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use either::{
Either,
Either::{Left, Right},
};
use llvm_sys::core::{LLVMGetNextUse, LLVMGetUsedValue, LLVMGetUser, LLVMIsABasicBlock, LLVMValueAsBasicBlock};
use llvm_sys::prelude::LLVMUseRef;
use std::marker::PhantomData;
use crate::basic_block::BasicBlock;
use crate::values::{AnyValueEnum, BasicValueEnum};
/// A usage of a `BasicValue` in another value.
#[derive(Clone, Copy, Debug, Eq, PartialEq)]
pub struct BasicValueUse<'ctx>(LLVMUseRef, PhantomData<&'ctx ()>);
impl<'ctx> BasicValueUse<'ctx> {
pub(crate) unsafe fn new(use_: LLVMUseRef) -> Self {
debug_assert!(!use_.is_null());
BasicValueUse(use_, PhantomData)
}
/// Gets the next use of a `BasicBlock`, `InstructionValue` or `BasicValue` if any.
///
/// The following example,
///
/// ```no_run
/// use inkwell::AddressSpace;
/// use inkwell::context::Context;
/// use inkwell::values::BasicValue;
///
/// let context = Context::create();
/// let module = context.create_module("ivs");
/// let builder = context.create_builder();
/// let void_type = context.void_type();
/// let f32_type = context.f32_type();
/// let f32_ptr_type = f32_type.ptr_type(AddressSpace::default());
/// let fn_type = void_type.fn_type(&[f32_ptr_type.into()], false);
///
/// let function = module.add_function("take_f32_ptr", fn_type, None);
/// let basic_block = context.append_basic_block(function, "entry");
///
/// builder.position_at_end(basic_block);
///
/// let arg1 = function.get_first_param().unwrap().into_pointer_value();
/// let f32_val = f32_type.const_float(::std::f64::consts::PI);
/// let store_instruction = builder.build_store(arg1, f32_val);
/// let free_instruction = builder.build_free(arg1);
/// let return_instruction = builder.build_return(None);
///
/// let arg1_first_use = arg1.get_first_use().unwrap();
///
/// assert!(arg1_first_use.get_next_use().is_some());
/// ```
///
/// will generate LLVM IR roughly like (varying slightly across LLVM versions):
///
/// ```ir
/// ; ModuleID = 'ivs'
/// source_filename = "ivs"
///
/// define void @take_f32_ptr(float* %0) {
/// entry:
/// store float 0x400921FB60000000, float* %0
/// %1 = bitcast float* %0 to i8*
/// tail call void @free(i8* %1)
/// ret void
/// }
///
/// declare void @free(i8*)
/// ```
///
/// which makes the arg1 (%0) uses clear:
/// 1) In the store instruction
/// 2) In the pointer bitcast
pub fn get_next_use(self) -> Option<Self> {
let use_ = unsafe { LLVMGetNextUse(self.0) };
if use_.is_null() {
return None;
}
unsafe { Some(Self::new(use_)) }
}
/// Gets the user (an `AnyValueEnum`) of this use.
///
/// ```no_run
/// use inkwell::AddressSpace;
/// use inkwell::context::Context;
/// use inkwell::values::BasicValue;
///
/// let context = Context::create();
/// let module = context.create_module("ivs");
/// let builder = context.create_builder();
/// let void_type = context.void_type();
/// let f32_type = context.f32_type();
/// let f32_ptr_type = f32_type.ptr_type(AddressSpace::default());
/// let fn_type = void_type.fn_type(&[f32_ptr_type.into()], false);
///
/// let function = module.add_function("take_f32_ptr", fn_type, None);
/// let basic_block = context.append_basic_block(function, "entry");
///
/// builder.position_at_end(basic_block);
///
/// let arg1 = function.get_first_param().unwrap().into_pointer_value();
/// let f32_val = f32_type.const_float(::std::f64::consts::PI);
/// let store_instruction = builder.build_store(arg1, f32_val);
/// let free_instruction = builder.build_free(arg1);
/// let return_instruction = builder.build_return(None);
///
/// let store_operand_use0 = store_instruction.get_operand_use(0).unwrap();
/// let store_operand_use1 = store_instruction.get_operand_use(1).unwrap();
///
/// assert_eq!(store_operand_use0.get_user(), store_instruction);
/// assert_eq!(store_operand_use1.get_user(), store_instruction);
/// ```
pub fn get_user(self) -> AnyValueEnum<'ctx> {
unsafe { AnyValueEnum::new(LLVMGetUser(self.0)) }
}
/// Gets the used value (a `BasicValueEnum` or `BasicBlock`) of this use.
///
/// ```no_run
/// use inkwell::AddressSpace;
/// use inkwell::context::Context;
/// use inkwell::values::BasicValue;
///
/// let context = Context::create();
/// let module = context.create_module("ivs");
/// let builder = context.create_builder();
/// let void_type = context.void_type();
/// let f32_type = context.f32_type();
/// let f32_ptr_type = f32_type.ptr_type(AddressSpace::default());
/// let fn_type = void_type.fn_type(&[f32_ptr_type.into()], false);
///
/// let function = module.add_function("take_f32_ptr", fn_type, None);
/// let basic_block = context.append_basic_block(function, "entry");
///
/// builder.position_at_end(basic_block);
///
/// let arg1 = function.get_first_param().unwrap().into_pointer_value();
/// let f32_val = f32_type.const_float(::std::f64::consts::PI);
/// let store_instruction = builder.build_store(arg1, f32_val);
/// let free_instruction = builder.build_free(arg1);
/// let return_instruction = builder.build_return(None);
///
/// let free_operand0 = free_instruction.get_operand(0).unwrap().left().unwrap();
/// let free_operand0_instruction = free_operand0.as_instruction_value().unwrap();
/// let bitcast_use_value = free_operand0_instruction
/// .get_first_use()
/// .unwrap()
/// .get_used_value()
/// .left()
/// .unwrap();
///
/// assert_eq!(bitcast_use_value, free_operand0);
/// ```
pub fn get_used_value(self) -> Either<BasicValueEnum<'ctx>, BasicBlock<'ctx>> {
let used_value = unsafe { LLVMGetUsedValue(self.0) };
let is_basic_block = unsafe { !LLVMIsABasicBlock(used_value).is_null() };
if is_basic_block {
let bb = unsafe { BasicBlock::new(LLVMValueAsBasicBlock(used_value)) };
Right(bb.expect("BasicBlock should always be valid"))
} else {
unsafe { Left(BasicValueEnum::new(used_value)) }
}
}
}