llvm-6502/include/llvm/Attributes.h
Charles Davis 970bfcc7d8 Add a new 'hotpatch' attribute. This attribute will insert a two-byte no-op
instruction at the beginning of each function that has the attribute, allowing
the function to be easily hooked and/or patched.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@117264 91177308-0d34-0410-b5e6-96231b3b80d8
2010-10-25 15:37:09 +00:00

291 lines
11 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/Support/MathExtras.h"
#include <cassert>
#include <string>
namespace llvm {
class Type;
/// Attributes - A bitset of attributes.
typedef unsigned Attributes;
namespace Attribute {
/// 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.
/// @brief Function attributes.
const Attributes None = 0; ///< No attributes have been set
const Attributes ZExt = 1<<0; ///< Zero extended before/after call
const Attributes SExt = 1<<1; ///< Sign extended before/after call
const Attributes NoReturn = 1<<2; ///< Mark the function as not returning
const Attributes InReg = 1<<3; ///< Force argument to be passed in register
const Attributes StructRet = 1<<4; ///< Hidden pointer to structure to return
const Attributes NoUnwind = 1<<5; ///< Function doesn't unwind stack
const Attributes NoAlias = 1<<6; ///< Considered to not alias after call
const Attributes ByVal = 1<<7; ///< Pass structure by value
const Attributes Nest = 1<<8; ///< Nested function static chain
const Attributes ReadNone = 1<<9; ///< Function does not access memory
const Attributes ReadOnly = 1<<10; ///< Function only reads from memory
const Attributes NoInline = 1<<11; ///< inline=never
const Attributes AlwaysInline = 1<<12; ///< inline=always
const Attributes OptimizeForSize = 1<<13; ///< opt_size
const Attributes StackProtect = 1<<14; ///< Stack protection.
const Attributes StackProtectReq = 1<<15; ///< Stack protection required.
const Attributes Alignment = 31<<16; ///< Alignment of parameter (5 bits)
// stored as log2 of alignment with +1 bias
// 0 means unaligned different from align 1
const Attributes NoCapture = 1<<21; ///< Function creates no aliases of pointer
const Attributes NoRedZone = 1<<22; /// disable redzone
const Attributes NoImplicitFloat = 1<<23; /// disable implicit floating point
/// instructions.
const Attributes Naked = 1<<24; ///< Naked function
const Attributes InlineHint = 1<<25; ///< source said inlining was
///desirable
const Attributes StackAlignment = 7<<26; ///< Alignment of stack for
///function (3 bits) stored as log2
///of alignment with +1 bias
///0 means unaligned (different from
///alignstack(1))
const Attributes Hotpatch = 1<<29; ///< Function should have special
///'hotpatch' sequence in prologue
/// @brief Attributes that only apply to function parameters.
const Attributes ParameterOnly = ByVal | Nest | StructRet | NoCapture;
/// @brief Attributes that may be applied to the function itself. These cannot
/// be used on return values or function parameters.
const Attributes FunctionOnly = NoReturn | NoUnwind | ReadNone | ReadOnly |
NoInline | AlwaysInline | OptimizeForSize | StackProtect | StackProtectReq |
NoRedZone | NoImplicitFloat | Naked | InlineHint | StackAlignment |
Hotpatch;
/// @brief Parameter attributes that do not apply to vararg call arguments.
const Attributes VarArgsIncompatible = StructRet;
/// @brief Attributes that are mutually incompatible.
const Attributes MutuallyIncompatible[4] = {
ByVal | InReg | Nest | StructRet,
ZExt | SExt,
ReadNone | ReadOnly,
NoInline | AlwaysInline
};
/// @brief Which attributes cannot be applied to a type.
Attributes typeIncompatible(const Type *Ty);
/// This turns an int alignment (a power of 2, normally) into the
/// form used internally in Attributes.
inline Attributes constructAlignmentFromInt(unsigned i) {
// Default alignment, allow the target to define how to align it.
if (i == 0)
return 0;
assert(isPowerOf2_32(i) && "Alignment must be a power of two.");
assert(i <= 0x40000000 && "Alignment too large.");
return (Log2_32(i)+1) << 16;
}
/// This returns the alignment field of an attribute as a byte alignment value.
inline unsigned getAlignmentFromAttrs(Attributes A) {
Attributes Align = A & Attribute::Alignment;
if (Align == 0)
return 0;
return 1U << ((Align >> 16) - 1);
}
/// This turns an int stack alignment (which must be a power of 2) into
/// the form used internally in Attributes.
inline Attributes constructStackAlignmentFromInt(unsigned i) {
// Default alignment, allow the target to define how to align it.
if (i == 0)
return 0;
assert(isPowerOf2_32(i) && "Alignment must be a power of two.");
assert(i <= 0x100 && "Alignment too large.");
return (Log2_32(i)+1) << 26;
}
/// This returns the stack alignment field of an attribute as a byte alignment
/// value.
inline unsigned getStackAlignmentFromAttrs(Attributes A) {
Attributes StackAlign = A & Attribute::StackAlignment;
if (StackAlign == 0)
return 0;
return 1U << ((StackAlign >> 26) - 1);
}
/// 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(Attributes Attrs);
} // end namespace Attribute
/// 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(unsigned Idx, Attributes Attrs) {
AttributeWithIndex P;
P.Index = Idx;
P.Attrs = Attrs;
return P;
}
};
//===----------------------------------------------------------------------===//
// AttrListPtr Smart Pointer
//===----------------------------------------------------------------------===//
class AttributeListImpl;
/// AttrListPtr - This class manages the ref count for the opaque
/// AttributeListImpl object and provides accessors for it.
class AttrListPtr {
/// AttrList - The attributes that we are managing. This can be null
/// to represent the empty attributes list.
AttributeListImpl *AttrList;
public:
AttrListPtr() : AttrList(0) {}
AttrListPtr(const AttrListPtr &P);
const AttrListPtr &operator=(const AttrListPtr &RHS);
~AttrListPtr();
//===--------------------------------------------------------------------===//
// Attribute List Construction and Mutation
//===--------------------------------------------------------------------===//
/// get - Return a Attributes list with the specified parameter in it.
static AttrListPtr get(const AttributeWithIndex *Attr, unsigned NumAttrs);
/// get - Return a Attribute list with the parameters specified by the
/// consecutive random access iterator range.
template <typename Iter>
static AttrListPtr get(const Iter &I, const Iter &E) {
if (I == E) return AttrListPtr(); // Empty list.
return get(&*I, static_cast<unsigned>(E-I));
}
/// addAttr - Add the specified attribute at the specified index to this
/// attribute list. Since attribute lists are immutable, this
/// returns the new list.
AttrListPtr addAttr(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.
AttrListPtr removeAttr(unsigned Idx, Attributes Attrs) const;
//===--------------------------------------------------------------------===//
// Attribute List Accessors
//===--------------------------------------------------------------------===//
/// getParamAttributes - The attributes for the specified index are
/// returned.
Attributes getParamAttributes(unsigned Idx) const {
assert (Idx && Idx != ~0U && "Invalid parameter index!");
return getAttributes(Idx);
}
/// getRetAttributes - The attributes for the ret value are
/// returned.
Attributes getRetAttributes() const {
return getAttributes(0);
}
/// getFnAttributes - The function attributes are returned.
Attributes getFnAttributes() const {
return getAttributes(~0U);
}
/// paramHasAttr - Return true if the specified parameter index has the
/// specified attribute set.
bool paramHasAttr(unsigned Idx, Attributes Attr) const {
return (getAttributes(Idx) & Attr) != 0;
}
/// getParamAlignment - Return the alignment for the specified function
/// parameter.
unsigned getParamAlignment(unsigned Idx) const {
return Attribute::getAlignmentFromAttrs(getAttributes(Idx));
}
/// hasAttrSomewhere - Return true if the specified attribute is set for at
/// least one parameter or for the return value.
bool hasAttrSomewhere(Attributes Attr) const;
/// operator==/!= - Provide equality predicates.
bool operator==(const AttrListPtr &RHS) const
{ return AttrList == RHS.AttrList; }
bool operator!=(const AttrListPtr &RHS) const
{ return AttrList != RHS.AttrList; }
void dump() const;
//===--------------------------------------------------------------------===//
// 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;
private:
explicit AttrListPtr(AttributeListImpl *L);
/// getAttributes - The attributes for the specified index are
/// returned. Attributes for the result are denoted with Idx = 0.
Attributes getAttributes(unsigned Idx) const;
};
} // End llvm namespace
#endif