#ifndef LLVM_ATTRIBUTES_H
#define LLVM_ATTRIBUTES_H
-#include "llvm/AttributesImpl.h"
-#include "llvm/Support/MathExtras.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;
-namespace Attribute {
-
-/// 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.
-
-/// 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 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
-
-} // namespace Attribute
-
-/// AttributeImpl - The internal representation of the Attributes class. This is
-/// uniquified.
-class AttributesImpl;
-
/// 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
/// uwtable + nounwind = Needs an entry because the ABI says so.
enum AttrVal {
- None = 0, ///< No attributes have been set
- AddressSafety = 1, ///< Address safety checking is on.
- Alignment = 2, ///< Alignment of parameter (5 bits)
+ // 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 = 3, ///< inline=always
- ByVal = 4, ///< Pass structure by value
- InlineHint = 5, ///< Source said inlining was desirable
- InReg = 6, ///< Force argument to be passed in register
- Naked = 7, ///< Naked function
- Nest = 8, ///< Nested function static chain
- NoAlias = 9, ///< Considered to not alias after call
- NoCapture = 10, ///< Function creates no aliases of pointer
- NoImplicitFloat = 11, ///< Disable implicit floating point insts
- NoInline = 12, ///< inline=never
- NonLazyBind = 13, ///< Function is called early and/or
+ 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 = 14, ///< Disable redzone
- NoReturn = 15, ///< Mark the function as not returning
- NoUnwind = 16, ///< Function doesn't unwind stack
- OptimizeForSize = 17, ///< opt_size
- ReadNone = 18, ///< Function does not access memory
- ReadOnly = 19, ///< Function only reads from memory
- ReturnsTwice = 20, ///< Function can return twice
- SExt = 21, ///< Sign extended before/after call
- StackAlignment = 22, ///< Alignment of stack for function (3 bits)
+ 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 = 23, ///< Stack protection.
- StackProtectReq = 24, ///< Stack protection required.
- StructRet = 25, ///< Hidden pointer to structure to return
- UWTable = 26, ///< Function must be in a unwind table
- ZExt = 27 ///< Zero extended before/after call
+ 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;
-
- explicit Attributes(AttributesImpl *A);
+ AttributesImpl *Attrs;
+ Attributes(AttributesImpl *A) : Attrs(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;
-
- Builder &addAttribute(Attributes::AttrVal Val);
- Builder &removeAttribute(Attributes::AttrVal Val);
-
- void addAlignmentAttr(unsigned Align);
- void addStackAlignmentAttr(unsigned Align);
-
- void removeAttributes(const Attributes &A);
-
- /// @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);
- }
- };
/// 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);
+ 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 {
- return Attrs.hasAttributes();
- }
+ bool hasAttributes() const;
/// @brief Return true if the attributes are a non-null intersection.
bool hasAttributes(const Attributes &A) const;
hasAttribute(Attributes::UWTable) ||
hasAttribute(Attributes::NonLazyBind) ||
hasAttribute(Attributes::ReturnsTwice) ||
- hasAttribute(Attributes::AddressSafety);
+ hasAttribute(Attributes::AddressSafety) ||
+ hasAttribute(Attributes::MinSize);
}
- 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 == A.Attrs;
}
- bool operator != (const Attributes &A) const {
- return Attrs.Bits != A.Attrs.Bits;
+ bool operator!=(const Attributes &A) const {
+ return Attrs != A.Attrs;
}
- 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 Attributes();
-
- 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 Attributes();
-
- assert(isPowerOf2_32(i) && "Alignment must be a power of two.");
- assert(i <= 0x100 && "Alignment too large.");
- return Attributes((Log2_32(i)+1) << 26);
- }
-
/// @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 |= Attrs.getAlignment() << 16;
- EncodedAttrs |= (Attrs.Raw() & (0xfffULL << 21)) << 11;
- return EncodedAttrs;
- }
+ 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(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;
- }
+ 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
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
//===----------------------------------------------------------------------===//
///< Index 0 is used for return value attributes.
///< Index ~0U is used for function attributes.
- static AttributeWithIndex get(unsigned Idx,
+ static AttributeWithIndex get(LLVMContext &C, unsigned Idx,
ArrayRef<Attributes::AttrVal> Attrs) {
- Attributes::Builder B;
-
- for (ArrayRef<Attributes::AttrVal>::iterator I = Attrs.begin(),
- E = Attrs.end(); I != E; ++I)
- B.addAttribute(*I);
-
- AttributeWithIndex P;
- P.Index = Idx;
- P.Attrs = Attributes::get(B);
- return P;
+ return get(Idx, Attributes::get(C, Attrs));
}
static AttributeWithIndex get(unsigned Idx, Attributes Attrs) {
AttributeWithIndex P;
/// 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.
+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 AttrListPtr(AttributeListImpl *LI) : AttrList(LI) {}
public:
AttrListPtr() : AttrList(0) {}
- AttrListPtr(const AttrListPtr &P);
+ AttrListPtr(const AttrListPtr &P) : AttrList(P.AttrList) {}
const AttrListPtr &operator=(const AttrListPtr &RHS);
- ~AttrListPtr();
//===--------------------------------------------------------------------===//
// Attribute List Construction and Mutation
//===--------------------------------------------------------------------===//
/// get - Return a Attributes list with the specified parameters in it.
- static AttrListPtr get(ArrayRef<AttributeWithIndex> Attrs);
+ static AttrListPtr 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.
- AttrListPtr addAttr(unsigned Idx, Attributes Attrs) const;
+ AttrListPtr 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.
- AttrListPtr removeAttr(unsigned Idx, Attributes Attrs) const;
+ AttrListPtr removeAttr(LLVMContext &C, unsigned Idx, Attributes Attrs) const;
//===--------------------------------------------------------------------===//
// Attribute List Accessors
/// getRetAttributes - The attributes for the ret value are
/// returned.
Attributes getRetAttributes() const {
- return getAttributes(0);
+ return getAttributes(ReturnIndex);
}
/// getFnAttributes - The function attributes are returned.
Attributes getFnAttributes() const {
- return getAttributes(~0U);
+ return getAttributes(FunctionIndex);
}
/// paramHasAttr - Return true if the specified parameter index has the
/// hasAttrSomewhere - Return true if the specified attribute is set for at
/// least one parameter or for the return value.
- bool hasAttrSomewhere(Attributes Attr) const;
+ bool hasAttrSomewhere(Attributes::AttrVal Attr) const;
unsigned getNumAttrs() const;
Attributes &getAttributesAtIndex(unsigned i) const;
bool operator!=(const AttrListPtr &RHS) const
{ return AttrList != RHS.AttrList; }
- void dump() const;
-
//===--------------------------------------------------------------------===//
// Attribute List Introspection
//===--------------------------------------------------------------------===//
/// 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;
+ void dump() const;
};
} // End llvm namespace