Struct inkwell::execution_engine::ExecutionEngine[][src]

pub struct ExecutionEngine<'ctx> { /* fields omitted */ }
Expand description

A reference-counted wrapper around LLVM’s execution engine.

Note

Cloning this object is essentially just a case of copying a couple pointers and incrementing one or two atomics, so this should be quite cheap to create copies. The underlying LLVM object will be automatically deallocated when there are no more references to it.

Implementations

This function probably doesn’t need to be called, but is here due to linking(?) requirements. Bad things happen if we don’t provide it.

This function probably doesn’t need to be called, but is here due to linking(?) requirements. Bad things happen if we don’t provide it.

Maps the specified value to an address.

Example

use inkwell::targets::{InitializationConfig, Target};
use inkwell::context::Context;
use inkwell::OptimizationLevel;

Target::initialize_native(&InitializationConfig::default()).unwrap();

extern fn sumf(a: f64, b: f64) -> f64 {
    a + b
}

let context = Context::create();
let module = context.create_module("test");
let builder = context.create_builder();

let ft = context.f64_type();
let fnt = ft.fn_type(&[], false);

let f = module.add_function("test_fn", fnt, None);
let b = context.append_basic_block(f, "entry");

builder.position_at_end(b);

let extf = module.add_function("sumf", ft.fn_type(&[ft.into(), ft.into()], false), None);

let argf = ft.const_float(64.);
let call_site_value = builder.build_call(extf, &[argf.into(), argf.into()], "retv");
let retv = call_site_value.try_as_basic_value().left().unwrap().into_float_value();

builder.build_return(Some(&retv));

let mut ee = module.create_jit_execution_engine(OptimizationLevel::None).unwrap();
ee.add_global_mapping(&extf, sumf as usize);

let result = unsafe { ee.run_function(f, &[]) }.as_float(&ft);

assert_eq!(result, 128.);

Adds a module to an ExecutionEngine.

The method will be Ok(()) if the module does not belong to an ExecutionEngine already and Err(()) otherwise.

use inkwell::targets::{InitializationConfig, Target};
use inkwell::context::Context;
use inkwell::OptimizationLevel;

Target::initialize_native(&InitializationConfig::default()).unwrap();

let context = Context::create();
let module = context.create_module("test");
let mut ee = module.create_jit_execution_engine(OptimizationLevel::None).unwrap();

assert!(ee.add_module(&module).is_err());

Try to load a function from the execution engine.

If a target hasn’t already been initialized, spurious “function not found” errors may be encountered.

The UnsafeFunctionPointer trait is designed so only unsafe extern "C" functions can be retrieved via the get_function() method. If you get funny type errors then it’s probably because you have specified the wrong calling convention or forgotten to specify the retrieved function as unsafe.

Examples

let context = Context::create();
let module = context.create_module("test");
let builder = context.create_builder();

// Set up the function signature
let double = context.f64_type();
let sig = double.fn_type(&[], false);

// Add the function to our module
let f = module.add_function("test_fn", sig, None);
let b = context.append_basic_block(f, "entry");
builder.position_at_end(b);

// Insert a return statement
let ret = double.const_float(64.0);
builder.build_return(Some(&ret));

// create the JIT engine
let mut ee = module.create_jit_execution_engine(OptimizationLevel::None).unwrap();

// fetch our JIT'd function and execute it
unsafe {
    let test_fn = ee.get_function::<unsafe extern "C" fn() -> f64>("test_fn").unwrap();
    let return_value = test_fn.call();
    assert_eq!(return_value, 64.0);
}

Safety

It is the caller’s responsibility to ensure they call the function with the correct signature and calling convention.

The JitFunction wrapper ensures a function won’t accidentally outlive the execution engine it came from, but adding functions after calling this method may invalidate the function pointer.

Attempts to look up a function’s address by its name. May return Err if the function cannot be found or some other unknown error has occurred.

It is recommended to use get_function instead of this method when intending to call the function pointer so that you don’t have to do error-prone transmutes yourself.

Trait Implementations

Returns a copy of the value. Read more

Performs copy-assignment from source. Read more

Formats the value using the given formatter. Read more

Executes the destructor for this type. Read more

This method tests for self and other values to be equal, and is used by ==. Read more

This method tests for !=.

Auto Trait Implementations

Blanket Implementations

Gets the TypeId of self. Read more

Immutably borrows from an owned value. Read more

Mutably borrows from an owned value. Read more

Performs the conversion.

Performs the conversion.

The resulting type after obtaining ownership.

Creates owned data from borrowed data, usually by cloning. Read more

🔬 This is a nightly-only experimental API. (toowned_clone_into)

recently added

Uses borrowed data to replace owned data, usually by cloning. Read more

The type returned in the event of a conversion error.

Performs the conversion.

The type returned in the event of a conversion error.

Performs the conversion.