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|
use libc::c_uint;
use rustc_ast::expand::allocator::{
ALLOCATOR_METHODS, AllocatorKind, AllocatorTy, NO_ALLOC_SHIM_IS_UNSTABLE,
alloc_error_handler_name, default_fn_name, global_fn_name,
};
use rustc_codegen_ssa::traits::BaseTypeCodegenMethods as _;
use rustc_middle::bug;
use rustc_middle::ty::TyCtxt;
use rustc_session::config::{DebugInfo, OomStrategy};
use rustc_symbol_mangling::mangle_internal_symbol;
use crate::builder::SBuilder;
use crate::declare::declare_simple_fn;
use crate::llvm::{self, False, True, Type, Value};
use crate::{SimpleCx, attributes, debuginfo};
pub(crate) unsafe fn codegen(
tcx: TyCtxt<'_>,
cx: SimpleCx<'_>,
module_name: &str,
kind: AllocatorKind,
alloc_error_handler_kind: AllocatorKind,
) {
let usize = match tcx.sess.target.pointer_width {
16 => cx.type_i16(),
32 => cx.type_i32(),
64 => cx.type_i64(),
tws => bug!("Unsupported target word size for int: {}", tws),
};
let i8 = cx.type_i8();
let i8p = cx.type_ptr();
if kind == AllocatorKind::Default {
for method in ALLOCATOR_METHODS {
let mut args = Vec::with_capacity(method.inputs.len());
for input in method.inputs.iter() {
match input.ty {
AllocatorTy::Layout => {
args.push(usize); // size
args.push(usize); // align
}
AllocatorTy::Ptr => args.push(i8p),
AllocatorTy::Usize => args.push(usize),
AllocatorTy::ResultPtr | AllocatorTy::Unit => panic!("invalid allocator arg"),
}
}
let output = match method.output {
AllocatorTy::ResultPtr => Some(i8p),
AllocatorTy::Unit => None,
AllocatorTy::Layout | AllocatorTy::Usize | AllocatorTy::Ptr => {
panic!("invalid allocator output")
}
};
let from_name = mangle_internal_symbol(tcx, &global_fn_name(method.name));
let to_name = mangle_internal_symbol(tcx, &default_fn_name(method.name));
create_wrapper_function(tcx, &cx, &from_name, Some(&to_name), &args, output, false);
}
}
// rust alloc error handler
create_wrapper_function(
tcx,
&cx,
&mangle_internal_symbol(tcx, "__rust_alloc_error_handler"),
Some(&mangle_internal_symbol(tcx, alloc_error_handler_name(alloc_error_handler_kind))),
&[usize, usize], // size, align
None,
true,
);
unsafe {
// __rust_alloc_error_handler_should_panic_v2
create_const_value_function(
tcx,
&cx,
&mangle_internal_symbol(tcx, OomStrategy::SYMBOL),
&i8,
&llvm::LLVMConstInt(i8, tcx.sess.opts.unstable_opts.oom.should_panic() as u64, False),
);
// __rust_no_alloc_shim_is_unstable_v2
create_wrapper_function(
tcx,
&cx,
&mangle_internal_symbol(tcx, NO_ALLOC_SHIM_IS_UNSTABLE),
None,
&[],
None,
false,
);
}
if tcx.sess.opts.debuginfo != DebugInfo::None {
let dbg_cx = debuginfo::CodegenUnitDebugContext::new(cx.llmod);
debuginfo::metadata::build_compile_unit_di_node(tcx, module_name, &dbg_cx);
dbg_cx.finalize(tcx.sess);
}
}
fn create_const_value_function(
tcx: TyCtxt<'_>,
cx: &SimpleCx<'_>,
name: &str,
output: &Type,
value: &Value,
) {
let ty = cx.type_func(&[], output);
let llfn = declare_simple_fn(
&cx,
name,
llvm::CallConv::CCallConv,
llvm::UnnamedAddr::Global,
llvm::Visibility::from_generic(tcx.sess.default_visibility()),
ty,
);
attributes::apply_to_llfn(
llfn,
llvm::AttributePlace::Function,
&[llvm::AttributeKind::AlwaysInline.create_attr(cx.llcx)],
);
let llbb = unsafe { llvm::LLVMAppendBasicBlockInContext(cx.llcx, llfn, c"entry".as_ptr()) };
let mut bx = SBuilder::build(&cx, llbb);
bx.ret(value);
}
fn create_wrapper_function(
tcx: TyCtxt<'_>,
cx: &SimpleCx<'_>,
from_name: &str,
to_name: Option<&str>,
args: &[&Type],
output: Option<&Type>,
no_return: bool,
) {
let ty = cx.type_func(args, output.unwrap_or_else(|| cx.type_void()));
let llfn = declare_simple_fn(
&cx,
from_name,
llvm::CallConv::CCallConv,
llvm::UnnamedAddr::Global,
llvm::Visibility::from_generic(tcx.sess.default_visibility()),
ty,
);
let no_return = if no_return {
// -> ! DIFlagNoReturn
let no_return = llvm::AttributeKind::NoReturn.create_attr(cx.llcx);
attributes::apply_to_llfn(llfn, llvm::AttributePlace::Function, &[no_return]);
Some(no_return)
} else {
None
};
if tcx.sess.must_emit_unwind_tables() {
let uwtable =
attributes::uwtable_attr(cx.llcx, tcx.sess.opts.unstable_opts.use_sync_unwind);
attributes::apply_to_llfn(llfn, llvm::AttributePlace::Function, &[uwtable]);
}
let llbb = unsafe { llvm::LLVMAppendBasicBlockInContext(cx.llcx, llfn, c"entry".as_ptr()) };
let mut bx = SBuilder::build(&cx, llbb);
if let Some(to_name) = to_name {
let callee = declare_simple_fn(
&cx,
to_name,
llvm::CallConv::CCallConv,
llvm::UnnamedAddr::Global,
llvm::Visibility::Hidden,
ty,
);
if let Some(no_return) = no_return {
// -> ! DIFlagNoReturn
attributes::apply_to_llfn(callee, llvm::AttributePlace::Function, &[no_return]);
}
llvm::set_visibility(callee, llvm::Visibility::Hidden);
let args = args
.iter()
.enumerate()
.map(|(i, _)| llvm::get_param(llfn, i as c_uint))
.collect::<Vec<_>>();
let ret = bx.call(ty, callee, &args, None);
llvm::LLVMSetTailCall(ret, True);
if output.is_some() {
bx.ret(ret);
} else {
bx.ret_void()
}
} else {
assert!(output.is_none());
bx.ret_void()
}
}
|
