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

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

MCP: https://github.com/rust-lang/compiler-team/issues/461

4 files changed, 23 insertions, 6 deletions

diff --git a/compiler/rustc_codegen_llvm/src/back/write.rs b/compiler/rustc_codegen_llvm/src/back/write.rs
index 92199f611ba..9b0e7526894 100644
--- a/compiler/rustc_codegen_llvm/src/back/write.rs
+++ b/compiler/rustc_codegen_llvm/src/back/write.rs
@@ -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,
diff --git a/compiler/rustc_codegen_llvm/src/context.rs b/compiler/rustc_codegen_llvm/src/context.rs
index 52a12b2fd81..7bdbec11d60 100644
--- a/compiler/rustc_codegen_llvm/src/context.rs
+++ b/compiler/rustc_codegen_llvm/src/context.rs
@@ -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);
         }
     }
diff --git a/compiler/rustc_codegen_llvm/src/lib.rs b/compiler/rustc_codegen_llvm/src/lib.rs
index 79bdace5158..c44cc656056 100644
--- a/compiler/rustc_codegen_llvm/src/lib.rs
+++ b/compiler/rustc_codegen_llvm/src/lib.rs
@@ -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!();
diff --git a/compiler/rustc_codegen_llvm/src/mono_item.rs b/compiler/rustc_codegen_llvm/src/mono_item.rs
index 34982f769d0..b9022a391e6 100644
--- a/compiler/rustc_codegen_llvm/src/mono_item.rs
+++ b/compiler/rustc_codegen_llvm/src/mono_item.rs
@@ -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;
     }
 }