more work leading up to exchange allocation header removal

src/librustc/middle/trans/base.rs

@@ -258,25 +258,43 @@ pub fn malloc_raw_dyn(bcx: block,
         }
     };
 
-    // Grab the TypeRef type of box_ptr_ty.
-    let box_ptr_ty = mk_fn(bcx.tcx(), t);
-    let llty = type_of(ccx, box_ptr_ty);
-
-    // Get the tydesc for the body:
-    let static_ti = get_tydesc(ccx, t);
-    glue::lazily_emit_all_tydesc_glue(ccx, static_ti);
-
-    // Allocate space:
-    let tydesc = PointerCast(bcx, static_ti.tydesc, Type::i8p());
-    let rval = alloca(bcx, Type::i8p());
-    let bcx = callee::trans_lang_call(
-        bcx,
-        langcall,
-        [tydesc, size],
-        expr::SaveIn(rval));
-    let r = rslt(bcx, PointerCast(bcx, Load(bcx, rval), llty));
-    maybe_set_managed_unique_rc(r.bcx, r.val, heap);
-    r
+    if heap == heap_exchange {
+        // Grab the TypeRef type of box_ptr_ty.
+        let box_ptr_ty = mk_fn(bcx.tcx(), t);
+        let llty = type_of(ccx, box_ptr_ty);
+
+        let llty_value = type_of::type_of(ccx, t);
+        let llalign = llalign_of_min(ccx, llty_value);
+
+        // Allocate space:
+        let rval = alloca(bcx, Type::i8p());
+        let bcx = callee::trans_lang_call(
+            bcx,
+            langcall,
+            [C_i32(llalign as i32), size],
+            expr::SaveIn(rval));
+        rslt(bcx, PointerCast(bcx, Load(bcx, rval), llty))
+    } else {
+        // Grab the TypeRef type of box_ptr_ty.
+        let box_ptr_ty = mk_fn(bcx.tcx(), t);
+        let llty = type_of(ccx, box_ptr_ty);
+
+        // Get the tydesc for the body:
+        let static_ti = get_tydesc(ccx, t);
+        glue::lazily_emit_all_tydesc_glue(ccx, static_ti);
+
+        // Allocate space:
+        let tydesc = PointerCast(bcx, static_ti.tydesc, Type::i8p());
+        let rval = alloca(bcx, Type::i8p());
+        let bcx = callee::trans_lang_call(
+            bcx,
+            langcall,
+            [tydesc, size],
+            expr::SaveIn(rval));
+        let r = rslt(bcx, PointerCast(bcx, Load(bcx, rval), llty));
+        maybe_set_managed_unique_rc(r.bcx, r.val, heap);
+        r
+    }
 }
 
 // malloc_raw: expects an unboxed type and returns a pointer to

src/libstd/libc.rs

@@ -1945,7 +1945,7 @@ pub mod funcs {
                 #[fast_ffi]
                 unsafe fn malloc(size: size_t) -> *c_void;
                 #[fast_ffi]
-                unsafe fn realloc(p: *c_void, size: size_t) -> *c_void;
+                unsafe fn realloc(p: *mut c_void, size: size_t) -> *mut c_void;
                 #[fast_ffi]
                 unsafe fn free(p: *c_void);
                 unsafe fn abort() -> !;

src/libstd/rt/global_heap.rs

@@ -8,7 +8,7 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-use libc::{c_char, c_void, size_t, uintptr_t, free, malloc};
+use libc::{c_char, c_void, size_t, uintptr_t, free, malloc, realloc};
 use managed::raw::{BoxHeaderRepr, BoxRepr};
 use unstable::intrinsics::TyDesc;
 use sys::size_of;
@@ -18,6 +18,7 @@ extern {
     fn abort();
 }
 
+#[inline]
 fn get_box_size(body_size: uint, body_align: uint) -> uint {
     let header_size = size_of::<BoxHeaderRepr>();
     // FIXME (#2699): This alignment calculation is suspicious. Is it right?
@@ -27,12 +28,14 @@ fn get_box_size(body_size: uint, body_align: uint) -> uint {
 
 // Rounds |size| to the nearest |alignment|. Invariant: |alignment| is a power
 // of two.
+#[inline]
 fn align_to(size: uint, align: uint) -> uint {
     assert!(align != 0);
     (size + align - 1) & !(align - 1)
 }
 
 /// A wrapper around libc::malloc, aborting on out-of-memory
+#[inline]
 pub unsafe fn malloc_raw(size: uint) -> *c_void {
     let p = malloc(size as size_t);
     if p.is_null() {
@@ -42,6 +45,17 @@ pub unsafe fn malloc_raw(size: uint) -> *c_void {
     p
 }
 
+/// A wrapper around libc::realloc, aborting on out-of-memory
+#[inline]
+pub unsafe fn realloc_raw(ptr: *mut c_void, size: uint) -> *mut c_void {
+    let p = realloc(ptr, size as size_t);
+    if p.is_null() {
+        // we need a non-allocating way to print an error here
+        abort();
+    }
+    p
+}
+
 // FIXME #4942: Make these signatures agree with exchange_alloc's signatures
 #[cfg(stage0, not(test))]
 #[lang="exchange_malloc"]
@@ -66,13 +80,8 @@ pub unsafe fn exchange_malloc(td: *c_char, size: uintptr_t) -> *c_char {
 #[cfg(not(stage0), not(test))]
 #[lang="exchange_malloc"]
 #[inline]
-pub unsafe fn exchange_malloc(td: *c_char, size: uintptr_t) -> *c_char {
-    let td = td as *TyDesc;
-    let size = size as uint;
-
-    assert!(td.is_not_null());
-
-    let total_size = get_box_size(size, (*td).align);
+pub unsafe fn exchange_malloc(align: u32, size: uintptr_t) -> *c_char {
+    let total_size = get_box_size(size as uint, align as uint);
     malloc_raw(total_size as uint) as *c_char
 }
 

src/libstd/vec.rs

@@ -22,12 +22,14 @@ use iterator::{FromIterator, Iterator, IteratorUtil};
 use iter::FromIter;
 use kinds::Copy;
 use libc;
+use libc::c_void;
 use num::Zero;
 use ops::Add;
 use option::{None, Option, Some};
 use ptr::to_unsafe_ptr;
 use ptr;
 use ptr::RawPtr;
+use rt::global_heap::realloc_raw;
 use sys;
 use sys::size_of;
 use uint;
@@ -52,12 +54,6 @@ pub mod rustrt {
 
     #[abi = "cdecl"]
     pub extern {
-        // These names are terrible. reserve_shared applies
-        // to ~[] and reserve_shared_actual applies to @[].
-        #[fast_ffi]
-        unsafe fn vec_reserve_shared(t: *TyDesc,
-                                     v: **raw::VecRepr,
-                                     n: libc::size_t);
         #[fast_ffi]
         unsafe fn vec_reserve_shared_actual(t: *TyDesc,
                                             v: **raw::VecRepr,
@@ -1523,13 +1519,16 @@ impl<T> OwnedVector<T> for ~[T] {
         use managed;
         if self.capacity() < n {
             unsafe {
-                let ptr: **raw::VecRepr = cast::transmute(self);
+                let ptr: *mut *mut raw::VecRepr = cast::transmute(self);
                 let td = get_tydesc::<T>();
                 if ((**ptr).box_header.ref_count ==
                     managed::raw::RC_MANAGED_UNIQUE) {
-                    rustrt::vec_reserve_shared_actual(td, ptr, n as libc::size_t);
+                    rustrt::vec_reserve_shared_actual(td, ptr as **raw::VecRepr, n as libc::size_t);
                 } else {
-                    rustrt::vec_reserve_shared(td, ptr, n as libc::size_t);
+                    let alloc = n * sys::nonzero_size_of::<T>();
+                    *ptr = realloc_raw(*ptr as *mut c_void, alloc + size_of::<raw::VecRepr>())
+                           as *mut raw::VecRepr;
+                    (**ptr).unboxed.alloc = alloc;
                 }
             }
         }
@@ -1551,12 +1550,15 @@ impl<T> OwnedVector<T> for ~[T] {
         // Only make the (slow) call into the runtime if we have to
         if self.capacity() < n {
             unsafe {
-                let ptr: **raw::VecRepr = cast::transmute(self);
+                let ptr: *mut *mut raw::VecRepr = cast::transmute(self);
                 let td = get_tydesc::<T>();
                 if contains_managed::<T>() {
-                    rustrt::vec_reserve_shared_actual(td, ptr, n as libc::size_t);
+                    rustrt::vec_reserve_shared_actual(td, ptr as **raw::VecRepr, n as libc::size_t);
                 } else {
-                    rustrt::vec_reserve_shared(td, ptr, n as libc::size_t);
+                    let alloc = n * sys::nonzero_size_of::<T>();
+                    *ptr = realloc_raw(*ptr as *mut c_void, alloc + size_of::<raw::VecRepr>())
+                           as *mut raw::VecRepr;
+                    (**ptr).unboxed.alloc = alloc;
                 }
             }
         }

src/rt/rust_builtin.cpp

@@ -75,13 +75,6 @@ vec_reserve_shared_actual(type_desc* ty, rust_vec_box** vp,
     reserve_vec_exact_shared(task, vp, n_elts * ty->size);
 }
 
-// This is completely misnamed.
-extern "C" CDECL void
-vec_reserve_shared(type_desc* ty, rust_vec_box** vp,
-                   size_t n_elts) {
-    reserve_vec_exact(vp, n_elts * ty->size);
-}
-
 extern "C" CDECL size_t
 rand_seed_size() {
     return rng_seed_size();

src/rt/rustrt.def.in

@@ -55,7 +55,6 @@ rust_get_c_stack
 rust_log_str
 start_task
 vec_reserve_shared_actual
-vec_reserve_shared
 task_clear_event_reject
 task_wait_event
 task_signal_event