Remove redundant NULL checks.

mrb_malloc causes an exception when memory was empty.

src/load.c

@@ -72,9 +72,6 @@ read_irep_record_1(mrb_state *mrb, const uint8_t *bin, size_t *len, mrb_bool all
       return NULL;
     }
     irep->iseq = (mrb_code *)mrb_malloc(mrb, sizeof(mrb_code) * irep->ilen);
-    if (irep->iseq == NULL) {
-      return NULL;
-    }
     for (i = 0; i < irep->ilen; i++) {
       irep->iseq[i] = (size_t)bin_to_uint32(src);     /* iseq */
       src += sizeof(uint32_t);
@@ -89,9 +86,6 @@ read_irep_record_1(mrb_state *mrb, const uint8_t *bin, size_t *len, mrb_bool all
       return NULL;
     }
     irep->pool = (mrb_value*)mrb_malloc(mrb, sizeof(mrb_value) * plen);
-    if (irep->pool == NULL) {
-      return NULL;
-    }
 
     for (i = 0; i < plen; i++) {
       mrb_value s;
@@ -137,9 +131,6 @@ read_irep_record_1(mrb_state *mrb, const uint8_t *bin, size_t *len, mrb_bool all
       return NULL;
     }
     irep->syms = (mrb_sym *)mrb_malloc(mrb, sizeof(mrb_sym) * irep->slen);
-    if (irep->syms == NULL) {
-      return NULL;
-    }
 
     for (i = 0; i < irep->slen; i++) {
       snl = bin_to_uint16(src);               /* symbol name length */
@@ -217,9 +208,6 @@ read_lineno_record_1(mrb_state *mrb, const uint8_t *bin, mrb_irep *irep, size_t
     return MRB_DUMP_GENERAL_FAILURE;
   }
   fname = (char *)mrb_malloc(mrb, fname_len + 1);
-  if (fname == NULL) {
-    return MRB_DUMP_GENERAL_FAILURE;
-  }
   memcpy(fname, bin, fname_len);
   fname[fname_len] = '\0';
   bin += fname_len;
@@ -233,9 +221,6 @@ read_lineno_record_1(mrb_state *mrb, const uint8_t *bin, mrb_irep *irep, size_t
     return MRB_DUMP_GENERAL_FAILURE;
   }
   lines = (uint16_t *)mrb_malloc(mrb, niseq * sizeof(uint16_t));
-  if (lines == NULL) {
-    return MRB_DUMP_GENERAL_FAILURE;
-  }
   for (i = 0; i < niseq; i++) {
     lines[i] = bin_to_uint16(bin);
     bin += sizeof(uint16_t); /* niseq */
@@ -543,9 +528,6 @@ read_lineno_record_file(mrb_state *mrb, FILE *fp, mrb_irep *irep)
     return MRB_DUMP_GENERAL_FAILURE;
   }
   ptr = mrb_malloc(mrb, buf_size);
-  if (!ptr) {
-    return MRB_DUMP_GENERAL_FAILURE;
-  }
   buf = (uint8_t *)ptr;
 
   if (fread(&buf[record_header_size], buf_size - record_header_size, 1, fp) == 0) {
@@ -593,7 +575,6 @@ read_irep_record_file(mrb_state *mrb, FILE *fp)
     return NULL;
   }
   ptr = mrb_malloc(mrb, buf_size);
-  if (!ptr) return NULL;
   buf = (uint8_t *)ptr;
   memcpy(buf, header, record_header_size);
   if (fread(&buf[record_header_size], buf_size - record_header_size, 1, fp) == 0) {
@@ -642,9 +623,6 @@ mrb_read_irep_file(mrb_state *mrb, FILE* fp)
 
   /* You don't need use SIZE_ERROR as buf_size is enough small. */
   buf = (uint8_t*)mrb_malloc(mrb, buf_size);
-  if (!buf) {
-    return NULL;
-  }
   if (fread(buf, buf_size, 1, fp) == 0) {
     mrb_free(mrb, buf);
     return NULL;

src/proc.c

@@ -195,9 +195,6 @@ mrb_init_proc(mrb_state *mrb)
   mrb_irep *call_irep = (mrb_irep *)mrb_malloc(mrb, sizeof(mrb_irep));
   static const mrb_irep mrb_irep_zero = { 0 };
 
-  if (call_irep == NULL)
-    return;
-
   *call_irep = mrb_irep_zero;
   call_irep->flags = MRB_ISEQ_NO_FREE;
   call_irep->iseq = call_iseq;

src/state.c

@@ -78,7 +78,6 @@ mrb_alloca(mrb_state *mrb, size_t size)
   struct alloca_header *p;
 
   p = (struct alloca_header*) mrb_malloc(mrb, sizeof(struct alloca_header)+size);
-  if (p == NULL) return NULL;
   p->next = mrb->mems;
   mrb->mems = p;
   return (void*)p->buf;

src/variable.c

@@ -46,11 +46,10 @@ iv_new(mrb_state *mrb)
   iv_tbl *t;
 
   t = mrb_malloc(mrb, sizeof(iv_tbl));
-  if (t) {
-    t->size = 0;
-    t->rootseg =  NULL;
-    t->last_len = 0;
-  }
+  t->size = 0;
+  t->rootseg =  NULL;
+  t->last_len = 0;
+
   return t;
 }