Add 'cppcheck' target.

Fix cppcheck warnings.

Makefile

@@ -61,6 +61,9 @@ fuzz: fuzz-roundtrip-driver
 test: lzw-eddy
 	${TEST_PREFIX} ./run-tests.sh
 
+cppcheck:
+	@cppcheck --verbose --error-exitcode=1 --enable=warning,performance,portability .
+
 backup:
 	@echo -e $(YELLOW)Making backup$(NC)
 	tar -cJf ../$(notdir $(CURDIR))-`date +"%Y-%m"`.tar.xz ../$(notdir $(CURDIR))

fuzzing/afl_roundtrip_driver.c

@@ -60,14 +60,14 @@ int main(int argc, char *argv[]) {
 		if (input && slen > 0) {
 			// Compress input from fuzzer.
 			while ((res = lzw_compress(&statec0, input, slen, comp, dest_size)) > 0) { comp_size += res; };
-			printf("compressed:%zd (res=%zd)\n", comp_size, res);
+			printf("compressed:%zu (res=%zd)\n", comp_size, res);
 			if (res < 0) {
 				abort();
 			}
 
 			// Decompress the compressed data...
 			while ((res = lzw_decompress(&stated0, comp, comp_size, decomp, dest_size)) > 0) { decomp_size += res; };
-			printf("decompressed:%zd (res=%zd)\n", decomp_size, res);
+			printf("decompressed:%zu (res=%zd)\n", decomp_size, res);
 			if (res < 0) {
 				abort();
 			}

lzw-eddy.c

@@ -81,7 +81,7 @@ static void lzw_compress_file(const char *srcfile, const char *destfile) {
 	if (ofile) {
 		uint8_t *src = malloc(slen);
 		if (!src) {
-			fprintf(stderr, "ERROR: memory allocation of %lu bytes failed.\n", slen);
+			fprintf(stderr, "ERROR: memory allocation of %ld bytes failed.\n", slen);
 			exit(1);
 		}
 		uint8_t dest[4096];
@@ -144,7 +144,7 @@ static void lzw_decompress_file(const char *srcfile, const char *destfile) {
 			}
 			uint8_t *src = malloc(slen);
 			if (!src) {
-				fprintf(stderr, "ERROR: memory allocation of %lu bytes failed.\n", slen);
+				fprintf(stderr, "ERROR: memory allocation of %ld bytes failed.\n", slen);
 				exit(1);
 			}
 
@@ -185,7 +185,7 @@ int main(int argc, char *argv []) {
 
 	if (!infile || !outfile) {
 		printf("Usage: %s -c file|-d file -o outfile\n", argv[0]);
-		printf("Compiled Configuration:\n LZW_MIN_CODE_WIDTH=%d, LZW_MAX_CODE_WIDTH=%d, LZW_MAX_CODES=%ld, sizeof(lzw_state)=%zu\n",
+		printf("Compiled Configuration:\n LZW_MIN_CODE_WIDTH=%d, LZW_MAX_CODE_WIDTH=%d, LZW_MAX_CODES=%lu, sizeof(lzw_state)=%zu\n",
 			LZW_MIN_CODE_WIDTH,
 			LZW_MAX_CODE_WIDTH,
 			LZW_MAX_CODES,