1 //===-- llvm/CodeGen/AsmPrinter.h - AsmPrinter Framework --------*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file was developed by the LLVM research group and is distributed under
6 // the University of Illinois Open Source License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This class is intended to be used as a base class for target-specific
11 // asmwriters. This class primarily takes care of printing global constants,
12 // which are printed in a very similar way across all targets.
14 //===----------------------------------------------------------------------===//
16 #ifndef LLVM_CODEGEN_ASMPRINTER_H
17 #define LLVM_CODEGEN_ASMPRINTER_H
19 #include "llvm/CodeGen/MachineFunctionPass.h"
20 #include "llvm/Support/DataTypes.h"
27 class AsmPrinter : public MachineFunctionPass {
28 /// CurrentSection - The current section we are emitting to. This is
29 /// controlled and used by the SwitchSection method.
30 std::string CurrentSection;
32 /// FunctionNumber - This provides a unique ID for each function emitted in
33 /// this translation unit. It is autoincremented by SetupMachineFunction,
34 /// and can be accessed with getFunctionNumber() and
35 /// IncrementFunctionNumber().
37 unsigned FunctionNumber;
40 /// Output stream on which we're printing assembly code.
44 /// Target machine description.
48 /// Name-mangler for global names.
52 /// Cache of mangled name for current function. This is recalculated at the
53 /// beginning of each call to runOnMachineFunction().
55 std::string CurrentFnName;
57 //===------------------------------------------------------------------===//
58 // Properties to be set by the derived class ctor, used to configure the
61 /// CommentString - This indicates the comment character used by the
63 const char *CommentString; // Defaults to "#"
65 /// GlobalPrefix - If this is set to a non-empty string, it is prepended
66 /// onto all global symbols. This is often used for "_" or ".".
67 const char *GlobalPrefix; // Defaults to ""
69 /// PrivateGlobalPrefix - This prefix is used for globals like constant
70 /// pool entries that are completely private to the .o file and should not
71 /// have names in the .o file. This is often "." or "L".
72 const char *PrivateGlobalPrefix; // Defaults to "."
74 /// GlobalVarAddrPrefix/Suffix - If these are nonempty, these strings
75 /// will enclose any GlobalVariable (that isn't a function)
77 const char *GlobalVarAddrPrefix; // Defaults to ""
78 const char *GlobalVarAddrSuffix; // Defaults to ""
80 /// FunctionAddrPrefix/Suffix - If these are nonempty, these strings
81 /// will enclose any GlobalVariable that points to a function.
82 /// For example, this is used by the IA64 backend to materialize
83 /// function descriptors, by decorating the ".data8" object with the
84 /// @fptr( ) link-relocation operator.
86 const char *FunctionAddrPrefix; // Defaults to ""
87 const char *FunctionAddrSuffix; // Defaults to ""
89 //===--- Data Emission Directives -------------------------------------===//
91 /// ZeroDirective - this should be set to the directive used to get some
92 /// number of zero bytes emitted to the current section. Common cases are
93 /// "\t.zero\t" and "\t.space\t". If this is set to null, the
94 /// Data*bitsDirective's will be used to emit zero bytes.
95 const char *ZeroDirective; // Defaults to "\t.zero\t"
97 /// AsciiDirective - This directive allows emission of an ascii string with
98 /// the standard C escape characters embedded into it.
99 const char *AsciiDirective; // Defaults to "\t.ascii\t"
101 /// AscizDirective - If not null, this allows for special handling of
102 /// zero terminated strings on this target. This is commonly supported as
103 /// ".asciz". If a target doesn't support this, it can be set to null.
104 const char *AscizDirective; // Defaults to "\t.asciz\t"
106 /// DataDirectives - These directives are used to output some unit of
107 /// integer data to the current section. If a data directive is set to
108 /// null, smaller data directives will be used to emit the large sizes.
109 const char *Data8bitsDirective; // Defaults to "\t.byte\t"
110 const char *Data16bitsDirective; // Defaults to "\t.short\t"
111 const char *Data32bitsDirective; // Defaults to "\t.long\t"
112 const char *Data64bitsDirective; // Defaults to "\t.quad\t"
114 //===--- Alignment Information ----------------------------------------===//
116 /// AlignDirective - The directive used to emit round up to an alignment
119 const char *AlignDirective; // Defaults to "\t.align\t"
121 /// AlignmentIsInBytes - If this is true (the default) then the asmprinter
122 /// emits ".align N" directives, where N is the number of bytes to align to.
123 /// Otherwise, it emits ".align log2(N)", e.g. 3 to align to an 8 byte
125 bool AlignmentIsInBytes; // Defaults to true
127 //===--- Section Switching Directives ---------------------------------===//
129 /// SwitchToSectionDirective - This is the directive used when we want to
130 /// emit a global to an arbitrary section. The section name is emited after
132 const char *SwitchToSectionDirective; // Defaults to "\t.section\t"
134 /// ConstantPoolSection - This is the section that we SwitchToSection right
135 /// before emitting the constant pool for a function.
136 const char *ConstantPoolSection; // Defaults to "\t.section .rodata\n"
138 /// StaticCtorsSection - This is the directive that is emitted to switch to
139 /// a section to emit the static constructor list.
140 /// Defaults to "\t.section .ctors,\"aw\",@progbits".
141 const char *StaticCtorsSection;
143 /// StaticDtorsSection - This is the directive that is emitted to switch to
144 /// a section to emit the static destructor list.
145 /// Defaults to "\t.section .dtors,\"aw\",@progbits".
146 const char *StaticDtorsSection;
148 //===--- Global Variable Emission Directives --------------------------===//
150 /// LCOMMDirective - This is the name of a directive (if supported) that can
151 /// be used to efficiently declare a local (internal) block of zero
152 /// initialized data in the .bss/.data section. The syntax expected is:
153 /// <LCOMMDirective> SYMBOLNAME LENGTHINBYTES, ALIGNMENT
154 const char *LCOMMDirective; // Defaults to null.
156 const char *COMMDirective; // Defaults to "\t.comm\t".
158 /// COMMDirectiveTakesAlignment - True if COMMDirective take a third
159 /// argument that specifies the alignment of the declaration.
160 bool COMMDirectiveTakesAlignment; // Defaults to true.
162 /// HasDotTypeDotSizeDirective - True if the target has .type and .size
163 /// directives, this is true for most ELF targets.
164 bool HasDotTypeDotSizeDirective; // Defaults to true.
166 AsmPrinter(std::ostream &o, TargetMachine &TM);
168 /// SwitchSection - Switch to the specified section of the executable if we
169 /// are not already in it! If GV is non-null and if the global has an
170 /// explicitly requested section, we switch to the section indicated for the
171 /// global instead of NewSection.
173 /// If the new section is an empty string, this method forgets what the
174 /// current section is, but does not emit a .section directive.
176 void SwitchSection(const char *NewSection, const GlobalValue *GV);
178 /// getFunctionNumber - Return a unique ID for the current function.
180 unsigned getFunctionNumber() const { return FunctionNumber; }
182 /// IncrementFunctionNumber - Increase Function Number. AsmPrinters should
183 /// not normally call this, as the counter is automatically bumped by
184 /// SetupMachineFunction.
185 void IncrementFunctionNumber() { FunctionNumber++; }
187 /// doInitialization - Set up the AsmPrinter when we are working on a new
188 /// module. If your pass overrides this, it must make sure to explicitly
189 /// call this implementation.
190 bool doInitialization(Module &M);
192 /// doFinalization - Shut down the asmprinter. If you override this in your
193 /// pass, you must make sure to call it explicitly.
194 bool doFinalization(Module &M);
196 /// SetupMachineFunction - This should be called when a new MachineFunction
197 /// is being processed from runOnMachineFunction.
198 void SetupMachineFunction(MachineFunction &MF);
200 /// EmitConstantPool - Print to the current output stream assembly
201 /// representations of the constants in the constant pool MCP. This is
202 /// used to print out constants which have been "spilled to memory" by
203 /// the code generator.
205 void EmitConstantPool(MachineConstantPool *MCP);
207 /// EmitSpecialLLVMGlobal - Check to see if the specified global is a
208 /// special global used by LLVM. If so, emit it and return true, otherwise
209 /// do nothing and return false.
210 bool EmitSpecialLLVMGlobal(const GlobalVariable *GV);
212 /// EmitAlignment - Emit an alignment directive to the specified power of
213 /// two boundary. For example, if you pass in 3 here, you will get an 8
214 /// byte alignment. If a global value is specified, and if that global has
215 /// an explicit alignment requested, it will override the alignment request.
216 void EmitAlignment(unsigned NumBits, const GlobalValue *GV = 0) const;
218 /// EmitZeros - Emit a block of zeros.
220 void EmitZeros(uint64_t NumZeros) const;
222 /// EmitConstantValueOnly - Print out the specified constant, without a
223 /// storage class. Only constants of first-class type are allowed here.
224 void EmitConstantValueOnly(const Constant *CV);
226 /// EmitGlobalConstant - Print a general LLVM constant to the .s file.
228 void EmitGlobalConstant(const Constant* CV);
231 void EmitXXStructorList(Constant *List);