-//===-- llvm/Attributes.h - Container for Attributes ---*---------- C++ -*-===//
+//===-- llvm/Attributes.h - Container for Attributes ------------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
#ifndef LLVM_ATTRIBUTES_H
#define LLVM_ATTRIBUTES_H
+#include "llvm/AttributesImpl.h"
+#include "llvm/Support/MathExtras.h"
+#include "llvm/ADT/ArrayRef.h"
+#include <cassert>
#include <string>
namespace llvm {
+
+class LLVMContext;
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
+/// AttrConst - We use this proxy POD type to allow constructing Attributes
+/// constants using initializer lists. Do not use this class directly.
+struct AttrConst {
+ uint64_t v;
+ AttrConst operator | (const AttrConst Attrs) const {
+ AttrConst Res = {v | Attrs.v};
+ return Res;
+ }
+ AttrConst operator ~ () const {
+ AttrConst Res = {~v};
+ return Res;
+ }
+};
+
+/// 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 Alignment = 0xffff<<16; ///< Alignment of parameter (16 bits)
- // 0 = unknown, else in clear (not log)
-
-/// @brief Attributes that only apply to function parameters.
-const Attributes ParameterOnly = ByVal | Nest | StructRet;
+/// We declare AttrConst objects that will be used throughout the code and also
+/// raw uint64_t objects with _i suffix to be used below for other constant
+/// declarations. This is done to avoid static CTORs and at the same time to
+/// keep type-safety of Attributes.
+#define DECLARE_LLVM_ATTRIBUTE(name, value) \
+ const uint64_t name##_i = value; \
+ const AttrConst name = {value};
+
+DECLARE_LLVM_ATTRIBUTE(None,0) ///< No attributes have been set
+DECLARE_LLVM_ATTRIBUTE(ZExt,1<<0) ///< Zero extended before/after call
+DECLARE_LLVM_ATTRIBUTE(SExt,1<<1) ///< Sign extended before/after call
+DECLARE_LLVM_ATTRIBUTE(NoReturn,1<<2) ///< Mark the function as not returning
+DECLARE_LLVM_ATTRIBUTE(InReg,1<<3) ///< Force argument to be passed in register
+DECLARE_LLVM_ATTRIBUTE(StructRet,1<<4) ///< Hidden pointer to structure to return
+DECLARE_LLVM_ATTRIBUTE(NoUnwind,1<<5) ///< Function doesn't unwind stack
+DECLARE_LLVM_ATTRIBUTE(NoAlias,1<<6) ///< Considered to not alias after call
+DECLARE_LLVM_ATTRIBUTE(ByVal,1<<7) ///< Pass structure by value
+DECLARE_LLVM_ATTRIBUTE(Nest,1<<8) ///< Nested function static chain
+DECLARE_LLVM_ATTRIBUTE(ReadNone,1<<9) ///< Function does not access memory
+DECLARE_LLVM_ATTRIBUTE(ReadOnly,1<<10) ///< Function only reads from memory
+DECLARE_LLVM_ATTRIBUTE(NoInline,1<<11) ///< inline=never
+DECLARE_LLVM_ATTRIBUTE(AlwaysInline,1<<12) ///< inline=always
+DECLARE_LLVM_ATTRIBUTE(OptimizeForSize,1<<13) ///< opt_size
+DECLARE_LLVM_ATTRIBUTE(StackProtect,1<<14) ///< Stack protection.
+DECLARE_LLVM_ATTRIBUTE(StackProtectReq,1<<15) ///< Stack protection required.
+DECLARE_LLVM_ATTRIBUTE(Alignment,31<<16) ///< Alignment of parameter (5 bits)
+ // stored as log2 of alignment with +1 bias
+ // 0 means unaligned different from align 1
+DECLARE_LLVM_ATTRIBUTE(NoCapture,1<<21) ///< Function creates no aliases of pointer
+DECLARE_LLVM_ATTRIBUTE(NoRedZone,1<<22) /// disable redzone
+DECLARE_LLVM_ATTRIBUTE(NoImplicitFloat,1<<23) /// disable implicit floating point
+ /// instructions.
+DECLARE_LLVM_ATTRIBUTE(Naked,1<<24) ///< Naked function
+DECLARE_LLVM_ATTRIBUTE(InlineHint,1<<25) ///< source said inlining was
+ ///desirable
+DECLARE_LLVM_ATTRIBUTE(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))
+DECLARE_LLVM_ATTRIBUTE(ReturnsTwice,1<<29) ///< Function can return twice
+DECLARE_LLVM_ATTRIBUTE(UWTable,1<<30) ///< Function must be in a unwind
+ ///table
+DECLARE_LLVM_ATTRIBUTE(NonLazyBind,1U<<31) ///< Function is called early and/or
+ /// often, so lazy binding isn't
+ /// worthwhile.
+DECLARE_LLVM_ATTRIBUTE(AddressSafety,1ULL<<32) ///< Address safety checking is on.
+
+#undef DECLARE_LLVM_ATTRIBUTE
-/// @brief Attributes that only apply to function return values.
-const Attributes ReturnOnly = NoReturn | NoUnwind | ReadNone | ReadOnly;
+/// 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.
+
+/// @brief Attributes that only apply to function parameters.
+const AttrConst ParameterOnly = {ByVal_i | Nest_i |
+ StructRet_i | NoCapture_i};
-/// @brief Parameter attributes that do not apply to vararg call arguments.
-const Attributes VarArgsIncompatible = StructRet;
+/// @brief Attributes that may be applied to the function itself. These cannot
+/// be used on return values or function parameters.
+const AttrConst FunctionOnly = {NoReturn_i | NoUnwind_i | ReadNone_i |
+ ReadOnly_i | NoInline_i | AlwaysInline_i | OptimizeForSize_i |
+ StackProtect_i | StackProtectReq_i | NoRedZone_i | NoImplicitFloat_i |
+ Naked_i | InlineHint_i | StackAlignment_i |
+ UWTable_i | NonLazyBind_i | ReturnsTwice_i | AddressSafety_i};
/// @brief Attributes that are mutually incompatible.
-const Attributes MutuallyIncompatible[3] = {
- ByVal | InReg | Nest | StructRet,
- ZExt | SExt,
- ReadNone | ReadOnly
+const AttrConst MutuallyIncompatible[5] = {
+ {ByVal_i | Nest_i | StructRet_i},
+ {ByVal_i | Nest_i | InReg_i },
+ {ZExt_i | SExt_i},
+ {ReadNone_i | ReadOnly_i},
+ {NoInline_i | AlwaysInline_i}
};
-/// @brief Which attributes cannot be applied to a type.
-Attributes typeIncompatible(const Type *Ty);
+} // namespace Attribute
-/// This turns an int alignment (a power of 2, normally) into the
-/// form used internally in Attributes.
-inline Attributes constructAlignmentFromInt(unsigned i) {
- return (i << 16);
-}
+/// AttributeImpl - The internal representation of the Attributes class. This is
+/// uniquified.
+class AttributesImpl;
-/// 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
+/// Attributes - A bitset of attributes.
+class Attributes {
+public:
+ enum AttrVal {
+ None = 0, ///< No attributes have been set
+ ZExt = 1, ///< Zero extended before/after call
+ SExt = 2, ///< Sign extended before/after call
+ NoReturn = 3, ///< Mark the function as not returning
+ InReg = 4, ///< Force argument to be passed in register
+ StructRet = 5, ///< Hidden pointer to structure to return
+ NoUnwind = 6, ///< Function doesn't unwind stack
+ NoAlias = 7, ///< Considered to not alias after call
+ ByVal = 8, ///< Pass structure by value
+ Nest = 9, ///< Nested function static chain
+ ReadNone = 10, ///< Function does not access memory
+ ReadOnly = 11, ///< Function only reads from memory
+ NoInline = 12, ///< inline=never
+ AlwaysInline = 13, ///< inline=always
+ OptimizeForSize = 14, ///< opt_size
+ StackProtect = 15, ///< Stack protection.
+ StackProtectReq = 16, ///< Stack protection required.
+ Alignment = 17, ///< Alignment of parameter (5 bits)
+ ///< stored as log2 of alignment with +1 bias
+ ///< 0 means unaligned different from align 1
+ NoCapture = 18, ///< Function creates no aliases of pointer
+ NoRedZone = 19, ///< Disable redzone
+ NoImplicitFloat = 20, ///< Disable implicit floating point insts
+ Naked = 21, ///< Naked function
+ InlineHint = 22, ///< Source said inlining was desirable
+ StackAlignment = 23, ///< Alignment of stack for function (3 bits)
+ ///< stored as log2 of alignment with +1 bias 0
+ ///< means unaligned (different from
+ ///< alignstack={1))
+ ReturnsTwice = 24, ///< Function can return twice
+ UWTable = 25, ///< Function must be in a unwind table
+ NonLazyBind = 26, ///< Function is called early and/or
+ ///< often, so lazy binding isn't worthwhile
+ AddressSafety = 27 ///< Address safety checking is on.
+ };
+private:
+ AttributesImpl Attrs;
-namespace Attribute {
-} // end namespace Attribute
+ explicit Attributes(AttributesImpl *A);
+public:
+ Attributes() : Attrs(0) {}
+ explicit Attributes(uint64_t Val);
+ /*implicit*/ Attributes(Attribute::AttrConst Val);
+ Attributes(const Attributes &A);
+
+ class Builder {
+ friend class Attributes;
+ uint64_t Bits;
+ public:
+ Builder() : Bits(0) {}
+ Builder(const Attributes &A) : Bits(A.Raw()) {}
+
+ void clear() { Bits = 0; }
+
+ bool hasAttributes() const;
+ bool hasAttributes(const Attributes &A) const;
+ bool hasAlignmentAttr() const;
+
+ uint64_t getAlignment() const;
+
+ void addAttribute(Attributes::AttrVal Val);
+ void removeAttribute(Attributes::AttrVal Val);
+
+ void addAlignmentAttr(unsigned Align);
+ void addStackAlignmentAttr(unsigned Align);
+
+ void removeAttributes(const Attributes &A);
+ };
+
+ /// get - Return a uniquified Attributes object. This takes the uniquified
+ /// value from the Builder and wraps it in the Attributes class.
+ static Attributes get(Builder &B);
+ static Attributes get(LLVMContext &Context, Builder &B);
+
+ /// @brief Parameter attributes that do not apply to vararg call arguments.
+ bool hasIncompatibleWithVarArgsAttrs() const {
+ return hasAttribute(Attributes::StructRet);
+ }
+
+ /// @brief Return true if the attribute is present.
+ bool hasAttribute(AttrVal Val) const;
+
+ /// @brief Return true if attributes exist
+ bool hasAttributes() const {
+ return Attrs.hasAttributes();
+ }
+
+ /// @brief Return true if the attributes are a non-null intersection.
+ bool hasAttributes(const Attributes &A) const;
+
+ /// This returns the alignment field of an attribute as a byte alignment
+ /// value.
+ unsigned getAlignment() const;
+
+ /// This returns the stack alignment field of an attribute as a byte alignment
+ /// value.
+ unsigned getStackAlignment() const;
+
+ bool isEmptyOrSingleton() const;
+
+ // This is a "safe bool() operator".
+ operator const void *() const { return Attrs.Bits ? this : 0; }
+ bool operator == (const Attributes &A) const {
+ return Attrs.Bits == A.Attrs.Bits;
+ }
+ bool operator != (const Attributes &A) const {
+ return Attrs.Bits != A.Attrs.Bits;
+ }
+
+ Attributes operator | (const Attributes &A) const;
+ Attributes operator & (const Attributes &A) const;
+ Attributes operator ^ (const Attributes &A) const;
+ Attributes &operator |= (const Attributes &A);
+ Attributes &operator &= (const Attributes &A);
+ Attributes operator ~ () const;
+
+ uint64_t Raw() const;
+
+ /// constructAlignmentFromInt - This turns an int alignment (a power of 2,
+ /// normally) into the form used internally in Attributes.
+ static Attributes constructAlignmentFromInt(unsigned i) {
+ // Default alignment, allow the target to define how to align it.
+ if (i == 0)
+ return Attribute::None;
+
+ assert(isPowerOf2_32(i) && "Alignment must be a power of two.");
+ assert(i <= 0x40000000 && "Alignment too large.");
+ return Attributes((Log2_32(i)+1) << 16);
+ }
+
+ /// constructStackAlignmentFromInt - This turns an int stack alignment (which
+ /// must be a power of 2) into the form used internally in Attributes.
+ static Attributes constructStackAlignmentFromInt(unsigned i) {
+ // Default alignment, allow the target to define how to align it.
+ if (i == 0)
+ return Attribute::None;
+
+ assert(isPowerOf2_32(i) && "Alignment must be a power of two.");
+ assert(i <= 0x100 && "Alignment too large.");
+ return Attributes((Log2_32(i)+1) << 26);
+ }
-/// This is just a pair of values to associate a set of attributes
-/// with an index.
+ /// @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) {
+ // FIXME: It doesn't make sense to store the alignment information as an
+ // expanded out value, we should store it as a log2 value. However, we
+ // can't just change that here without breaking bitcode compatibility. If
+ // this ever becomes a problem in practice, we should introduce new tag
+ // numbers in the bitcode file and have those tags use a more efficiently
+ // encoded alignment field.
+
+ // Store the alignment in the bitcode as a 16-bit raw value instead of a
+ // 5-bit log2 encoded value. Shift the bits above the alignment up by 11
+ // bits.
+ uint64_t EncodedAttrs = Attrs.Raw() & 0xffff;
+ if (Attrs.hasAttribute(Attributes::Alignment))
+ EncodedAttrs |= (1ULL << 16) <<
+ (((Attrs.Raw() & Attribute::Alignment_i) - 1) >> 16);
+ EncodedAttrs |= (Attrs.Raw() & (0xfffULL << 21)) << 11;
+ return EncodedAttrs;
+ }
+
+ /// 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(uint64_t EncodedAttrs) {
+ // The alignment is stored as a 16-bit raw value from bits 31--16. We shift
+ // the bits above 31 down by 11 bits.
+ unsigned Alignment = (EncodedAttrs & (0xffffULL << 16)) >> 16;
+ assert((!Alignment || isPowerOf2_32(Alignment)) &&
+ "Alignment must be a power of two.");
+
+ Attributes Attrs(EncodedAttrs & 0xffff);
+ if (Alignment)
+ Attrs |= Attributes::constructAlignmentFromInt(Alignment);
+ Attrs |= Attributes((EncodedAttrs & (0xfffULL << 32)) >> 11);
+ return Attrs;
+ }
+
+ /// 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;
+};
+
+//===----------------------------------------------------------------------===//
+// 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.
-
+ 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;
return P;
}
};
-
+
//===----------------------------------------------------------------------===//
// AttrListPtr Smart Pointer
//===----------------------------------------------------------------------===//
class AttributeListImpl;
-
-/// AttrListPtr - This class manages the ref count for the opaque
+
+/// 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
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));
- }
+
+ /// get - Return a Attributes list with the specified parameters in it.
+ static AttrListPtr get(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.
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
//===--------------------------------------------------------------------===//
-
- /// getAttributes - The attributes for the specified index are
- /// returned. Attributes for the result are denoted with Idx = 0.
- Attributes getAttributes(unsigned Idx) const;
-
+ /// 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(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;
+ return getAttributes(Idx).hasAttributes(Attr);
}
-
+
/// getParamAlignment - Return the alignment for the specified function
/// parameter.
unsigned getParamAlignment(unsigned Idx) const {
- return (getAttributes(Idx) & Attribute::Alignment) >> 16;
+ 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 Attr) const;
+ unsigned getNumAttrs() const;
+ Attributes &getAttributesAtIndex(unsigned i) 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; }
-
+ 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.
+ /// 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.
+
+ /// 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