all: fix compiler warninings

Use compiler warnings from coreutils to check nothing complains, and
fix everything that did.

CFLAGS='-Wall -W -Wformat-y2k -Wformat-security -Winit-self
-Wmissing-include-dirs -Wunused -Wunknown-pragmas -Wstrict-aliasing
-Wshadow -Wpointer-arith -Wbad-function-cast -Wcast-align
-Wwrite-strings -Wmissing-declarations -Wmissing-noreturn -Wpacked
-Winvalid-pch -Wvolatile-register-var -Wdisabled-optimization
-Woverlength-strings -Wbuiltin-macro-redefined -Wmudflap
-Wpacked-bitfield-compat -Wsync-nand -Wattributes -Wcoverage-mismatch
-Wabi -Wcpp -Wdeprecated -Wdeprecated-declarations -Wdiv-by-zero
-Wendif-labels -Wextra -Wformat-contains-nul -Wformat-extra-args
-Wformat-zero-length -Wformat=2 -Wmultichar -Wnormalized=nfc -Woverflow
-Wpointer-to-int-cast -Wpragmas -Wsuggest-attribute=noreturn
-Wtrampolines -Wno-sign-compare -Wno-unused-parameter
-Wsuggest-attribute=noreturn -Wno-format-nonliteral -Wno-logical-op
-fdiagnostics-show-option -funit-at-a-time'

Signed-off-by: Sami Kerola <kerolasa@iki.fi>

src/analyze.c

@@ -42,7 +42,7 @@
 #include "dhcpd-pools.h"
 
 /* Clean up data */
-int ip_sort(struct leases_t *a, struct leases_t *b)
+static int ip_sort(struct leases_t *a, struct leases_t *b)
 {
 	if (a->ip < b->ip)
 		return -1;

src/dhcpd-pools.c

@@ -61,7 +61,7 @@ int main(int argc, char **argv)
 {
 	int i, c, sorts = 0;
 	int option_index = 0;
-	char *tmp;
+	char const *tmp;
 	struct range_t *tmp_ranges;
 	enum {
 		OPT_WARN = CHAR_MAX + 1,

src/dhcpd-pools.h

@@ -178,7 +178,7 @@ void *safe_malloc(const size_t size)
     ;
 void *safe_realloc(void *__restrict ptr, const size_t size);
 char *safe_strdup(const char *__restrict str) __attribute__ ((nonnull(1)));
-int xstrstr(char *__restrict a, char *__restrict b, int len);
+int xstrstr(char *__restrict a, const char *__restrict b, int len);
 double strtod_or_err(const char *__restrict str, const char *__restrict errmesg);
 int close_stream(FILE * stream);
 void close_stdout(void);

src/getdata.c

@@ -200,7 +200,7 @@ int nth_field(int n, char *restrict dest, const char *restrict src)
 }
 
 /* dhcpd.conf interesting words */
-int is_interesting_config_clause(char *restrict s)
+static int is_interesting_config_clause(char const *restrict s)
 {
 	if (strstr(s, "range")) {
 		return 3;

src/other.c

@@ -104,7 +104,7 @@ int
 #if __GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 3)
     __attribute__ ((hot))
 #endif
-    xstrstr(char *restrict a, char *restrict b, int len)
+    xstrstr(char *restrict a, const char *restrict b, int len)
 {
 	int i;
 	/* two spaces are very common in lease file, after them
@@ -137,7 +137,7 @@ char *safe_strdup(const char *restrict str)
 }
 
 /* Return percentage value */
-double strtod_or_err(const char *str, const char *errmesg)
+double strtod_or_err(const char *restrict str, const char *restrict errmesg)
 {
 	double num;
 	char *end = NULL;
@@ -158,16 +158,17 @@ double strtod_or_err(const char *str, const char *errmesg)
 	errx(EXIT_FAILURE, "%s: '%s'", errmesg, str);
 }
 
-void flip_ranges(struct range_t *restrict ranges, struct range_t *restrict tmp_ranges)
+void flip_ranges(struct range_t *restrict flip_me,
+		 struct range_t *restrict tmp_ranges)
 {
 	unsigned int i = num_ranges - 1, j;
 
 	for (j = 0; j < num_ranges; j++) {
-		*(tmp_ranges + j) = *(ranges + i);
+		*(tmp_ranges + j) = *(flip_me + i);
 		i--;
 	}
 
-	memcpy(ranges, tmp_ranges, num_ranges * sizeof(struct range_t));
+	memcpy(flip_me, tmp_ranges, num_ranges * sizeof(struct range_t));
 }
 
 /* Free memory, flush buffers etc */

src/output.c

@@ -314,7 +314,7 @@ int output_xml(void)
 	return 0;
 }
 
-void html_header(FILE *restrict f)
+static void html_header(FILE *restrict f)
 {
 	char outstr[200];
 	struct tm *tmp;
@@ -388,7 +388,7 @@ void html_header(FILE *restrict f)
 	fprintf(f, "<a name=\"ranges\">The lease file mtime: %s</a>", outstr);
 }
 
-void html_footer(FILE *restrict f)
+static void html_footer(FILE *restrict f)
 {
 	fprintf(f, "<p><br></p>\n");
 	fprintf(f, "<hr>\n");
@@ -404,44 +404,46 @@ void html_footer(FILE *restrict f)
 	fprintf(f, "</html>\n");
 }
 
-void newrow(FILE *restrict f)
+static void newrow(FILE *restrict f)
 {
 	fprintf(f, "<tr>\n");
 }
 
-void endrow(FILE *restrict f)
+static void endrow(FILE *restrict f)
 {
 	fprintf(f, "</tr>\n\n");
 }
 
-void output_line(FILE *restrict f, char *restrict type, char *restrict class, char *restrict text)
+static void output_line(FILE *restrict f, char const *restrict type,
+			char const *restrict class, char const *restrict text)
 {
 	fprintf(f, "  <%s class=%s>%s</%s>\n", type, class, text, type);
 }
 
-void output_long(FILE *restrict f, char *restrict type, unsigned long unlong)
+static void output_long(FILE *restrict f, char const *restrict type,
+			unsigned long unlong)
 {
 	fprintf(f, "  <%s class=ralign>%lu</%s>\n", type, unlong, type);
 }
 
-void output_float(FILE * f, char *restrict type, float fl)
+static void output_float(FILE * f, char const *restrict type, float fl)
 {
 	fprintf(f, "  <%s class=ralign>%.3f</%s>\n", type, fl, type);
 }
 
-void table_start(FILE *restrict f)
+static void table_start(FILE *restrict f)
 {
 	fprintf(f, "<table width=\"75%%\" ");
 	fprintf(f, "class=\"%s\" ", PACKAGE_NAME);
 	fprintf(f, "summary=\"ISC dhcpd pool usage report\">\n");
 }
 
-void table_end(FILE *restrict f)
+static void table_end(FILE *restrict f)
 {
 	fprintf(f, "</table>\n");
 }
 
-void newsection(FILE *restrict f, char *restrict title)
+static void newsection(FILE *restrict f, char const *restrict title)
 {
 	newrow(f);
 	output_line(f, "td", "calign", "&nbsp;");