Module rustc_mir::interpret

An interpreter for MIR used in CTFE and by miri

Modules

cast
eval_context
intern	This module specifies the type based interner for constants.
intrinsics	Intrinsics and other functions that the miri engine executes without looking at their MIR. Intrinsics/functions supported here are shared by CTFE and miri.
machine	This module contains everything needed to instantiate an interpreter. This separation exists to ensure that no fancy miri features like interpreting common C functions leak into CTFE.
memory	The memory subsystem.
operand	Functions concerning immediate values and operands, and reading from operands. All high-level functions to read from memory work on operands as sources.
operator
place	Computations on places -- field projections, going from mir::Place, and writing into a place. All high-level functions to write to memory work on places as destinations.
step	This module contains the InterpCx methods for executing a single step of the interpreter.
terminator
traits
util
validity	Check the validity invariant of a given value, and tell the user where in the value it got violated. In const context, this goes even further and tries to approximate const safety. That's useful because it means other passes (e.g. promotion) can rely on consts to be const-safe.
visitor	Visitor for a run-time value with a given layout: Traverse enums, structs and other compound types until we arrive at the leaves, with custom handling for primitive types.

Macros

compile_time_machine

Structs

AllocDecodingSession
AllocDecodingState
AllocId
Allocation
ConstAlloc	Represents the result of const evaluation via the eval_to_allocation query.
Frame	A stack frame.
FrameInfo	What we store about a frame in an interpreter backtrace.
GlobalId	Uniquely identifies one of the following:
ImmTy
InitMask	A bitmask where each bit refers to the byte with the same index. If the bit is true, the byte is initialized. If it is false the byte is uninitialized.
InterpCx
InterpErrorInfo	Packages the kind of error we got from the const code interpreter up with a Rust-level backtrace of where the error occurred. Thsese should always be constructed by calling .into() on a InterpError. In librustc_mir::interpret, we have throw_err_* macros for this.
LitToConstInput	Input argument for tcx.lit_to_const.
LocalState	State of a local variable including a memoized layout
MPlaceTy	A MemPlace with its layout. Constructing it is only possible in this module.
MemPlace
Memory
OpTy
PlaceTy
Pointer	Represents a pointer in the Miri engine.
RefTracking	State for tracking recursive validation of references
Relocations	Relocations.
UninitBytesAccess	Details of an access to uninitialized bytes where it is not allowed.

Enums

AllocCheck	Used by get_size_and_align to indicate whether the allocation needs to be live.
CheckInAllocMsg	Details of why a pointer had to be in-bounds.
ConstValue	Represents a constant value in Rust. Scalar and Slice are optimizations for array length computations, enum discriminants and the pattern matching logic.
CtfeValidationMode	Extra things to check for during validation of CTFE results.
ErrorHandled
FnVal	The value of a function pointer.
GlobalAlloc	An allocation in the global (tcx-managed) memory can be either a function pointer, a static, or a "real" allocation with some data in it.
Immediate	An Immediate represents a single immediate self-contained Rust value.
InternKind
InterpError
InvalidProgramInfo	Error information for when the program we executed turned out not to actually be a valid program. This cannot happen in stand-alone Miri, but it can happen during CTFE/ConstProp where we work on generic code or execution does not have all information available.
LitToConstError	Error type for tcx.lit_to_const.
LocalValue	Current value of a local variable
MemPlaceMeta	Information required for the sound usage of a MemPlace.
MemoryKind
Operand	An Operand is the result of computing a mir::Operand. It can be immediate, or still in memory. The latter is an optimization, to delay reading that chunk of memory and to avoid having to store arbitrary-sized data here.
Place
ResourceExhaustionInfo	Error information for when the program exhausted the resources granted to it by the interpreter.
Scalar	A Scalar represents an immediate, primitive value existing outside of a memory::Allocation. It is in many ways like a small chunk of a Allocation, up to 8 bytes in size. Like a range of bytes in an Allocation, a Scalar can either represent the raw bytes of a simple value or a pointer into another Allocation
ScalarMaybeUninit
StackPopCleanup
StackPopJump	Data returned by Machine::stack_pop, to provide further control over the popping of the stack frame
UndefinedBehaviorInfo	Error information for when the program caused Undefined Behavior.
UnsupportedOpInfo	Error information for when the program did something that might (or might not) be correct to do according to the Rust spec, but due to limitations in the interpreter, the operation could not be carried out. These limitations can differ between CTFE and the Miri engine, e.g., CTFE does not support dereferencing pointers at integral addresses.

Traits

AllocMap	The functionality needed by memory to manage its allocations
AllocationExtra
Machine	Methods of this trait signifies a point where CTFE evaluation would fail and some use case dependent behaviour can instead be applied.
MachineStopType	A trait for machine-specific errors (or other "machine stop" conditions).
MayLeak	Whether this kind of memory is allowed to leak
MutValueVisitor
PointerArithmetic
ValueVisitor

Functions

get_slice_bytes	Gets the bytes of a constant slice value.
intern_const_alloc_recursive	Intern ret and everything it references.
read_target_uint
specialized_encode_alloc_id
struct_error
uabs	Computes the unsigned absolute value without wrapping or panicking.
write_target_uint

Type Definitions

EvalToAllocationRawResult
EvalToConstValueResult
InterpResult