaebd..4b50ffd0f 100644
--- a/examples/showindex.c
+++ b/examples/showindex.c
@@ -3,42 +3,53 @@
 
 int main (int argc, char** argv)
 {
-  git_repository *repo;
-  git_index *index;
-  unsigned int i, e, ecount;
-  git_index_entry **entries;
-  git_oid oid;
-
-  char out[41];
-  out[40] = '\0';
-
-  git_repository_open(&repo, "/opt/libgit2-test/.git");
-
-  git_repository_index(&index, repo);
-  git_index_read(index);
-
-  ecount = git_index_entrycount(index);
-  for (i = 0; i < ecount; ++i) {
-    git_index_entry *e = git_index_get_byindex(index, i);
-
-    oid = e->oid;
-    git_oid_fmt(out, &oid);
-
-    printf("File Path: %s\n", e->path);
-	printf("    Stage: %d\n", git_index_entry_stage(e));
-    printf(" Blob SHA: %s\n", out);
-    printf("File Size: %d\n", (int)e->file_size);
-    printf("   Device: %d\n", (int)e->dev);
-    printf("    Inode: %d\n", (int)e->ino);
-    printf("      UID: %d\n", (int)e->uid);
-    printf("      GID: %d\n", (int)e->gid);
-    printf("    ctime: %d\n", (int)e->ctime.seconds);
-    printf("    mtime: %d\n", (int)e->mtime.seconds);
-    printf("\n");
-  }
-
-  git_index_free(index);
-
-  git_repository_free(repo);
+	git_repository *repo;
+	git_index *index;
+	unsigned int i, ecount;
+	char *dir = ".";
+	char out[41];
+	out[40] = '\0';
+
+	if (argc > 1)
+		dir = argv[1];
+	if (argc > 2) {
+		fprintf(stderr, "usage: showindex [<repo-dir>]\n");
+		return 1;
+	}
+
+	if (git_repository_open_ext(&repo, dir, 0, NULL) < 0) {
+		fprintf(stderr, "could not open repository: %s\n", dir);
+		return 1;
+	}
+
+	git_repository_index(&index, repo);
+	git_index_read(index);
+
+	ecount = git_index_entrycount(index);
+	if (!ecount)
+		printf("Empty index\n");
+
+	for (i = 0; i < ecount; ++i) {
+		const git_index_entry *e = git_index_get_byindex(index, i);
+
+		git_oid_fmt(out, &e->oid);
+
+		printf("File Path: %s\n", e->path);
+		printf("    Stage: %d\n", git_index_entry_stage(e));
+		printf(" Blob SHA: %s\n", out);
+		printf("File Size: %d\n", (int)e->file_size);
+		printf("   Device: %d\n", (int)e->dev);
+		printf("    Inode: %d\n", (int)e->ino);
+		printf("      UID: %d\n", (int)e->uid);
+		printf("      GID: %d\n", (int)e->gid);
+		printf("    ctime: %d\n", (int)e->ctime.seconds);
+		printf("    mtime: %d\n", (int)e->mtime.seconds);
+		printf("\n");
+	}
+
+	git_index_free(index);
+	git_repository_free(repo);
+
+	return 0;
 }