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Remove DeclareMethods

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This commit is contained in:
khyperia 2020-09-18 13:06:53 +02:00
parent a0925fba74
commit 0bc405e352
6 changed files with 62 additions and 66 deletions
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11
compiler/rustc_codegen_llvm/src/context.rs
View file

@ -433,6 +433,17 @@ impl MiscMethods<'tcx> for CodegenCx<'ll, 'tcx> {
llvm::LLVMSetSection(g, section.as_ptr());
}
}
fn declare_c_main(&self, fn_type: Self::Type) -> Option<Self::Function> {
if self.get_declared_value("main").is_none() {
Some(self.declare_cfn("main", fn_type))
} else {
// If the symbol already exists, it is an error: for example, the user wrote
// #[no_mangle] extern "C" fn main(..) {..}
// instead of #[start]
None
}
}
}
impl CodegenCx<'b, 'tcx> {

43
compiler/rustc_codegen_llvm/src/declare.rs
View file

@ -51,17 +51,32 @@ fn declare_raw_fn(
llfn
}
impl DeclareMethods<'tcx> for CodegenCx<'ll, 'tcx> {
fn declare_global(&self, name: &str, ty: &'ll Type) -> &'ll Value {
impl CodegenCx<'ll, 'tcx> {
/// Declare a global value.
///
/// If there’s a value with the same name already declared, the function will
/// return its Value instead.
pub fn declare_global(&self, name: &str, ty: &'ll Type) -> &'ll Value {
debug!("declare_global(name={:?})", name);
unsafe { llvm::LLVMRustGetOrInsertGlobal(self.llmod, name.as_ptr().cast(), name.len(), ty) }
}
fn declare_cfn(&self, name: &str, fn_type: &'ll Type) -> &'ll Value {
/// Declare a C ABI function.
///
/// Only use this for foreign function ABIs and glue. For Rust functions use
/// `declare_fn` instead.
///
/// If there’s a value with the same name already declared, the function will
/// update the declaration and return existing Value instead.
pub fn declare_cfn(&self, name: &str, fn_type: &'ll Type) -> &'ll Value {
declare_raw_fn(self, name, llvm::CCallConv, fn_type)
}
fn declare_fn(&self, name: &str, fn_abi: &FnAbi<'tcx, Ty<'tcx>>) -> &'ll Value {
/// Declare a Rust function.
///
/// If there’s a value with the same name already declared, the function will
/// update the declaration and return existing Value instead.
pub fn declare_fn(&self, name: &str, fn_abi: &FnAbi<'tcx, Ty<'tcx>>) -> &'ll Value {
debug!("declare_rust_fn(name={:?}, fn_abi={:?})", name, fn_abi);
let llfn = declare_raw_fn(self, name, fn_abi.llvm_cconv(), fn_abi.llvm_type(self));
@ -69,7 +84,13 @@ impl DeclareMethods<'tcx> for CodegenCx<'ll, 'tcx> {
llfn
}
fn define_global(&self, name: &str, ty: &'ll Type) -> Option<&'ll Value> {
/// Declare a global with an intention to define it.
///
/// Use this function when you intend to define a global. This function will
/// return `None` if the name already has a definition associated with it. In that
/// case an error should be reported to the user, because it usually happens due
/// to user’s fault (e.g., misuse of `#[no_mangle]` or `#[export_name]` attributes).
pub fn define_global(&self, name: &str, ty: &'ll Type) -> Option<&'ll Value> {
if self.get_defined_value(name).is_some() {
None
} else {
@ -77,16 +98,22 @@ impl DeclareMethods<'tcx> for CodegenCx<'ll, 'tcx> {
}
}
fn define_private_global(&self, ty: &'ll Type) -> &'ll Value {
/// Declare a private global
///
/// Use this function when you intend to define a global without a name.
pub fn define_private_global(&self, ty: &'ll Type) -> &'ll Value {
unsafe { llvm::LLVMRustInsertPrivateGlobal(self.llmod, ty) }
}
fn get_declared_value(&self, name: &str) -> Option<&'ll Value> {
/// Gets declared value by name.
pub fn get_declared_value(&self, name: &str) -> Option<&'ll Value> {
debug!("get_declared_value(name={:?})", name);
unsafe { llvm::LLVMRustGetNamedValue(self.llmod, name.as_ptr().cast(), name.len()) }
}
fn get_defined_value(&self, name: &str) -> Option<&'ll Value> {
/// Gets defined or externally defined (AvailableExternally linkage) value by
/// name.
pub fn get_defined_value(&self, name: &str) -> Option<&'ll Value> {
self.get_declared_value(name).and_then(|val| {
let declaration = unsafe { llvm::LLVMIsDeclaration(val) != 0 };
if !declaration { Some(val) } else { None }

22
compiler/rustc_codegen_ssa/src/base.rs
View file

@ -407,16 +407,18 @@ pub fn maybe_create_entry_wrapper<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>(
// listing.
let main_ret_ty = cx.tcx().erase_regions(&main_ret_ty.no_bound_vars().unwrap());
if cx.get_declared_value("main").is_some() {
// FIXME: We should be smart and show a better diagnostic here.
cx.sess()
.struct_span_err(sp, "entry symbol `main` declared multiple times")
.help("did you use `#[no_mangle]` on `fn main`? Use `#[start]` instead")
.emit();
cx.sess().abort_if_errors();
bug!();
}
let llfn = cx.declare_cfn("main", llfty);
let llfn = match cx.declare_c_main(llfty) {
Some(llfn) => llfn,
None => {
// FIXME: We should be smart and show a better diagnostic here.
cx.sess()
.struct_span_err(sp, "entry symbol `main` declared multiple times")
.help("did you use `#[no_mangle]` on `fn main`? Use `#[start]` instead")
.emit();
cx.sess().abort_if_errors();
bug!();
}
};
// `main` should respect same config for frame pointer elimination as rest of code
cx.set_frame_pointer_elimination(llfn);

46
compiler/rustc_codegen_ssa/src/traits/declare.rs
View file

@ -1,51 +1,7 @@
use super::BackendTypes;
use rustc_hir::def_id::DefId;
use rustc_middle::mir::mono::{Linkage, Visibility};
use rustc_middle::ty::{Instance, Ty};
use rustc_target::abi::call::FnAbi;
pub trait DeclareMethods<'tcx>: BackendTypes {
/// Declare a global value.
///
/// If there’s a value with the same name already declared, the function will
/// return its Value instead.
fn declare_global(&self, name: &str, ty: Self::Type) -> Self::Value;
/// Declare a C ABI function.
///
/// Only use this for foreign function ABIs and glue. For Rust functions use
/// `declare_fn` instead.
///
/// If there’s a value with the same name already declared, the function will
/// update the declaration and return existing Value instead.
fn declare_cfn(&self, name: &str, fn_type: Self::Type) -> Self::Function;
/// Declare a Rust 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_fn(&self, name: &str, fn_abi: &FnAbi<'tcx, Ty<'tcx>>) -> Self::Function;
/// Declare a global with an intention to define it.
///
/// Use this function when you intend to define a global. This function will
/// return `None` if the name already has a definition associated with it. In that
/// case an error should be reported to the user, because it usually happens due
/// to user’s fault (e.g., misuse of `#[no_mangle]` or `#[export_name]` attributes).
fn define_global(&self, name: &str, ty: Self::Type) -> Option<Self::Value>;
/// Declare a private global
///
/// Use this function when you intend to define a global without a name.
fn define_private_global(&self, ty: Self::Type) -> Self::Value;
/// Gets declared value by name.
fn get_declared_value(&self, name: &str) -> Option<Self::Value>;
/// Gets defined or externally defined (AvailableExternally linkage) value by
/// name.
fn get_defined_value(&self, name: &str) -> Option<Self::Value>;
}
use rustc_middle::ty::Instance;
pub trait PreDefineMethods<'tcx>: BackendTypes {
fn predefine_static(

2
compiler/rustc_codegen_ssa/src/traits/misc.rs
View file

@ -19,4 +19,6 @@ pub trait MiscMethods<'tcx>: BackendTypes {
fn set_frame_pointer_elimination(&self, llfn: Self::Function);
fn apply_target_cpu_attr(&self, llfn: Self::Function);
fn create_used_variable(&self);
/// Declares the extern "C" main function for the entry point. Returns None if the symbol already exists.
fn declare_c_main(&self, fn_type: Self::Type) -> Option<Self::Function>;
}

4
compiler/rustc_codegen_ssa/src/traits/mod.rs
View file

@ -35,7 +35,7 @@ pub use self::builder::{BuilderMethods, OverflowOp};
pub use self::consts::ConstMethods;
pub use self::coverageinfo::{CoverageInfoBuilderMethods, CoverageInfoMethods};
pub use self::debuginfo::{DebugInfoBuilderMethods, DebugInfoMethods};
pub use self::declare::{DeclareMethods, PreDefineMethods};
pub use self::declare::PreDefineMethods;
pub use self::intrinsic::IntrinsicCallMethods;
pub use self::misc::MiscMethods;
pub use self::statics::{StaticBuilderMethods, StaticMethods};
@ -60,7 +60,6 @@ pub trait CodegenMethods<'tcx>:
+ StaticMethods
+ CoverageInfoMethods
+ DebugInfoMethods<'tcx>
+ DeclareMethods<'tcx>
+ AsmMethods
+ PreDefineMethods<'tcx>
+ HasParamEnv<'tcx>
@ -77,7 +76,6 @@ impl<'tcx, T> CodegenMethods<'tcx> for T where
+ StaticMethods
+ CoverageInfoMethods
+ DebugInfoMethods<'tcx>
+ DeclareMethods<'tcx>
+ AsmMethods
+ PreDefineMethods<'tcx>
+ HasParamEnv<'tcx>