Merge pull request #1831 from monaka/pr-make-type-casts-safer

Make type casts safer

1 files changed, 70 insertions, 43 deletions

diff --git a/src/load.c b/src/load.c
index de517f89f..aa39efba4 100644
--- a/src/load.c
+++ b/src/load.c
@@ -26,6 +26,10 @@
 # error This code assumes CHAR_BIT == 8
 #endif
 
+#if UINT32_MAX > SIZE_MAX
+# error This code cannot be built on your environment.
+#endif
+
 static size_t
 offset_crc_body(void)
 {
@@ -34,10 +38,11 @@ offset_crc_body(void)
 }
 
 static mrb_irep*
-read_irep_record_1(mrb_state *mrb, const uint8_t *bin, uint32_t *len, mrb_bool alloc)
+read_irep_record_1(mrb_state *mrb, const uint8_t *bin, size_t *len, mrb_bool alloc)
 {
   size_t i;
   const uint8_t *src = bin;
+  ptrdiff_t diff;
   uint16_t tt, pool_data_len, snl;
   size_t plen;
   int ai = mrb_gc_arena_save(mrb);
@@ -55,12 +60,12 @@ read_irep_record_1(mrb_state *mrb, const uint8_t *bin, uint32_t *len, mrb_bool a
   src += sizeof(uint16_t);
 
   /* number of child irep */
-  irep->rlen = bin_to_uint16(src);
+  irep->rlen = (size_t)bin_to_uint16(src);
   src += sizeof(uint16_t);
 
   /* Binary Data Section */
   /* ISEQ BLOCK */
-  irep->ilen = bin_to_uint32(src);
+  irep->ilen = (size_t)bin_to_uint32(src);
   src += sizeof(uint32_t);
   if (irep->ilen > 0) {
     if (SIZE_ERROR_MUL(sizeof(mrb_code), irep->ilen)) {
@@ -71,13 +76,13 @@ read_irep_record_1(mrb_state *mrb, const uint8_t *bin, uint32_t *len, mrb_bool a
       return NULL;
     }
     for (i = 0; i < irep->ilen; i++) {
-      irep->iseq[i] = bin_to_uint32(src);     /* iseq */
+      irep->iseq[i] = (size_t)bin_to_uint32(src);     /* iseq */
       src += sizeof(uint32_t);
     }
   }
 
   /* POOL BLOCK */
-  plen = bin_to_uint32(src); /* number of pool */
+  plen = (size_t)bin_to_uint32(src); /* number of pool */
   src += sizeof(uint32_t);
   if (plen > 0) {
     if (SIZE_ERROR_MUL(sizeof(mrb_value), plen)) {
@@ -125,7 +130,7 @@ read_irep_record_1(mrb_state *mrb, const uint8_t *bin, uint32_t *len, mrb_bool a
   }
 
   /* SYMS BLOCK */
-  irep->slen = bin_to_uint32(src);  /* syms length */
+  irep->slen = (size_t)bin_to_uint32(src);  /* syms length */
   src += sizeof(uint32_t);
   if (irep->slen > 0) {
     if (SIZE_ERROR_MUL(sizeof(mrb_sym), irep->slen)) {
@@ -158,20 +163,24 @@ read_irep_record_1(mrb_state *mrb, const uint8_t *bin, uint32_t *len, mrb_bool a
   }
 
   irep->reps = (mrb_irep**)mrb_malloc(mrb, sizeof(mrb_irep*)*irep->rlen);
-  *len = src - bin;
+
+  diff = src - bin;
+  mrb_assert(diff >= 0);
+  mrb_assert((size_t)diff <= SIZE_MAX);
+  *len = (size_t)diff;
 
   return irep;
 }
 
 static mrb_irep*
-read_irep_record(mrb_state *mrb, const uint8_t *bin, uint32_t *len, mrb_bool alloc)
+read_irep_record(mrb_state *mrb, const uint8_t *bin, size_t *len, mrb_bool alloc)
 {
   mrb_irep *irep = read_irep_record_1(mrb, bin, len, alloc);
   size_t i;
 
   bin += *len;
   for (i=0; i<irep->rlen; i++) {
-    uint32_t rlen;
+    size_t rlen;
 
     irep->reps[i] = read_irep_record(mrb, bin, &rlen, alloc);
     bin += rlen;
@@ -183,14 +192,14 @@ read_irep_record(mrb_state *mrb, const uint8_t *bin, uint32_t *len, mrb_bool all
 static mrb_irep*
 read_section_irep(mrb_state *mrb, const uint8_t *bin, mrb_bool alloc)
 {
-  uint32_t len;
+  size_t len;
 
   bin += sizeof(struct rite_section_irep_header);
   return read_irep_record(mrb, bin, &len, alloc);
 }
 
 static int
-read_lineno_record_1(mrb_state *mrb, const uint8_t *bin, mrb_irep *irep, uint32_t *len)
+read_lineno_record_1(mrb_state *mrb, const uint8_t *bin, mrb_irep *irep, size_t *len)
 {
   int ret;
   size_t i, fname_len, niseq;
@@ -216,7 +225,7 @@ read_lineno_record_1(mrb_state *mrb, const uint8_t *bin, mrb_irep *irep, uint32_
   bin += fname_len;
   *len += fname_len;
 
-  niseq = bin_to_uint32(bin);
+  niseq = (size_t)bin_to_uint32(bin);
   bin += sizeof(uint32_t); /* niseq */
   *len += sizeof(uint32_t);
 
@@ -239,14 +248,14 @@ read_lineno_record_1(mrb_state *mrb, const uint8_t *bin, mrb_irep *irep, uint32_
 }
 
 static int
-read_lineno_record(mrb_state *mrb, const uint8_t *bin, mrb_irep *irep, uint32_t *lenp)
+read_lineno_record(mrb_state *mrb, const uint8_t *bin, mrb_irep *irep, size_t *lenp)
 {
   int result = read_lineno_record_1(mrb, bin, irep, lenp);
   size_t i;
 
   if (result != MRB_DUMP_OK) return result;
   for (i = 0; i < irep->rlen; i++) {
-    uint32_t len;
+    size_t len;
 
     result = read_lineno_record(mrb, bin, irep->reps[i], &len);
     if (result != MRB_DUMP_OK) break;
@@ -259,7 +268,7 @@ read_lineno_record(mrb_state *mrb, const uint8_t *bin, mrb_irep *irep, uint32_t
 static int
 read_section_lineno(mrb_state *mrb, const uint8_t *bin, mrb_irep *irep)
 {
-  uint32_t len;
+  size_t len;
 
   len = 0;
   bin += sizeof(struct rite_section_lineno_header);
@@ -269,9 +278,10 @@ read_section_lineno(mrb_state *mrb, const uint8_t *bin, mrb_irep *irep)
 }
 
 static int
-read_debug_record(mrb_state *mrb, const uint8_t *start, mrb_irep* irep, uint32_t *len, const mrb_sym *filenames, size_t filenames_len)
+read_debug_record(mrb_state *mrb, const uint8_t *start, mrb_irep* irep, size_t *record_len, const mrb_sym *filenames, size_t filenames_len)
 {
   const uint8_t *bin = start;
+  ptrdiff_t diff;
   size_t record_size, i;
   uint16_t f_idx;
 
@@ -280,7 +290,7 @@ read_debug_record(mrb_state *mrb, const uint8_t *start, mrb_irep* irep, uint32_t
   irep->debug_info = (mrb_irep_debug_info*)mrb_malloc(mrb, sizeof(mrb_irep_debug_info));
   irep->debug_info->pc_count = irep->ilen;
 
-  record_size = bin_to_uint32(bin);
+  record_size = (size_t)bin_to_uint32(bin);
   bin += sizeof(uint32_t);
 
   irep->debug_info->flen = bin_to_uint16(bin);
@@ -295,7 +305,8 @@ read_debug_record(mrb_state *mrb, const uint8_t *start, mrb_irep* irep, uint32_t
     file = (mrb_irep_debug_info_file *)mrb_malloc(mrb, sizeof(*file));
     irep->debug_info->files[f_idx] = file;
 
-    file->start_pos = bin_to_uint32(bin); bin += sizeof(uint32_t);
+    file->start_pos = bin_to_uint32(bin);
+    bin += sizeof(uint32_t);
 
     /* filename */
     filename_idx = bin_to_uint16(bin);
@@ -305,26 +316,31 @@ read_debug_record(mrb_state *mrb, const uint8_t *start, mrb_irep* irep, uint32_t
     len = 0;
     file->filename = mrb_sym2name_len(mrb, file->filename_sym, &len);
 
-    file->line_entry_count = bin_to_uint32(bin); bin += sizeof(uint32_t);
-    file->line_type = (mrb_debug_line_type)bin_to_uint8(bin); bin += sizeof(uint8_t);
+    file->line_entry_count = bin_to_uint32(bin);
+    bin += sizeof(uint32_t);
+    file->line_type = (mrb_debug_line_type)bin_to_uint8(bin);
+    bin += sizeof(uint8_t);
     switch(file->line_type) {
       case mrb_debug_line_ary: {
-        size_t l;
+        uint32_t l;
 
-        file->line_ary = (uint16_t *)mrb_malloc(mrb, sizeof(uint16_t) * file->line_entry_count);
+        file->line_ary = (uint16_t *)mrb_malloc(mrb, sizeof(uint16_t) * (size_t)(file->line_entry_count));
         for(l = 0; l < file->line_entry_count; ++l) {
-          file->line_ary[l] = bin_to_uint16(bin); bin += sizeof(uint16_t);
+          file->line_ary[l] = bin_to_uint16(bin);
+          bin += sizeof(uint16_t);
         }
       } break;
 
       case mrb_debug_line_flat_map: {
-        size_t l;
+        uint32_t l;
 
         file->line_flat_map = (mrb_irep_debug_info_line*)mrb_malloc(
-            mrb, sizeof(mrb_irep_debug_info_line) * file->line_entry_count);
+            mrb, sizeof(mrb_irep_debug_info_line) * (size_t)(file->line_entry_count));
         for(l = 0; l < file->line_entry_count; ++l) {
-          file->line_flat_map[l].start_pos = bin_to_uint32(bin); bin += sizeof(uint32_t);
-          file->line_flat_map[l].line = bin_to_uint16(bin); bin += sizeof(uint16_t);
+          file->line_flat_map[l].start_pos = bin_to_uint32(bin);
+          bin += sizeof(uint32_t);
+          file->line_flat_map[l].line = bin_to_uint16(bin);
+          bin += sizeof(uint16_t);
         }
       } break;
 
@@ -332,12 +348,16 @@ read_debug_record(mrb_state *mrb, const uint8_t *start, mrb_irep* irep, uint32_t
     }
   }
 
-  if((long)record_size != (bin - start)) {
+  diff = bin - start;
+  mrb_assert(diff >= 0);
+  mrb_assert((size_t)diff <= SIZE_MAX);
+
+  if(record_size != (size_t)diff) {
     return MRB_DUMP_GENERAL_FAILURE;
   }
 
   for (i = 0; i < irep->rlen; i++) {
-    uint32_t len;
+    size_t len;
     int ret;
 
     ret =read_debug_record(mrb, bin, irep->reps[i], &len, filenames, filenames_len);
@@ -345,7 +365,10 @@ read_debug_record(mrb_state *mrb, const uint8_t *start, mrb_irep* irep, uint32_t
     bin += len;
   }
 
-  *len = bin - start;
+  diff = bin - start;
+  mrb_assert(diff >= 0);
+  mrb_assert((size_t)diff <= SIZE_MAX);
+  *record_len = (size_t)diff;
 
   return MRB_DUMP_OK;
 }
@@ -354,11 +377,12 @@ static int
 read_section_debug(mrb_state *mrb, const uint8_t *start, mrb_irep *irep, mrb_bool alloc)
 {
   const uint8_t *bin;
+  ptrdiff_t diff;
   struct rite_section_debug_header *header;
   uint16_t i;
-  uint32_t len = 0;
+  size_t len = 0;
   int result;
-  size_t filenames_len;
+  uint16_t filenames_len;
   mrb_sym *filenames;
 
   bin = start;
@@ -367,15 +391,15 @@ read_section_debug(mrb_state *mrb, const uint8_t *start, mrb_irep *irep, mrb_boo
 
   filenames_len = bin_to_uint16(bin);
   bin += sizeof(uint16_t);
-  filenames = (mrb_sym*)mrb_malloc(mrb, sizeof(mrb_sym) * filenames_len);
+  filenames = (mrb_sym*)mrb_malloc(mrb, sizeof(mrb_sym) * (size_t)filenames_len);
   for(i = 0; i < filenames_len; ++i) {
     uint16_t f_len = bin_to_uint16(bin);
     bin += sizeof(uint16_t);
     if (alloc) {
-      filenames[i] = mrb_intern(mrb, (const char *)bin, f_len);
+      filenames[i] = mrb_intern(mrb, (const char *)bin, (size_t)f_len);
     }
     else {
-      filenames[i] = mrb_intern_static(mrb, (const char *)bin, f_len);
+      filenames[i] = mrb_intern_static(mrb, (const char *)bin, (size_t)f_len);
     }
     bin += f_len;
   }
@@ -384,7 +408,10 @@ read_section_debug(mrb_state *mrb, const uint8_t *start, mrb_irep *irep, mrb_boo
   if (result != MRB_DUMP_OK) goto debug_exit;
 
   bin += len;
-  if ((bin - start) != bin_to_uint32(header->section_size)) {
+  diff = bin - start;
+  mrb_assert(diff >= 0);
+  mrb_assert(diff <= UINT32_MAX);
+  if ((uint32_t)diff != bin_to_uint32(header->section_size)) {
     result = MRB_DUMP_GENERAL_FAILURE;
   }
 
@@ -408,7 +435,7 @@ read_binary_header(const uint8_t *bin, size_t *bin_size, uint16_t *crc)
 
   *crc = bin_to_uint16(header->binary_crc);
   if (bin_size) {
-    *bin_size = bin_to_uint32(header->binary_size);
+    *bin_size = (size_t)bin_to_uint32(header->binary_size);
   }
 
   return MRB_DUMP_OK;
@@ -504,14 +531,14 @@ read_lineno_record_file(mrb_state *mrb, FILE *fp, mrb_irep *irep)
   const size_t record_header_size = sizeof(header);
   int result;
   size_t i, buf_size;
-  uint32_t len;
+  size_t len;
   void *ptr;
   uint8_t *buf;
 
   if (fread(header, record_header_size, 1, fp) == 0) {
     return MRB_DUMP_READ_FAULT;
   }
-  buf_size = bin_to_uint32(&header[0]);
+  buf_size = (size_t)bin_to_uint32(&header[0]);
   if (SIZE_ERROR(buf_size)) {
     return MRB_DUMP_GENERAL_FAILURE;
   }
@@ -553,7 +580,7 @@ read_irep_record_file(mrb_state *mrb, FILE *fp)
   uint8_t header[1 + 4];
   const size_t record_header_size = sizeof(header);
   size_t buf_size, i;
-  uint32_t len;
+  size_t len;
   mrb_irep *irep = NULL;
   void *ptr;
   uint8_t *buf;
@@ -561,7 +588,7 @@ read_irep_record_file(mrb_state *mrb, FILE *fp)
   if (fread(header, record_header_size, 1, fp) == 0) {
     return NULL;
   }
-  buf_size = bin_to_uint32(&header[0]);
+  buf_size = (size_t)bin_to_uint32(&header[0]);
   if (SIZE_ERROR(buf_size)) {
     return NULL;
   }
@@ -600,7 +627,7 @@ mrb_read_irep_file(mrb_state *mrb, FILE* fp)
   int result;
   uint8_t *buf;
   uint16_t crc, crcwk = 0;
-  uint32_t section_size = 0;
+  size_t section_size = 0;
   size_t nbytes;
   struct rite_section_header section_header;
   long fpos;
@@ -657,7 +684,7 @@ mrb_read_irep_file(mrb_state *mrb, FILE* fp)
     if (fread(&section_header, sizeof(struct rite_section_header), 1, fp) == 0) {
       return NULL;
     }
-    section_size = bin_to_uint32(section_header.section_size);
+    section_size = (size_t)bin_to_uint32(section_header.section_size);
 
     if (memcmp(section_header.section_identify, RITE_SECTION_IREP_IDENTIFIER, sizeof(section_header.section_identify)) == 0) {
       fseek(fp, fpos, SEEK_SET);