bjoernager/rust
bjoernager/rust
1
Fork 0
Code Activity

cg_llvm: Reuse LLVM-C Comdat support

Browse source 
Migrate `llvm::set_comdat` and `llvm::SetUniqueComdat` to LLVM-C FFI.

Note, now we can call `llvm::set_comdat` only when the target actually
supports adding comdat. As this has no convenient LLVM-C API, we
implement this as `TargetOptions::supports_comdat`.

Co-authored-by: Stuart Cook <Zalathar@users.noreply.github.com>
This commit is contained in:
Jubilee Young 2024-10-18 00:31:28 -07:00
parent 888efe74a3
commit 45d61b0d26
6 changed files with 32 additions and 10 deletions
Download patch file Download diff file Expand all files Collapse all files

5
compiler/rustc_codegen_llvm/src/llvm/ffi.rs
View file

@ -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);

17
compiler/rustc_codegen_llvm/src/llvm/mod.rs
View file

@ -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) {
@ -251,9 +251,14 @@ 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);
}
}