Don't use an allocator shim for #[global_allocator]

This makes it possible to use liballoc/libstd in combination with
`--emit obj` if you use `#[global_allocator]`. Making it work for the
default libstd allocator would require weak functions, which are not
well supported on all systems.
This commit is contained in:
bjorn3 2021-07-03 16:46:41 +02:00 committed by bjorn3
parent 59177fcb60
commit 35836b326b

View File

@ -1,11 +1,12 @@
#[cfg(feature="master")]
use gccjit::FnAttribute;
use gccjit::{FunctionType, GlobalKind, ToRValue};
use rustc_ast::expand::allocator::{AllocatorKind, AllocatorTy, ALLOCATOR_METHODS};
use rustc_ast::expand::allocator::{
alloc_error_handler_name, AllocatorKind, AllocatorTy, ALLOCATOR_METHODS,
};
use rustc_middle::bug;
use rustc_middle::ty::TyCtxt;
use rustc_session::config::OomStrategy;
use rustc_span::symbol::sym;
use crate::GccContext;
@ -22,69 +23,71 @@ pub(crate) unsafe fn codegen(tcx: TyCtxt<'_>, mods: &mut GccContext, _module_nam
let i8p = i8.make_pointer();
let void = context.new_type::<()>();
for method in ALLOCATOR_METHODS {
let mut types = Vec::with_capacity(method.inputs.len());
for ty in method.inputs.iter() {
match *ty {
AllocatorTy::Layout => {
types.push(usize);
types.push(usize);
if kind == AllocatorKind::Default {
for method in ALLOCATOR_METHODS {
let mut types = Vec::with_capacity(method.inputs.len());
for ty in method.inputs.iter() {
match *ty {
AllocatorTy::Layout => {
types.push(usize);
types.push(usize);
}
AllocatorTy::Ptr => types.push(i8p),
AllocatorTy::Usize => types.push(usize),
AllocatorTy::ResultPtr | AllocatorTy::Unit => panic!("invalid allocator arg"),
}
AllocatorTy::Ptr => types.push(i8p),
AllocatorTy::Usize => types.push(usize),
AllocatorTy::ResultPtr | AllocatorTy::Unit => panic!("invalid allocator arg"),
}
}
let output = match method.output {
AllocatorTy::ResultPtr => Some(i8p),
AllocatorTy::Unit => None,
let output = match method.output {
AllocatorTy::ResultPtr => Some(i8p),
AllocatorTy::Unit => None,
AllocatorTy::Layout | AllocatorTy::Usize | AllocatorTy::Ptr => {
panic!("invalid allocator output")
AllocatorTy::Layout | AllocatorTy::Usize | AllocatorTy::Ptr => {
panic!("invalid allocator output")
}
};
let name = format!("__rust_{}", method.name);
let args: Vec<_> = types.iter().enumerate()
.map(|(index, typ)| context.new_parameter(None, *typ, &format!("param{}", index)))
.collect();
let func = context.new_function(None, FunctionType::Exported, output.unwrap_or(void), &args, name, false);
if tcx.sess.target.options.default_hidden_visibility {
#[cfg(feature="master")]
func.add_attribute(FnAttribute::Visibility(gccjit::Visibility::Hidden));
}
if tcx.sess.must_emit_unwind_tables() {
// TODO(antoyo): emit unwind tables.
}
};
let name = format!("__rust_{}", method.name);
let args: Vec<_> = types.iter().enumerate()
.map(|(index, typ)| context.new_parameter(None, *typ, &format!("param{}", index)))
.collect();
let func = context.new_function(None, FunctionType::Exported, output.unwrap_or(void), &args, name, false);
if tcx.sess.target.options.default_hidden_visibility {
let callee = AllocatorKind::Default.fn_name(method.name);
let args: Vec<_> = types.iter().enumerate()
.map(|(index, typ)| context.new_parameter(None, *typ, &format!("param{}", index)))
.collect();
let callee = context.new_function(None, FunctionType::Extern, output.unwrap_or(void), &args, callee, false);
#[cfg(feature="master")]
func.add_attribute(FnAttribute::Visibility(gccjit::Visibility::Hidden));
}
if tcx.sess.must_emit_unwind_tables() {
// TODO(antoyo): emit unwind tables.
}
callee.add_attribute(FnAttribute::Visibility(gccjit::Visibility::Hidden));
let callee = kind.fn_name(method.name);
let args: Vec<_> = types.iter().enumerate()
.map(|(index, typ)| context.new_parameter(None, *typ, &format!("param{}", index)))
.collect();
let callee = context.new_function(None, FunctionType::Extern, output.unwrap_or(void), &args, callee, false);
#[cfg(feature="master")]
callee.add_attribute(FnAttribute::Visibility(gccjit::Visibility::Hidden));
let block = func.new_block("entry");
let block = func.new_block("entry");
let args = args
.iter()
.enumerate()
.map(|(i, _)| func.get_param(i as i32).to_rvalue())
.collect::<Vec<_>>();
let ret = context.new_call(None, callee, &args);
//llvm::LLVMSetTailCall(ret, True);
if output.is_some() {
block.end_with_return(None, ret);
}
else {
block.end_with_void_return(None);
}
let args = args
.iter()
.enumerate()
.map(|(i, _)| func.get_param(i as i32).to_rvalue())
.collect::<Vec<_>>();
let ret = context.new_call(None, callee, &args);
//llvm::LLVMSetTailCall(ret, True);
if output.is_some() {
block.end_with_return(None, ret);
// TODO(@Commeownist): Check if we need to emit some extra debugging info in certain circumstances
// as described in https://github.com/rust-lang/rust/commit/77a96ed5646f7c3ee8897693decc4626fe380643
}
else {
block.end_with_void_return(None);
}
// TODO(@Commeownist): Check if we need to emit some extra debugging info in certain circumstances
// as described in https://github.com/rust-lang/rust/commit/77a96ed5646f7c3ee8897693decc4626fe380643
}
let types = [usize, usize];
@ -99,7 +102,7 @@ pub(crate) unsafe fn codegen(tcx: TyCtxt<'_>, mods: &mut GccContext, _module_nam
func.add_attribute(FnAttribute::Visibility(gccjit::Visibility::Hidden));
}
let callee = alloc_error_handler_kind.fn_name(sym::oom);
let callee = alloc_error_handler_name(alloc_error_handler_kind);
let args: Vec<_> = types.iter().enumerate()
.map(|(index, typ)| context.new_parameter(None, *typ, &format!("param{}", index)))
.collect();