9aad2d551e
Fixes rebase fallout, makes code correct in presence of 128-bit constants. This commit includes manual merge conflict resolution changes from a rebase by @est31.
282 lines
11 KiB
Rust
282 lines
11 KiB
Rust
// Copyright 2012 The Rust Project Developers. See the COPYRIGHT
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// file at the top-level directory of this distribution and at
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// http://rust-lang.org/COPYRIGHT.
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//
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// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
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// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
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// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
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// option. This file may not be copied, modified, or distributed
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// except according to those terms.
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use llvm;
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use llvm::{SetUnnamedAddr};
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use llvm::{ValueRef, True};
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use rustc_const_eval::ConstEvalErr;
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use rustc::hir::def_id::DefId;
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use rustc::hir::map as hir_map;
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use {debuginfo, machine};
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use base;
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use trans_item::TransItem;
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use common::{CrateContext, val_ty};
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use declare;
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use monomorphize::{Instance};
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use type_::Type;
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use type_of;
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use rustc::ty;
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use rustc::hir;
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use std::ffi::{CStr, CString};
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use syntax::ast;
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use syntax::attr;
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pub fn ptrcast(val: ValueRef, ty: Type) -> ValueRef {
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unsafe {
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llvm::LLVMConstPointerCast(val, ty.to_ref())
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}
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}
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pub fn addr_of_mut(ccx: &CrateContext,
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cv: ValueRef,
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align: machine::llalign,
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kind: &str)
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-> ValueRef {
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unsafe {
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let name = ccx.generate_local_symbol_name(kind);
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let gv = declare::define_global(ccx, &name[..], val_ty(cv)).unwrap_or_else(||{
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bug!("symbol `{}` is already defined", name);
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});
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llvm::LLVMSetInitializer(gv, cv);
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llvm::LLVMSetAlignment(gv, align);
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llvm::LLVMRustSetLinkage(gv, llvm::Linkage::InternalLinkage);
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SetUnnamedAddr(gv, true);
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gv
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}
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}
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pub fn addr_of(ccx: &CrateContext,
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cv: ValueRef,
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align: machine::llalign,
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kind: &str)
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-> ValueRef {
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if let Some(&gv) = ccx.const_globals().borrow().get(&cv) {
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unsafe {
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// Upgrade the alignment in cases where the same constant is used with different
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// alignment requirements
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if align > llvm::LLVMGetAlignment(gv) {
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llvm::LLVMSetAlignment(gv, align);
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}
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}
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return gv;
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}
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let gv = addr_of_mut(ccx, cv, align, kind);
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unsafe {
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llvm::LLVMSetGlobalConstant(gv, True);
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}
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ccx.const_globals().borrow_mut().insert(cv, gv);
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gv
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}
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pub fn get_static(ccx: &CrateContext, def_id: DefId) -> ValueRef {
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let instance = Instance::mono(ccx.shared(), def_id);
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if let Some(&g) = ccx.instances().borrow().get(&instance) {
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return g;
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}
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let ty = ccx.tcx().item_type(def_id);
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let g = if let Some(id) = ccx.tcx().map.as_local_node_id(def_id) {
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let llty = type_of::type_of(ccx, ty);
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let (g, attrs) = match ccx.tcx().map.get(id) {
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hir_map::NodeItem(&hir::Item {
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ref attrs, span, node: hir::ItemStatic(..), ..
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}) => {
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let sym = ccx.symbol_map()
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.get(TransItem::Static(id))
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.expect("Local statics should always be in the SymbolMap");
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// Make sure that this is never executed for something inlined.
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assert!(!ccx.tcx().map.is_inlined_node_id(id));
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let defined_in_current_codegen_unit = ccx.codegen_unit()
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.items()
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.contains_key(&TransItem::Static(id));
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assert!(!defined_in_current_codegen_unit);
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if declare::get_declared_value(ccx, sym).is_some() {
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span_bug!(span, "trans: Conflicting symbol names for static?");
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}
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let g = declare::define_global(ccx, sym, llty).unwrap();
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(g, attrs)
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}
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hir_map::NodeForeignItem(&hir::ForeignItem {
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ref attrs, span, node: hir::ForeignItemStatic(..), ..
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}) => {
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let sym = instance.symbol_name(ccx.shared());
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let g = if let Some(name) =
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attr::first_attr_value_str_by_name(&attrs, "linkage") {
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// If this is a static with a linkage specified, then we need to handle
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// it a little specially. The typesystem prevents things like &T and
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// extern "C" fn() from being non-null, so we can't just declare a
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// static and call it a day. Some linkages (like weak) will make it such
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// that the static actually has a null value.
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let linkage = match base::llvm_linkage_by_name(&name.as_str()) {
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Some(linkage) => linkage,
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None => {
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ccx.sess().span_fatal(span, "invalid linkage specified");
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}
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};
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let llty2 = match ty.sty {
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ty::TyRawPtr(ref mt) => type_of::type_of(ccx, mt.ty),
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_ => {
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ccx.sess().span_fatal(span, "must have type `*const T` or `*mut T`");
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}
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};
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unsafe {
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// Declare a symbol `foo` with the desired linkage.
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let g1 = declare::declare_global(ccx, &sym, llty2);
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llvm::LLVMRustSetLinkage(g1, linkage);
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// Declare an internal global `extern_with_linkage_foo` which
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// is initialized with the address of `foo`. If `foo` is
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// discarded during linking (for example, if `foo` has weak
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// linkage and there are no definitions), then
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// `extern_with_linkage_foo` will instead be initialized to
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// zero.
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let mut real_name = "_rust_extern_with_linkage_".to_string();
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real_name.push_str(&sym);
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let g2 = declare::define_global(ccx, &real_name, llty).unwrap_or_else(||{
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ccx.sess().span_fatal(span,
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&format!("symbol `{}` is already defined", &sym))
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});
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llvm::LLVMRustSetLinkage(g2, llvm::Linkage::InternalLinkage);
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llvm::LLVMSetInitializer(g2, g1);
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g2
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}
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} else {
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// Generate an external declaration.
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declare::declare_global(ccx, &sym, llty)
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};
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(g, attrs)
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}
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item => bug!("get_static: expected static, found {:?}", item)
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};
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for attr in attrs {
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if attr.check_name("thread_local") {
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llvm::set_thread_local(g, true);
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}
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}
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g
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} else {
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let sym = instance.symbol_name(ccx.shared());
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// FIXME(nagisa): perhaps the map of externs could be offloaded to llvm somehow?
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// FIXME(nagisa): investigate whether it can be changed into define_global
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let g = declare::declare_global(ccx, &sym, type_of::type_of(ccx, ty));
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// Thread-local statics in some other crate need to *always* be linked
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// against in a thread-local fashion, so we need to be sure to apply the
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// thread-local attribute locally if it was present remotely. If we
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// don't do this then linker errors can be generated where the linker
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// complains that one object files has a thread local version of the
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// symbol and another one doesn't.
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for attr in ccx.tcx().get_attrs(def_id).iter() {
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if attr.check_name("thread_local") {
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llvm::set_thread_local(g, true);
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}
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}
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if ccx.use_dll_storage_attrs() && !ccx.sess().cstore.is_foreign_item(def_id) {
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// This item is external but not foreign, i.e. it originates from an external Rust
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// crate. Since we don't know whether this crate will be linked dynamically or
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// statically in the final application, we always mark such symbols as 'dllimport'.
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// If final linkage happens to be static, we rely on compiler-emitted __imp_ stubs to
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// make things work.
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unsafe {
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llvm::LLVMSetDLLStorageClass(g, llvm::DLLStorageClass::DllImport);
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}
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}
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g
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};
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if ccx.use_dll_storage_attrs() && ccx.sess().cstore.is_dllimport_foreign_item(def_id) {
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// For foreign (native) libs we know the exact storage type to use.
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unsafe {
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llvm::LLVMSetDLLStorageClass(g, llvm::DLLStorageClass::DllImport);
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}
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}
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ccx.instances().borrow_mut().insert(instance, g);
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ccx.statics().borrow_mut().insert(g, def_id);
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g
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}
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pub fn trans_static(ccx: &CrateContext,
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m: hir::Mutability,
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id: ast::NodeId,
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attrs: &[ast::Attribute])
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-> Result<ValueRef, ConstEvalErr> {
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unsafe {
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let def_id = ccx.tcx().map.local_def_id(id);
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let g = get_static(ccx, def_id);
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let v = ::mir::trans_static_initializer(ccx, def_id)?;
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// boolean SSA values are i1, but they have to be stored in i8 slots,
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// otherwise some LLVM optimization passes don't work as expected
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let mut val_llty = val_ty(v);
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let v = if val_llty == Type::i1(ccx) {
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val_llty = Type::i8(ccx);
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llvm::LLVMConstZExt(v, val_llty.to_ref())
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} else {
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v
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};
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let ty = ccx.tcx().item_type(def_id);
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let llty = type_of::type_of(ccx, ty);
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let g = if val_llty == llty {
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g
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} else {
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// If we created the global with the wrong type,
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// correct the type.
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let empty_string = CString::new("").unwrap();
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let name_str_ref = CStr::from_ptr(llvm::LLVMGetValueName(g));
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let name_string = CString::new(name_str_ref.to_bytes()).unwrap();
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llvm::LLVMSetValueName(g, empty_string.as_ptr());
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let new_g = llvm::LLVMRustGetOrInsertGlobal(
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ccx.llmod(), name_string.as_ptr(), val_llty.to_ref());
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// To avoid breaking any invariants, we leave around the old
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// global for the moment; we'll replace all references to it
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// with the new global later. (See base::trans_crate.)
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ccx.statics_to_rauw().borrow_mut().push((g, new_g));
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new_g
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};
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llvm::LLVMSetAlignment(g, type_of::align_of(ccx, ty));
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llvm::LLVMSetInitializer(g, v);
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// As an optimization, all shared statics which do not have interior
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// mutability are placed into read-only memory.
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if m != hir::MutMutable {
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let tcontents = ty.type_contents(ccx.tcx());
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if !tcontents.interior_unsafe() {
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llvm::LLVMSetGlobalConstant(g, llvm::True);
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}
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}
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debuginfo::create_global_var_metadata(ccx, id, g);
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if attr::contains_name(attrs,
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"thread_local") {
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llvm::set_thread_local(g, true);
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}
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base::set_link_section(ccx, g, attrs);
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Ok(g)
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}
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}
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