stdlib: Implement str::unsafe_from_bytes_ivec()

Author: pcwalton

src/lib/str.rs

@@ -55,6 +55,7 @@ native "rust" mod rustrt {
     fn str_vec(str s) -> vec[u8];
     fn str_byte_len(str s) -> uint;
     fn str_alloc(uint n_bytes) -> str;
+    fn str_from_ivec(&u8[mutable?] b) -> str;
     fn str_from_vec(vec[mutable? u8] b) -> str;
     fn str_from_cstr(sbuf cstr) -> str;
     fn str_from_buf(sbuf buf, uint len) -> str;
@@ -170,6 +171,10 @@ fn unsafe_from_bytes(vec[mutable? u8] v) -> str {
     ret rustrt::str_from_vec(v);
 }
 
+fn unsafe_from_bytes_ivec(&u8[mutable?] v) -> str {
+    ret rustrt::str_from_ivec(v);
+}
+
 fn unsafe_from_byte(u8 u) -> str { ret rustrt::str_from_vec([u]); }
 
 fn str_from_cstr(sbuf cstr) -> str { ret rustrt::str_from_cstr(cstr); }

src/rt/rust_builtin.cpp

@@ -313,6 +313,26 @@ str_byte_len(rust_task *task, rust_str *s)
     return s->fill - 1;  // -1 for the '\0' terminator.
 }
 
+extern "C" CDECL rust_str *
+str_from_ivec(rust_task *task, rust_ivec *v)
+{
+    uintptr_t fill = v->fill ? v->fill : v->payload.ptr->fill;
+    void *data = v->fill ? v->payload.data : v->payload.ptr->data;
+
+    rust_str *st =
+        vec_alloc_with_data(task,
+                            fill + 1,   // +1 to fit at least '\0'
+                            fill,
+                            1,
+                            fill ? data : NULL);
+    if (!st) {
+        task->fail(2);
+        return NULL;
+    }
+    st->data[st->fill++] = '\0';
+    return st;
+}
+
 extern "C" CDECL rust_str *
 str_from_vec(rust_task *task, rust_vec *v)
 {

src/rt/rustrt.def.in

@@ -41,6 +41,7 @@ str_buf
 str_byte_len
 str_from_buf
 str_from_cstr
+str_from_ivec
 str_from_vec
 str_push_byte
 str_slice