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 CLANG_CODEGEN_TARGETINFO_H
16#define CLANG_CODEGEN_TARGETINFO_H
17
18namespace llvm {
19 class GlobalValue;
20 class Value;
21}
22
23namespace clang {
24 class ABIInfo;
25 class Decl;
26
27 namespace CodeGen {
28 class CodeGenModule;
29 class CodeGenFunction;
30 }
31
32 /// TargetCodeGenInfo - This class organizes various target-specific
33 /// codegeneration issues, like target-specific attributes, builtins and so
34 /// on.
35 class TargetCodeGenInfo {
36 ABIInfo *Info;
37 public:
38 // WARNING: Acquires the ownership of ABIInfo.
39 TargetCodeGenInfo(ABIInfo *info = 0):Info(info) { }
40 virtual ~TargetCodeGenInfo();
41
42 /// getABIInfo() - Returns ABI info helper for the target.
43 const ABIInfo& getABIInfo() const { return *Info; }
44
45 /// SetTargetAttributes - Provides a convenient hook to handle extra
46 /// target-specific attributes for the given global.
47 virtual void SetTargetAttributes(const Decl *D, llvm::GlobalValue *GV,
48 CodeGen::CodeGenModule &M) const { }
49
50 /// Controls whether __builtin_extend_pointer should sign-extend
51 /// pointers to uint64_t or zero-extend them (the default). Has
52 /// no effect for targets:
53 /// - that have 64-bit pointers, or
54 /// - that cannot address through registers larger than pointers, or
55 /// - that implicitly ignore/truncate the top bits when addressing
56 /// through such registers.
57 virtual bool extendPointerWithSExt() const { return false; }
58
59 /// Determines the DWARF register number for the stack pointer, for
60 /// exception-handling purposes. Implements __builtin_dwarf_sp_column.
61 ///
62 /// Returns -1 if the operation is unsupported by this target.
63 virtual int getDwarfEHStackPointer(CodeGen::CodeGenModule &M) const {
64 return -1;
65 }
66
67 /// Initializes the given DWARF EH register-size table, a char*.
68 /// Implements __builtin_init_dwarf_reg_size_table.
69 ///
70 /// Returns true if the operation is unsupported by this target.
71 virtual bool initDwarfEHRegSizeTable(CodeGen::CodeGenFunction &CGF,
72 llvm::Value *Address) const {
73 return true;
74 }
75
76 /// Performs the code-generation required to convert a return
77 /// address as stored by the system into the actual address of the
78 /// next instruction that will be executed.
79 ///
80 /// Used by __builtin_extract_return_addr().
81 virtual llvm::Value *decodeReturnAddress(CodeGen::CodeGenFunction &CGF,
82 llvm::Value *Address) const {
83 return Address;
84 }
85
86 /// Performs the code-generation required to convert the address
87 /// of an instruction into a return address suitable for storage
88 /// by the system in a return slot.
89 ///
90 /// Used by __builtin_frob_return_addr().
91 virtual llvm::Value *encodeReturnAddress(CodeGen::CodeGenFunction &CGF,
92 llvm::Value *Address) const {
93 return Address;
94 }
95 };
96}
97
98#endif // CLANG_CODEGEN_TARGETINFO_H