clang 8.0.0

TargetInfo.h
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1 //===---- TargetInfo.h - Encapsulate target details -------------*- C++ -*-===//
2 //
3 // The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // These classes wrap the information about a call or function
11 // definition used to handle ABI compliancy.
12 //
13 //===----------------------------------------------------------------------===//
14
15 #ifndef LLVM_CLANG_LIB_CODEGEN_TARGETINFO_H
16 #define LLVM_CLANG_LIB_CODEGEN_TARGETINFO_H
17
18 #include "CodeGenModule.h"
19 #include "CGValue.h"
20 #include "clang/AST/Type.h"
21 #include "clang/Basic/LLVM.h"
22 #include "clang/Basic/SyncScope.h"
23 #include "llvm/ADT/SmallString.h"
24 #include "llvm/ADT/StringRef.h"
25
26 namespace llvm {
27 class Constant;
28 class GlobalValue;
29 class Type;
30 class Value;
31 }
32
33 namespace clang {
34 class Decl;
35
36 namespace CodeGen {
37 class ABIInfo;
38 class CallArgList;
39 class CodeGenFunction;
40 class CGBlockInfo;
41 class CGFunctionInfo;
42
43 /// TargetCodeGenInfo - This class organizes various target-specific
44 /// codegeneration issues, like target-specific attributes, builtins and so
45 /// on.
46 class TargetCodeGenInfo {
47 ABIInfo *Info;
48
49 public:
50 // WARNING: Acquires the ownership of ABIInfo.
51 TargetCodeGenInfo(ABIInfo *info = nullptr) : Info(info) {}
52 virtual ~TargetCodeGenInfo();
53
54 /// getABIInfo() - Returns ABI info helper for the target.
55 const ABIInfo &getABIInfo() const { return *Info; }
56
57 /// setTargetAttributes - Provides a convenient hook to handle extra
58 /// target-specific attributes for the given global.
59 virtual void setTargetAttributes(const Decl *D, llvm::GlobalValue *GV,
60 CodeGen::CodeGenModule &M) const {}
61
62 /// emitTargetMD - Provides a convenient hook to handle extra
63 /// target-specific metadata for the given global.
64 virtual void emitTargetMD(const Decl *D, llvm::GlobalValue *GV,
65 CodeGen::CodeGenModule &M) const {}
66
67 /// Determines the size of struct _Unwind_Exception on this platform,
68 /// in 8-bit units. The Itanium ABI defines this as:
69 /// struct _Unwind_Exception {
70 /// uint64 exception_class;
71 /// _Unwind_Exception_Cleanup_Fn exception_cleanup;
72 /// uint64 private_1;
73 /// uint64 private_2;
74 /// };
75 virtual unsigned getSizeOfUnwindException() const;
76
77 /// Controls whether __builtin_extend_pointer should sign-extend
78 /// pointers to uint64_t or zero-extend them (the default). Has
79 /// no effect for targets:
80 /// - that have 64-bit pointers, or
81 /// - that cannot address through registers larger than pointers, or
82 /// - that implicitly ignore/truncate the top bits when addressing
83 /// through such registers.
84 virtual bool extendPointerWithSExt() const { return false; }
85
86 /// Determines the DWARF register number for the stack pointer, for
87 /// exception-handling purposes. Implements __builtin_dwarf_sp_column.
88 ///
89 /// Returns -1 if the operation is unsupported by this target.
90 virtual int getDwarfEHStackPointer(CodeGen::CodeGenModule &M) const {
91 return -1;
92 }
93
94 /// Initializes the given DWARF EH register-size table, a char*.
95 /// Implements __builtin_init_dwarf_reg_size_table.
96 ///
97 /// Returns true if the operation is unsupported by this target.
98 virtual bool initDwarfEHRegSizeTable(CodeGen::CodeGenFunction &CGF,
99 llvm::Value *Address) const {
100 return true;
101 }
102
103 /// Performs the code-generation required to convert a return
104 /// address as stored by the system into the actual address of the
105 /// next instruction that will be executed.
106 ///
107 /// Used by __builtin_extract_return_addr().
108 virtual llvm::Value *decodeReturnAddress(CodeGen::CodeGenFunction &CGF,
109 llvm::Value *Address) const {
110 return Address;
111 }
112
113 /// Performs the code-generation required to convert the address
114 /// of an instruction into a return address suitable for storage
115 /// by the system in a return slot.
116 ///
117 /// Used by __builtin_frob_return_addr().
118 virtual llvm::Value *encodeReturnAddress(CodeGen::CodeGenFunction &CGF,
119 llvm::Value *Address) const {
120 return Address;
121 }
122
123 /// Corrects the low-level LLVM type for a given constraint and "usual"
124 /// type.
125 ///
126 /// \returns A pointer to a new LLVM type, possibly the same as the original
127 /// on success; 0 on failure.
128 virtual llvm::Type *adjustInlineAsmType(CodeGen::CodeGenFunction &CGF,
129 StringRef Constraint,
130 llvm::Type *Ty) const {
131 return Ty;
132 }
133
134 /// Adds constraints and types for result registers.
135 virtual void addReturnRegisterOutputs(
136 CodeGen::CodeGenFunction &CGF, CodeGen::LValue ReturnValue,
137 std::string &Constraints, std::vector<llvm::Type *> &ResultRegTypes,
138 std::vector<llvm::Type *> &ResultTruncRegTypes,
139 std::vector<CodeGen::LValue> &ResultRegDests, std::string &AsmString,
140 unsigned NumOutputs) const {}
141
142 /// doesReturnSlotInterfereWithArgs - Return true if the target uses an
143 /// argument slot for an 'sret' type.
144 virtual bool doesReturnSlotInterfereWithArgs() const { return true; }
145
146 /// Retrieve the address of a function to call immediately before
147 /// calling objc_retainAutoreleasedReturnValue. The
148 /// implementation of objc_autoreleaseReturnValue sniffs the
149 /// instruction stream following its return address to decide
150 /// whether it's a call to objc_retainAutoreleasedReturnValue.
151 /// This can be prohibitively expensive, depending on the
152 /// relocation model, and so on some targets it instead sniffs for
153 /// a particular instruction sequence. This functions returns
154 /// that instruction sequence in inline assembly, which will be
155 /// empty if none is required.
156 virtual StringRef getARCRetainAutoreleasedReturnValueMarker() const {
157 return "";
158 }
159
160 /// Return a constant used by UBSan as a signature to identify functions
161 /// possessing type information, or 0 if the platform is unsupported.
162 virtual llvm::Constant *
163 getUBSanFunctionSignature(CodeGen::CodeGenModule &CGM) const {
164 return nullptr;
165 }
166
167 /// Determine whether a call to an unprototyped functions under
168 /// the given calling convention should use the variadic
169 /// convention or the non-variadic convention.
170 ///
171 /// There's a good reason to make a platform's variadic calling
172 /// convention be different from its non-variadic calling
173 /// convention: the non-variadic arguments can be passed in
174 /// registers (better for performance), and the variadic arguments
175 /// can be passed on the stack (also better for performance). If
176 /// this is done, however, unprototyped functions *must* use the
177 /// non-variadic convention, because C99 states that a call
178 /// through an unprototyped function type must succeed if the
179 /// function was defined with a non-variadic prototype with
180 /// compatible parameters. Therefore, splitting the conventions
181 /// makes it impossible to call a variadic function through an
182 /// unprototyped type. Since function prototypes came out in the
183 /// late 1970s, this is probably an acceptable trade-off.
184 /// Nonetheless, not all platforms are willing to make it, and in
185 /// particularly x86-64 bends over backwards to make the
186 /// conventions compatible.
187 ///
188 /// The default is false. This is correct whenever:
189 /// - the conventions are exactly the same, because it does not
190 /// matter and the resulting IR will be somewhat prettier in
191 /// certain cases; or
192 /// - the conventions are substantively different in how they pass
193 /// arguments, because in this case using the variadic convention
194 /// will lead to C99 violations.
195 ///
196 /// However, some platforms make the conventions identical except
197 /// for passing additional out-of-band information to a variadic
198 /// function: for example, x86-64 passes the number of SSE
199 /// arguments in %al. On these platforms, it is desirable to
200 /// call unprototyped functions using the variadic convention so
201 /// that unprototyped calls to varargs functions still succeed.
202 ///
203 /// Relatedly, platforms which pass the fixed arguments to this:
204 /// A foo(B, C, D);
205 /// differently than they would pass them to this:
206 /// A foo(B, C, D, ...);
207 /// may need to adjust the debugger-support code in Sema to do the
208 /// right thing when calling a function with no know signature.
209 virtual bool isNoProtoCallVariadic(const CodeGen::CallArgList &args,
210 const FunctionNoProtoType *fnType) const;
211
212 /// Gets the linker options necessary to link a dependent library on this
213 /// platform.
214 virtual void getDependentLibraryOption(llvm::StringRef Lib,
215 llvm::SmallString<24> &Opt) const;
216
217 /// Gets the linker options necessary to detect object file mismatches on
218 /// this platform.
219 virtual void getDetectMismatchOption(llvm::StringRef Name,
220 llvm::StringRef Value,
221 llvm::SmallString<32> &Opt) const {}
222
223 /// Get LLVM calling convention for OpenCL kernel.
224 virtual unsigned getOpenCLKernelCallingConv() const;
225
226 /// Get target specific null pointer.
227 /// \param T is the LLVM type of the null pointer.
228 /// \param QT is the clang QualType of the null pointer.
229 /// \return ConstantPointerNull with the given type \p T.
230 /// Each target can override it to return its own desired constant value.
231 virtual llvm::Constant *getNullPointer(const CodeGen::CodeGenModule &CGM,
232 llvm::PointerType *T, QualType QT) const;
233
234 /// Get target favored AST address space of a global variable for languages
235 /// other than OpenCL and CUDA.
236 /// If \p D is nullptr, returns the default target favored address space
237 /// for global variable.
238 virtual LangAS getGlobalVarAddressSpace(CodeGenModule &CGM,
239 const VarDecl *D) const;
240
241 /// Get the AST address space for alloca.
242 virtual LangAS getASTAllocaAddressSpace() const { return LangAS::Default; }
243
244 /// Perform address space cast of an expression of pointer type.
245 /// \param V is the LLVM value to be casted to another address space.
246 /// \param SrcAddr is the language address space of \p V.
247 /// \param DestAddr is the targeted language address space.
248 /// \param DestTy is the destination LLVM pointer type.
249 /// \param IsNonNull is the flag indicating \p V is known to be non null.
250 virtual llvm::Value *performAddrSpaceCast(CodeGen::CodeGenFunction &CGF,
251 llvm::Value *V, LangAS SrcAddr,
252 LangAS DestAddr, llvm::Type *DestTy,
253 bool IsNonNull = false) const;
254
255 /// Perform address space cast of a constant expression of pointer type.
256 /// \param V is the LLVM constant to be casted to another address space.
257 /// \param SrcAddr is the language address space of \p V.
258 /// \param DestAddr is the targeted language address space.
259 /// \param DestTy is the destination LLVM pointer type.
260 virtual llvm::Constant *performAddrSpaceCast(CodeGenModule &CGM,
261 llvm::Constant *V,
262 LangAS SrcAddr, LangAS DestAddr,
263 llvm::Type *DestTy) const;
264
265 /// Get the syncscope used in LLVM IR.
266 virtual llvm::SyncScope::ID getLLVMSyncScopeID(SyncScope S,
267 llvm::LLVMContext &C) const;
268
269 /// Interface class for filling custom fields of a block literal for OpenCL.
270 class TargetOpenCLBlockHelper {
271 public:
272 typedef std::pair<llvm::Value *, StringRef> ValueTy;
273 TargetOpenCLBlockHelper() {}
274 virtual ~TargetOpenCLBlockHelper() {}
275 /// Get the custom field types for OpenCL blocks.
276 virtual llvm::SmallVector<llvm::Type *, 1> getCustomFieldTypes() = 0;
277 /// Get the custom field values for OpenCL blocks.
278 virtual llvm::SmallVector<ValueTy, 1>
279 getCustomFieldValues(CodeGenFunction &CGF, const CGBlockInfo &Info) = 0;
280 virtual bool areAllCustomFieldValuesConstant(const CGBlockInfo &Info) = 0;
281 /// Get the custom field values for OpenCL blocks if all values are LLVM
282 /// constants.
283 virtual llvm::SmallVector<llvm::Constant *, 1>
284 getCustomFieldValues(CodeGenModule &CGM, const CGBlockInfo &Info) = 0;
285 };
286 virtual TargetOpenCLBlockHelper *getTargetOpenCLBlockHelper() const {
287 return nullptr;
288 }
289
290 /// Create an OpenCL kernel for an enqueued block. The kernel function is
291 /// a wrapper for the block invoke function with target-specific calling
292 /// convention and ABI as an OpenCL kernel. The wrapper function accepts
293 /// block context and block arguments in target-specific way and calls
294 /// the original block invoke function.
295 virtual llvm::Function *
296 createEnqueuedBlockKernel(CodeGenFunction &CGF,
297 llvm::Function *BlockInvokeFunc,
298 llvm::Value *BlockLiteral) const;
299
300 /// \return true if the target supports alias from the unmangled name to the
301 /// mangled name of functions declared within an extern "C" region and marked
302 /// as 'used', and having internal linkage.
303 virtual bool shouldEmitStaticExternCAliases() const { return true; }
304
305 virtual void setCUDAKernelCallingConvention(const FunctionType *&FT) const {}
306 };
307
308 } // namespace CodeGen
309 } // namespace clang
310
311 #endif // LLVM_CLANG_LIB_CODEGEN_TARGETINFO_H
clang::Builtin::ID
ID
Definition: Builtins.h:49
clang::QualType
A (possibly-)qualified type.
Definition: Type.h:638
llvm
DominatorTree GraphTraits specialization so the DominatorTree can be iterable by generic graph iterat...
Definition: Dominators.h:30
clang::FunctionType
FunctionType - C99 6.7.5.3 - Function Declarators.
Definition: Type.h:3355
Type.h
C Language Family Type Representation.
clang::Decl
Decl - This represents one declaration (or definition), e.g.
Definition: DeclBase.h:87
clang::CodeGen::TargetCodeGenInfo::getABIInfo
const ABIInfo & getABIInfo() const
getABIInfo() - Returns ABI info helper for the target.
Definition: TargetInfo.h:55
clang::CodeGen::AlignmentSource::Decl
The l-value was an access to a declared entity or something equivalently strong, like the address of ...
clang::CodeGen::TargetCodeGenInfo::extendPointerWithSExt
virtual bool extendPointerWithSExt() const
Controls whether __builtin_extend_pointer should sign-extend pointers to uint64_t or zero-extend them...
Definition: TargetInfo.h:84
Value
Value
Definition: UninitializedValues.cpp:102
clang::VarDecl
Represents a variable declaration or definition.
Definition: Decl.h:813
clang::CodeGen::TargetCodeGenInfo::getARCRetainAutoreleasedReturnValueMarker
virtual StringRef getARCRetainAutoreleasedReturnValueMarker() const
Retrieve the address of a function to call immediately before calling objc_retainAutoreleasedReturnVa...
Definition: TargetInfo.h:156
clang::LangAS
LangAS
Defines the address space values used by the address space qualifier of QualType. ...
Definition: AddressSpaces.h:26
clang::CodeGen::TargetCodeGenInfo::TargetOpenCLBlockHelper::ValueTy
std::pair< llvm::Value *, StringRef > ValueTy
Definition: TargetInfo.h:272
clang::CodeGen::TargetCodeGenInfo::getUBSanFunctionSignature
virtual llvm::Constant * getUBSanFunctionSignature(CodeGen::CodeGenModule &CGM) const
Return a constant used by UBSan as a signature to identify functions possessing type information...
Definition: TargetInfo.h:163
clang::CodeGen::TargetCodeGenInfo::getDetectMismatchOption
virtual void getDetectMismatchOption(llvm::StringRef Name, llvm::StringRef Value, llvm::SmallString< 32 > &Opt) const
Gets the linker options necessary to detect object file mismatches on this platform.
Definition: TargetInfo.h:219
clang::CodeGen::CodeGenFunction
CodeGenFunction - This class organizes the per-function state that is used while generating LLVM code...
Definition: CodeGenFunction.h:227
CGValue.h
LLVM.h
Forward-declares and imports various common LLVM datatypes that clang wants to use unqualified...
clang::CodeGen::TargetCodeGenInfo::getTargetOpenCLBlockHelper
virtual TargetOpenCLBlockHelper * getTargetOpenCLBlockHelper() const
Definition: TargetInfo.h:286
llvm::SmallString
Definition: LLVM.h:35
clang::CodeGen::TargetCodeGenInfo::setCUDAKernelCallingConvention
virtual void setCUDAKernelCallingConvention(const FunctionType *&FT) const
Definition: TargetInfo.h:305
clang::FunctionNoProtoType
Represents a K&R-style &#39;int foo()&#39; function, which has no information available about its arguments...
Definition: Type.h:3650
clang::CodeGen::TargetCodeGenInfo::TargetOpenCLBlockHelper
Interface class for filling custom fields of a block literal for OpenCL.
Definition: TargetInfo.h:270
clang::CodeGen::CGBlockInfo
CGBlockInfo - Information to generate a block literal.
Definition: CGBlocks.h:153
clang::CodeGen::TargetCodeGenInfo::TargetCodeGenInfo
TargetCodeGenInfo(ABIInfo *info=nullptr)
Definition: TargetInfo.h:51
CodeGenModule.h
clang::CodeGen::TargetCodeGenInfo::shouldEmitStaticExternCAliases
virtual bool shouldEmitStaticExternCAliases() const
Definition: TargetInfo.h:303
clang::CodeGen::TargetCodeGenInfo::initDwarfEHRegSizeTable
virtual bool initDwarfEHRegSizeTable(CodeGen::CodeGenFunction &CGF, llvm::Value *Address) const
Initializes the given DWARF EH register-size table, a char*.
Definition: TargetInfo.h:98
clang::CodeGen::TargetCodeGenInfo::doesReturnSlotInterfereWithArgs
virtual bool doesReturnSlotInterfereWithArgs() const
doesReturnSlotInterfereWithArgs - Return true if the target uses an argument slot for an &#39;sret&#39; type...
Definition: TargetInfo.h:144
clang::SyncScope
SyncScope
Defines synch scope values used internally by clang.
Definition: SyncScope.h:43
llvm::SmallVector
Definition: LLVM.h:36
clang::CodeGen::Address
An aligned address.
Definition: Address.h:25
clang::CodeGen::TargetCodeGenInfo
TargetCodeGenInfo - This class organizes various target-specific codegeneration issues, like target-specific attributes, builtins and so on.
Definition: TargetInfo.h:46
clang::CodeGen::CodeGenModule
This class organizes the cross-function state that is used while generating LLVM code.
Definition: CodeGenModule.h:274
Type
Optional< types::ID > Type
Definition: InterpolatingCompilationDatabase.cpp:128
clang
Dataflow Directional Tag Classes.
Definition: CFGReachabilityAnalysis.h:22
clang::CodeGen::TargetCodeGenInfo::TargetOpenCLBlockHelper::~TargetOpenCLBlockHelper
virtual ~TargetOpenCLBlockHelper()
Definition: TargetInfo.h:274
clang::CodeGen::TargetCodeGenInfo::setTargetAttributes
virtual void setTargetAttributes(const Decl *D, llvm::GlobalValue *GV, CodeGen::CodeGenModule &M) const
setTargetAttributes - Provides a convenient hook to handle extra target-specific attributes for the g...
Definition: TargetInfo.h:59
clang::CodeGen::TargetCodeGenInfo::emitTargetMD
virtual void emitTargetMD(const Decl *D, llvm::GlobalValue *GV, CodeGen::CodeGenModule &M) const
emitTargetMD - Provides a convenient hook to handle extra target-specific metadata for the given glob...
Definition: TargetInfo.h:64
clang::CodeGen::TargetCodeGenInfo::getASTAllocaAddressSpace
virtual LangAS getASTAllocaAddressSpace() const
Get the AST address space for alloca.
Definition: TargetInfo.h:242
SyncScope.h
Provides definitions for the atomic synchronization scopes.
clang::CodeGen::TargetCodeGenInfo::getDwarfEHStackPointer
virtual int getDwarfEHStackPointer(CodeGen::CodeGenModule &M) const
Determines the DWARF register number for the stack pointer, for exception-handling purposes...
Definition: TargetInfo.h:90
clang::CodeGen::TargetCodeGenInfo::adjustInlineAsmType
virtual llvm::Type * adjustInlineAsmType(CodeGen::CodeGenFunction &CGF, StringRef Constraint, llvm::Type *Ty) const
Corrects the low-level LLVM type for a given constraint and "usual" type.
Definition: TargetInfo.h:128
clang::CodeGen::TargetCodeGenInfo::TargetOpenCLBlockHelper::TargetOpenCLBlockHelper
TargetOpenCLBlockHelper()
Definition: TargetInfo.h:273
clang::CodeGen::TargetCodeGenInfo::addReturnRegisterOutputs
virtual void addReturnRegisterOutputs(CodeGen::CodeGenFunction &CGF, CodeGen::LValue ReturnValue, std::string &Constraints, std::vector< llvm::Type *> &ResultRegTypes, std::vector< llvm::Type *> &ResultTruncRegTypes, std::vector< CodeGen::LValue > &ResultRegDests, std::string &AsmString, unsigned NumOutputs) const
Adds constraints and types for result registers.
Definition: TargetInfo.h:135
clang::CodeGen::ABIInfo
ABIInfo - Target specific hooks for defining how a type should be passed or returned from functions...
Definition: ABIInfo.h:51
clang::CodeGen::TargetCodeGenInfo::decodeReturnAddress
virtual llvm::Value * decodeReturnAddress(CodeGen::CodeGenFunction &CGF, llvm::Value *Address) const
Performs the code-generation required to convert a return address as stored by the system into the ac...
Definition: TargetInfo.h:108
clang::CodeGen::LValue
LValue - This represents an lvalue references.
Definition: CGValue.h:167
clang::CodeGen::CallArgList
CallArgList - Type for representing both the value and type of arguments in a call.
Definition: CGCall.h:260
clang::CodeGen::TargetCodeGenInfo::encodeReturnAddress
virtual llvm::Value * encodeReturnAddress(CodeGen::CodeGenFunction &CGF, llvm::Value *Address) const
Performs the code-generation required to convert the address of an instruction into a return address ...
Definition: TargetInfo.h:118