Don't use int. It decreases portability. Use size_t as array index and length. It avoids overflow in the extreme situations.

3 files changed, 53 insertions, 34 deletions

diff --git a/src/crc.c b/src/crc.c
index 70fa60dfb..db852f6cb 100644
--- a/src/crc.c
+++ b/src/crc.c
@@ -18,9 +18,10 @@
 #define  CRC_CARRY_BIT      (1 << 24)
 
 uint16_t
-calc_crc_16_ccitt(const uint8_t *src, uint32_t nbytes, uint16_t crc)
+calc_crc_16_ccitt(const uint8_t *src, size_t nbytes, uint16_t crc)
 {
-  uint32_t ibyte, ibit;
+  size_t ibyte;
+  uint32_t ibit;
   uint32_t crcwk = crc << 8;
 
   for (ibyte = 0; ibyte < nbytes; ibyte++) {
diff --git a/src/dump.c b/src/dump.c
index 94cdeebb2..fb5bb5e7c 100644
--- a/src/dump.c
+++ b/src/dump.c
@@ -53,7 +53,7 @@ static int
 write_iseq_block(mrb_state *mrb, mrb_irep *irep, uint8_t *buf)
 {
   uint8_t *cur = buf;
-  int iseq_no;
+  size_t iseq_no;
 
   cur += uint32_to_bin(irep->ilen, cur); /* number of opcode */
   for (iseq_no = 0; iseq_no < irep->ilen; iseq_no++) {
@@ -68,7 +68,8 @@ static size_t
 get_pool_block_size(mrb_state *mrb, mrb_irep *irep)
 {
   size_t size = 0;
-  int pool_no, len;
+  size_t pool_no;
+  int len;
   mrb_value str;
   char buf[32];
 
@@ -103,7 +104,8 @@ get_pool_block_size(mrb_state *mrb, mrb_irep *irep)
 static int
 write_pool_block(mrb_state *mrb, mrb_irep *irep, uint8_t *buf)
 {
-  int result, pool_no;
+  int result;
+  size_t pool_no;
   uint8_t *cur = buf;
   size_t buf_size, len;
   mrb_value str;
@@ -169,7 +171,8 @@ static size_t
 get_syms_block_size(mrb_state *mrb, mrb_irep *irep)
 {
   size_t size = 0;
-  int sym_no, len;
+  size_t sym_no;
+  int len;
 
   size += sizeof(uint32_t); /* slen */
   for (sym_no = 0; sym_no < irep->slen; sym_no++) {
@@ -186,7 +189,9 @@ get_syms_block_size(mrb_state *mrb, mrb_irep *irep)
 static int
 write_syms_block(mrb_state *mrb, mrb_irep *irep, uint8_t *buf)
 {
-  int result, sym_no, len, buf_size;
+  int result, len;
+  size_t sym_no;
+  size_t buf_size;
   uint8_t *cur = buf;
   uint16_t nlen;
   char *char_buf = NULL;
@@ -298,13 +303,14 @@ mrb_write_section_irep_header(mrb_state *mrb, uint32_t section_size, uint16_t ni
 }
 
 static int
-mrb_write_section_irep(mrb_state *mrb, int start_index, uint8_t *bin)
+mrb_write_section_irep(mrb_state *mrb, size_t start_index, uint8_t *bin)
 {
-  int result, irep_no;
+  int result;
+  size_t irep_no;
   uint32_t section_size = 0, rlen = 0; /* size of irep record */
   uint8_t *cur = bin;
 
-  if (mrb == NULL || start_index < 0 || start_index >= mrb->irep_len || bin == NULL) {
+  if (mrb == NULL || start_index >= mrb->irep_len || bin == NULL) {
     return MRB_DUMP_INVALID_ARGUMENT;
   }
 
@@ -326,7 +332,7 @@ mrb_write_section_irep(mrb_state *mrb, int start_index, uint8_t *bin)
 }
 
 static int
-write_rite_binary_header(mrb_state *mrb, uint32_t binary_size, uint8_t* bin)
+write_rite_binary_header(mrb_state *mrb, size_t binary_size, uint8_t* bin)
 { 
   struct rite_binary_header *header = (struct rite_binary_header*)bin;
   uint16_t crc;
@@ -346,12 +352,14 @@ write_rite_binary_header(mrb_state *mrb, uint32_t binary_size, uint8_t* bin)
 }
 
 static int
-mrb_dump_irep(mrb_state *mrb, int start_index, uint8_t **bin, uint32_t *bin_size)
+mrb_dump_irep(mrb_state *mrb, size_t start_index, uint8_t **bin, size_t *bin_size)
 {
-  int result, irep_no, section_irep_size;
+  int result;
+  size_t section_irep_size;
+  size_t irep_no;
   uint8_t *cur = NULL;
 
-  if (mrb == NULL || start_index < 0 || start_index >= mrb->irep_len) {
+  if (mrb == NULL || start_index >= mrb->irep_len) {
     *bin = NULL;
     goto error_exit;
   }
@@ -391,10 +399,10 @@ error_exit:
 #ifdef ENABLE_STDIO
 
 int
-mrb_dump_irep_binary(mrb_state *mrb, int start_index, FILE* fp)
+mrb_dump_irep_binary(mrb_state *mrb, size_t start_index, FILE* fp)
 {
   uint8_t *bin = NULL;
-  uint32_t bin_size = 0;
+  size_t bin_size = 0;
   int result;
 
   if (fp == NULL) {
@@ -411,10 +419,10 @@ mrb_dump_irep_binary(mrb_state *mrb, int start_index, FILE* fp)
 }
 
 int
-mrb_dump_irep_cfunc(mrb_state *mrb, int start_index, FILE *fp, const char *initname)
+mrb_dump_irep_cfunc(mrb_state *mrb, size_t start_index, FILE *fp, const char *initname)
 {
   uint8_t *bin = NULL;
-  uint32_t bin_size = 0, bin_idx = 0;
+  size_t bin_size = 0, bin_idx = 0;
   int result;
 
   if (fp == NULL || initname == NULL) {
diff --git a/src/load.c b/src/load.c
index 8cd303ca5..92799eb49 100644
--- a/src/load.c
+++ b/src/load.c
@@ -28,13 +28,14 @@ offset_crc_body()
 static int
 read_rite_irep_record(mrb_state *mrb, const uint8_t *bin, uint32_t *len)
 {
-  int i, ret;
+  int ret;
+  size_t i;
   char *char_buf;
   const uint8_t *src = bin;
   uint16_t tt, pool_data_len, snl, buf_size = MRB_DUMP_DEFAULT_STR_LEN;
   mrb_int fix_num;
   mrb_float f;
-  int plen;
+  size_t plen;
   int ai = mrb_gc_arena_save(mrb);
   mrb_irep *irep = mrb_add_irep(mrb);
 
@@ -170,9 +171,12 @@ error_exit:
 static int
 read_rite_section_irep(mrb_state *mrb, const uint8_t *bin)
 {
-  int n, i, result;
-  uint32_t len, sirep;
+  int result;
+  size_t sirep;
+  size_t i;
+  uint32_t len;
   uint16_t nirep;
+  uint16_t n;
   const struct rite_section_irep_header *header;
 
   header = (const struct rite_section_irep_header*)bin;
@@ -212,7 +216,7 @@ error_exit:
 }
 
 static int
-read_rite_binary_header(const uint8_t *bin, uint32_t *bin_size, uint16_t *crc)
+read_rite_binary_header(const uint8_t *bin, size_t *bin_size, uint16_t *crc)
 {
   const struct rite_binary_header *header = (const struct rite_binary_header *)bin;
 
@@ -232,13 +236,15 @@ read_rite_binary_header(const uint8_t *bin, uint32_t *bin_size, uint16_t *crc)
   return MRB_DUMP_OK;
 }
 
-int
+int32_t
 mrb_read_irep(mrb_state *mrb, const uint8_t *bin)
 {
-  int total_nirep = 0, result;
+  int result;
+  int32_t total_nirep = 0;
   const struct rite_section_header *section_header;
   uint16_t crc;
-  uint32_t bin_size = 0, n;
+  size_t bin_size = 0;
+  size_t n;
 
   if ((mrb == NULL) || (bin == NULL)) {
     return MRB_DUMP_INVALID_ARGUMENT;
@@ -280,7 +286,7 @@ irep_error(mrb_state *mrb, const char *msg)
 mrb_value
 mrb_load_irep(mrb_state *mrb, const uint8_t *bin)
 {
-  int n;
+  int32_t n;
 
   n = mrb_read_irep(mrb, bin);
   if (n < 0) {
@@ -292,14 +298,17 @@ mrb_load_irep(mrb_state *mrb, const uint8_t *bin)
 
 #ifdef ENABLE_STDIO
 
-static int
+static int32_t
 read_rite_section_irep_file(mrb_state *mrb, FILE *fp)
 {
-  int n, i, result;
-  uint16_t sirep, nirep;
+  int32_t result;
+  size_t sirep;
+  size_t i;
+  uint16_t nirep;
+  uint16_t n;
   uint32_t len, buf_size;
   uint8_t *buf = NULL;
-  const int record_header_size = 1 + 4;
+  const size_t record_header_size = 1 + 4;
 
   struct rite_section_irep_header header;
   fread(&header, sizeof(struct rite_section_irep_header), 1, fp);
@@ -344,13 +353,14 @@ error_exit:
   return sirep + bin_to_uint16(header.sirep);
 }
 
-int
+int32_t
 mrb_read_irep_file(mrb_state *mrb, FILE* fp)
 {
-  int total_nirep = 0, result;
+  int result;
+  int32_t total_nirep = 0;
   uint8_t *buf;
   uint16_t crc, crcwk = 0;
-  uint32_t bin_size = 0, buf_size = 0, section_size = 0;
+  uint32_t section_size = 0;
   size_t nbytes;
   struct rite_section_header section_header;
   long fpos;