diff options
Diffstat (limited to 'compiler/rustc_codegen_gcc/src/declare.rs')
| -rw-r--r-- | compiler/rustc_codegen_gcc/src/declare.rs | 278 |
1 files changed, 278 insertions, 0 deletions
diff --git a/compiler/rustc_codegen_gcc/src/declare.rs b/compiler/rustc_codegen_gcc/src/declare.rs new file mode 100644 index 00000000000..442488b7fd6 --- /dev/null +++ b/compiler/rustc_codegen_gcc/src/declare.rs @@ -0,0 +1,278 @@ +#[cfg(feature = "master")] +use gccjit::{FnAttribute, ToRValue}; +use gccjit::{Function, FunctionType, GlobalKind, LValue, RValue, Type}; +use rustc_codegen_ssa::traits::BaseTypeCodegenMethods; +use rustc_middle::ty::Ty; +use rustc_span::Symbol; +use rustc_target::abi::call::FnAbi; + +use crate::abi::{FnAbiGcc, FnAbiGccExt}; +use crate::context::CodegenCx; +use crate::intrinsic::llvm; + +impl<'gcc, 'tcx> CodegenCx<'gcc, 'tcx> { + pub fn get_or_insert_global( + &self, + name: &str, + ty: Type<'gcc>, + is_tls: bool, + link_section: Option<Symbol>, + ) -> LValue<'gcc> { + if self.globals.borrow().contains_key(name) { + let typ = self.globals.borrow()[name].get_type(); + let global = self.context.new_global(None, GlobalKind::Imported, typ, name); + if is_tls { + global.set_tls_model(self.tls_model); + } + if let Some(link_section) = link_section { + global.set_link_section(link_section.as_str()); + } + global + } else { + self.declare_global(name, ty, GlobalKind::Exported, is_tls, link_section) + } + } + + pub fn declare_unnamed_global(&self, ty: Type<'gcc>) -> LValue<'gcc> { + let name = self.generate_local_symbol_name("global"); + self.context.new_global(None, GlobalKind::Internal, ty, name) + } + + pub fn declare_global_with_linkage( + &self, + name: &str, + ty: Type<'gcc>, + linkage: GlobalKind, + ) -> LValue<'gcc> { + let global = self.context.new_global(None, linkage, ty, name); + let global_address = global.get_address(None); + self.globals.borrow_mut().insert(name.to_string(), global_address); + global + } + + pub fn declare_func( + &self, + name: &str, + return_type: Type<'gcc>, + params: &[Type<'gcc>], + variadic: bool, + ) -> Function<'gcc> { + self.linkage.set(FunctionType::Extern); + declare_raw_fn(self, name, () /*llvm::CCallConv*/, return_type, params, variadic) + } + + pub fn declare_global( + &self, + name: &str, + ty: Type<'gcc>, + global_kind: GlobalKind, + is_tls: bool, + link_section: Option<Symbol>, + ) -> LValue<'gcc> { + let global = self.context.new_global(None, global_kind, ty, name); + if is_tls { + global.set_tls_model(self.tls_model); + } + if let Some(link_section) = link_section { + global.set_link_section(link_section.as_str()); + } + let global_address = global.get_address(None); + self.globals.borrow_mut().insert(name.to_string(), global_address); + global + } + + pub fn declare_private_global(&self, name: &str, ty: Type<'gcc>) -> LValue<'gcc> { + let global = self.context.new_global(None, GlobalKind::Internal, ty, name); + let global_address = global.get_address(None); + self.globals.borrow_mut().insert(name.to_string(), global_address); + global + } + + pub fn declare_entry_fn( + &self, + name: &str, + _fn_type: Type<'gcc>, + callconv: (), /*llvm::CCallConv*/ + ) -> RValue<'gcc> { + // TODO(antoyo): use the fn_type parameter. + let const_string = self.context.new_type::<u8>().make_pointer().make_pointer(); + let return_type = self.type_i32(); + let variadic = false; + self.linkage.set(FunctionType::Exported); + let func = declare_raw_fn( + self, + name, + callconv, + return_type, + &[self.type_i32(), const_string], + variadic, + ); + // NOTE: it is needed to set the current_func here as well, because get_fn() is not called + // for the main function. + *self.current_func.borrow_mut() = Some(func); + // FIXME(antoyo): this is a wrong cast. That requires changing the compiler API. + unsafe { std::mem::transmute(func) } + } + + pub fn declare_fn(&self, name: &str, fn_abi: &FnAbi<'tcx, Ty<'tcx>>) -> Function<'gcc> { + let FnAbiGcc { + return_type, + arguments_type, + is_c_variadic, + on_stack_param_indices, + #[cfg(feature = "master")] + fn_attributes, + } = fn_abi.gcc_type(self); + let func = declare_raw_fn( + self, + name, + (), /*fn_abi.llvm_cconv()*/ + return_type, + &arguments_type, + is_c_variadic, + ); + self.on_stack_function_params.borrow_mut().insert(func, on_stack_param_indices); + #[cfg(feature = "master")] + for fn_attr in fn_attributes { + func.add_attribute(fn_attr); + } + func + } + + pub fn define_global( + &self, + name: &str, + ty: Type<'gcc>, + is_tls: bool, + link_section: Option<Symbol>, + ) -> LValue<'gcc> { + self.get_or_insert_global(name, ty, is_tls, link_section) + } + + pub fn get_declared_value(&self, name: &str) -> Option<RValue<'gcc>> { + // TODO(antoyo): use a different field than globals, because this seems to return a function? + self.globals.borrow().get(name).cloned() + } +} + +/// Declare a function. +/// +/// If there’s a value with the same name already declared, the function will +/// update the declaration and return existing Value instead. +fn declare_raw_fn<'gcc>( + cx: &CodegenCx<'gcc, '_>, + name: &str, + _callconv: (), /*llvm::CallConv*/ + return_type: Type<'gcc>, + param_types: &[Type<'gcc>], + variadic: bool, +) -> Function<'gcc> { + if name.starts_with("llvm.") { + let intrinsic = match name { + "llvm.fma.f16" => { + // fma is not a target builtin, but a normal builtin, so we handle it differently + // here. + cx.context.get_builtin_function("fma") + } + _ => llvm::intrinsic(name, cx), + }; + + cx.intrinsics.borrow_mut().insert(name.to_string(), intrinsic); + return intrinsic; + } + let func = if cx.functions.borrow().contains_key(name) { + cx.functions.borrow()[name] + } else { + let params: Vec<_> = param_types + .iter() + .enumerate() + .map(|(index, param)| cx.context.new_parameter(None, *param, format!("param{}", index))) // TODO(antoyo): set name. + .collect(); + #[cfg(not(feature = "master"))] + let name = &mangle_name(name); + let func = + cx.context.new_function(None, cx.linkage.get(), return_type, ¶ms, name, variadic); + cx.functions.borrow_mut().insert(name.to_string(), func); + + #[cfg(feature = "master")] + if name == "rust_eh_personality" { + // NOTE: GCC will sometimes change the personality function set on a function from + // rust_eh_personality to __gcc_personality_v0 as an optimization. + // As such, we need to create a weak alias from __gcc_personality_v0 to + // rust_eh_personality in order to avoid a linker error. + // This needs to be weak in order to still allow using the standard + // __gcc_personality_v0 when the linking to it. + // Since aliases don't work (maybe because of a bug in LTO partitioning?), we + // create a wrapper function that calls rust_eh_personality. + + let params: Vec<_> = param_types + .iter() + .enumerate() + .map(|(index, param)| { + cx.context.new_parameter(None, *param, format!("param{}", index)) + }) // TODO(antoyo): set name. + .collect(); + let gcc_func = cx.context.new_function( + None, + FunctionType::Exported, + return_type, + ¶ms, + "__gcc_personality_v0", + variadic, + ); + + // We need a normal extern function for the crates that access rust_eh_personality + // without defining it, otherwise we'll get a compiler error. + // + // For the crate defining it, that needs to be a weak alias instead. + gcc_func.add_attribute(FnAttribute::Weak); + + let block = gcc_func.new_block("start"); + let mut args = vec![]; + for param in ¶ms { + args.push(param.to_rvalue()); + } + let call = cx.context.new_call(None, func, &args); + if return_type == cx.type_void() { + block.add_eval(None, call); + block.end_with_void_return(None); + } else { + block.end_with_return(None, call); + } + } + + func + }; + + // TODO(antoyo): set function calling convention. + // TODO(antoyo): set unnamed address. + // TODO(antoyo): set no red zone function attribute. + // TODO(antoyo): set attributes for optimisation. + // TODO(antoyo): set attributes for non lazy bind. + + // FIXME(antoyo): invalid cast. + func +} + +// FIXME(antoyo): this is a hack because libgccjit currently only supports alpha, num and _. +// Unsupported characters: `$`, `.` and `*`. +// FIXME(antoyo): `*` might not be expected: https://github.com/rust-lang/rust/issues/116979#issuecomment-1840926865 +#[cfg(not(feature = "master"))] +fn mangle_name(name: &str) -> String { + name.replace( + |char: char| { + if !char.is_alphanumeric() && char != '_' { + debug_assert!( + "$.*".contains(char), + "Unsupported char in function name {}: {}", + name, + char + ); + true + } else { + false + } + }, + "_", + ) +} |