Merge pull request #4019 from rust-lang/rustup-2024-11-09

Automatic Rustup

25 files changed, 406 insertions, 328 deletions

diff --git a/compiler/rustc_codegen_llvm/src/abi.rs b/compiler/rustc_codegen_llvm/src/abi.rs
index 855ca010611..1d35138b013 100644
--- a/compiler/rustc_codegen_llvm/src/abi.rs
+++ b/compiler/rustc_codegen_llvm/src/abi.rs
@@ -2,6 +2,7 @@ use std::cmp;
 
 use libc::c_uint;
 use rustc_abi as abi;
+pub(crate) use rustc_abi::ExternAbi;
 use rustc_abi::Primitive::Int;
 use rustc_abi::{HasDataLayout, Size};
 use rustc_codegen_ssa::MemFlags;
@@ -13,9 +14,8 @@ use rustc_middle::ty::layout::LayoutOf;
 pub(crate) use rustc_middle::ty::layout::{WIDE_PTR_ADDR, WIDE_PTR_EXTRA};
 use rustc_middle::{bug, ty};
 use rustc_session::config;
-pub(crate) use rustc_target::abi::call::*;
+pub(crate) use rustc_target::callconv::*;
 use rustc_target::spec::SanitizerSet;
-pub(crate) use rustc_target::spec::abi::Abi;
 use smallvec::SmallVec;
 
 use crate::attributes::llfn_attrs_from_instance;
@@ -436,7 +436,7 @@ impl<'ll, 'tcx> FnAbiLlvmExt<'ll, 'tcx> for FnAbi<'tcx, Ty<'tcx>> {
             i - 1
         };
 
-        let apply_range_attr = |idx: AttributePlace, scalar: rustc_target::abi::Scalar| {
+        let apply_range_attr = |idx: AttributePlace, scalar: rustc_abi::Scalar| {
             if cx.sess().opts.optimize != config::OptLevel::No
                 && llvm_util::get_version() >= (19, 0, 0)
                 && matches!(scalar.primitive(), Int(..))
diff --git a/compiler/rustc_codegen_llvm/src/asm.rs b/compiler/rustc_codegen_llvm/src/asm.rs
index 53758967552..bb74dfe1487 100644
--- a/compiler/rustc_codegen_llvm/src/asm.rs
+++ b/compiler/rustc_codegen_llvm/src/asm.rs
@@ -1,6 +1,7 @@
 use std::assert_matches::assert_matches;
 
 use libc::{c_char, c_uint};
+use rustc_abi::{BackendRepr, Float, Integer, Primitive, Scalar};
 use rustc_ast::{InlineAsmOptions, InlineAsmTemplatePiece};
 use rustc_codegen_ssa::mir::operand::OperandValue;
 use rustc_codegen_ssa::traits::*;
@@ -9,7 +10,6 @@ use rustc_middle::ty::Instance;
 use rustc_middle::ty::layout::TyAndLayout;
 use rustc_middle::{bug, span_bug};
 use rustc_span::{Pos, Span, Symbol, sym};
-use rustc_target::abi::*;
 use rustc_target::asm::*;
 use smallvec::SmallVec;
 use tracing::debug;
@@ -268,6 +268,15 @@ impl<'ll, 'tcx> AsmBuilderMethods<'tcx> for Builder<'_, 'll, 'tcx> {
                 InlineAsmArch::S390x => {
                     constraints.push("~{cc}".to_string());
                 }
+                InlineAsmArch::Sparc | InlineAsmArch::Sparc64 => {
+                    // In LLVM, ~{icc} represents icc and xcc in 64-bit code.
+                    // https://github.com/llvm/llvm-project/blob/llvmorg-19.1.0/llvm/lib/Target/Sparc/SparcRegisterInfo.td#L64
+                    constraints.push("~{icc}".to_string());
+                    constraints.push("~{fcc0}".to_string());
+                    constraints.push("~{fcc1}".to_string());
+                    constraints.push("~{fcc2}".to_string());
+                    constraints.push("~{fcc3}".to_string());
+                }
                 InlineAsmArch::SpirV => {}
                 InlineAsmArch::Wasm32 | InlineAsmArch::Wasm64 => {}
                 InlineAsmArch::Bpf => {}
@@ -638,7 +647,9 @@ fn reg_to_llvm(reg: InlineAsmRegOrRegClass, layout: Option<&TyAndLayout<'_>>) ->
             PowerPC(PowerPCInlineAsmRegClass::reg) => "r",
             PowerPC(PowerPCInlineAsmRegClass::reg_nonzero) => "b",
             PowerPC(PowerPCInlineAsmRegClass::freg) => "f",
-            PowerPC(PowerPCInlineAsmRegClass::cr) | PowerPC(PowerPCInlineAsmRegClass::xer) => {
+            PowerPC(PowerPCInlineAsmRegClass::cr)
+            | PowerPC(PowerPCInlineAsmRegClass::xer)
+            | PowerPC(PowerPCInlineAsmRegClass::vreg) => {
                 unreachable!("clobber-only")
             }
             RiscV(RiscVInlineAsmRegClass::reg) => "r",
@@ -670,6 +681,8 @@ fn reg_to_llvm(reg: InlineAsmRegOrRegClass, layout: Option<&TyAndLayout<'_>>) ->
             S390x(S390xInlineAsmRegClass::vreg | S390xInlineAsmRegClass::areg) => {
                 unreachable!("clobber-only")
             }
+            Sparc(SparcInlineAsmRegClass::reg) => "r",
+            Sparc(SparcInlineAsmRegClass::yreg) => unreachable!("clobber-only"),
             Msp430(Msp430InlineAsmRegClass::reg) => "r",
             M68k(M68kInlineAsmRegClass::reg) => "r",
             M68k(M68kInlineAsmRegClass::reg_addr) => "a",
@@ -763,6 +776,7 @@ fn modifier_to_llvm(
         },
         Avr(_) => None,
         S390x(_) => None,
+        Sparc(_) => None,
         Msp430(_) => None,
         SpirV(SpirVInlineAsmRegClass::reg) => bug!("LLVM backend does not support SPIR-V"),
         M68k(_) => None,
@@ -800,7 +814,9 @@ fn dummy_output_type<'ll>(cx: &CodegenCx<'ll, '_>, reg: InlineAsmRegClass) -> &'
         PowerPC(PowerPCInlineAsmRegClass::reg) => cx.type_i32(),
         PowerPC(PowerPCInlineAsmRegClass::reg_nonzero) => cx.type_i32(),
         PowerPC(PowerPCInlineAsmRegClass::freg) => cx.type_f64(),
-        PowerPC(PowerPCInlineAsmRegClass::cr) | PowerPC(PowerPCInlineAsmRegClass::xer) => {
+        PowerPC(PowerPCInlineAsmRegClass::cr)
+        | PowerPC(PowerPCInlineAsmRegClass::xer)
+        | PowerPC(PowerPCInlineAsmRegClass::vreg) => {
             unreachable!("clobber-only")
         }
         RiscV(RiscVInlineAsmRegClass::reg) => cx.type_i32(),
@@ -831,6 +847,8 @@ fn dummy_output_type<'ll>(cx: &CodegenCx<'ll, '_>, reg: InlineAsmRegClass) -> &'
         S390x(S390xInlineAsmRegClass::vreg | S390xInlineAsmRegClass::areg) => {
             unreachable!("clobber-only")
         }
+        Sparc(SparcInlineAsmRegClass::reg) => cx.type_i32(),
+        Sparc(SparcInlineAsmRegClass::yreg) => unreachable!("clobber-only"),
         Msp430(Msp430InlineAsmRegClass::reg) => cx.type_i16(),
         M68k(M68kInlineAsmRegClass::reg) => cx.type_i32(),
         M68k(M68kInlineAsmRegClass::reg_addr) => cx.type_i32(),
diff --git a/compiler/rustc_codegen_llvm/src/attributes.rs b/compiler/rustc_codegen_llvm/src/attributes.rs
index 64bb22e8cb2..cb958c1d4d7 100644
--- a/compiler/rustc_codegen_llvm/src/attributes.rs
+++ b/compiler/rustc_codegen_llvm/src/attributes.rs
@@ -419,7 +419,10 @@ pub(crate) fn llfn_attrs_from_instance<'ll, 'tcx>(
                 if bti {
                     to_add.push(llvm::CreateAttrString(cx.llcx, "branch-target-enforcement"));
                 }
-                if let Some(PacRet { leaf, key }) = pac_ret {
+                if let Some(PacRet { leaf, pc, key }) = pac_ret {
+                    if pc {
+                        to_add.push(llvm::CreateAttrString(cx.llcx, "branch-protection-pauth-lr"));
+                    }
                     to_add.push(llvm::CreateAttrStringValue(
                         cx.llcx,
                         "sign-return-address",
diff --git a/compiler/rustc_codegen_llvm/src/back/write.rs b/compiler/rustc_codegen_llvm/src/back/write.rs
index 647e9e13fbc..a65ae4df1e3 100644
--- a/compiler/rustc_codegen_llvm/src/back/write.rs
+++ b/compiler/rustc_codegen_llvm/src/back/write.rs
@@ -945,23 +945,10 @@ fn create_section_with_flags_asm(section_name: &str, section_flags: &str, data:
     asm
 }
 
-fn target_is_apple(cgcx: &CodegenContext<LlvmCodegenBackend>) -> bool {
-    let triple = cgcx.opts.target_triple.tuple();
-    triple.contains("-ios")
-        || triple.contains("-darwin")
-        || triple.contains("-tvos")
-        || triple.contains("-watchos")
-        || triple.contains("-visionos")
-}
-
-fn target_is_aix(cgcx: &CodegenContext<LlvmCodegenBackend>) -> bool {
-    cgcx.opts.target_triple.tuple().contains("-aix")
-}
-
 pub(crate) fn bitcode_section_name(cgcx: &CodegenContext<LlvmCodegenBackend>) -> &'static CStr {
-    if target_is_apple(cgcx) {
+    if cgcx.target_is_like_osx {
         c"__LLVM,__bitcode"
-    } else if target_is_aix(cgcx) {
+    } else if cgcx.target_is_like_aix {
         c".ipa"
     } else {
         c".llvmbc"
@@ -1028,10 +1015,12 @@ unsafe fn embed_bitcode(
     // Unfortunately, LLVM provides no way to set custom section flags. For ELF
     // and COFF we emit the sections using module level inline assembly for that
     // reason (see issue #90326 for historical background).
-    let is_aix = target_is_aix(cgcx);
-    let is_apple = target_is_apple(cgcx);
     unsafe {
-        if is_apple || is_aix || cgcx.opts.target_triple.tuple().starts_with("wasm") {
+        if cgcx.target_is_like_osx
+            || cgcx.target_is_like_aix
+            || cgcx.target_arch == "wasm32"
+            || cgcx.target_arch == "wasm64"
+        {
             // We don't need custom section flags, create LLVM globals.
             let llconst = common::bytes_in_context(llcx, bitcode);
             let llglobal = llvm::LLVMAddGlobal(
@@ -1052,9 +1041,9 @@ unsafe fn embed_bitcode(
                 c"rustc.embedded.cmdline".as_ptr(),
             );
             llvm::LLVMSetInitializer(llglobal, llconst);
-            let section = if is_apple {
+            let section = if cgcx.target_is_like_osx {
                 c"__LLVM,__cmdline"
-            } else if is_aix {
+            } else if cgcx.target_is_like_aix {
                 c".info"
             } else {
                 c".llvmcmd"
diff --git a/compiler/rustc_codegen_llvm/src/builder.rs b/compiler/rustc_codegen_llvm/src/builder.rs
index 15883c91053..751b2235dc8 100644
--- a/compiler/rustc_codegen_llvm/src/builder.rs
+++ b/compiler/rustc_codegen_llvm/src/builder.rs
@@ -21,7 +21,7 @@ use rustc_middle::ty::{self, Instance, Ty, TyCtxt};
 use rustc_sanitizers::{cfi, kcfi};
 use rustc_session::config::OptLevel;
 use rustc_span::Span;
-use rustc_target::abi::call::FnAbi;
+use rustc_target::callconv::FnAbi;
 use rustc_target::spec::{HasTargetSpec, SanitizerSet, Target};
 use smallvec::SmallVec;
 use tracing::{debug, instrument};
diff --git a/compiler/rustc_codegen_llvm/src/callee.rs b/compiler/rustc_codegen_llvm/src/callee.rs
index 25037b97375..dcea9d3b391 100644
--- a/compiler/rustc_codegen_llvm/src/callee.rs
+++ b/compiler/rustc_codegen_llvm/src/callee.rs
@@ -44,6 +44,22 @@ pub(crate) fn get_fn<'ll, 'tcx>(cx: &CodegenCx<'ll, 'tcx>, instance: Instance<'t
         let llfn = if tcx.sess.target.arch == "x86"
             && let Some(dllimport) = crate::common::get_dllimport(tcx, instance_def_id, sym)
         {
+            // When calling functions in generated import libraries, MSVC needs
+            // the fully decorated name (as would have been in the declaring
+            // object file), but MinGW wants the name as exported (as would be
+            // in the def file) which may be missing decorations.
+            let mingw_gnu_toolchain = common::is_mingw_gnu_toolchain(&tcx.sess.target);
+            let llfn = cx.declare_fn(
+                &common::i686_decorated_name(
+                    dllimport,
+                    mingw_gnu_toolchain,
+                    true,
+                    !mingw_gnu_toolchain,
+                ),
+                fn_abi,
+                Some(instance),
+            );
+
             // Fix for https://github.com/rust-lang/rust/issues/104453
             // On x86 Windows, LLVM uses 'L' as the prefix for any private
             // global symbols, so when we create an undecorated function symbol
@@ -55,15 +71,6 @@ pub(crate) fn get_fn<'ll, 'tcx>(cx: &CodegenCx<'ll, 'tcx>, instance: Instance<'t
             // LLVM will prefix the name with `__imp_`. Ideally, we'd like the
             // existing logic below to set the Storage Class, but it has an
             // exemption for MinGW for backwards compatibility.
-            let llfn = cx.declare_fn(
-                &common::i686_decorated_name(
-                    dllimport,
-                    common::is_mingw_gnu_toolchain(&tcx.sess.target),
-                    true,
-                ),
-                fn_abi,
-                Some(instance),
-            );
             unsafe {
                 llvm::LLVMSetDLLStorageClass(llfn, llvm::DLLStorageClass::DllImport);
             }
diff --git a/compiler/rustc_codegen_llvm/src/consts.rs b/compiler/rustc_codegen_llvm/src/consts.rs
index 21d996ef460..7ab4f45cd73 100644
--- a/compiler/rustc_codegen_llvm/src/consts.rs
+++ b/compiler/rustc_codegen_llvm/src/consts.rs
@@ -1,5 +1,8 @@
 use std::ops::Range;
 
+use rustc_abi::{
+    Align, AlignFromBytesError, HasDataLayout, Primitive, Scalar, Size, WrappingRange,
+};
 use rustc_codegen_ssa::common;
 use rustc_codegen_ssa::traits::*;
 use rustc_hir::def::DefKind;
@@ -14,9 +17,6 @@ use rustc_middle::ty::layout::LayoutOf;
 use rustc_middle::ty::{self, Instance};
 use rustc_middle::{bug, span_bug};
 use rustc_session::config::Lto;
-use rustc_target::abi::{
-    Align, AlignFromBytesError, HasDataLayout, Primitive, Scalar, Size, WrappingRange,
-};
 use tracing::{debug, instrument, trace};
 
 use crate::common::{AsCCharPtr, CodegenCx};
@@ -194,16 +194,10 @@ fn check_and_apply_linkage<'ll, 'tcx>(
         unsafe { llvm::LLVMSetInitializer(g2, g1) };
         g2
     } else if cx.tcx.sess.target.arch == "x86"
+        && common::is_mingw_gnu_toolchain(&cx.tcx.sess.target)
         && let Some(dllimport) = crate::common::get_dllimport(cx.tcx, def_id, sym)
     {
-        cx.declare_global(
-            &common::i686_decorated_name(
-                dllimport,
-                common::is_mingw_gnu_toolchain(&cx.tcx.sess.target),
-                true,
-            ),
-            llty,
-        )
+        cx.declare_global(&common::i686_decorated_name(dllimport, true, true, false), llty)
     } else {
         // Generate an external declaration.
         // FIXME(nagisa): investigate whether it can be changed into define_global
diff --git a/compiler/rustc_codegen_llvm/src/context.rs b/compiler/rustc_codegen_llvm/src/context.rs
index 03f4fb527a8..ba863d9d74b 100644
--- a/compiler/rustc_codegen_llvm/src/context.rs
+++ b/compiler/rustc_codegen_llvm/src/context.rs
@@ -3,6 +3,7 @@ use std::cell::{Cell, RefCell};
 use std::ffi::{CStr, c_uint};
 use std::str;
 
+use rustc_abi::{HasDataLayout, TargetDataLayout, VariantIdx};
 use rustc_codegen_ssa::back::versioned_llvm_target;
 use rustc_codegen_ssa::base::{wants_msvc_seh, wants_wasm_eh};
 use rustc_codegen_ssa::errors as ssa_errors;
@@ -24,7 +25,6 @@ use rustc_session::config::{
 };
 use rustc_span::source_map::Spanned;
 use rustc_span::{DUMMY_SP, Span};
-use rustc_target::abi::{HasDataLayout, TargetDataLayout, VariantIdx};
 use rustc_target::spec::{HasTargetSpec, RelocModel, SmallDataThresholdSupport, Target, TlsModel};
 use smallvec::SmallVec;
 
@@ -154,6 +154,11 @@ pub(crate) unsafe fn create_module<'ll>(
             // See https://github.com/llvm/llvm-project/pull/106951
             target_data_layout = target_data_layout.replace("-i128:128", "");
         }
+        if sess.target.arch.starts_with("mips64") {
+            // LLVM 20 updates the mips64 layout to correctly align 128 bit integers to 128 bit.
+            // See https://github.com/llvm/llvm-project/pull/112084
+            target_data_layout = target_data_layout.replace("-i128:128", "");
+        }
     }
 
     // Ensure the data-layout values hardcoded remain the defaults.
@@ -308,7 +313,13 @@ pub(crate) unsafe fn create_module<'ll>(
                 "sign-return-address",
                 pac_ret.is_some().into(),
             );
-            let pac_opts = pac_ret.unwrap_or(PacRet { leaf: false, key: PAuthKey::A });
+            let pac_opts = pac_ret.unwrap_or(PacRet { leaf: false, pc: false, key: PAuthKey::A });
+            llvm::add_module_flag_u32(
+                llmod,
+                llvm::ModuleFlagMergeBehavior::Min,
+                "branch-protection-pauth-lr",
+                pac_opts.pc.into(),
+            );
             llvm::add_module_flag_u32(
                 llmod,
                 llvm::ModuleFlagMergeBehavior::Min,
diff --git a/compiler/rustc_codegen_llvm/src/coverageinfo/llvm_cov.rs b/compiler/rustc_codegen_llvm/src/coverageinfo/llvm_cov.rs
new file mode 100644
index 00000000000..99c2d12b261
--- /dev/null
+++ b/compiler/rustc_codegen_llvm/src/coverageinfo/llvm_cov.rs
@@ -0,0 +1,100 @@
+//! Safe wrappers for coverage-specific FFI functions.
+
+use std::ffi::CString;
+
+use crate::common::AsCCharPtr;
+use crate::coverageinfo::ffi;
+use crate::llvm;
+
+pub(crate) fn covmap_var_name() -> CString {
+    CString::new(llvm::build_byte_buffer(|s| unsafe {
+        llvm::LLVMRustCoverageWriteCovmapVarNameToString(s);
+    }))
+    .expect("covmap variable name should not contain NUL")
+}
+
+pub(crate) fn covmap_section_name(llmod: &llvm::Module) -> CString {
+    CString::new(llvm::build_byte_buffer(|s| unsafe {
+        llvm::LLVMRustCoverageWriteCovmapSectionNameToString(llmod, s);
+    }))
+    .expect("covmap section name should not contain NUL")
+}
+
+pub(crate) fn covfun_section_name(llmod: &llvm::Module) -> CString {
+    CString::new(llvm::build_byte_buffer(|s| unsafe {
+        llvm::LLVMRustCoverageWriteCovfunSectionNameToString(llmod, s);
+    }))
+    .expect("covfun section name should not contain NUL")
+}
+
+pub(crate) fn create_pgo_func_name_var<'ll>(
+    llfn: &'ll llvm::Value,
+    mangled_fn_name: &str,
+) -> &'ll llvm::Value {
+    unsafe {
+        llvm::LLVMRustCoverageCreatePGOFuncNameVar(
+            llfn,
+            mangled_fn_name.as_c_char_ptr(),
+            mangled_fn_name.len(),
+        )
+    }
+}
+
+pub(crate) fn write_filenames_to_buffer<'a>(
+    filenames: impl IntoIterator<Item = &'a str>,
+) -> Vec<u8> {
+    let (pointers, lengths) = filenames
+        .into_iter()
+        .map(|s: &str| (s.as_c_char_ptr(), s.len()))
+        .unzip::<_, _, Vec<_>, Vec<_>>();
+
+    llvm::build_byte_buffer(|buffer| unsafe {
+        llvm::LLVMRustCoverageWriteFilenamesToBuffer(
+            pointers.as_ptr(),
+            pointers.len(),
+            lengths.as_ptr(),
+            lengths.len(),
+            buffer,
+        );
+    })
+}
+
+pub(crate) fn write_function_mappings_to_buffer(
+    virtual_file_mapping: &[u32],
+    expressions: &[ffi::CounterExpression],
+    code_regions: &[ffi::CodeRegion],
+    branch_regions: &[ffi::BranchRegion],
+    mcdc_branch_regions: &[ffi::MCDCBranchRegion],
+    mcdc_decision_regions: &[ffi::MCDCDecisionRegion],
+) -> Vec<u8> {
+    llvm::build_byte_buffer(|buffer| unsafe {
+        llvm::LLVMRustCoverageWriteFunctionMappingsToBuffer(
+            virtual_file_mapping.as_ptr(),
+            virtual_file_mapping.len(),
+            expressions.as_ptr(),
+            expressions.len(),
+            code_regions.as_ptr(),
+            code_regions.len(),
+            branch_regions.as_ptr(),
+            branch_regions.len(),
+            mcdc_branch_regions.as_ptr(),
+            mcdc_branch_regions.len(),
+            mcdc_decision_regions.as_ptr(),
+            mcdc_decision_regions.len(),
+            buffer,
+        )
+    })
+}
+
+/// Hashes some bytes into a 64-bit hash, via LLVM's `IndexedInstrProf::ComputeHash`,
+/// as required for parts of the LLVM coverage mapping format.
+pub(crate) fn hash_bytes(bytes: &[u8]) -> u64 {
+    unsafe { llvm::LLVMRustCoverageHashBytes(bytes.as_c_char_ptr(), bytes.len()) }
+}
+
+/// Returns LLVM's `coverage::CovMapVersion::CurrentVersion` (CoverageMapping.h)
+/// as a raw numeric value. For historical reasons, the numeric value is 1 less
+/// than the number in the version's name, so `Version7` is actually `6u32`.
+pub(crate) fn mapping_version() -> u32 {
+    unsafe { llvm::LLVMRustCoverageMappingVersion() }
+}
diff --git a/compiler/rustc_codegen_llvm/src/coverageinfo/mapgen.rs b/compiler/rustc_codegen_llvm/src/coverageinfo/mapgen.rs
index f6378199fe2..bb2f634cb25 100644
--- a/compiler/rustc_codegen_llvm/src/coverageinfo/mapgen.rs
+++ b/compiler/rustc_codegen_llvm/src/coverageinfo/mapgen.rs
@@ -1,4 +1,5 @@
 use std::ffi::CString;
+use std::iter;
 
 use itertools::Itertools as _;
 use rustc_abi::Align;
@@ -17,9 +18,9 @@ use rustc_target::spec::HasTargetSpec;
 use tracing::debug;
 
 use crate::common::CodegenCx;
-use crate::coverageinfo::ffi;
 use crate::coverageinfo::map_data::{FunctionCoverage, FunctionCoverageCollector};
-use crate::{coverageinfo, llvm};
+use crate::coverageinfo::{ffi, llvm_cov};
+use crate::llvm;
 
 /// Generates and exports the coverage map, which is embedded in special
 /// linker sections in the final binary.
@@ -33,7 +34,7 @@ pub(crate) fn finalize(cx: &CodegenCx<'_, '_>) {
     // agrees with our Rust-side code. Expected versions (encoded as n-1) are:
     // - `CovMapVersion::Version7` (6) used by LLVM 18-19
     let covmap_version = {
-        let llvm_covmap_version = coverageinfo::mapping_version();
+        let llvm_covmap_version = llvm_cov::mapping_version();
         let expected_versions = 6..=6;
         assert!(
             expected_versions.contains(&llvm_covmap_version),
@@ -78,7 +79,7 @@ pub(crate) fn finalize(cx: &CodegenCx<'_, '_>) {
 
     let filenames_size = filenames_buffer.len();
     let filenames_val = cx.const_bytes(&filenames_buffer);
-    let filenames_ref = coverageinfo::hash_bytes(&filenames_buffer);
+    let filenames_ref = llvm_cov::hash_bytes(&filenames_buffer);
 
     // Generate the coverage map header, which contains the filenames used by
     // this CGU's coverage mappings, and store it in a well-known global.
@@ -187,13 +188,10 @@ impl GlobalFileTable {
             .for_scope(tcx.sess, RemapPathScopeComponents::MACRO)
             .to_string_lossy();
 
-        llvm::build_byte_buffer(|buffer| {
-            coverageinfo::write_filenames_section_to_buffer(
-                // Insert the working dir at index 0, before the other filenames.
-                std::iter::once(working_dir).chain(self.raw_file_table.iter().map(Symbol::as_str)),
-                buffer,
-            );
-        })
+        // Insert the working dir at index 0, before the other filenames.
+        let filenames =
+            iter::once(working_dir).chain(self.raw_file_table.iter().map(Symbol::as_str));
+        llvm_cov::write_filenames_to_buffer(filenames)
     }
 }
 
@@ -296,17 +294,14 @@ fn encode_mappings_for_function(
     }
 
     // Encode the function's coverage mappings into a buffer.
-    llvm::build_byte_buffer(|buffer| {
-        coverageinfo::write_mapping_to_buffer(
-            virtual_file_mapping.into_vec(),
-            expressions,
-            &code_regions,
-            &branch_regions,
-            &mcdc_branch_regions,
-            &mcdc_decision_regions,
-            buffer,
-        );
-    })
+    llvm_cov::write_function_mappings_to_buffer(
+        &virtual_file_mapping.into_vec(),
+        &expressions,
+        &code_regions,
+        &branch_regions,
+        &mcdc_branch_regions,
+        &mcdc_decision_regions,
+    )
 }
 
 /// Generates the contents of the covmap record for this CGU, which mostly
@@ -335,23 +330,11 @@ fn generate_covmap_record<'ll>(
     let covmap_data =
         cx.const_struct(&[cov_data_header_val, filenames_val], /*packed=*/ false);
 
-    let covmap_var_name = CString::new(llvm::build_byte_buffer(|s| unsafe {
-        llvm::LLVMRustCoverageWriteMappingVarNameToString(s);
-    }))
-    .unwrap();
-    debug!("covmap var name: {:?}", covmap_var_name);
-
-    let covmap_section_name = CString::new(llvm::build_byte_buffer(|s| unsafe {
-        llvm::LLVMRustCoverageWriteMapSectionNameToString(cx.llmod, s);
-    }))
-    .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(covmap_data), &covmap_var_name);
+    let llglobal = llvm::add_global(cx.llmod, cx.val_ty(covmap_data), &llvm_cov::covmap_var_name());
     llvm::set_initializer(llglobal, covmap_data);
     llvm::set_global_constant(llglobal, true);
     llvm::set_linkage(llglobal, llvm::Linkage::PrivateLinkage);
-    llvm::set_section(llglobal, &covmap_section_name);
+    llvm::set_section(llglobal, &llvm_cov::covmap_section_name(cx.llmod));
     // LLVM's coverage mapping format specifies 8-byte alignment for items in this section.
     // <https://llvm.org/docs/CoverageMappingFormat.html>
     llvm::set_alignment(llglobal, Align::EIGHT);
@@ -373,7 +356,7 @@ fn generate_covfun_record(
     let coverage_mapping_size = coverage_mapping_buffer.len();
     let coverage_mapping_val = cx.const_bytes(&coverage_mapping_buffer);
 
-    let func_name_hash = coverageinfo::hash_bytes(mangled_function_name.as_bytes());
+    let func_name_hash = llvm_cov::hash_bytes(mangled_function_name.as_bytes());
     let func_name_hash_val = cx.const_u64(func_name_hash);
     let coverage_mapping_size_val = cx.const_u32(coverage_mapping_size as u32);
     let source_hash_val = cx.const_u64(source_hash);
diff --git a/compiler/rustc_codegen_llvm/src/coverageinfo/mod.rs b/compiler/rustc_codegen_llvm/src/coverageinfo/mod.rs
index e4ff50816b9..bf773cd2667 100644
--- a/compiler/rustc_codegen_llvm/src/coverageinfo/mod.rs
+++ b/compiler/rustc_codegen_llvm/src/coverageinfo/mod.rs
@@ -1,24 +1,23 @@
 use std::cell::{OnceCell, RefCell};
 use std::ffi::{CStr, CString};
 
-use libc::c_uint;
+use rustc_abi::Size;
 use rustc_codegen_ssa::traits::{
     BuilderMethods, ConstCodegenMethods, CoverageInfoBuilderMethods, MiscCodegenMethods,
 };
 use rustc_data_structures::fx::{FxHashMap, FxIndexMap};
-use rustc_llvm::RustString;
 use rustc_middle::mir::coverage::CoverageKind;
 use rustc_middle::ty::Instance;
 use rustc_middle::ty::layout::HasTyCtxt;
-use rustc_target::abi::Size;
 use tracing::{debug, instrument};
 
 use crate::builder::Builder;
-use crate::common::{AsCCharPtr, CodegenCx};
+use crate::common::CodegenCx;
 use crate::coverageinfo::map_data::FunctionCoverageCollector;
 use crate::llvm;
 
 pub(crate) mod ffi;
+mod llvm_cov;
 pub(crate) mod map_data;
 mod mapgen;
 
@@ -80,12 +79,9 @@ impl<'ll, 'tcx> CodegenCx<'ll, 'tcx> {
     /// - `__LLVM_COV,__llvm_covfun` on macOS (includes `__LLVM_COV,` segment prefix)
     /// - `.lcovfun$M` on Windows (includes `$M` sorting suffix)
     fn covfun_section_name(&self) -> &CStr {
-        self.coverage_cx().covfun_section_name.get_or_init(|| {
-            CString::new(llvm::build_byte_buffer(|s| unsafe {
-                llvm::LLVMRustCoverageWriteFuncSectionNameToString(self.llmod, s);
-            }))
-            .expect("covfun section name should not contain NUL")
-        })
+        self.coverage_cx()
+            .covfun_section_name
+            .get_or_init(|| llvm_cov::covfun_section_name(self.llmod))
     }
 
     /// For LLVM codegen, returns a function-specific `Value` for a global
@@ -95,9 +91,11 @@ impl<'ll, 'tcx> CodegenCx<'ll, 'tcx> {
     fn get_pgo_func_name_var(&self, instance: Instance<'tcx>) -> &'ll llvm::Value {
         debug!("getting pgo_func_name_var for instance={:?}", instance);
         let mut pgo_func_name_var_map = self.coverage_cx().pgo_func_name_var_map.borrow_mut();
-        pgo_func_name_var_map
-            .entry(instance)
-            .or_insert_with(|| create_pgo_func_name_var(self, instance))
+        pgo_func_name_var_map.entry(instance).or_insert_with(|| {
+            let llfn = self.get_fn(instance);
+            let mangled_fn_name: &str = self.tcx.symbol_name(instance).name;
+            llvm_cov::create_pgo_func_name_var(llfn, mangled_fn_name)
+        })
     }
 }
 
@@ -225,80 +223,3 @@ impl<'tcx> CoverageInfoBuilderMethods<'tcx> for Builder<'_, '_, 'tcx> {
         }
     }
 }
-
-/// Calls llvm::createPGOFuncNameVar() with the given function instance's
-/// mangled function name. The LLVM API returns an llvm::GlobalVariable
-/// containing the function name, with the specific variable name and linkage
-/// required by LLVM InstrProf source-based coverage instrumentation. Use
-/// `bx.get_pgo_func_name_var()` to ensure the variable is only created once per
-/// `Instance`.
-fn create_pgo_func_name_var<'ll, 'tcx>(
-    cx: &CodegenCx<'ll, 'tcx>,
-    instance: Instance<'tcx>,
-) -> &'ll llvm::Value {
-    let mangled_fn_name: &str = cx.tcx.symbol_name(instance).name;
-    let llfn = cx.get_fn(instance);
-    unsafe {
-        llvm::LLVMRustCoverageCreatePGOFuncNameVar(
-            llfn,
-            mangled_fn_name.as_c_char_ptr(),
-            mangled_fn_name.len(),
-        )
-    }
-}
-
-pub(crate) fn write_filenames_section_to_buffer<'a>(
-    filenames: impl IntoIterator<Item = &'a str>,
-    buffer: &RustString,
-) {
-    let (pointers, lengths) = filenames
-        .into_iter()
-        .map(|s: &str| (s.as_c_char_ptr(), s.len()))
-        .unzip::<_, _, Vec<_>, Vec<_>>();
-
-    unsafe {
-        llvm::LLVMRustCoverageWriteFilenamesSectionToBuffer(
-            pointers.as_ptr(),
-            pointers.len(),
-            lengths.as_ptr(),
-            lengths.len(),
-            buffer,
-        );
-    }
-}
-
-pub(crate) fn write_mapping_to_buffer(
-    virtual_file_mapping: Vec<u32>,
-    expressions: Vec<ffi::CounterExpression>,
-    code_regions: &[ffi::CodeRegion],
-    branch_regions: &[ffi::BranchRegion],
-    mcdc_branch_regions: &[ffi::MCDCBranchRegion],
-    mcdc_decision_regions: &[ffi::MCDCDecisionRegion],
-    buffer: &RustString,
-) {
-    unsafe {
-        llvm::LLVMRustCoverageWriteMappingToBuffer(
-            virtual_file_mapping.as_ptr(),
-            virtual_file_mapping.len() as c_uint,
-            expressions.as_ptr(),
-            expressions.len() as c_uint,
-            code_regions.as_ptr(),
-            code_regions.len() as c_uint,
-            branch_regions.as_ptr(),
-            branch_regions.len() as c_uint,
-            mcdc_branch_regions.as_ptr(),
-            mcdc_branch_regions.len() as c_uint,
-            mcdc_decision_regions.as_ptr(),
-            mcdc_decision_regions.len() as c_uint,
-            buffer,
-        );
-    }
-}
-
-pub(crate) fn hash_bytes(bytes: &[u8]) -> u64 {
-    unsafe { llvm::LLVMRustCoverageHashByteArray(bytes.as_c_char_ptr(), bytes.len()) }
-}
-
-pub(crate) fn mapping_version() -> u32 {
-    unsafe { llvm::LLVMRustCoverageMappingVersion() }
-}
diff --git a/compiler/rustc_codegen_llvm/src/debuginfo/metadata.rs b/compiler/rustc_codegen_llvm/src/debuginfo/metadata.rs
index 0d1fd0163eb..151923a3bd2 100644
--- a/compiler/rustc_codegen_llvm/src/debuginfo/metadata.rs
+++ b/compiler/rustc_codegen_llvm/src/debuginfo/metadata.rs
@@ -5,6 +5,7 @@ use std::path::{Path, PathBuf};
 use std::{iter, ptr};
 
 use libc::{c_char, c_longlong, c_uint};
+use rustc_abi::{Align, Size};
 use rustc_codegen_ssa::debuginfo::type_names::{VTableNameKind, cpp_like_debuginfo};
 use rustc_codegen_ssa::traits::*;
 use rustc_hir::def::{CtorKind, DefKind};
@@ -19,7 +20,6 @@ use rustc_session::config::{self, DebugInfo, Lto};
 use rustc_span::symbol::Symbol;
 use rustc_span::{DUMMY_SP, FileName, FileNameDisplayPreference, SourceFile, hygiene};
 use rustc_symbol_mangling::typeid_for_trait_ref;
-use rustc_target::abi::{Align, Size};
 use rustc_target::spec::DebuginfoKind;
 use smallvec::smallvec;
 use tracing::{debug, instrument};
diff --git a/compiler/rustc_codegen_llvm/src/debuginfo/metadata/enums/cpp_like.rs b/compiler/rustc_codegen_llvm/src/debuginfo/metadata/enums/cpp_like.rs
index 5385d3a9212..100b046cee2 100644
--- a/compiler/rustc_codegen_llvm/src/debuginfo/metadata/enums/cpp_like.rs
+++ b/compiler/rustc_codegen_llvm/src/debuginfo/metadata/enums/cpp_like.rs
@@ -1,6 +1,7 @@
 use std::borrow::Cow;
 
 use libc::c_uint;
+use rustc_abi::{Align, Endian, Size, TagEncoding, VariantIdx, Variants};
 use rustc_codegen_ssa::debuginfo::type_names::compute_debuginfo_type_name;
 use rustc_codegen_ssa::debuginfo::{tag_base_type, wants_c_like_enum_debuginfo};
 use rustc_codegen_ssa::traits::ConstCodegenMethods;
@@ -8,7 +9,6 @@ use rustc_index::IndexVec;
 use rustc_middle::bug;
 use rustc_middle::ty::layout::{LayoutOf, TyAndLayout};
 use rustc_middle::ty::{self, AdtDef, CoroutineArgs, CoroutineArgsExt, Ty};
-use rustc_target::abi::{Align, Endian, Size, TagEncoding, VariantIdx, Variants};
 use smallvec::smallvec;
 
 use crate::common::{AsCCharPtr, CodegenCx};
diff --git a/compiler/rustc_codegen_llvm/src/debuginfo/metadata/enums/mod.rs b/compiler/rustc_codegen_llvm/src/debuginfo/metadata/enums/mod.rs
index 4c848027b55..b3d4a6642a1 100644
--- a/compiler/rustc_codegen_llvm/src/debuginfo/metadata/enums/mod.rs
+++ b/compiler/rustc_codegen_llvm/src/debuginfo/metadata/enums/mod.rs
@@ -1,5 +1,6 @@
 use std::borrow::Cow;
 
+use rustc_abi::{FieldIdx, TagEncoding, VariantIdx, Variants};
 use rustc_codegen_ssa::debuginfo::type_names::{compute_debuginfo_type_name, cpp_like_debuginfo};
 use rustc_codegen_ssa::debuginfo::{tag_base_type, wants_c_like_enum_debuginfo};
 use rustc_hir::def::CtorKind;
@@ -9,7 +10,6 @@ use rustc_middle::mir::CoroutineLayout;
 use rustc_middle::ty::layout::{LayoutOf, TyAndLayout};
 use rustc_middle::ty::{self, AdtDef, CoroutineArgs, CoroutineArgsExt, Ty, VariantDef};
 use rustc_span::Symbol;
-use rustc_target::abi::{FieldIdx, TagEncoding, VariantIdx, Variants};
 
 use super::type_map::{DINodeCreationResult, UniqueTypeId};
 use super::{SmallVec, size_and_align_of};
diff --git a/compiler/rustc_codegen_llvm/src/debuginfo/metadata/enums/native.rs b/compiler/rustc_codegen_llvm/src/debuginfo/metadata/enums/native.rs
index b7400c5aeb2..d4006691d37 100644
--- a/compiler/rustc_codegen_llvm/src/debuginfo/metadata/enums/native.rs
+++ b/compiler/rustc_codegen_llvm/src/debuginfo/metadata/enums/native.rs
@@ -1,13 +1,13 @@
 use std::borrow::Cow;
 
 use libc::c_uint;
+use rustc_abi::{Size, TagEncoding, VariantIdx, Variants};
 use rustc_codegen_ssa::debuginfo::type_names::compute_debuginfo_type_name;
 use rustc_codegen_ssa::debuginfo::{tag_base_type, wants_c_like_enum_debuginfo};
 use rustc_codegen_ssa::traits::ConstCodegenMethods;
 use rustc_middle::bug;
 use rustc_middle::ty::layout::{LayoutOf, TyAndLayout};
 use rustc_middle::ty::{self};
-use rustc_target::abi::{Size, TagEncoding, VariantIdx, Variants};
 use smallvec::smallvec;
 
 use crate::common::{AsCCharPtr, CodegenCx};
diff --git a/compiler/rustc_codegen_llvm/src/debuginfo/metadata/type_map.rs b/compiler/rustc_codegen_llvm/src/debuginfo/metadata/type_map.rs
index d050dc9b406..5120b63d173 100644
--- a/compiler/rustc_codegen_llvm/src/debuginfo/metadata/type_map.rs
+++ b/compiler/rustc_codegen_llvm/src/debuginfo/metadata/type_map.rs
@@ -1,12 +1,12 @@
 use std::cell::RefCell;
 
+use rustc_abi::{Align, Size, VariantIdx};
 use rustc_data_structures::fingerprint::Fingerprint;
 use rustc_data_structures::fx::FxHashMap;
 use rustc_data_structures::stable_hasher::{HashStable, StableHasher};
 use rustc_macros::HashStable;
 use rustc_middle::bug;
 use rustc_middle::ty::{ParamEnv, PolyExistentialTraitRef, Ty, TyCtxt};
-use rustc_target::abi::{Align, Size, VariantIdx};
 
 use super::{SmallVec, UNKNOWN_LINE_NUMBER, unknown_file_metadata};
 use crate::common::{AsCCharPtr, CodegenCx};
diff --git a/compiler/rustc_codegen_llvm/src/debuginfo/mod.rs b/compiler/rustc_codegen_llvm/src/debuginfo/mod.rs
index b6c20cdcf0c..9e1e5127e80 100644
--- a/compiler/rustc_codegen_llvm/src/debuginfo/mod.rs
+++ b/compiler/rustc_codegen_llvm/src/debuginfo/mod.rs
@@ -5,6 +5,7 @@ use std::ops::Range;
 use std::{iter, ptr};
 
 use libc::c_uint;
+use rustc_abi::Size;
 use rustc_codegen_ssa::debuginfo::type_names;
 use rustc_codegen_ssa::mir::debuginfo::VariableKind::*;
 use rustc_codegen_ssa::mir::debuginfo::{DebugScope, FunctionDebugContext, VariableKind};
@@ -22,7 +23,6 @@ use rustc_span::symbol::Symbol;
 use rustc_span::{
     BytePos, Pos, SourceFile, SourceFileAndLine, SourceFileHash, Span, StableSourceFileId,
 };
-use rustc_target::abi::Size;
 use smallvec::SmallVec;
 use tracing::debug;
 
diff --git a/compiler/rustc_codegen_llvm/src/errors.rs b/compiler/rustc_codegen_llvm/src/errors.rs
index 0d436e1891e..3cdb5b971d9 100644
--- a/compiler/rustc_codegen_llvm/src/errors.rs
+++ b/compiler/rustc_codegen_llvm/src/errors.rs
@@ -31,6 +31,15 @@ pub(crate) struct UnstableCTargetFeature<'a> {
     pub feature: &'a str,
 }
 
+#[derive(Diagnostic)]
+#[diag(codegen_llvm_forbidden_ctarget_feature)]
+#[note]
+#[note(codegen_llvm_forbidden_ctarget_feature_issue)]
+pub(crate) struct ForbiddenCTargetFeature<'a> {
+    pub feature: &'a str,
+    pub reason: &'a str,
+}
+
 #[derive(Subdiagnostic)]
 pub(crate) enum PossibleFeature<'a> {
     #[help(codegen_llvm_possible_feature)]
diff --git a/compiler/rustc_codegen_llvm/src/intrinsic.rs b/compiler/rustc_codegen_llvm/src/intrinsic.rs
index c77e00aed9a..e9c687d75e3 100644
--- a/compiler/rustc_codegen_llvm/src/intrinsic.rs
+++ b/compiler/rustc_codegen_llvm/src/intrinsic.rs
@@ -1,6 +1,7 @@
 use std::assert_matches::assert_matches;
 use std::cmp::Ordering;
 
+use rustc_abi::{self as abi, Align, Float, HasDataLayout, Primitive, Size};
 use rustc_codegen_ssa::base::{compare_simd_types, wants_msvc_seh, wants_wasm_eh};
 use rustc_codegen_ssa::common::{IntPredicate, TypeKind};
 use rustc_codegen_ssa::errors::{ExpectedPointerMutability, InvalidMonomorphization};
@@ -13,11 +14,10 @@ use rustc_middle::ty::layout::{FnAbiOf, HasTyCtxt, LayoutOf};
 use rustc_middle::ty::{self, GenericArgsRef, Ty};
 use rustc_middle::{bug, span_bug};
 use rustc_span::{Span, Symbol, sym};
-use rustc_target::abi::{self, Align, Float, HasDataLayout, Primitive, Size};
 use rustc_target::spec::{HasTargetSpec, PanicStrategy};
 use tracing::debug;
 
-use crate::abi::{Abi, FnAbi, FnAbiLlvmExt, LlvmType, PassMode};
+use crate::abi::{ExternAbi, FnAbi, FnAbiLlvmExt, LlvmType, PassMode};
 use crate::builder::Builder;
 use crate::context::CodegenCx;
 use crate::llvm::{self, Metadata};
@@ -1094,7 +1094,7 @@ fn get_rust_try_fn<'ll, 'tcx>(
             tcx.types.unit,
             false,
             hir::Safety::Unsafe,
-            Abi::Rust,
+            ExternAbi::Rust,
         )),
     );
     // `unsafe fn(*mut i8, *mut i8) -> ()`
@@ -1105,7 +1105,7 @@ fn get_rust_try_fn<'ll, 'tcx>(
             tcx.types.unit,
             false,
             hir::Safety::Unsafe,
-            Abi::Rust,
+            ExternAbi::Rust,
         )),
     );
     // `unsafe fn(unsafe fn(*mut i8) -> (), *mut i8, unsafe fn(*mut i8, *mut i8) -> ()) -> i32`
@@ -1114,7 +1114,7 @@ fn get_rust_try_fn<'ll, 'tcx>(
         tcx.types.i32,
         false,
         hir::Safety::Unsafe,
-        Abi::Rust,
+        ExternAbi::Rust,
     ));
     let rust_try = gen_fn(cx, "__rust_try", rust_fn_sig, codegen);
     cx.rust_try_fn.set(Some(rust_try));
diff --git a/compiler/rustc_codegen_llvm/src/lib.rs b/compiler/rustc_codegen_llvm/src/lib.rs
index b85d28a2f1f..49e616b5371 100644
--- a/compiler/rustc_codegen_llvm/src/lib.rs
+++ b/compiler/rustc_codegen_llvm/src/lib.rs
@@ -22,7 +22,6 @@
 
 use std::any::Any;
 use std::ffi::CStr;
-use std::io::Write;
 use std::mem::ManuallyDrop;
 
 use back::owned_target_machine::OwnedTargetMachine;
@@ -165,30 +164,12 @@ impl WriteBackendMethods for LlvmCodegenBackend {
     type ThinData = back::lto::ThinData;
     type ThinBuffer = back::lto::ThinBuffer;
     fn print_pass_timings(&self) {
-        unsafe {
-            let mut size = 0;
-            let cstr = llvm::LLVMRustPrintPassTimings(&raw mut size);
-            if cstr.is_null() {
-                println!("failed to get pass timings");
-            } else {
-                let timings = std::slice::from_raw_parts(cstr as *const u8, size);
-                std::io::stdout().write_all(timings).unwrap();
-                libc::free(cstr as *mut _);
-            }
-        }
+        let timings = llvm::build_string(|s| unsafe { llvm::LLVMRustPrintPassTimings(s) }).unwrap();
+        print!("{timings}");
     }
     fn print_statistics(&self) {
-        unsafe {
-            let mut size = 0;
-            let cstr = llvm::LLVMRustPrintStatistics(&raw mut size);
-            if cstr.is_null() {
-                println!("failed to get pass stats");
-            } else {
-                let stats = std::slice::from_raw_parts(cstr as *const u8, size);
-                std::io::stdout().write_all(stats).unwrap();
-                libc::free(cstr as *mut _);
-            }
-        }
+        let stats = llvm::build_string(|s| unsafe { llvm::LLVMRustPrintStatistics(s) }).unwrap();
+        print!("{stats}");
     }
     fn run_link(
         cgcx: &CodegenContext<Self>,
diff --git a/compiler/rustc_codegen_llvm/src/llvm/ffi.rs b/compiler/rustc_codegen_llvm/src/llvm/ffi.rs
index 5fad7583e1a..8508f87c8d3 100644
--- a/compiler/rustc_codegen_llvm/src/llvm/ffi.rs
+++ b/compiler/rustc_codegen_llvm/src/llvm/ffi.rs
@@ -1765,11 +1765,13 @@ unsafe extern "C" {
     /// Returns a string describing the last error caused by an LLVMRust* call.
     pub fn LLVMRustGetLastError() -> *const c_char;
 
-    /// Print the pass timings since static dtors aren't picking them up.
-    pub fn LLVMRustPrintPassTimings(size: *const size_t) -> *const c_char;
+    /// Prints the timing information collected by `-Ztime-llvm-passes`.
+    #[expect(improper_ctypes)]
+    pub(crate) fn LLVMRustPrintPassTimings(OutStr: &RustString);
 
-    /// Print the statistics since static dtors aren't picking them up.
-    pub fn LLVMRustPrintStatistics(size: *const size_t) -> *const c_char;
+    /// Prints the statistics collected by `-Zprint-codegen-stats`.
+    #[expect(improper_ctypes)]
+    pub(crate) fn LLVMRustPrintStatistics(OutStr: &RustString);
 
     /// Prepares inline assembly.
     pub fn LLVMRustInlineAsm(
@@ -1790,7 +1792,7 @@ unsafe extern "C" {
     ) -> bool;
 
     #[allow(improper_ctypes)]
-    pub(crate) fn LLVMRustCoverageWriteFilenamesSectionToBuffer(
+    pub(crate) fn LLVMRustCoverageWriteFilenamesToBuffer(
         Filenames: *const *const c_char,
         FilenamesLen: size_t,
         Lengths: *const size_t,
@@ -1799,19 +1801,19 @@ unsafe extern "C" {
     );
 
     #[allow(improper_ctypes)]
-    pub(crate) fn LLVMRustCoverageWriteMappingToBuffer(
+    pub(crate) fn LLVMRustCoverageWriteFunctionMappingsToBuffer(
         VirtualFileMappingIDs: *const c_uint,
-        NumVirtualFileMappingIDs: c_uint,
+        NumVirtualFileMappingIDs: size_t,
         Expressions: *const crate::coverageinfo::ffi::CounterExpression,
-        NumExpressions: c_uint,
+        NumExpressions: size_t,
         CodeRegions: *const crate::coverageinfo::ffi::CodeRegion,
-        NumCodeRegions: c_uint,
+        NumCodeRegions: size_t,
         BranchRegions: *const crate::coverageinfo::ffi::BranchRegion,
-        NumBranchRegions: c_uint,
+        NumBranchRegions: size_t,
         MCDCBranchRegions: *const crate::coverageinfo::ffi::MCDCBranchRegion,
-        NumMCDCBranchRegions: c_uint,
+        NumMCDCBranchRegions: size_t,
         MCDCDecisionRegions: *const crate::coverageinfo::ffi::MCDCDecisionRegion,
-        NumMCDCDecisionRegions: c_uint,
+        NumMCDCDecisionRegions: size_t,
         BufferOut: &RustString,
     );
 
@@ -1820,16 +1822,16 @@ unsafe extern "C" {
         FuncName: *const c_char,
         FuncNameLen: size_t,
     ) -> &Value;
-    pub(crate) fn LLVMRustCoverageHashByteArray(Bytes: *const c_char, NumBytes: size_t) -> u64;
+    pub(crate) fn LLVMRustCoverageHashBytes(Bytes: *const c_char, NumBytes: size_t) -> u64;
 
     #[allow(improper_ctypes)]
-    pub(crate) fn LLVMRustCoverageWriteMapSectionNameToString(M: &Module, Str: &RustString);
+    pub(crate) fn LLVMRustCoverageWriteCovmapSectionNameToString(M: &Module, OutStr: &RustString);
 
     #[allow(improper_ctypes)]
-    pub(crate) fn LLVMRustCoverageWriteFuncSectionNameToString(M: &Module, Str: &RustString);
+    pub(crate) fn LLVMRustCoverageWriteCovfunSectionNameToString(M: &Module, OutStr: &RustString);
 
     #[allow(improper_ctypes)]
-    pub(crate) fn LLVMRustCoverageWriteMappingVarNameToString(Str: &RustString);
+    pub(crate) fn LLVMRustCoverageWriteCovmapVarNameToString(OutStr: &RustString);
 
     pub(crate) fn LLVMRustCoverageMappingVersion() -> u32;
     pub fn LLVMRustDebugMetadataVersion() -> u32;
@@ -2190,12 +2192,8 @@ unsafe extern "C" {
 
     pub fn LLVMRustHasFeature(T: &TargetMachine, s: *const c_char) -> bool;
 
-    pub fn LLVMRustPrintTargetCPUs(
-        T: &TargetMachine,
-        cpu: *const c_char,
-        print: unsafe extern "C" fn(out: *mut c_void, string: *const c_char, len: usize),
-        out: *mut c_void,
-    );
+    #[allow(improper_ctypes)]
+    pub(crate) fn LLVMRustPrintTargetCPUs(TM: &TargetMachine, OutStr: &RustString);
     pub fn LLVMRustGetTargetFeaturesCount(T: &TargetMachine) -> size_t;
     pub fn LLVMRustGetTargetFeature(
         T: &TargetMachine,
@@ -2204,7 +2202,7 @@ unsafe extern "C" {
         Desc: &mut *const c_char,
     );
 
-    pub fn LLVMRustGetHostCPUName(len: *mut usize) -> *const c_char;
+    pub fn LLVMRustGetHostCPUName(LenOut: &mut size_t) -> *const u8;
 
     // This function makes copies of pointed to data, so the data's lifetime may end after this
     // function returns.
diff --git a/compiler/rustc_codegen_llvm/src/llvm/mod.rs b/compiler/rustc_codegen_llvm/src/llvm/mod.rs
index 00a5cd3b859..3b0bf47366e 100644
--- a/compiler/rustc_codegen_llvm/src/llvm/mod.rs
+++ b/compiler/rustc_codegen_llvm/src/llvm/mod.rs
@@ -8,8 +8,8 @@ use std::str::FromStr;
 use std::string::FromUtf8Error;
 
 use libc::c_uint;
+use rustc_abi::{Align, Size, WrappingRange};
 use rustc_llvm::RustString;
-use rustc_target::abi::{Align, Size, WrappingRange};
 
 pub use self::AtomicRmwBinOp::*;
 pub use self::CallConv::*;
diff --git a/compiler/rustc_codegen_llvm/src/llvm_util.rs b/compiler/rustc_codegen_llvm/src/llvm_util.rs
index 9adb1299b3d..6f2d86cc601 100644
--- a/compiler/rustc_codegen_llvm/src/llvm_util.rs
+++ b/compiler/rustc_codegen_llvm/src/llvm_util.rs
@@ -1,4 +1,5 @@
-use std::ffi::{CStr, CString, c_char, c_void};
+use std::collections::VecDeque;
+use std::ffi::{CStr, CString};
 use std::fmt::Write;
 use std::path::Path;
 use std::sync::Once;
@@ -16,12 +17,12 @@ use rustc_session::Session;
 use rustc_session::config::{PrintKind, PrintRequest};
 use rustc_span::symbol::Symbol;
 use rustc_target::spec::{MergeFunctions, PanicStrategy, SmallDataThresholdSupport};
-use rustc_target::target_features::{RUSTC_SPECIAL_FEATURES, RUSTC_SPECIFIC_FEATURES};
+use rustc_target::target_features::{RUSTC_SPECIAL_FEATURES, RUSTC_SPECIFIC_FEATURES, Stability};
 
 use crate::back::write::create_informational_target_machine;
 use crate::errors::{
-    FixedX18InvalidArch, InvalidTargetFeaturePrefix, PossibleFeature, UnknownCTargetFeature,
-    UnknownCTargetFeaturePrefix, UnstableCTargetFeature,
+    FixedX18InvalidArch, ForbiddenCTargetFeature, InvalidTargetFeaturePrefix, PossibleFeature,
+    UnknownCTargetFeature, UnknownCTargetFeaturePrefix, UnstableCTargetFeature,
 };
 use crate::llvm;
 
@@ -276,23 +277,36 @@ pub(crate) fn to_llvm_features<'a>(sess: &Session, s: &'a str) -> Option<LLVMFea
         ("x86", s) if s.starts_with("avx512") => {
             Some(LLVMFeature::with_dependency(s, TargetFeatureFoldStrength::EnableOnly("evex512")))
         }
+        // Support for `wide-arithmetic` will first land in LLVM 20 as part of
+        // llvm/llvm-project#111598
+        ("wasm32" | "wasm64", "wide-arithmetic") if get_version() < (20, 0, 0) => None,
         (_, s) => Some(LLVMFeature::new(s)),
     }
 }
 
-/// Used to generate cfg variables and apply features
-/// Must express features in the way Rust understands them
+/// Used to generate cfg variables and apply features.
+/// Must express features in the way Rust understands them.
+///
+/// We do not have to worry about RUSTC_SPECIFIC_FEATURES here, those are handled outside codegen.
 pub fn target_features(sess: &Session, allow_unstable: bool) -> Vec<Symbol> {
-    let mut features = vec![];
-
-    // Add base features for the target
+    let mut features: FxHashSet<Symbol> = Default::default();
+
+    // Add base features for the target.
+    // We do *not* add the -Ctarget-features there, and instead duplicate the logic for that below.
+    // The reason is that if LLVM considers a feature implied but we do not, we don't want that to
+    // show up in `cfg`. That way, `cfg` is entirely under our control -- except for the handling of
+    // the target CPU, that is still expanded to target features (with all their implied features) by
+    // LLVM.
     let target_machine = create_informational_target_machine(sess, true);
+    // Compute which of the known target features are enabled in the 'base' target machine.
+    // We only consider "supported" features; "forbidden" features are not reflected in `cfg` as of now.
     features.extend(
         sess.target
-            .supported_target_features()
+            .rust_target_features()
             .iter()
+            .filter(|(_, gate, _)| gate.is_supported())
             .filter(|(feature, _, _)| {
-                // skip checking special features, as LLVM may not understands them
+                // skip checking special features, as LLVM may not understand them
                 if RUSTC_SPECIAL_FEATURES.contains(feature) {
                     return true;
                 }
@@ -323,7 +337,12 @@ pub fn target_features(sess: &Session, allow_unstable: bool) -> Vec<Symbol> {
         if enabled {
             features.extend(sess.target.implied_target_features(std::iter::once(feature)));
         } else {
+            // We don't care about the order in `features` since the only thing we use it for is the
+            // `features.contains` below.
+            #[allow(rustc::potential_query_instability)]
             features.retain(|f| {
+                // Keep a feature if it does not imply `feature`. Or, equivalently,
+                // remove the reverse-dependencies of `feature`.
                 !sess.target.implied_target_features(std::iter::once(*f)).contains(&feature)
             });
         }
@@ -331,8 +350,9 @@ pub fn target_features(sess: &Session, allow_unstable: bool) -> Vec<Symbol> {
 
     // Filter enabled features based on feature gates
     sess.target
-        .supported_target_features()
+        .rust_target_features()
         .iter()
+        .filter(|(_, gate, _)| gate.is_supported())
         .filter_map(|&(feature, gate, _)| {
             if sess.is_nightly_build() || allow_unstable || gate.is_stable() {
                 Some(feature)
@@ -387,14 +407,76 @@ fn llvm_target_features(tm: &llvm::TargetMachine) -> Vec<(&str, &str)> {
     ret
 }
 
-fn print_target_features(out: &mut String, sess: &Session, tm: &llvm::TargetMachine) {
+pub(crate) fn print(req: &PrintRequest, out: &mut String, sess: &Session) {
+    require_inited();
+    let tm = create_informational_target_machine(sess, false);
+    match req.kind {
+        PrintKind::TargetCPUs => print_target_cpus(sess, &tm, out),
+        PrintKind::TargetFeatures => print_target_features(sess, &tm, out),
+        _ => bug!("rustc_codegen_llvm can't handle print request: {:?}", req),
+    }
+}
+
+fn print_target_cpus(sess: &Session, tm: &llvm::TargetMachine, out: &mut String) {
+    let cpu_names = llvm::build_string(|s| unsafe {
+        llvm::LLVMRustPrintTargetCPUs(&tm, s);
+    })
+    .unwrap();
+
+    struct Cpu<'a> {
+        cpu_name: &'a str,
+        remark: String,
+    }
+    // Compare CPU against current target to label the default.
+    let target_cpu = handle_native(&sess.target.cpu);
+    let make_remark = |cpu_name| {
+        if cpu_name == target_cpu {
+            // FIXME(#132514): This prints the LLVM target string, which can be
+            // different from the Rust target string. Is that intended?
+            let target = &sess.target.llvm_target;
+            format!(
+                " - This is the default target CPU for the current build target (currently {target})."
+            )
+        } else {
+            "".to_owned()
+        }
+    };
+    let mut cpus = cpu_names
+        .lines()
+        .map(|cpu_name| Cpu { cpu_name, remark: make_remark(cpu_name) })
+        .collect::<VecDeque<_>>();
+
+    // Only print the "native" entry when host and target are the same arch,
+    // since otherwise it could be wrong or misleading.
+    if sess.host.arch == sess.target.arch {
+        let host = get_host_cpu_name();
+        cpus.push_front(Cpu {
+            cpu_name: "native",
+            remark: format!(" - Select the CPU of the current host (currently {host})."),
+        });
+    }
+
+    let max_name_width = cpus.iter().map(|cpu| cpu.cpu_name.len()).max().unwrap_or(0);
+    writeln!(out, "Available CPUs for this target:").unwrap();
+    for Cpu { cpu_name, remark } in cpus {
+        // Only pad the CPU name if there's a remark to print after it.
+        let width = if remark.is_empty() { 0 } else { max_name_width };
+        writeln!(out, "    {cpu_name:<width$}{remark}").unwrap();
+    }
+}
+
+fn print_target_features(sess: &Session, tm: &llvm::TargetMachine, out: &mut String) {
     let mut llvm_target_features = llvm_target_features(tm);
     let mut known_llvm_target_features = FxHashSet::<&'static str>::default();
     let mut rustc_target_features = sess
         .target
-        .supported_target_features()
+        .rust_target_features()
         .iter()
-        .filter_map(|(feature, _gate, _implied)| {
+        .filter_map(|(feature, gate, _implied)| {
+            if !gate.is_supported() {
+                // Only list (experimentally) supported features.
+                return None;
+            }
             // LLVM asserts that these are sorted. LLVM and Rust both use byte comparison for these
             // strings.
             let llvm_feature = to_llvm_features(sess, *feature)?.llvm_feature_name;
@@ -447,52 +529,31 @@ fn print_target_features(out: &mut String, sess: &Session, tm: &llvm::TargetMach
     writeln!(out, "and may be renamed or removed in a future version of LLVM or rustc.\n").unwrap();
 }
 
-pub(crate) fn print(req: &PrintRequest, mut out: &mut String, sess: &Session) {
-    require_inited();
-    let tm = create_informational_target_machine(sess, false);
-    match req.kind {
-        PrintKind::TargetCPUs => {
-            // SAFETY generate a C compatible string from a byte slice to pass
-            // the target CPU name into LLVM, the lifetime of the reference is
-            // at least as long as the C function
-            let cpu_cstring = CString::new(handle_native(sess.target.cpu.as_ref()))
-                .unwrap_or_else(|e| bug!("failed to convert to cstring: {}", e));
-            unsafe extern "C" fn callback(out: *mut c_void, string: *const c_char, len: usize) {
-                let out = unsafe { &mut *(out as *mut &mut String) };
-                let bytes = unsafe { slice::from_raw_parts(string as *const u8, len) };
-                write!(out, "{}", String::from_utf8_lossy(bytes)).unwrap();
-            }
-            unsafe {
-                llvm::LLVMRustPrintTargetCPUs(
-                    &tm,
-                    cpu_cstring.as_ptr(),
-                    callback,
-                    (&raw mut out) as *mut c_void,
-                );
-            }
-        }
-        PrintKind::TargetFeatures => print_target_features(out, sess, &tm),
-        _ => bug!("rustc_codegen_llvm can't handle print request: {:?}", req),
-    }
+/// Returns the host CPU name, according to LLVM.
+fn get_host_cpu_name() -> &'static str {
+    let mut len = 0;
+    // SAFETY: The underlying C++ global function returns a `StringRef` that
+    // isn't tied to any particular backing buffer, so it must be 'static.
+    let slice: &'static [u8] = unsafe {
+        let ptr = llvm::LLVMRustGetHostCPUName(&mut len);
+        assert!(!ptr.is_null());
+        slice::from_raw_parts(ptr, len)
+    };
+    str::from_utf8(slice).expect("host CPU name should be UTF-8")
 }
 
-fn handle_native(name: &str) -> &str {
-    if name != "native" {
-        return name;
-    }
-
-    unsafe {
-        let mut len = 0;
-        let ptr = llvm::LLVMRustGetHostCPUName(&mut len);
-        str::from_utf8(slice::from_raw_parts(ptr as *const u8, len)).unwrap()
+/// If the given string is `"native"`, returns the host CPU name according to
+/// LLVM. Otherwise, the string is returned as-is.
+fn handle_native(cpu_name: &str) -> &str {
+    match cpu_name {
+        "native" => get_host_cpu_name(),
+        _ => cpu_name,
     }
 }
 
 pub(crate) fn target_cpu(sess: &Session) -> &str {
-    match sess.opts.cg.target_cpu {
-        Some(ref name) => handle_native(name),
-        None => handle_native(sess.target.cpu.as_ref()),
-    }
+    let cpu_name = sess.opts.cg.target_cpu.as_deref().unwrap_or_else(|| &sess.target.cpu);
+    handle_native(cpu_name)
 }
 
 /// The list of LLVM features computed from CLI flags (`-Ctarget-cpu`, `-Ctarget-feature`,
@@ -567,7 +628,7 @@ pub(crate) fn global_llvm_features(
 
     // -Ctarget-features
     if !only_base_features {
-        let supported_features = sess.target.supported_target_features();
+        let known_features = sess.target.rust_target_features();
         let mut featsmap = FxHashMap::default();
 
         // insert implied features
@@ -601,50 +662,53 @@ pub(crate) fn global_llvm_features(
                     }
                 };
 
+                // Get the backend feature name, if any.
+                // This excludes rustc-specific features, which do not get passed to LLVM.
                 let feature = backend_feature_name(sess, s)?;
                 // Warn against use of LLVM specific feature names and unstable features on the CLI.
                 if diagnostics {
-                    let feature_state = supported_features.iter().find(|&&(v, _, _)| v == feature);
-                    if feature_state.is_none() {
-                        let rust_feature =
-                            supported_features.iter().find_map(|&(rust_feature, _, _)| {
-                                let llvm_features = to_llvm_features(sess, rust_feature)?;
-                                if llvm_features.contains(feature)
-                                    && !llvm_features.contains(rust_feature)
-                                {
-                                    Some(rust_feature)
-                                } else {
-                                    None
+                    let feature_state = known_features.iter().find(|&&(v, _, _)| v == feature);
+                    match feature_state {
+                        None => {
+                            let rust_feature =
+                                known_features.iter().find_map(|&(rust_feature, _, _)| {
+                                    let llvm_features = to_llvm_features(sess, rust_feature)?;
+                                    if llvm_features.contains(feature)
+                                        && !llvm_features.contains(rust_feature)
+                                    {
+                                        Some(rust_feature)
+                                    } else {
+                                        None
+                                    }
+                                });
+                            let unknown_feature = if let Some(rust_feature) = rust_feature {
+                                UnknownCTargetFeature {
+                                    feature,
+                                    rust_feature: PossibleFeature::Some { rust_feature },
                                 }
-                            });
-                        let unknown_feature = if let Some(rust_feature) = rust_feature {
-                            UnknownCTargetFeature {
-                                feature,
-                                rust_feature: PossibleFeature::Some { rust_feature },
-                            }
-                        } else {
-                            UnknownCTargetFeature { feature, rust_feature: PossibleFeature::None }
-                        };
-                        sess.dcx().emit_warn(unknown_feature);
-                    } else if feature_state
-                        .is_some_and(|(_name, feature_gate, _implied)| !feature_gate.is_stable())
-                    {
-                        // An unstable feature. Warn about using it.
-                        sess.dcx().emit_warn(UnstableCTargetFeature { feature });
+                            } else {
+                                UnknownCTargetFeature {
+                                    feature,
+                                    rust_feature: PossibleFeature::None,
+                                }
+                            };
+                            sess.dcx().emit_warn(unknown_feature);
+                        }
+                        Some((_, Stability::Stable, _)) => {}
+                        Some((_, Stability::Unstable(_), _)) => {
+                            // An unstable feature. Warn about using it.
+                            sess.dcx().emit_warn(UnstableCTargetFeature { feature });
+                        }
+                        Some((_, Stability::Forbidden { reason }, _)) => {
+                            sess.dcx().emit_warn(ForbiddenCTargetFeature { feature, reason });
+                        }
                     }
-                }
 
-                if diagnostics {
                     // FIXME(nagisa): figure out how to not allocate a full hashset here.
                     featsmap.insert(feature, enable_disable == '+');
                 }
 
-                // rustc-specific features do not get passed down to LLVM…
-                if RUSTC_SPECIFIC_FEATURES.contains(&feature) {
-                    return None;
-                }
-
-                // ... otherwise though we run through `to_llvm_features` when
+                // We run through `to_llvm_features` when
                 // passing requests down to LLVM. This means that all in-language
                 // features also work on the command line instead of having two
                 // different names when the LLVM name and the Rust name differ.
diff --git a/compiler/rustc_codegen_llvm/src/type_.rs b/compiler/rustc_codegen_llvm/src/type_.rs
index f1efc7a3dac..6aec078e0de 100644
--- a/compiler/rustc_codegen_llvm/src/type_.rs
+++ b/compiler/rustc_codegen_llvm/src/type_.rs
@@ -1,14 +1,14 @@
 use std::{fmt, ptr};
 
 use libc::{c_char, c_uint};
+use rustc_abi::{AddressSpace, Align, Integer, Size};
 use rustc_codegen_ssa::common::TypeKind;
 use rustc_codegen_ssa::traits::*;
 use rustc_data_structures::small_c_str::SmallCStr;
 use rustc_middle::bug;
 use rustc_middle::ty::layout::TyAndLayout;
 use rustc_middle::ty::{self, Ty};
-use rustc_target::abi::call::{CastTarget, FnAbi, Reg};
-use rustc_target::abi::{AddressSpace, Align, Integer, Size};
+use rustc_target::callconv::{CastTarget, FnAbi, Reg};
 
 use crate::abi::{FnAbiLlvmExt, LlvmType};
 use crate::context::CodegenCx;
diff --git a/compiler/rustc_codegen_llvm/src/va_arg.rs b/compiler/rustc_codegen_llvm/src/va_arg.rs
index f12b94d5887..e4c3e748cb5 100644
--- a/compiler/rustc_codegen_llvm/src/va_arg.rs
+++ b/compiler/rustc_codegen_llvm/src/va_arg.rs
@@ -1,9 +1,9 @@
+use rustc_abi::{Align, Endian, HasDataLayout, Size};
 use rustc_codegen_ssa::common::IntPredicate;
 use rustc_codegen_ssa::mir::operand::OperandRef;
 use rustc_codegen_ssa::traits::{BaseTypeCodegenMethods, BuilderMethods, ConstCodegenMethods};
 use rustc_middle::ty::Ty;
 use rustc_middle::ty::layout::{HasTyCtxt, LayoutOf};
-use rustc_target::abi::{Align, Endian, HasDataLayout, Size};
 
 use crate::builder::Builder;
 use crate::type_::Type;