Auto merge of #3980 - rust-lang:rustup-2024-10-20, r=RalfJung

Automatic Rustup

6 files changed, 46 insertions, 29 deletions

diff --git a/compiler/rustc_codegen_llvm/src/coverageinfo/mapgen.rs b/compiler/rustc_codegen_llvm/src/coverageinfo/mapgen.rs
index c2c261da79b..cee704a9c22 100644
--- a/compiler/rustc_codegen_llvm/src/coverageinfo/mapgen.rs
+++ b/compiler/rustc_codegen_llvm/src/coverageinfo/mapgen.rs
@@ -1,3 +1,5 @@
+use std::ffi::CStr;
+
 use itertools::Itertools as _;
 use rustc_codegen_ssa::traits::{BaseTypeCodegenMethods, ConstCodegenMethods};
 use rustc_data_structures::fx::{FxHashSet, FxIndexMap, FxIndexSet};
@@ -132,7 +134,7 @@ pub(crate) fn finalize(cx: &CodegenCx<'_, '_>) {
             .collect::<Vec<_>>();
         let initializer = cx.const_array(cx.type_ptr(), &name_globals);
 
-        let array = llvm::add_global(cx.llmod, cx.val_ty(initializer), "__llvm_coverage_names");
+        let array = llvm::add_global(cx.llmod, cx.val_ty(initializer), c"__llvm_coverage_names");
         llvm::set_global_constant(array, true);
         llvm::set_linkage(array, llvm::Linkage::InternalLinkage);
         llvm::set_initializer(array, initializer);
@@ -305,7 +307,7 @@ fn generate_coverage_map<'ll>(
 /// specific, well-known section and name.
 fn save_function_record(
     cx: &CodegenCx<'_, '_>,
-    covfun_section_name: &str,
+    covfun_section_name: &CStr,
     mangled_function_name: &str,
     source_hash: u64,
     filenames_ref: u64,
diff --git a/compiler/rustc_codegen_llvm/src/coverageinfo/mod.rs b/compiler/rustc_codegen_llvm/src/coverageinfo/mod.rs
index d7d29eebf85..484a4d00c13 100644
--- a/compiler/rustc_codegen_llvm/src/coverageinfo/mod.rs
+++ b/compiler/rustc_codegen_llvm/src/coverageinfo/mod.rs
@@ -1,4 +1,5 @@
 use std::cell::RefCell;
+use std::ffi::{CStr, CString};
 
 use libc::c_uint;
 use rustc_codegen_ssa::traits::{
@@ -12,6 +13,7 @@ use rustc_middle::mir::coverage::CoverageKind;
 use rustc_middle::ty::Instance;
 use rustc_middle::ty::layout::HasTyCtxt;
 use rustc_target::abi::{Align, Size};
+use rustc_target::spec::HasTargetSpec;
 use tracing::{debug, instrument};
 
 use crate::builder::Builder;
@@ -284,16 +286,16 @@ pub(crate) fn save_cov_data_to_mod<'ll, 'tcx>(
     cx: &CodegenCx<'ll, 'tcx>,
     cov_data_val: &'ll llvm::Value,
 ) {
-    let covmap_var_name = llvm::build_string(|s| unsafe {
+    let covmap_var_name = CString::new(llvm::build_byte_buffer(|s| unsafe {
         llvm::LLVMRustCoverageWriteMappingVarNameToString(s);
-    })
-    .expect("Rust Coverage Mapping var name failed UTF-8 conversion");
+    }))
+    .unwrap();
     debug!("covmap var name: {:?}", covmap_var_name);
 
-    let covmap_section_name = llvm::build_string(|s| unsafe {
+    let covmap_section_name = CString::new(llvm::build_byte_buffer(|s| unsafe {
         llvm::LLVMRustCoverageWriteMapSectionNameToString(cx.llmod, s);
-    })
-    .expect("Rust Coverage section name failed UTF-8 conversion");
+    }))
+    .expect("covmap section name should not contain NUL");
     debug!("covmap section name: {:?}", covmap_section_name);
 
     let llglobal = llvm::add_global(cx.llmod, cx.val_ty(cov_data_val), &covmap_var_name);
@@ -308,7 +310,7 @@ pub(crate) fn save_cov_data_to_mod<'ll, 'tcx>(
 
 pub(crate) fn save_func_record_to_mod<'ll, 'tcx>(
     cx: &CodegenCx<'ll, 'tcx>,
-    covfun_section_name: &str,
+    covfun_section_name: &CStr,
     func_name_hash: u64,
     func_record_val: &'ll llvm::Value,
     is_used: bool,
@@ -322,7 +324,8 @@ pub(crate) fn save_func_record_to_mod<'ll, 'tcx>(
     // of descriptions play distinct roles in LLVM IR; therefore, assign them different names (by
     // appending "u" to the end of the function record var name, to prevent `linkonce_odr` merging.
     let func_record_var_name =
-        format!("__covrec_{:X}{}", func_name_hash, if is_used { "u" } else { "" });
+        CString::new(format!("__covrec_{:X}{}", func_name_hash, if is_used { "u" } else { "" }))
+            .unwrap();
     debug!("function record var name: {:?}", func_record_var_name);
     debug!("function record section name: {:?}", covfun_section_name);
 
@@ -334,7 +337,9 @@ pub(crate) fn save_func_record_to_mod<'ll, 'tcx>(
     llvm::set_section(llglobal, covfun_section_name);
     // LLVM's coverage mapping format specifies 8-byte alignment for items in this section.
     llvm::set_alignment(llglobal, Align::EIGHT);
-    llvm::set_comdat(cx.llmod, llglobal, &func_record_var_name);
+    if cx.target_spec().supports_comdat() {
+        llvm::set_comdat(cx.llmod, llglobal, &func_record_var_name);
+    }
     cx.add_used_global(llglobal);
 }
 
@@ -349,9 +354,9 @@ pub(crate) fn save_func_record_to_mod<'ll, 'tcx>(
 /// - `__llvm_covfun` on Linux
 /// - `__LLVM_COV,__llvm_covfun` on macOS (includes `__LLVM_COV,` segment prefix)
 /// - `.lcovfun$M` on Windows (includes `$M` sorting suffix)
-pub(crate) fn covfun_section_name(cx: &CodegenCx<'_, '_>) -> String {
-    llvm::build_string(|s| unsafe {
+pub(crate) fn covfun_section_name(cx: &CodegenCx<'_, '_>) -> CString {
+    CString::new(llvm::build_byte_buffer(|s| unsafe {
         llvm::LLVMRustCoverageWriteFuncSectionNameToString(cx.llmod, s);
-    })
-    .expect("Rust Coverage function record section name failed UTF-8 conversion")
+    }))
+    .expect("covfun section name should not contain NUL")
 }
diff --git a/compiler/rustc_codegen_llvm/src/intrinsic.rs b/compiler/rustc_codegen_llvm/src/intrinsic.rs
index bfe623e7fc3..64f1d21b438 100644
--- a/compiler/rustc_codegen_llvm/src/intrinsic.rs
+++ b/compiler/rustc_codegen_llvm/src/intrinsic.rs
@@ -787,7 +787,9 @@ fn codegen_msvc_try<'ll>(
         let tydesc = bx.declare_global("__rust_panic_type_info", bx.val_ty(type_info));
         unsafe {
             llvm::LLVMRustSetLinkage(tydesc, llvm::Linkage::LinkOnceODRLinkage);
-            llvm::SetUniqueComdat(bx.llmod, tydesc);
+            if bx.cx.tcx.sess.target.supports_comdat() {
+                llvm::SetUniqueComdat(bx.llmod, tydesc);
+            }
             llvm::LLVMSetInitializer(tydesc, type_info);
         }
 
diff --git a/compiler/rustc_codegen_llvm/src/llvm/ffi.rs b/compiler/rustc_codegen_llvm/src/llvm/ffi.rs
index 661debbb9f1..d0034de06c7 100644
--- a/compiler/rustc_codegen_llvm/src/llvm/ffi.rs
+++ b/compiler/rustc_codegen_llvm/src/llvm/ffi.rs
@@ -646,6 +646,7 @@ unsafe extern "C" {
     pub type Attribute;
     pub type Metadata;
     pub type BasicBlock;
+    pub type Comdat;
 }
 #[repr(C)]
 pub struct Builder<'a>(InvariantOpaque<'a>);
@@ -1490,6 +1491,9 @@ unsafe extern "C" {
     pub fn LLVMSetUnnamedAddress(Global: &Value, UnnamedAddr: UnnamedAddr);
 
     pub fn LLVMIsAConstantInt(value_ref: &Value) -> Option<&ConstantInt>;
+
+    pub fn LLVMGetOrInsertComdat(M: &Module, Name: *const c_char) -> &Comdat;
+    pub fn LLVMSetComdat(V: &Value, C: &Comdat);
 }
 
 #[link(name = "llvm-wrapper", kind = "static")]
@@ -2320,7 +2324,6 @@ unsafe extern "C" {
 
     pub fn LLVMRustPositionBuilderAtStart<'a>(B: &Builder<'a>, BB: &'a BasicBlock);
 
-    pub fn LLVMRustSetComdat<'a>(M: &'a Module, V: &'a Value, Name: *const c_char, NameLen: size_t);
     pub fn LLVMRustSetModulePICLevel(M: &Module);
     pub fn LLVMRustSetModulePIELevel(M: &Module);
     pub fn LLVMRustSetModuleCodeModel(M: &Module, Model: CodeModel);
diff --git a/compiler/rustc_codegen_llvm/src/llvm/mod.rs b/compiler/rustc_codegen_llvm/src/llvm/mod.rs
index d0db350a149..e837022044e 100644
--- a/compiler/rustc_codegen_llvm/src/llvm/mod.rs
+++ b/compiler/rustc_codegen_llvm/src/llvm/mod.rs
@@ -178,10 +178,10 @@ pub fn SetFunctionCallConv(fn_: &Value, cc: CallConv) {
 // function.
 // For more details on COMDAT sections see e.g., https://www.airs.com/blog/archives/52
 pub fn SetUniqueComdat(llmod: &Module, val: &Value) {
-    unsafe {
-        let name = get_value_name(val);
-        LLVMRustSetComdat(llmod, val, name.as_ptr().cast(), name.len());
-    }
+    let name_buf = get_value_name(val).to_vec();
+    let name =
+        CString::from_vec_with_nul(name_buf).or_else(|buf| CString::new(buf.into_bytes())).unwrap();
+    set_comdat(llmod, val, &name);
 }
 
 pub fn SetUnnamedAddress(global: &Value, unnamed: UnnamedAddr) {
@@ -210,15 +210,13 @@ impl MemoryEffects {
     }
 }
 
-pub fn set_section(llglobal: &Value, section_name: &str) {
-    let section_name_cstr = CString::new(section_name).expect("unexpected CString error");
+pub fn set_section(llglobal: &Value, section_name: &CStr) {
     unsafe {
-        LLVMSetSection(llglobal, section_name_cstr.as_ptr());
+        LLVMSetSection(llglobal, section_name.as_ptr());
     }
 }
 
-pub fn add_global<'a>(llmod: &'a Module, ty: &'a Type, name: &str) -> &'a Value {
-    let name_cstr = CString::new(name).expect("unexpected CString error");
+pub fn add_global<'a>(llmod: &'a Module, ty: &'a Type, name_cstr: &CStr) -> &'a Value {
     unsafe { LLVMAddGlobal(llmod, ty, name_cstr.as_ptr()) }
 }
 
@@ -252,9 +250,14 @@ pub fn set_alignment(llglobal: &Value, align: Align) {
     }
 }
 
-pub fn set_comdat(llmod: &Module, llglobal: &Value, name: &str) {
+/// Get the `name`d comdat from `llmod` and assign it to `llglobal`.
+///
+/// Inserts the comdat into `llmod` if it does not exist.
+/// It is an error to call this if the target does not support comdat.
+pub fn set_comdat(llmod: &Module, llglobal: &Value, name: &CStr) {
     unsafe {
-        LLVMRustSetComdat(llmod, llglobal, name.as_ptr().cast(), name.len());
+        let comdat = LLVMGetOrInsertComdat(llmod, name.as_ptr());
+        LLVMSetComdat(llglobal, comdat);
     }
 }
 
diff --git a/compiler/rustc_codegen_llvm/src/mono_item.rs b/compiler/rustc_codegen_llvm/src/mono_item.rs
index 02e1995620b..bf6ef219873 100644
--- a/compiler/rustc_codegen_llvm/src/mono_item.rs
+++ b/compiler/rustc_codegen_llvm/src/mono_item.rs
@@ -64,7 +64,9 @@ impl<'tcx> PreDefineCodegenMethods<'tcx> for CodegenCx<'_, 'tcx> {
         unsafe { llvm::LLVMRustSetLinkage(lldecl, base::linkage_to_llvm(linkage)) };
         let attrs = self.tcx.codegen_fn_attrs(instance.def_id());
         base::set_link_section(lldecl, attrs);
-        if linkage == Linkage::LinkOnceODR || linkage == Linkage::WeakODR {
+        if (linkage == Linkage::LinkOnceODR || linkage == Linkage::WeakODR)
+            && self.tcx.sess.target.supports_comdat()
+        {
             llvm::SetUniqueComdat(self.llmod, lldecl);
         }