all files: use restrict key word for all pointer arguments

Limit the effects of pointer aliasing and aiding caching
optimizations.

http://cellperformance.beyond3d.com/articles/2006/05/demystifying-the-restrict-keyword.html

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

configure.ac

@@ -14,7 +14,8 @@ AC_GNU_SOURCE
 
 # Checks for programs
 AC_PROG_AWK
-AC_PROG_CC
+AC_PROG_CC_C99
+AC_C_RESTRICT
 AC_PROG_CXX
 AC_PROG_MAKE_SET
 AC_PROG_LIBTOOL

src/dhcpd-pools.h

@@ -145,9 +145,9 @@ struct macaddr_t *macaddr;
 /* Function prototypes */
 int prepare_memory(void);
 int parse_leases(void);
-void parse_config(int, char *, struct shared_network_t *)
+void parse_config(int, const char *__restrict, struct shared_network_t *__restrict)
     __attribute__ ((nonnull(2, 3)));
-int nth_field(int n, char *dest, const char *src)
+int nth_field(int n, char *__restrict dest, const char *__restrict src)
     __attribute__ ((nonnull(2, 3)))
 #if __GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 3)
     __attribute__ ((__hot__))
@@ -155,7 +155,7 @@ int nth_field(int n, char *dest, const char *src)
     ;
 int prepare_data(void);
 int do_counting(void);
-void flip_ranges(struct range_t *ranges, struct range_t *tmp_ranges)
+void flip_ranges(struct range_t *__restrict ranges, struct range_t *__restrict tmp_ranges)
     __attribute__ ((nonnull(1, 2)));
 /* support functions */
 void *safe_malloc(const size_t size)
@@ -166,15 +166,15 @@ void *safe_malloc(const size_t size)
 #endif
 #endif
     ;
-void *safe_realloc(void *ptr, const size_t size);
-char *safe_strdup(const char *str) __attribute__ ((nonnull(1)));
-int xstrstr(char *a, char *b, int len);
+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);
 void print_version(void) __attribute__ ((noreturn));
 void usage(int status) __attribute__ ((noreturn));
 /* qsort required functions... */
 /* ...for ranges and... */
-int intcomp(const void *x, const void *y) __attribute__ ((nonnull(1, 2)));
-int rangecomp(const void *r1, const void *r2)
+int intcomp(const void *__restrict x, const void *__restrict y) __attribute__ ((nonnull(1, 2)));
+int rangecomp(const void *__restrict r1, const void *__restrict r2)
     __attribute__ ((nonnull(1, 2)));
 /* sort function pointer and functions */
 int sort_name(void);
@@ -187,9 +187,9 @@ unsigned long int ret_touched(struct range_t r);
 unsigned long int ret_tc(struct range_t r);
 unsigned long int ret_tcperc(struct range_t r);
 void field_selector(char c);
-int get_order(struct range_t *left, struct range_t *right)
+int get_order(struct range_t *__restrict left, struct range_t *__restrict right)
     __attribute__ ((nonnull(1, 2)));
-void mergesort_ranges(struct range_t *orig, int size, struct range_t *temp)
+void mergesort_ranges(struct range_t *__restrict orig, int size, struct range_t *__restrict temp)
     __attribute__ ((nonnull(1, 3)));
 /* output function pointer and functions */
 int (*output_analysis) (void);

src/getdata.c

@@ -198,7 +198,7 @@ int parse_leases(void)
  * first field is 1 and not 0 like C programs should have. Question of
  * semantics, send mail to author if this annoys. All performance boosts for
  * this function are well come. */
-int nth_field(int n, char *dest, const char *src)
+int nth_field(int n, char *restrict dest, const char *restrict src)
 {
 	int i, j = 0, wordn = 0, len;
 
@@ -225,7 +225,7 @@ int nth_field(int n, char *dest, const char *src)
 }
 
 /* dhcpd.conf interesting words */
-int is_interesting_config_clause(char *s)
+int is_interesting_config_clause(char *restrict s)
 {
 	if (strstr(s, "range")) {
 		return 3;
@@ -239,8 +239,8 @@ int is_interesting_config_clause(char *s)
 }
 
 /* FIXME: This spagetti monster function need to be rewrote at least ones. */
-void parse_config(int is_include, char *config_file,
-		  struct shared_network_t *shared_p)
+void parse_config(int is_include, const char *restrict config_file,
+		  struct shared_network_t *restrict shared_p)
 {
 	FILE *dhcpd_config;
 	int newclause = true, argument = false, comment =

src/other.c

@@ -82,7 +82,7 @@ int
 #if __GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 3)
     __attribute__ ((hot))
 #endif
-    xstrstr(char *a, char *b, int len)
+    xstrstr(char *restrict a, char *restrict b, int len)
 {
 	int i;
 	/* two spaces are very common in lease file, after them
@@ -105,7 +105,7 @@ int
 }
 
 /* Simple strdup wrapper */
-char *safe_strdup(const char *str)
+char *safe_strdup(const char *restrict str)
 {
 	char *ret = strdup(str);
 
@@ -114,7 +114,7 @@ char *safe_strdup(const char *str)
 	return ret;
 }
 
-void flip_ranges(struct range_t *ranges, struct range_t *tmp_ranges)
+void flip_ranges(struct range_t *restrict ranges, struct range_t *restrict tmp_ranges)
 {
 	unsigned int i = num_ranges - 1, j;
 

src/output.c

@@ -313,7 +313,7 @@ int output_xml(void)
 	return 0;
 }
 
-void html_header(FILE * f)
+void html_header(FILE *restrict f)
 {
 	char outstr[200];
 	struct tm *tmp;
@@ -387,7 +387,7 @@ void html_header(FILE * f)
 	fprintf(f, "<a name=\"ranges\">The lease file mtime: %s</a>", outstr);
 }
 
-void html_footer(FILE * f)
+void html_footer(FILE *restrict f)
 {
 	fprintf(f, "<p><br></p>\n");
 	fprintf(f, "<hr>\n");
@@ -403,44 +403,44 @@ void html_footer(FILE * f)
 	fprintf(f, "</html>\n");
 }
 
-void newrow(FILE * f)
+void newrow(FILE *restrict f)
 {
 	fprintf(f, "<tr>\n");
 }
 
-void endrow(FILE * f)
+void endrow(FILE *restrict f)
 {
 	fprintf(f, "</tr>\n\n");
 }
 
-void output_line(FILE * f, char *type, char *class, char *text)
+void output_line(FILE *restrict f, char *restrict type, char *restrict class, char *restrict text)
 {
 	fprintf(f, "  <%s class=%s>%s</%s>\n", type, class, text, type);
 }
 
-void output_long(FILE * f, char *type, unsigned long unlong)
+void output_long(FILE *restrict f, char *restrict type, unsigned long unlong)
 {
 	fprintf(f, "  <%s class=ralign>%lu</%s>\n", type, unlong, type);
 }
 
-void output_float(FILE * f, char *type, float fl)
+void output_float(FILE * f, char *restrict type, float fl)
 {
 	fprintf(f, "  <%s class=ralign>%.3f</%s>\n", type, fl, type);
 }
 
-void table_start(FILE * f)
+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 * f)
+void table_end(FILE *restrict f)
 {
 	fprintf(f, "</table>\n");
 }
 
-void newsection(FILE * f, char *title)
+void newsection(FILE *restrict f, char *restrict title)
 {
 	newrow(f);
 	output_line(f, "td", "calign", "&nbsp;");

src/sort.c

@@ -44,7 +44,7 @@
 #include "dhcpd-pools.h"
 
 /* Sort functions for range sorting */
-int intcomp(const void *x, const void *y)
+int intcomp(const void *restrict x, const void *restrict y)
 {
 	if (*(uint32_t *) x < *(uint32_t *) y)
 		return -1;
@@ -54,7 +54,7 @@ int intcomp(const void *x, const void *y)
 		return 0;
 }
 
-int rangecomp(const void *r1, const void *r2)
+int rangecomp(const void *restrict r1, const void *restrict r2)
 {
 	if ((((struct range_t *)r1)->first_ip) <
 	    (((struct range_t *)r2)->first_ip))
@@ -139,7 +139,7 @@ void field_selector(char c)
 }
 
 /* Needed to support multiple key sorting. */
-int get_order(struct range_t *left, struct range_t *right)
+int get_order(struct range_t *restrict left, struct range_t *restrict right)
 {
 	int i, len, ret;
 	unsigned long int lint, rint;
@@ -178,7 +178,7 @@ int get_order(struct range_t *left, struct range_t *right)
 	return (0);
 }
 
-void mergesort_ranges(struct range_t *orig, int size, struct range_t *temp)
+void mergesort_ranges(struct range_t *restrict orig, int size, struct range_t *restrict temp)
 {
 	int left, right, i;
 	struct range_t hold;