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Rollup merge of #88820 - hlopko:add_pie_relocation_model, r=petrochenkov

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Add `pie` as another `relocation-model` value

MCP: https://github.com/rust-lang/compiler-team/issues/461
This commit is contained in:
Manish Goregaokar 2021-10-01 09:18:16 -07:00 • committed by GitHub
commit 6f1e930581
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11 changed files with 147 additions and 8 deletions
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3
compiler/rustc_codegen_llvm/src/back/write.rs
View file

@ -129,7 +129,8 @@ fn to_pass_builder_opt_level(cfg: config::OptLevel) -> llvm::PassBuilderOptLevel
fn to_llvm_relocation_model(relocation_model: RelocModel) -> llvm::RelocModel {
match relocation_model {
RelocModel::Static => llvm::RelocModel::Static,
RelocModel::Pic => llvm::RelocModel::PIC,
// LLVM doesn't have a PIE relocation model, it represents PIE as PIC with an extra attribute.
RelocModel::Pic | RelocModel::Pie => llvm::RelocModel::PIC,
RelocModel::DynamicNoPic => llvm::RelocModel::DynamicNoPic,
RelocModel::Ropi => llvm::RelocModel::ROPI,
RelocModel::Rwpi => llvm::RelocModel::RWPI,

7
compiler/rustc_codegen_llvm/src/context.rs
View file

@ -195,11 +195,14 @@ pub unsafe fn create_module(
let llvm_target = SmallCStr::new(&sess.target.llvm_target);
llvm::LLVMRustSetNormalizedTarget(llmod, llvm_target.as_ptr());
if sess.relocation_model() == RelocModel::Pic {
let reloc_model = sess.relocation_model();
if matches!(reloc_model, RelocModel::Pic | RelocModel::Pie) {
llvm::LLVMRustSetModulePICLevel(llmod);
// PIE is potentially more effective than PIC, but can only be used in executables.
// If all our outputs are executables, then we can relax PIC to PIE.
if sess.crate_types().iter().all(|ty| *ty == CrateType::Executable) {
if reloc_model == RelocModel::Pie
|| sess.crate_types().iter().all(|ty| *ty == CrateType::Executable)
{
llvm::LLVMRustSetModulePIELevel(llmod);
}
}

13
compiler/rustc_codegen_llvm/src/lib.rs
View file

@ -211,9 +211,16 @@ impl CodegenBackend for LlvmCodegenBackend {
match req {
PrintRequest::RelocationModels => {
println!("Available relocation models:");
for name in
&["static", "pic", "dynamic-no-pic", "ropi", "rwpi", "ropi-rwpi", "default"]
{
for name in &[
"static",
"pic",
"pie",
"dynamic-no-pic",
"ropi",
"rwpi",
"ropi-rwpi",
"default",
] {
println!(" {}", name);
}
println!();

6
compiler/rustc_codegen_llvm/src/mono_item.rs
View file

@ -143,6 +143,12 @@ impl CodegenCx<'ll, 'tcx> {
return true;
}
// With pie relocation model calls of functions defined in the translation
// unit can use copy relocations.
if self.tcx.sess.relocation_model() == RelocModel::Pie && !is_declaration {
return true;
}
return false;
}
}