diff options
| -rw-r--r-- | src/librustc_trans/back/write.rs | 61 | ||||
| -rw-r--r-- | src/librustc_trans/base.rs | 52 | ||||
| -rw-r--r-- | src/test/run-pass/thinlto/auxiliary/msvc-imp-present.rs | 21 | ||||
| -rw-r--r-- | src/test/run-pass/thinlto/msvc-imp-present.rs | 31 |
4 files changed, 115 insertions, 50 deletions
diff --git a/src/librustc_trans/back/write.rs b/src/librustc_trans/back/write.rs index f7e0ad029af..f8dbe68dba9 100644 --- a/src/librustc_trans/back/write.rs +++ b/src/librustc_trans/back/write.rs @@ -12,6 +12,8 @@ use back::lto; use back::link::{self, get_linker, remove}; use back::linker::LinkerInfo; use back::symbol_export::ExportedSymbols; +use base; +use consts; use rustc_incremental::{save_trans_partition, in_incr_comp_dir}; use rustc::dep_graph::DepGraph; use rustc::middle::cstore::{LinkMeta, EncodedMetadata}; @@ -35,12 +37,13 @@ use syntax::attr; use syntax::ext::hygiene::Mark; use syntax_pos::MultiSpan; use syntax_pos::symbol::Symbol; +use type_::Type; use context::{is_pie_binary, get_reloc_model}; use jobserver::{Client, Acquired}; use rustc_demangle; use std::any::Any; -use std::ffi::CString; +use std::ffi::{CString, CStr}; use std::fs; use std::io; use std::io::Write; @@ -315,6 +318,8 @@ pub struct CodegenContext { metadata_module_config: Arc<ModuleConfig>, allocator_module_config: Arc<ModuleConfig>, pub tm_factory: Arc<Fn() -> Result<TargetMachineRef, String> + Send + Sync>, + pub msvc_imps_needed: bool, + pub target_pointer_width: String, // Number of cgus excluding the allocator/metadata modules pub total_cgus: usize, @@ -586,6 +591,10 @@ unsafe fn codegen(cgcx: &CodegenContext, let module_name = Some(&module_name[..]); let handlers = DiagnosticHandlers::new(cgcx, diag_handler, llcx); + if cgcx.msvc_imps_needed { + create_msvc_imps(cgcx, llcx, llmod); + } + // A codegen-specific pass manager is used to generate object // files for an LLVM module. // @@ -1300,6 +1309,8 @@ fn start_executing_work(tcx: TyCtxt, allocator_module_config: allocator_config, tm_factory: target_machine_factory(tcx.sess), total_cgus, + msvc_imps_needed: msvc_imps_needed(tcx), + target_pointer_width: tcx.sess.target.target.target_pointer_width.clone(), }; // This is the "main loop" of parallel work happening for parallel codegen. @@ -2133,3 +2144,51 @@ pub fn submit_translated_module_to_llvm(tcx: TyCtxt, cost, }))); } + +fn msvc_imps_needed(tcx: TyCtxt) -> bool { + tcx.sess.target.target.options.is_like_msvc && + tcx.sess.crate_types.borrow().iter().any(|ct| *ct == config::CrateTypeRlib) +} + +// Create a `__imp_<symbol> = &symbol` global for every public static `symbol`. +// This is required to satisfy `dllimport` references to static data in .rlibs +// when using MSVC linker. We do this only for data, as linker can fix up +// code references on its own. +// See #26591, #27438 +fn create_msvc_imps(cgcx: &CodegenContext, llcx: ContextRef, llmod: ModuleRef) { + if !cgcx.msvc_imps_needed { + return + } + // The x86 ABI seems to require that leading underscores are added to symbol + // names, so we need an extra underscore on 32-bit. There's also a leading + // '\x01' here which disables LLVM's symbol mangling (e.g. no extra + // underscores added in front). + let prefix = if cgcx.target_pointer_width == "32" { + "\x01__imp__" + } else { + "\x01__imp_" + }; + unsafe { + let i8p_ty = Type::i8p_llcx(llcx); + let globals = base::iter_globals(llmod) + .filter(|&val| { + llvm::LLVMRustGetLinkage(val) == llvm::Linkage::ExternalLinkage && + llvm::LLVMIsDeclaration(val) == 0 + }) + .map(move |val| { + let name = CStr::from_ptr(llvm::LLVMGetValueName(val)); + let mut imp_name = prefix.as_bytes().to_vec(); + imp_name.extend(name.to_bytes()); + let imp_name = CString::new(imp_name).unwrap(); + (imp_name, val) + }) + .collect::<Vec<_>>(); + for (imp_name, val) in globals { + let imp = llvm::LLVMAddGlobal(llmod, + i8p_ty.to_ref(), + imp_name.as_ptr() as *const _); + llvm::LLVMSetInitializer(imp, consts::ptrcast(val, i8p_ty)); + llvm::LLVMRustSetLinkage(imp, llvm::Linkage::ExternalLinkage); + } + } +} diff --git a/src/librustc_trans/base.rs b/src/librustc_trans/base.rs index 6b53b5b6411..7bc33a88956 100644 --- a/src/librustc_trans/base.rs +++ b/src/librustc_trans/base.rs @@ -78,7 +78,7 @@ use rustc::util::nodemap::{NodeSet, FxHashMap, FxHashSet, DefIdSet}; use CrateInfo; use std::any::Any; -use std::ffi::{CStr, CString}; +use std::ffi::CString; use std::str; use std::sync::Arc; use std::time::{Instant, Duration}; @@ -812,47 +812,7 @@ fn write_metadata<'a, 'gcx>(tcx: TyCtxt<'a, 'gcx, 'gcx>, return (metadata_llcx, metadata_llmod, metadata, hashes); } -// Create a `__imp_<symbol> = &symbol` global for every public static `symbol`. -// This is required to satisfy `dllimport` references to static data in .rlibs -// when using MSVC linker. We do this only for data, as linker can fix up -// code references on its own. -// See #26591, #27438 -fn create_imps(sess: &Session, - llvm_module: &ModuleLlvm) { - // The x86 ABI seems to require that leading underscores are added to symbol - // names, so we need an extra underscore on 32-bit. There's also a leading - // '\x01' here which disables LLVM's symbol mangling (e.g. no extra - // underscores added in front). - let prefix = if sess.target.target.target_pointer_width == "32" { - "\x01__imp__" - } else { - "\x01__imp_" - }; - unsafe { - let exported: Vec<_> = iter_globals(llvm_module.llmod) - .filter(|&val| { - llvm::LLVMRustGetLinkage(val) == - llvm::Linkage::ExternalLinkage && - llvm::LLVMIsDeclaration(val) == 0 - }) - .collect(); - - let i8p_ty = Type::i8p_llcx(llvm_module.llcx); - for val in exported { - let name = CStr::from_ptr(llvm::LLVMGetValueName(val)); - let mut imp_name = prefix.as_bytes().to_vec(); - imp_name.extend(name.to_bytes()); - let imp_name = CString::new(imp_name).unwrap(); - let imp = llvm::LLVMAddGlobal(llvm_module.llmod, - i8p_ty.to_ref(), - imp_name.as_ptr() as *const _); - llvm::LLVMSetInitializer(imp, consts::ptrcast(val, i8p_ty)); - llvm::LLVMRustSetLinkage(imp, llvm::Linkage::ExternalLinkage); - } - } -} - -struct ValueIter { +pub struct ValueIter { cur: ValueRef, step: unsafe extern "C" fn(ValueRef) -> ValueRef, } @@ -871,7 +831,7 @@ impl Iterator for ValueIter { } } -fn iter_globals(llmod: llvm::ModuleRef) -> ValueIter { +pub fn iter_globals(llmod: llvm::ModuleRef) -> ValueIter { unsafe { ValueIter { cur: llvm::LLVMGetFirstGlobal(llmod), @@ -1437,12 +1397,6 @@ fn compile_codegen_unit<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>, tm: create_target_machine(ccx.sess()), }; - // Adjust exported symbols for MSVC dllimport - if ccx.sess().target.target.options.is_like_msvc && - ccx.sess().crate_types.borrow().iter().any(|ct| *ct == config::CrateTypeRlib) { - create_imps(ccx.sess(), &llvm_module); - } - ModuleTranslation { name: cgu_name, source: ModuleSource::Translated(llvm_module), diff --git a/src/test/run-pass/thinlto/auxiliary/msvc-imp-present.rs b/src/test/run-pass/thinlto/auxiliary/msvc-imp-present.rs new file mode 100644 index 00000000000..eff7802a245 --- /dev/null +++ b/src/test/run-pass/thinlto/auxiliary/msvc-imp-present.rs @@ -0,0 +1,21 @@ +// Copyright 2017 The Rust Project Developers. See the COPYRIGHT +// file at the top-level directory of this distribution and at +// http://rust-lang.org/COPYRIGHT. +// +// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or +// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license +// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your +// option. This file may not be copied, modified, or distributed +// except according to those terms. + +// no-prefer-dynamic +// compile-flags: -Z thinlto -C codegen-units=8 -C prefer-dynamic + +#![crate_type = "rlib"] +#![crate_type = "dylib"] + +pub static A: u32 = 43; + +pub mod a { + pub static A: u32 = 43; +} diff --git a/src/test/run-pass/thinlto/msvc-imp-present.rs b/src/test/run-pass/thinlto/msvc-imp-present.rs new file mode 100644 index 00000000000..8329c7032f1 --- /dev/null +++ b/src/test/run-pass/thinlto/msvc-imp-present.rs @@ -0,0 +1,31 @@ +// Copyright 2017 The Rust Project Developers. See the COPYRIGHT +// file at the top-level directory of this distribution and at +// http://rust-lang.org/COPYRIGHT. +// +// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or +// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license +// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your +// option. This file may not be copied, modified, or distributed +// except according to those terms. + +// aux-build:msvc-imp-present.rs +// compile-flags: -Z thinlto -C codegen-units=8 +// min-llvm-version: 4.0 +// no-prefer-dynamic + +// On MSVC we have a "hack" where we emit symbols that look like `_imp_$name` +// for all exported statics. This is done because we apply `dllimport` to all +// imported constants and this allows everything to actually link correctly. +// +// The ThinLTO passes aggressively remove symbols if they can, and this test +// asserts that the ThinLTO passes don't remove these compiler-generated +// `_imp_*` symbols. The external library that we link in here is compiled with +// ThinLTO and multiple codegen units and has a few exported constants. Note +// that we also namely compile the library as both a dylib and an rlib, but we +// link the rlib to ensure that we assert those generated symbols exist. + +extern crate msvc_imp_present as bar; + +fn main() { + println!("{}", bar::A); +} |