llvm-6502/include/llvm/Attributes.h

426 lines
16 KiB
C++

//===-- llvm/Attributes.h - Container for Attributes ------------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file contains the simple types necessary to represent the
// attributes associated with functions and their calls.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_ATTRIBUTES_H
#define LLVM_ATTRIBUTES_H
#include "llvm/ADT/ArrayRef.h"
#include "llvm/Support/MathExtras.h"
#include <cassert>
#include <string>
namespace llvm {
class AttrBuilder;
class AttributesImpl;
class LLVMContext;
class Type;
/// Attributes - A bitset of attributes.
class Attributes {
public:
/// Function parameters and results can have attributes to indicate how they
/// should be treated by optimizations and code generation. This enumeration
/// lists the attributes that can be associated with parameters, function
/// results or the function itself.
///
/// Note that uwtable is about the ABI or the user mandating an entry in the
/// unwind table. The nounwind attribute is about an exception passing by the
/// function.
///
/// In a theoretical system that uses tables for profiling and sjlj for
/// exceptions, they would be fully independent. In a normal system that uses
/// tables for both, the semantics are:
///
/// nil = Needs an entry because an exception might pass by.
/// nounwind = No need for an entry
/// uwtable = Needs an entry because the ABI says so and because
/// an exception might pass by.
/// uwtable + nounwind = Needs an entry because the ABI says so.
enum AttrVal {
// IR-Level Attributes
None, ///< No attributes have been set
AddressSafety, ///< Address safety checking is on.
Alignment, ///< Alignment of parameter (5 bits)
///< stored as log2 of alignment with +1 bias
///< 0 means unaligned different from align 1
AlwaysInline, ///< inline=always
ByVal, ///< Pass structure by value
InlineHint, ///< Source said inlining was desirable
InReg, ///< Force argument to be passed in register
MinSize, ///< Function must be optimized for size first
Naked, ///< Naked function
Nest, ///< Nested function static chain
NoAlias, ///< Considered to not alias after call
NoCapture, ///< Function creates no aliases of pointer
NoImplicitFloat, ///< Disable implicit floating point insts
NoInline, ///< inline=never
NonLazyBind, ///< Function is called early and/or
///< often, so lazy binding isn't worthwhile
NoRedZone, ///< Disable redzone
NoReturn, ///< Mark the function as not returning
NoUnwind, ///< Function doesn't unwind stack
OptimizeForSize, ///< opt_size
ReadNone, ///< Function does not access memory
ReadOnly, ///< Function only reads from memory
ReturnsTwice, ///< Function can return twice
SExt, ///< Sign extended before/after call
StackAlignment, ///< Alignment of stack for function (3 bits)
///< stored as log2 of alignment with +1 bias 0
///< means unaligned (different from
///< alignstack={1))
StackProtect, ///< Stack protection.
StackProtectReq, ///< Stack protection required.
StructRet, ///< Hidden pointer to structure to return
UWTable, ///< Function must be in a unwind table
ZExt ///< Zero extended before/after call
};
private:
AttributesImpl *Attrs;
Attributes(AttributesImpl *A) : Attrs(A) {}
public:
Attributes() : Attrs(0) {}
/// get - Return a uniquified Attributes object. This takes the uniquified
/// value from the Builder and wraps it in the Attributes class.
static Attributes get(LLVMContext &Context, ArrayRef<AttrVal> Vals);
static Attributes get(LLVMContext &Context, AttrBuilder &B);
/// @brief Return true if the attribute is present.
bool hasAttribute(AttrVal Val) const;
/// @brief Return true if attributes exist
bool hasAttributes() const;
/// @brief Return true if the attributes are a non-null intersection.
bool hasAttributes(const Attributes &A) const;
/// @brief Returns the alignment field of an attribute as a byte alignment
/// value.
unsigned getAlignment() const;
/// @brief Returns the stack alignment field of an attribute as a byte
/// alignment value.
unsigned getStackAlignment() const;
/// @brief Parameter attributes that do not apply to vararg call arguments.
bool hasIncompatibleWithVarArgsAttrs() const {
return hasAttribute(Attributes::StructRet);
}
/// @brief Attributes that only apply to function parameters.
bool hasParameterOnlyAttrs() const {
return hasAttribute(Attributes::ByVal) ||
hasAttribute(Attributes::Nest) ||
hasAttribute(Attributes::StructRet) ||
hasAttribute(Attributes::NoCapture);
}
/// @brief Attributes that may be applied to the function itself. These cannot
/// be used on return values or function parameters.
bool hasFunctionOnlyAttrs() const {
return hasAttribute(Attributes::NoReturn) ||
hasAttribute(Attributes::NoUnwind) ||
hasAttribute(Attributes::ReadNone) ||
hasAttribute(Attributes::ReadOnly) ||
hasAttribute(Attributes::NoInline) ||
hasAttribute(Attributes::AlwaysInline) ||
hasAttribute(Attributes::OptimizeForSize) ||
hasAttribute(Attributes::StackProtect) ||
hasAttribute(Attributes::StackProtectReq) ||
hasAttribute(Attributes::NoRedZone) ||
hasAttribute(Attributes::NoImplicitFloat) ||
hasAttribute(Attributes::Naked) ||
hasAttribute(Attributes::InlineHint) ||
hasAttribute(Attributes::StackAlignment) ||
hasAttribute(Attributes::UWTable) ||
hasAttribute(Attributes::NonLazyBind) ||
hasAttribute(Attributes::ReturnsTwice) ||
hasAttribute(Attributes::AddressSafety) ||
hasAttribute(Attributes::MinSize);
}
bool operator==(const Attributes &A) const {
return Attrs == A.Attrs;
}
bool operator!=(const Attributes &A) const {
return Attrs != A.Attrs;
}
uint64_t Raw() const;
/// @brief Which attributes cannot be applied to a type.
static Attributes typeIncompatible(Type *Ty);
/// encodeLLVMAttributesForBitcode - This returns an integer containing an
/// encoding of all the LLVM attributes found in the given attribute bitset.
/// Any change to this encoding is a breaking change to bitcode compatibility.
static uint64_t encodeLLVMAttributesForBitcode(Attributes Attrs);
/// decodeLLVMAttributesForBitcode - This returns an attribute bitset
/// containing the LLVM attributes that have been decoded from the given
/// integer. This function must stay in sync with
/// 'encodeLLVMAttributesForBitcode'.
static Attributes decodeLLVMAttributesForBitcode(LLVMContext &C,
uint64_t EncodedAttrs);
/// getAsString - The set of Attributes set in Attributes is converted to a
/// string of equivalent mnemonics. This is, presumably, for writing out the
/// mnemonics for the assembly writer.
/// @brief Convert attribute bits to text
std::string getAsString() const;
};
//===----------------------------------------------------------------------===//
/// AttrBuilder - This class is used in conjunction with the Attributes::get
/// method to create an Attributes object. The object itself is uniquified. The
/// Builder's value, however, is not. So this can be used as a quick way to test
/// for equality, presence of attributes, etc.
class AttrBuilder {
uint64_t Bits;
public:
AttrBuilder() : Bits(0) {}
explicit AttrBuilder(uint64_t B) : Bits(B) {}
AttrBuilder(const Attributes &A) : Bits(A.Raw()) {}
void clear() { Bits = 0; }
/// addAttribute - Add an attribute to the builder.
AttrBuilder &addAttribute(Attributes::AttrVal Val);
/// removeAttribute - Remove an attribute from the builder.
AttrBuilder &removeAttribute(Attributes::AttrVal Val);
/// addAttribute - Add the attributes from A to the builder.
AttrBuilder &addAttributes(const Attributes &A);
/// removeAttribute - Remove the attributes from A from the builder.
AttrBuilder &removeAttributes(const Attributes &A);
/// hasAttribute - Return true if the builder has the specified attribute.
bool hasAttribute(Attributes::AttrVal A) const;
/// hasAttributes - Return true if the builder has IR-level attributes.
bool hasAttributes() const;
/// hasAttributes - Return true if the builder has any attribute that's in the
/// specified attribute.
bool hasAttributes(const Attributes &A) const;
/// hasAlignmentAttr - Return true if the builder has an alignment attribute.
bool hasAlignmentAttr() const;
/// getAlignment - Retrieve the alignment attribute, if it exists.
uint64_t getAlignment() const;
/// getStackAlignment - Retrieve the stack alignment attribute, if it exists.
uint64_t getStackAlignment() const;
/// addAlignmentAttr - This turns an int alignment (which must be a power of
/// 2) into the form used internally in Attributes.
AttrBuilder &addAlignmentAttr(unsigned Align);
/// addStackAlignmentAttr - This turns an int stack alignment (which must be a
/// power of 2) into the form used internally in Attributes.
AttrBuilder &addStackAlignmentAttr(unsigned Align);
/// addRawValue - Add the raw value to the internal representation.
/// N.B. This should be used ONLY for decoding LLVM bitcode!
AttrBuilder &addRawValue(uint64_t Val);
/// @brief Remove attributes that are used on functions only.
void removeFunctionOnlyAttrs() {
removeAttribute(Attributes::NoReturn)
.removeAttribute(Attributes::NoUnwind)
.removeAttribute(Attributes::ReadNone)
.removeAttribute(Attributes::ReadOnly)
.removeAttribute(Attributes::NoInline)
.removeAttribute(Attributes::AlwaysInline)
.removeAttribute(Attributes::OptimizeForSize)
.removeAttribute(Attributes::StackProtect)
.removeAttribute(Attributes::StackProtectReq)
.removeAttribute(Attributes::NoRedZone)
.removeAttribute(Attributes::NoImplicitFloat)
.removeAttribute(Attributes::Naked)
.removeAttribute(Attributes::InlineHint)
.removeAttribute(Attributes::StackAlignment)
.removeAttribute(Attributes::UWTable)
.removeAttribute(Attributes::NonLazyBind)
.removeAttribute(Attributes::ReturnsTwice)
.removeAttribute(Attributes::AddressSafety)
.removeAttribute(Attributes::MinSize);
}
uint64_t Raw() const { return Bits; }
bool operator==(const AttrBuilder &B) {
return Bits == B.Bits;
}
bool operator!=(const AttrBuilder &B) {
return Bits != B.Bits;
}
};
//===----------------------------------------------------------------------===//
// AttributeWithIndex
//===----------------------------------------------------------------------===//
/// AttributeWithIndex - This is just a pair of values to associate a set of
/// attributes with an index.
struct AttributeWithIndex {
Attributes Attrs; ///< The attributes that are set, or'd together.
unsigned Index; ///< Index of the parameter for which the attributes apply.
///< Index 0 is used for return value attributes.
///< Index ~0U is used for function attributes.
static AttributeWithIndex get(LLVMContext &C, unsigned Idx,
ArrayRef<Attributes::AttrVal> Attrs) {
return get(Idx, Attributes::get(C, Attrs));
}
static AttributeWithIndex get(unsigned Idx, Attributes Attrs) {
AttributeWithIndex P;
P.Index = Idx;
P.Attrs = Attrs;
return P;
}
};
//===----------------------------------------------------------------------===//
// AttributeSet Smart Pointer
//===----------------------------------------------------------------------===//
class AttributeListImpl;
/// AttributeSet - This class manages the ref count for the opaque
/// AttributeListImpl object and provides accessors for it.
class AttributeSet {
public:
enum AttrIndex {
ReturnIndex = 0U,
FunctionIndex = ~0U
};
private:
/// @brief The attributes that we are managing. This can be null to represent
/// the empty attributes list.
AttributeListImpl *AttrList;
/// @brief The attributes for the specified index are returned. Attributes
/// for the result are denoted with Idx = 0.
Attributes getAttributes(unsigned Idx) const;
explicit AttributeSet(AttributeListImpl *LI) : AttrList(LI) {}
public:
AttributeSet() : AttrList(0) {}
AttributeSet(const AttributeSet &P) : AttrList(P.AttrList) {}
const AttributeSet &operator=(const AttributeSet &RHS);
//===--------------------------------------------------------------------===//
// Attribute List Construction and Mutation
//===--------------------------------------------------------------------===//
/// get - Return a Attributes list with the specified parameters in it.
static AttributeSet get(LLVMContext &C, ArrayRef<AttributeWithIndex> Attrs);
/// addAttr - Add the specified attribute at the specified index to this
/// attribute list. Since attribute lists are immutable, this
/// returns the new list.
AttributeSet addAttr(LLVMContext &C, unsigned Idx, Attributes Attrs) const;
/// removeAttr - Remove the specified attribute at the specified index from
/// this attribute list. Since attribute lists are immutable, this
/// returns the new list.
AttributeSet removeAttr(LLVMContext &C, unsigned Idx, Attributes Attrs) const;
//===--------------------------------------------------------------------===//
// Attribute List Accessors
//===--------------------------------------------------------------------===//
/// getParamAttributes - The attributes for the specified index are
/// returned.
Attributes getParamAttributes(unsigned Idx) const {
return getAttributes(Idx);
}
/// getRetAttributes - The attributes for the ret value are
/// returned.
Attributes getRetAttributes() const {
return getAttributes(ReturnIndex);
}
/// getFnAttributes - The function attributes are returned.
Attributes getFnAttributes() const {
return getAttributes(FunctionIndex);
}
/// paramHasAttr - Return true if the specified parameter index has the
/// specified attribute set.
bool paramHasAttr(unsigned Idx, Attributes Attr) const {
return getAttributes(Idx).hasAttributes(Attr);
}
/// getParamAlignment - Return the alignment for the specified function
/// parameter.
unsigned getParamAlignment(unsigned Idx) const {
return getAttributes(Idx).getAlignment();
}
/// hasAttrSomewhere - Return true if the specified attribute is set for at
/// least one parameter or for the return value.
bool hasAttrSomewhere(Attributes::AttrVal Attr) const;
unsigned getNumAttrs() const;
Attributes &getAttributesAtIndex(unsigned i) const;
/// operator==/!= - Provide equality predicates.
bool operator==(const AttributeSet &RHS) const
{ return AttrList == RHS.AttrList; }
bool operator!=(const AttributeSet &RHS) const
{ return AttrList != RHS.AttrList; }
//===--------------------------------------------------------------------===//
// Attribute List Introspection
//===--------------------------------------------------------------------===//
/// getRawPointer - Return a raw pointer that uniquely identifies this
/// attribute list.
void *getRawPointer() const {
return AttrList;
}
// Attributes are stored as a dense set of slots, where there is one
// slot for each argument that has an attribute. This allows walking over the
// dense set instead of walking the sparse list of attributes.
/// isEmpty - Return true if there are no attributes.
///
bool isEmpty() const {
return AttrList == 0;
}
/// getNumSlots - Return the number of slots used in this attribute list.
/// This is the number of arguments that have an attribute set on them
/// (including the function itself).
unsigned getNumSlots() const;
/// getSlot - Return the AttributeWithIndex at the specified slot. This
/// holds a index number plus a set of attributes.
const AttributeWithIndex &getSlot(unsigned Slot) const;
void dump() const;
};
} // End llvm namespace
#endif