rust-lang/rust
1
0
Fork 0
Code Issues Pull Requests Actions 1 Packages Projects Releases Wiki Activity

Rollup merge of #145420 - Zalathar:llvm-c, r=WaffleLapkin

Browse Source 
cg_llvm: Use LLVM-C bindings for `LLVMSetTailCallKind`, `LLVMGetTypeKind`

This PR replaces two existing `LLVMRust` bindings with equivalent calls to the LLVM-C API.

For `LLVMGetTypeKind`, we avoid the UB hazard by declaring the foreign function to return `RawEnum<TypeKind>` (which is a wrapper around `u32`), and then perform checked conversion from `u32` to `TypeKind`.
This commit is contained in:
Stuart Cook
2025-08-18 15:31:12 +10:00
committed by GitHub
parent 3a694c7595 e193b5342b
commit aa2dcbe583
4 changed files with 14 additions and 89 deletions
Download Patch File Download Diff File Expand all files Collapse all files

19
compiler/rustc_codegen_llvm/src/llvm/ffi.rs
View File

@@ -97,6 +97,7 @@ pub(crate) enum ModuleFlagMergeBehavior {
// Consts for the LLVM CallConv type, pre-cast to usize.
/// Must match the layout of `LLVMTailCallKind`.
#[derive(Copy, Clone, PartialEq, Debug)]
#[repr(C)]
#[allow(dead_code)]
@@ -332,10 +333,15 @@ impl RealPredicate {
}
}
/// LLVMTypeKind
#[derive(Copy, Clone, PartialEq, Debug)]
/// Must match the layout of `LLVMTypeKind`.
///
/// Use [`RawEnum<TypeKind>`] for values of `LLVMTypeKind` returned from LLVM,
/// to avoid risk of UB if LLVM adds new enum values.
///
/// All of LLVM's variants should be declared here, even if no Rust-side code refers
/// to them, because unknown variants will cause [`RawEnum::to_rust`] to panic.
#[derive(Copy, Clone, PartialEq, Debug, TryFromU32)]
#[repr(C)]
#[expect(dead_code, reason = "Some variants are unused, but are kept to match LLVM-C")]
pub(crate) enum TypeKind {
Void = 0,
Half = 1,
@@ -1046,6 +1052,8 @@ unsafe extern "C" {
CanThrow: llvm::Bool,
) -> &'ll Value;
pub(crate) safe fn LLVMGetTypeKind(Ty: &Type) -> RawEnum<TypeKind>;
// Operations on integer types
pub(crate) fn LLVMInt1TypeInContext(C: &Context) -> &Type;
pub(crate) fn LLVMInt8TypeInContext(C: &Context) -> &Type;
@@ -1197,7 +1205,7 @@ unsafe extern "C" {
pub(crate) safe fn LLVMIsGlobalConstant(GlobalVar: &Value) -> Bool;
pub(crate) safe fn LLVMSetGlobalConstant(GlobalVar: &Value, IsConstant: Bool);
pub(crate) safe fn LLVMSetTailCall(CallInst: &Value, IsTailCall: Bool);
pub(crate) safe fn LLVMRustSetTailCallKind(CallInst: &Value, Kind: TailCallKind);
pub(crate) safe fn LLVMSetTailCallKind(CallInst: &Value, kind: TailCallKind);
// Operations on attributes
pub(crate) fn LLVMCreateStringAttribute(
@@ -1841,9 +1849,6 @@ unsafe extern "C" {
// Create and destroy contexts.
pub(crate) fn LLVMRustContextCreate(shouldDiscardNames: bool) -> &'static mut Context;
/// See llvm::LLVMTypeKind::getTypeID.
pub(crate) fn LLVMRustGetTypeKind(Ty: &Type) -> TypeKind;
// Operations on all values
pub(crate) fn LLVMRustGlobalAddMetadata<'a>(
Val: &'a Value,