Fix some compiler warnings about signed comparisons

Makefile

@@ -9,7 +9,7 @@ CXX := $(CXX)
 CFLAGS := $(CFLAGS)
 CXXFLAGS := $(CXXFLAGS) -std=c++11
 LDFLAGS := $(LDFLAGS)
-WARNING_FLAGS := -Wall -Wshadow
+WARNING_FLAGS := -Wall -Wshadow -Wabsolute-value -Wsign-compare
 RELEASE_FLAGS := -O3 -DNDEBUG
 DEBUG_FLAGS := -O0 -DDEBUG -fno-inline-functions -fno-omit-frame-pointer
 

main.cpp

@@ -67,8 +67,8 @@ struct source {
 	std::string file;
 };
 
-int CPUS;
+size_t CPUS;
-int TEMP_FILES;
+size_t TEMP_FILES;
 long long MAX_FILES;
 static long long diskfree;
 
@@ -267,7 +267,7 @@ int calc_feature_minzoom(struct index *ix, struct drop_state *ds, int maxzoom, i
 	return feature_minzoom;
 }
 
-static void merge(struct mergelist *merges, int nmerges, unsigned char *map, FILE *indexfile, int bytes, long long nrec, char *geom_map, FILE *geom_out, long long *geompos, long long *progress, long long *progress_max, long long *progress_reported, int maxzoom, int basezoom, double droprate, double gamma, struct drop_state *ds) {
+static void merge(struct mergelist *merges, size_t nmerges, unsigned char *map, FILE *indexfile, int bytes, long long nrec, char *geom_map, FILE *geom_out, long long *geompos, long long *progress, long long *progress_max, long long *progress_reported, int maxzoom, int basezoom, double droprate, double gamma, struct drop_state *ds) {
 	struct mergelist *head = NULL;
 
 	for (size_t i = 0; i < nmerges; i++) {
@@ -312,7 +312,7 @@ struct sort_arg {
 	long long indexpos;
 	struct mergelist *merges;
 	int indexfd;
-	int nmerges;
+	size_t nmerges;
 	long long unit;
 	int bytes;
 };
@@ -367,8 +367,7 @@ void do_read_parallel(char *map, long long len, long long initial_offset, const
 	segs[0] = 0;
 	segs[CPUS] = len;
 
-	int i;
+	for (size_t i = 1; i < CPUS; i++) {
-	for (i = 1; i < CPUS; i++) {
 		segs[i] = len * i / CPUS;
 
 		while (segs[i] < len && map[segs[i]] != '\n') {
@@ -377,7 +376,7 @@ void do_read_parallel(char *map, long long len, long long initial_offset, const
 	}
 
 	volatile long long layer_seq[CPUS];
-	for (i = 0; i < CPUS; i++) {
+	for (size_t i = 0; i < CPUS; i++) {
 		// To preserve feature ordering, unique id for each segment
 		// begins with that segment's offset into the input
 		layer_seq[i] = segs[i] + initial_offset;
@@ -387,11 +386,11 @@ void do_read_parallel(char *map, long long len, long long initial_offset, const
 	pthread_t pthreads[CPUS];
 	std::vector<std::set<type_and_string> > file_subkeys;
 
-	for (i = 0; i < CPUS; i++) {
+	for (size_t i = 0; i < CPUS; i++) {
 		file_subkeys.push_back(std::set<type_and_string>());
 	}
 
-	for (i = 0; i < CPUS; i++) {
+	for (size_t i = 0; i < CPUS; i++) {
 		pja[i].jp = json_begin_map(map + segs[i], segs[i + 1] - segs[i]);
 		pja[i].reading = reading;
 		pja[i].layer_seq = &layer_seq[i];
@@ -427,7 +426,7 @@ void do_read_parallel(char *map, long long len, long long initial_offset, const
 		}
 	}
 
-	for (i = 0; i < CPUS; i++) {
+	for (size_t i = 0; i < CPUS; i++) {
 		void *retval;
 
 		if (pthread_join(pthreads[i], &retval) != 0) {
@@ -706,18 +705,17 @@ void radix1(int *geomfds_in, int *indexfds_in, int inputs, int prefix, int split
 				}
 				unit = ((unit + page - 1) / page) * page;
 
-				int nmerges = (indexpos + unit - 1) / unit;
+				size_t nmerges = (indexpos + unit - 1) / unit;
 				struct mergelist merges[nmerges];
 
-				int a;
+				for (size_t a = 0; a < nmerges; a++) {
-				for (a = 0; a < nmerges; a++) {
 					merges[a].start = merges[a].end = 0;
 				}
 
 				pthread_t pthreads[CPUS];
 				struct sort_arg args[CPUS];
 
-				for (a = 0; a < CPUS; a++) {
+				for (size_t a = 0; a < CPUS; a++) {
 					args[a].task = a;
 					args[a].cpus = CPUS;
 					args[a].indexpos = indexpos;
@@ -733,7 +731,7 @@ void radix1(int *geomfds_in, int *indexfds_in, int inputs, int prefix, int split
 					}
 				}
 
-				for (a = 0; a < CPUS; a++) {
+				for (size_t a = 0; a < CPUS; a++) {
 					void *retval;
 
 					if (pthread_join(pthreads[a], &retval) != 0) {
@@ -945,8 +943,7 @@ int read_input(std::vector<source> &sources, char *fname, const char *layername,
 	int ret = EXIT_SUCCESS;
 
 	struct reader reader[CPUS];
-	int i;
+	for (size_t i = 0; i < CPUS; i++) {
-	for (i = 0; i < CPUS; i++) {
 		struct reader *r = reader + i;
 
 		char metaname[strlen(tmpdir) + strlen("/meta.XXXXXXXX") + 1];
@@ -1045,7 +1042,7 @@ int read_input(std::vector<source> &sources, char *fname, const char *layername,
 
 	int initialized[CPUS];
 	unsigned initial_x[CPUS], initial_y[CPUS];
-	for (i = 0; i < CPUS; i++) {
+	for (size_t i = 0; i < CPUS; i++) {
 		initialized[i] = initial_x[i] = initial_y[i] = 0;
 	}
 
@@ -1298,7 +1295,7 @@ int read_input(std::vector<source> &sources, char *fname, const char *layername,
 		//     (stderr, "Read 10000.00 million features\r", *progress_seq / 1000000.0);
 	}
 
-	for (i = 0; i < CPUS; i++) {
+	for (size_t i = 0; i < CPUS; i++) {
 		if (fclose(reader[i].metafile) != 0) {
 			perror("fclose meta");
 			exit(EXIT_FAILURE);
@@ -1367,7 +1364,7 @@ int read_input(std::vector<source> &sources, char *fname, const char *layername,
 	long long metapos = 0;
 	long long poolpos = 0;
 
-	for (i = 0; i < CPUS; i++) {
+	for (size_t i = 0; i < CPUS; i++) {
 		if (reader[i].metapos > 0) {
 			void *map = mmap(NULL, reader[i].metapos, PROT_READ, MAP_PRIVATE, reader[i].metafd, 0);
 			if (map == MAP_FAILED) {
@@ -1718,8 +1715,7 @@ int read_input(std::vector<source> &sources, char *fname, const char *layername,
 	fd[0] = geomfd;
 	size[0] = geomst.st_size;
 
-	int j;
+	for (size_t j = 1; j < TEMP_FILES; j++) {
-	for (j = 1; j < TEMP_FILES; j++) {
 		fd[j] = -1;
 		size[j] = 0;
 	}
@@ -1760,7 +1756,7 @@ int read_input(std::vector<source> &sources, char *fname, const char *layername,
 	midlon = (maxlon + minlon) / 2;
 
 	long long file_bbox[4] = {UINT_MAX, UINT_MAX, 0, 0};
-	for (i = 0; i < CPUS; i++) {
+	for (size_t i = 0; i < CPUS; i++) {
 		if (reader[i].file_bbox[0] < file_bbox[0]) {
 			file_bbox[0] = reader[i].file_bbox[0];
 		}

main.hpp

@@ -12,5 +12,5 @@ void checkdisk(struct reader *r, int nreader);
 extern int geometry_scale;
 extern int quiet;
 
-extern int CPUS;
+extern size_t CPUS;
-extern int TEMP_FILES;
+extern size_t TEMP_FILES;

mbtiles.cpp

@@ -236,8 +236,7 @@ void mbtiles_write_metadata(sqlite3 *outdb, const char *fname, int minzoom, int
 		lnames.push_back(ai->first);
 	}
 
-	int i;
+	for (size_t i = 0; i < lnames.size(); i++) {
-	for (i = 0; i < lnames.size(); i++) {
 		if (i != 0) {
 			aprintf(&buf, ", ");
 		}

text.cpp

@@ -7,7 +7,7 @@
  */
 std::string check_utf8(std::string s) {
 	for (size_t i = 0; i < s.size(); i++) {
-		int fail = 0;
+		size_t fail = 0;
 
 		if ((s[i] & 0x80) == 0x80) {
 			if ((s[i] & 0xE0) == 0xC0) {

tile.cpp

@@ -826,7 +826,7 @@ void find_common_edges(std::vector<partial> &partials, int z, int line_detail, d
 							for (size_t m = necessary; m < l - 1; m++) {
 								tmp.push_back(g[m]);
 							}
-							for (size_t m = k; m < necessary; m++) {
+							for (ssize_t m = k; m < necessary; m++) {
 								tmp.push_back(g[m]);
 							}
 
@@ -1667,10 +1667,9 @@ int traverse_zooms(int *geomfd, off_t *geom_size, char *metabase, char *stringpo
 
 		FILE *sub[TEMP_FILES];
 		int subfd[TEMP_FILES];
-		int j;
+		for (size_t j = 0; j < TEMP_FILES; j++) {
-		for (j = 0; j < TEMP_FILES; j++) {
 			char geomname[strlen(tmpdir) + strlen("/geom.XXXXXXXX" XSTRINGIFY(INT_MAX)) + 1];
-			sprintf(geomname, "%s/geom%d.XXXXXXXX", tmpdir, j);
+			sprintf(geomname, "%s/geom%zu.XXXXXXXX", tmpdir, j);
 			subfd[j] = mkstemp(geomname);
 			// printf("%s\n", geomname);
 			if (subfd[j] < 0) {
@@ -1685,17 +1684,17 @@ int traverse_zooms(int *geomfd, off_t *geom_size, char *metabase, char *stringpo
 			unlink(geomname);
 		}
 
-		int useful_threads = 0;
+		size_t useful_threads = 0;
 		long long todo = 0;
 		long long along = 0;
-		for (j = 0; j < TEMP_FILES; j++) {
+		for (size_t j = 0; j < TEMP_FILES; j++) {
 			todo += geom_size[j];
 			if (geom_size[j] > 0) {
 				useful_threads++;
 			}
 		}
 
-		int threads = CPUS;
+		size_t threads = CPUS;
 		if (threads > TEMP_FILES / 4) {
 			threads = TEMP_FILES / 4;
 		}
@@ -1726,7 +1725,7 @@ int traverse_zooms(int *geomfd, off_t *geom_size, char *metabase, char *stringpo
 			struct dispatch *next;
 		} dispatches[threads];
 		struct dispatch *dispatch_head = &dispatches[0];
-		for (j = 0; j < threads; j++) {
+		for (size_t j = 0; j < threads; j++) {
 			dispatches[j].tasks = NULL;
 			dispatches[j].todo = 0;
 			if (j + 1 < threads) {
@@ -1736,7 +1735,7 @@ int traverse_zooms(int *geomfd, off_t *geom_size, char *metabase, char *stringpo
 			}
 		}
 
-		for (j = 0; j < TEMP_FILES; j++) {
+		for (size_t j = 0; j < TEMP_FILES; j++) {
 			if (geom_size[j] == 0) {
 				continue;
 			}
@@ -1764,8 +1763,7 @@ int traverse_zooms(int *geomfd, off_t *geom_size, char *metabase, char *stringpo
 		write_tile_args args[threads];
 		int running = threads;
 
-		int thread;
+		for (size_t thread = 0; thread < threads; thread++) {
-		for (thread = 0; thread < threads; thread++) {
 			args[thread].metabase = metabase;
 			args[thread].stringpool = stringpool;
 			args[thread].min_detail = min_detail;
@@ -1808,7 +1806,7 @@ int traverse_zooms(int *geomfd, off_t *geom_size, char *metabase, char *stringpo
 
 		int err = INT_MAX;
 
-		for (thread = 0; thread < threads; thread++) {
+		for (size_t thread = 0; thread < threads; thread++) {
 			void *retval;
 
 			if (pthread_join(pthreads[thread], &retval) != 0) {
@@ -1820,7 +1818,7 @@ int traverse_zooms(int *geomfd, off_t *geom_size, char *metabase, char *stringpo
 			}
 		}
 
-		for (j = 0; j < TEMP_FILES; j++) {
+		for (size_t j = 0; j < TEMP_FILES; j++) {
 			// Can be < 0 if there is only one source file, at z0
 			if (geomfd[j] >= 0) {
 				if (close(geomfd[j]) != 0) {
@@ -1848,8 +1846,7 @@ int traverse_zooms(int *geomfd, off_t *geom_size, char *metabase, char *stringpo
 		}
 	}
 
-	int j;
+	for (size_t j = 0; j < TEMP_FILES; j++) {
-	for (j = 0; j < TEMP_FILES; j++) {
 		// Can be < 0 if there is only one source file, at z0
 		if (geomfd[j] >= 0) {
 			if (close(geomfd[j]) != 0) {