AbstractCallSite

Synopsis

Declared in <llvm/IR/AbstractCallSite.h>

class AbstractCallSite;

Description

An abstract call site is a wrapper that allows to treat direct, indirect, and callback calls the same. If an abstract call site represents a direct or indirect call site it behaves like a stripped down version of a normal call site object. The abstract call site can also represent a callback call, thus the fact that the initially called function (=broker) may invoke a third one (=callback callee). In this case, the abstract call site hides the middle man, hence the broker function. The result is a representation of the callback call, inside the broker, but in the context of the original call to the broker.

There are up to three functions involved when we talk about callback call sites. The caller (1), which invokes the broker function. The broker function (2), that will invoke the callee zero or more times. And finally the callee (3), which is the target of the callback call.

The abstract call site will handle the mapping from parameters to arguments depending on the semantic of the broker function. However, it is important to note that the mapping is often partial. Thus, some arguments of the call/invoke instruction are mapped to parameters of the callee while others are not.

Types

Name

Description

CallbackInfo

The encoding of a callback with regards to the underlying instruction.

Member Functions

Name

Description

AbstractCallSite [constructor]

Sole constructor for abstract call sites (ACS).

getCallArgOperand

getCallArgOperand overloads

getCallArgOperandNo

getCallArgOperandNo overloads

getCallArgOperandNoForCallee

Return the operand index of the underlying instruction associated with the callee of this ACS. Only valid for callback calls!

getCalledFunction

Return the function being called if this is a direct call, otherwise return null (if it's an indirect call).

getCalledOperand

Return the pointer to function that is being called.

getCalleeUseForCallback

Return the use of the callee value in the underlying instruction. Only valid for callback calls!

getInstruction

Return the underlying instruction.

getNumArgOperands

Return the number of parameters of the callee.

isCallbackCall

Return true if this ACS represents a callback call.

isCallee

isCallee overloads

isDirectCall

Return true if this ACS represents a direct call.

isIndirectCall

Return true if this ACS represents an indirect call.

operator bool

Conversion operator to conveniently check for a valid/initialized ACS.

Static Member Functions

Name

Description

getCallbackUses

Add operand uses of CB that represent callback uses into CallbackUses.

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