Extract a create_wrapper_function for use in allocator shim writing

This deduplicates some logic and makes it easier to follow what wrappers
are produced. In the future it may allow moving the code to determine
which wrappers to create to cg_ssa.
This commit is contained in:
bjorn3 2023-07-15 12:38:59 +00:00
parent 4f7bb9890c
commit 49ae3b7867

View File

@ -9,7 +9,7 @@ use rustc_middle::ty::TyCtxt;
use rustc_session::config::{DebugInfo, OomStrategy};
use crate::debuginfo;
use crate::llvm::{self, False, True};
use crate::llvm::{self, Context, False, Module, True, Type};
use crate::ModuleLlvm;
pub(crate) unsafe fn codegen(
@ -29,7 +29,6 @@ pub(crate) unsafe fn codegen(
};
let i8 = llvm::LLVMInt8TypeInContext(llcx);
let i8p = llvm::LLVMPointerTypeInContext(llcx, 0);
let void = llvm::LLVMVoidTypeInContext(llcx);
if kind == AllocatorKind::Default {
for method in ALLOCATOR_METHODS {
@ -54,102 +53,25 @@ pub(crate) unsafe fn codegen(
panic!("invalid allocator output")
}
};
let ty = llvm::LLVMFunctionType(
output.unwrap_or(void),
args.as_ptr(),
args.len() as c_uint,
False,
);
let name = global_fn_name(method.name);
let llfn =
llvm::LLVMRustGetOrInsertFunction(llmod, name.as_ptr().cast(), name.len(), ty);
if tcx.sess.target.default_hidden_visibility {
llvm::LLVMRustSetVisibility(llfn, llvm::Visibility::Hidden);
}
if tcx.sess.must_emit_unwind_tables() {
let uwtable = attributes::uwtable_attr(llcx);
attributes::apply_to_llfn(llfn, llvm::AttributePlace::Function, &[uwtable]);
}
let from_name = global_fn_name(method.name);
let to_name = default_fn_name(method.name);
let callee = default_fn_name(method.name);
let callee =
llvm::LLVMRustGetOrInsertFunction(llmod, callee.as_ptr().cast(), callee.len(), ty);
llvm::LLVMRustSetVisibility(callee, llvm::Visibility::Hidden);
let llbb = llvm::LLVMAppendBasicBlockInContext(llcx, llfn, "entry\0".as_ptr().cast());
let llbuilder = llvm::LLVMCreateBuilderInContext(llcx);
llvm::LLVMPositionBuilderAtEnd(llbuilder, llbb);
let args = args
.iter()
.enumerate()
.map(|(i, _)| llvm::LLVMGetParam(llfn, i as c_uint))
.collect::<Vec<_>>();
let ret = llvm::LLVMRustBuildCall(
llbuilder,
ty,
callee,
args.as_ptr(),
args.len() as c_uint,
[].as_ptr(),
0 as c_uint,
);
llvm::LLVMSetTailCall(ret, True);
if output.is_some() {
llvm::LLVMBuildRet(llbuilder, ret);
} else {
llvm::LLVMBuildRetVoid(llbuilder);
}
llvm::LLVMDisposeBuilder(llbuilder);
create_wrapper_function(tcx, llcx, llmod, &from_name, &to_name, &args, output, false);
}
}
// rust alloc error handler
let args = [usize, usize]; // size, align
let ty = llvm::LLVMFunctionType(void, args.as_ptr(), args.len() as c_uint, False);
let name = "__rust_alloc_error_handler";
let llfn = llvm::LLVMRustGetOrInsertFunction(llmod, name.as_ptr().cast(), name.len(), ty);
// -> ! DIFlagNoReturn
let no_return = llvm::AttributeKind::NoReturn.create_attr(llcx);
attributes::apply_to_llfn(llfn, llvm::AttributePlace::Function, &[no_return]);
if tcx.sess.target.default_hidden_visibility {
llvm::LLVMRustSetVisibility(llfn, llvm::Visibility::Hidden);
}
if tcx.sess.must_emit_unwind_tables() {
let uwtable = attributes::uwtable_attr(llcx);
attributes::apply_to_llfn(llfn, llvm::AttributePlace::Function, &[uwtable]);
}
let callee = alloc_error_handler_name(alloc_error_handler_kind);
let callee = llvm::LLVMRustGetOrInsertFunction(llmod, callee.as_ptr().cast(), callee.len(), ty);
// -> ! DIFlagNoReturn
attributes::apply_to_llfn(callee, llvm::AttributePlace::Function, &[no_return]);
llvm::LLVMRustSetVisibility(callee, llvm::Visibility::Hidden);
let llbb = llvm::LLVMAppendBasicBlockInContext(llcx, llfn, "entry\0".as_ptr().cast());
let llbuilder = llvm::LLVMCreateBuilderInContext(llcx);
llvm::LLVMPositionBuilderAtEnd(llbuilder, llbb);
let args = args
.iter()
.enumerate()
.map(|(i, _)| llvm::LLVMGetParam(llfn, i as c_uint))
.collect::<Vec<_>>();
let ret = llvm::LLVMRustBuildCall(
llbuilder,
ty,
callee,
args.as_ptr(),
args.len() as c_uint,
[].as_ptr(),
0 as c_uint,
create_wrapper_function(
tcx,
llcx,
llmod,
"__rust_alloc_error_handler",
&alloc_error_handler_name(alloc_error_handler_kind),
&[usize, usize], // size, align
None,
true,
);
llvm::LLVMSetTailCall(ret, True);
llvm::LLVMBuildRetVoid(llbuilder);
llvm::LLVMDisposeBuilder(llbuilder);
// __rust_alloc_error_handler_should_panic
let name = OomStrategy::SYMBOL;
@ -175,3 +97,79 @@ pub(crate) unsafe fn codegen(
dbg_cx.finalize(tcx.sess);
}
}
fn create_wrapper_function(
tcx: TyCtxt<'_>,
llcx: &Context,
llmod: &Module,
from_name: &str,
to_name: &str,
args: &[&Type],
output: Option<&Type>,
no_return: bool,
) {
unsafe {
let ty = llvm::LLVMFunctionType(
output.unwrap_or_else(|| llvm::LLVMVoidTypeInContext(llcx)),
args.as_ptr(),
args.len() as c_uint,
False,
);
let llfn = llvm::LLVMRustGetOrInsertFunction(
llmod,
from_name.as_ptr().cast(),
from_name.len(),
ty,
);
let no_return = if no_return {
// -> ! DIFlagNoReturn
let no_return = llvm::AttributeKind::NoReturn.create_attr(llcx);
attributes::apply_to_llfn(llfn, llvm::AttributePlace::Function, &[no_return]);
Some(no_return)
} else {
None
};
if tcx.sess.target.default_hidden_visibility {
llvm::LLVMRustSetVisibility(llfn, llvm::Visibility::Hidden);
}
if tcx.sess.must_emit_unwind_tables() {
let uwtable = attributes::uwtable_attr(llcx);
attributes::apply_to_llfn(llfn, llvm::AttributePlace::Function, &[uwtable]);
}
let callee =
llvm::LLVMRustGetOrInsertFunction(llmod, to_name.as_ptr().cast(), to_name.len(), ty);
if let Some(no_return) = no_return {
// -> ! DIFlagNoReturn
attributes::apply_to_llfn(callee, llvm::AttributePlace::Function, &[no_return]);
}
llvm::LLVMRustSetVisibility(callee, llvm::Visibility::Hidden);
let llbb = llvm::LLVMAppendBasicBlockInContext(llcx, llfn, "entry\0".as_ptr().cast());
let llbuilder = llvm::LLVMCreateBuilderInContext(llcx);
llvm::LLVMPositionBuilderAtEnd(llbuilder, llbb);
let args = args
.iter()
.enumerate()
.map(|(i, _)| llvm::LLVMGetParam(llfn, i as c_uint))
.collect::<Vec<_>>();
let ret = llvm::LLVMRustBuildCall(
llbuilder,
ty,
callee,
args.as_ptr(),
args.len() as c_uint,
[].as_ptr(),
0 as c_uint,
);
llvm::LLVMSetTailCall(ret, True);
if output.is_some() {
llvm::LLVMBuildRet(llbuilder, ret);
} else {
llvm::LLVMBuildRetVoid(llbuilder);
}
llvm::LLVMDisposeBuilder(llbuilder);
}
}