VM: new functions raw_fclose and raw_fread

These need to be used when the image is loaded because there is no
context so you can't throw io errors yet.

vm/image.cpp

@@ -18,7 +18,7 @@ void factor_vm::load_data_heap(FILE* file, image_header* h, vm_parameters* p) {
   init_data_heap(p->young_size, p->aging_size, p->tenured_size);
 
   fixnum bytes_read =
-      safe_fread((void*)data->tenured->start, 1, h->data_size, file);
+      raw_fread((void*)data->tenured->start, 1, h->data_size, file);
 
   if ((cell)bytes_read != h->data_size) {
     std::cout << "truncated image: " << bytes_read << " bytes read, ";
@@ -37,7 +37,7 @@ void factor_vm::load_code_heap(FILE* file, image_header* h, vm_parameters* p) {
 
   if (h->code_size != 0) {
     size_t bytes_read =
-        safe_fread((void*)code->allocator->start, 1, h->code_size, file);
+        raw_fread((void*)code->allocator->start, 1, h->code_size, file);
     if (bytes_read != h->code_size) {
       std::cout << "truncated image: " << bytes_read << " bytes read, ";
       std::cout << h->code_size << " bytes expected\n";
@@ -239,9 +239,8 @@ void factor_vm::load_image(vm_parameters* p) {
     free(msg);
     exit(1);
   }
-
   image_header h;
-  if (safe_fread(&h, sizeof(image_header), 1, file) != 1)
+  if (raw_fread(&h, sizeof(image_header), 1, file) != 1)
     fatal_error("Cannot read image header", 0);
 
   if (h.magic != image_magic)
@@ -253,7 +252,7 @@ void factor_vm::load_image(vm_parameters* p) {
   load_data_heap(file, &h, p);
   load_code_heap(file, &h, p);
 
-  safe_fclose(file);
+  raw_fclose(file);
 
   init_objects(&h);
 

vm/io.cpp

@@ -13,6 +13,34 @@ The Factor library provides platform-specific code for Unix and Windows
 with many more capabilities so these words are not usually used in
 normal operation. */
 
+size_t raw_fread(void* ptr, size_t size, size_t nitems, FILE* stream) {
+  size_t items_read = 0;
+  size_t ret = 0;
+
+  do {
+    ret = fread((void*)((int*)ptr + items_read * size), size,
+                nitems - items_read, stream);
+    if (ret == 0) {
+      if (feof(stream))
+        break;
+      else if (errno != EINTR) {
+        return 0;
+      }
+    }
+    items_read += ret;
+  } while (items_read != nitems);
+
+  return items_read;
+}
+
+// Call fclose() once only. Issues #1335, #908.
+int raw_fclose(FILE* stream) {
+  if (fclose(stream) == EOF && errno != EINTR)
+    return -1;
+  return 0;
+}
+
+
 void factor_vm::init_c_io() {
   special_objects[OBJ_STDIN] = allot_alien(false_object, (cell)stdin);
   special_objects[OBJ_STDOUT] = allot_alien(false_object, (cell)stdout);
@@ -56,22 +84,10 @@ int factor_vm::safe_fgetc(FILE* stream) {
 
 size_t factor_vm::safe_fread(void* ptr, size_t size, size_t nitems,
                              FILE* stream) {
-  size_t items_read = 0;
+  size_t ret = raw_fread(ptr, size, nitems, stream);
-  size_t ret = 0;
+  if (!ret)
-
+    io_error_if_not_EINTR();
-  do {
+  return ret;
-    ret = fread((void*)((int*)ptr + items_read * size), size,
-                nitems - items_read, stream);
-    if (ret == 0) {
-      if (feof(stream))
-        break;
-      else
-        io_error_if_not_EINTR();
-    }
-    items_read += ret;
-  } while (items_read != nitems);
-
-  return items_read;
 }
 
 void factor_vm::safe_fputc(int c, FILE* stream) {
@@ -142,10 +158,9 @@ void factor_vm::safe_fflush(FILE* stream) {
   }
 }
 
-// Call fclose() once only. Issues #1335, #908.
 void factor_vm::safe_fclose(FILE* stream) {
-  if (fclose(stream) == EOF && errno != EINTR)
+  if (raw_fclose(stream) == -1)
-    general_error(ERROR_IO, tag_fixnum(errno), false_object);
+    io_error_if_not_EINTR();
 }
 
 void factor_vm::primitive_fopen() {

vm/io.hpp

@@ -1,5 +1,9 @@
 namespace factor {
 
+/* Safe IO functions that does not throw Factor errors. */
+int raw_fclose(FILE* stream);
+size_t raw_fread(void* ptr, size_t size, size_t nitems, FILE* stream);
+
 /* Platform specific primitives */
 
 VM_C_API int err_no();