Auto merge of #28521 - arielb1:metadiet, r=eddyb

libcore.rlib reduced from 19121 kiB to 15934 kiB - 20% win.

The librustc encoded AST is 9013500 bytes long - for the record, librustc consists of about 2254126 characters. Might be worth looking at.

r? @eddyb

Author: bors

src/librbml/lib.rs

@@ -467,37 +467,44 @@ pub mod reader {
         f(&d.data[d.start..d.end])
     }
 
-
     pub fn doc_as_u8(d: Doc) -> u8 {
         assert_eq!(d.end, d.start + 1);
         d.data[d.start]
     }
 
-    pub fn doc_as_u16(d: Doc) -> u16 {
-        assert_eq!(d.end, d.start + 2);
-        let mut b = [0; 2];
-        bytes::copy_memory(&d.data[d.start..d.end], &mut b);
-        unsafe { (*(b.as_ptr() as *const u16)).to_be() }
-    }
-
-    pub fn doc_as_u32(d: Doc) -> u32 {
-        assert_eq!(d.end, d.start + 4);
-        let mut b = [0; 4];
-        bytes::copy_memory(&d.data[d.start..d.end], &mut b);
-        unsafe { (*(b.as_ptr() as *const u32)).to_be() }
-    }
-
     pub fn doc_as_u64(d: Doc) -> u64 {
-        assert_eq!(d.end, d.start + 8);
-        let mut b = [0; 8];
-        bytes::copy_memory(&d.data[d.start..d.end], &mut b);
-        unsafe { (*(b.as_ptr() as *const u64)).to_be() }
+        if d.end >= 8 {
+            // For performance, we read 8 big-endian bytes,
+            // and mask off the junk if there is any. This
+            // obviously won't work on the first 8 bytes
+            // of a file - we will fall of the start
+            // of the page and segfault.
+
+            let mut b = [0; 8];
+            bytes::copy_memory(&d.data[d.end-8..d.end], &mut b);
+            let data = unsafe { (*(b.as_ptr() as *const u64)).to_be() };
+            let len = d.end - d.start;
+            if len < 8 {
+                data & ((1<<(len*8))-1)
+            } else {
+                data
+            }
+        } else {
+            let mut result = 0;
+            for b in &d.data[d.start..d.end] {
+                result = (result<<8) + (*b as u64);
+            }
+            result
+        }
     }
 
-    pub fn doc_as_i8(d: Doc) -> i8 { doc_as_u8(d) as i8 }
-    pub fn doc_as_i16(d: Doc) -> i16 { doc_as_u16(d) as i16 }
-    pub fn doc_as_i32(d: Doc) -> i32 { doc_as_u32(d) as i32 }
-    pub fn doc_as_i64(d: Doc) -> i64 { doc_as_u64(d) as i64 }
+    #[inline] pub fn doc_as_u16(d: Doc) -> u16 { doc_as_u64(d) as u16 }
+    #[inline] pub fn doc_as_u32(d: Doc) -> u32 { doc_as_u64(d) as u32 }
+
+    #[inline] pub fn doc_as_i8(d: Doc) -> i8 { doc_as_u8(d) as i8 }
+    #[inline] pub fn doc_as_i16(d: Doc) -> i16 { doc_as_u16(d) as i16 }
+    #[inline] pub fn doc_as_i32(d: Doc) -> i32 { doc_as_u32(d) as i32 }
+    #[inline] pub fn doc_as_i64(d: Doc) -> i64 { doc_as_u64(d) as i64 }
 
     pub struct Decoder<'a> {
         parent: Doc<'a>,
@@ -907,7 +914,7 @@ pub mod writer {
         }
     }
 
-    fn write_vuint<W: Write>(w: &mut W, n: usize) -> EncodeResult {
+    pub fn write_vuint<W: Write>(w: &mut W, n: usize) -> EncodeResult {
         if n < 0x7f { return write_sized_vuint(w, n, 1); }
         if n < 0x4000 { return write_sized_vuint(w, n, 2); }
         if n < 0x200000 { return write_sized_vuint(w, n, 3); }
@@ -996,35 +1003,43 @@ pub mod writer {
 
         pub fn wr_tagged_u64(&mut self, tag_id: usize, v: u64) -> EncodeResult {
             let bytes: [u8; 8] = unsafe { mem::transmute(v.to_be()) };
-            self.wr_tagged_bytes(tag_id, &bytes)
+            // tagged integers are emitted in big-endian, with no
+            // leading zeros.
+            let leading_zero_bytes = v.leading_zeros()/8;
+            self.wr_tagged_bytes(tag_id, &bytes[leading_zero_bytes as usize..])
         }
 
-        pub fn wr_tagged_u32(&mut self, tag_id: usize, v: u32)  -> EncodeResult{
-            let bytes: [u8; 4] = unsafe { mem::transmute(v.to_be()) };
-            self.wr_tagged_bytes(tag_id, &bytes)
+        #[inline]
+        pub fn wr_tagged_u32(&mut self, tag_id: usize, v: u32)  -> EncodeResult {
+            self.wr_tagged_u64(tag_id, v as u64)
         }
 
+        #[inline]
         pub fn wr_tagged_u16(&mut self, tag_id: usize, v: u16) -> EncodeResult {
-            let bytes: [u8; 2] = unsafe { mem::transmute(v.to_be()) };
-            self.wr_tagged_bytes(tag_id, &bytes)
+            self.wr_tagged_u64(tag_id, v as u64)
         }
 
+        #[inline]
         pub fn wr_tagged_u8(&mut self, tag_id: usize, v: u8) -> EncodeResult {
             self.wr_tagged_bytes(tag_id, &[v])
         }
 
+        #[inline]
         pub fn wr_tagged_i64(&mut self, tag_id: usize, v: i64) -> EncodeResult {
             self.wr_tagged_u64(tag_id, v as u64)
         }
 
+        #[inline]
         pub fn wr_tagged_i32(&mut self, tag_id: usize, v: i32) -> EncodeResult {
             self.wr_tagged_u32(tag_id, v as u32)
         }
 
+        #[inline]
         pub fn wr_tagged_i16(&mut self, tag_id: usize, v: i16) -> EncodeResult {
             self.wr_tagged_u16(tag_id, v as u16)
         }
 
+        #[inline]
         pub fn wr_tagged_i8(&mut self, tag_id: usize, v: i8) -> EncodeResult {
             self.wr_tagged_bytes(tag_id, &[v as u8])
         }

src/librustc/metadata/common.rs

@@ -44,14 +44,14 @@ pub const tag_items_data_parent_item: usize = 0x28;
 pub const tag_items_data_item_is_tuple_struct_ctor: usize = 0x29;
 
 pub const tag_items_closure_kind: usize = 0x2a;
-
 pub const tag_items_closure_ty: usize = 0x2b;
+pub const tag_def_key: usize = 0x2c;
 
-pub const tag_index: usize = 0x2c;
-
-pub const tag_def_key: usize = 0x2d;
+// GAP 0x2d 0x2e
 
-// GAP 0x2e
+pub const tag_index: usize = 0x110; // top-level only
+pub const tag_xref_index: usize = 0x111; // top-level only
+pub const tag_xref_data: usize = 0x112; // top-level only
 
 pub const tag_meta_item_name_value: usize = 0x2f;
 
@@ -80,8 +80,6 @@ pub const tag_crate_dep_crate_name: usize = 0x36;
 pub const tag_crate_dep_hash: usize = 0x37;
 pub const tag_crate_dep_explicitly_linked: usize = 0x38; // top-level only
 
-pub const tag_mod_impl: usize = 0x39;
-
 pub const tag_item_trait_item: usize = 0x3a;
 
 pub const tag_item_trait_ref: usize = 0x3b;
@@ -95,7 +93,6 @@ pub const tag_path_len: usize = 0x3e;
 pub const tag_path_elem_mod: usize = 0x3f;
 pub const tag_path_elem_name: usize = 0x40;
 pub const tag_item_field: usize = 0x41;
-pub const tag_item_field_origin: usize = 0x42;
 
 pub const tag_item_variances: usize = 0x43;
 /*
@@ -125,39 +122,27 @@ enum_from_u32! {
 
         tag_tree = 0x51,
 
-        tag_id_range = 0x52,
-
+        // GAP 0x52
         tag_table = 0x53,
         // GAP 0x54, 0x55
         tag_table_def = 0x56,
         tag_table_node_type = 0x57,
         tag_table_item_subst = 0x58,
         tag_table_freevars = 0x59,
-        tag_table_tcache = 0x5a,
-        tag_table_param_defs = 0x5b,
-        tag_table_mutbl = 0x5c,
-        tag_table_last_use = 0x5d,
-        tag_table_spill = 0x5e,
+        // GAP 0x5a, 0x5b, 0x5c, 0x5d, 0x5e
         tag_table_method_map = 0x5f,
-        tag_table_vtable_map = 0x60,
+        // GAP 0x60
         tag_table_adjustments = 0x61,
-        tag_table_moves_map = 0x62,
-        tag_table_capture_map = 0x63,
-            // GAP 0x64, 0x65
+        // GAP 0x62, 0x63, 0x64, 0x65
         tag_table_upvar_capture_map = 0x66,
-        tag_table_capture_modes = 0x67,
-        // GAP 0x68
+        // GAP 0x67, 0x68
         tag_table_const_qualif = 0x69,
         tag_table_cast_kinds = 0x6a,
     }
 }
 
 pub const tag_item_trait_item_sort: usize = 0x70;
 
-pub const tag_item_trait_parent_sort: usize = 0x71;
-
-pub const tag_item_impl_type_basename: usize = 0x72;
-
 pub const tag_crate_triple: usize = 0x105; // top-level only
 
 pub const tag_dylib_dependency_formats: usize = 0x106; // top-level only
@@ -177,23 +162,17 @@ pub const tag_lang_items_missing: usize = 0x76;
 
 pub const tag_item_unnamed_field: usize = 0x77;
 pub const tag_items_data_item_visibility: usize = 0x78;
-
-pub const tag_item_method_tps: usize = 0x79;
-pub const tag_item_method_fty: usize = 0x7a;
-
+pub const tag_items_data_item_inherent_impl: usize = 0x79;
+// GAP 0x7a
 pub const tag_mod_child: usize = 0x7b;
 pub const tag_misc_info: usize = 0x108; // top-level only
 pub const tag_misc_info_crate_items: usize = 0x7c;
 
-// GAP 0x7d
-pub const tag_item_impl_vtables: usize = 0x7e;
-
 pub const tag_impls: usize = 0x109; // top-level only
-pub const tag_impls_impl: usize = 0x7f;
-pub const tag_impls_impl_trait_def_id: usize = 0x8d;
+pub const tag_impls_trait: usize = 0x7d;
+pub const tag_impls_trait_impl: usize = 0x7e;
 
-pub const tag_items_data_item_inherent_impl: usize = 0x80;
-pub const tag_items_data_item_extension_impl: usize = 0x81;
+// GAP 0x7f, 0x80, 0x81
 
 pub const tag_native_libraries: usize = 0x10a; // top-level only
 pub const tag_native_libraries_lib: usize = 0x82;
@@ -220,10 +199,10 @@ pub struct LinkMeta {
 
 pub const tag_struct_fields: usize = 0x10d; // top-level only
 pub const tag_struct_field: usize = 0x8a;
-// GAP 0x8b
 
+pub const tag_items_data_item_struct_ctor: usize = 0x8b;
 pub const tag_attribute_is_sugared_doc: usize = 0x8c;
-
+// GAP 0x8d
 pub const tag_items_data_region: usize = 0x8e;
 
 pub const tag_region_param_def: usize = 0x8f;
@@ -237,9 +216,9 @@ pub const tag_type_param_def: usize = 0x94;
 pub const tag_item_generics: usize = 0x95;
 pub const tag_method_ty_generics: usize = 0x96;
 
-pub const tag_predicate: usize = 0x97;
-pub const tag_predicate_space: usize = 0x98;
-pub const tag_predicate_data: usize = 0x99;
+pub const tag_type_predicate: usize = 0x97;
+pub const tag_self_predicate: usize = 0x98;
+pub const tag_fn_predicate: usize = 0x99;
 
 pub const tag_unsafety: usize = 0x9a;
 

src/librustc/metadata/creader.rs

@@ -327,6 +327,7 @@ impl<'a> CrateReader<'a> {
             local_path: RefCell::new(SmallVector::zero()),
             local_def_path: RefCell::new(vec![]),
             index: decoder::load_index(metadata.as_slice()),
+            xref_index: decoder::load_xrefs(metadata.as_slice()),
             data: metadata,
             cnum_map: RefCell::new(cnum_map),
             cnum: cnum,

src/librustc/metadata/csearch.rs

@@ -171,12 +171,6 @@ pub fn get_associated_consts<'tcx>(tcx: &ty::ctxt<'tcx>, def: DefId)
     decoder::get_associated_consts(cstore.intr.clone(), &*cdata, def.index, tcx)
 }
 
-pub fn get_type_name_if_impl(cstore: &cstore::CStore, def: DefId)
-                          -> Option<ast::Name> {
-    let cdata = cstore.get_crate_data(def.krate);
-    decoder::get_type_name_if_impl(&*cdata, def.index)
-}
-
 pub fn get_methods_if_impl(cstore: &cstore::CStore,
                                   def: DefId)
                                -> Option<Vec<MethodInfo> > {

src/librustc/metadata/cstore.rs

@@ -66,7 +66,9 @@ pub struct crate_metadata {
     pub codemap_import_info: RefCell<Vec<ImportedFileMap>>,
     pub span: codemap::Span,
     pub staged_api: bool,
+
     pub index: index::Index,
+    pub xref_index: index::DenseIndex,
 
     /// Flag if this crate is required by an rlib version of this crate, or in
     /// other words whether it was explicitly linked to. An example of a crate