1//===-- llvm/CodeGen/MachineModuleInfo.h ------------------------*- C++ -*-===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8//
9// Collect meta information for a module. This information should be in a
10// neutral form that can be used by different debugging and exception handling
11// schemes.
12//
13// The organization of information is primarily clustered around the source
14// compile units. The main exception is source line correspondence where
15// inlining may interleave code from various compile units.
16//
17// The following information can be retrieved from the MachineModuleInfo.
18//
19// -- Source directories - Directories are uniqued based on their canonical
20// string and assigned a sequential numeric ID (base 1.)
21// -- Source files - Files are also uniqued based on their name and directory
22// ID. A file ID is sequential number (base 1.)
23// -- Source line correspondence - A vector of file ID, line#, column# triples.
24// A DEBUG_LOCATION instruction is generated by the DAG Legalizer
25// corresponding to each entry in the source line list. This allows a debug
26// emitter to generate labels referenced by debug information tables.
27//
28//===----------------------------------------------------------------------===//
29
30#ifndef LLVM_CODEGEN_MACHINEMODULEINFO_H
31#define LLVM_CODEGEN_MACHINEMODULEINFO_H
32
33#include "llvm/ADT/DenseMap.h"
34#include "llvm/ADT/PointerIntPair.h"
35#include "llvm/IR/PassManager.h"
36#include "llvm/MC/MCContext.h"
37#include "llvm/MC/MCSymbol.h"
38#include "llvm/Pass.h"
39#include <memory>
40#include <utility>
41#include <vector>
42
43namespace llvm {
44
45class Function;
46class LLVMTargetMachine;
47class MachineFunction;
48class Module;
49
50//===----------------------------------------------------------------------===//
51/// This class can be derived from and used by targets to hold private
52/// target-specific information for each Module. Objects of type are
53/// accessed/created with MachineModuleInfo::getObjFileInfo and destroyed when
54/// the MachineModuleInfo is destroyed.
55///
56class MachineModuleInfoImpl {
57public:
58 using StubValueTy = PointerIntPair<MCSymbol *, 1, bool>;
59 using SymbolListTy = std::vector<std::pair<MCSymbol *, StubValueTy>>;
60
61 virtual ~MachineModuleInfoImpl();
62
63protected:
64 /// Return the entries from a DenseMap in a deterministic sorted orer.
65 /// Clears the map.
66 static SymbolListTy getSortedStubs(DenseMap<MCSymbol*, StubValueTy>&);
67};
68
69//===----------------------------------------------------------------------===//
70/// This class contains meta information specific to a module. Queries can be
71/// made by different debugging and exception handling schemes and reformated
72/// for specific use.
73///
74class MachineModuleInfo {
75 friend class MachineModuleInfoWrapperPass;
76 friend class MachineModuleAnalysis;
77
78 const LLVMTargetMachine &TM;
79
80 /// This is the MCContext used for the entire code generator.
81 MCContext Context;
82 // This is an external context, that if assigned, will be used instead of the
83 // internal context.
84 MCContext *ExternalContext = nullptr;
85
86 /// This is the LLVM Module being worked on.
87 const Module *TheModule = nullptr;
88
89 /// This is the object-file-format-specific implementation of
90 /// MachineModuleInfoImpl, which lets targets accumulate whatever info they
91 /// want.
92 MachineModuleInfoImpl *ObjFileMMI;
93
94 /// \name Exception Handling
95 /// \{
96
97 /// The current call site index being processed, if any. 0 if none.
98 unsigned CurCallSite = 0;
99
100 /// \}
101
102 // TODO: Ideally, what we'd like is to have a switch that allows emitting
103 // synchronous (precise at call-sites only) CFA into .eh_frame. However,
104 // even under this switch, we'd like .debug_frame to be precise when using
105 // -g. At this moment, there's no way to specify that some CFI directives
106 // go into .eh_frame only, while others go into .debug_frame only.
107
108 /// True if debugging information is available in this module.
109 bool DbgInfoAvailable = false;
110
111 /// True if this module is being built for windows/msvc, and uses floating
112 /// point. This is used to emit an undefined reference to _fltused.
113 bool UsesMSVCFloatingPoint = false;
114
115 /// Maps IR Functions to their corresponding MachineFunctions.
116 DenseMap<const Function*, std::unique_ptr<MachineFunction>> MachineFunctions;
117 /// Next unique number available for a MachineFunction.
118 unsigned NextFnNum = 0;
119 const Function *LastRequest = nullptr; ///< Used for shortcut/cache.
120 MachineFunction *LastResult = nullptr; ///< Used for shortcut/cache.
121
122 MachineModuleInfo &operator=(MachineModuleInfo &&MMII) = delete;
123
124public:
125 explicit MachineModuleInfo(const LLVMTargetMachine *TM = nullptr);
126
127 explicit MachineModuleInfo(const LLVMTargetMachine *TM,
128 MCContext *ExtContext);
129
130 MachineModuleInfo(MachineModuleInfo &&MMII);
131
132 ~MachineModuleInfo();
133
134 void initialize();
135 void finalize();
136
137 const LLVMTargetMachine &getTarget() const { return TM; }
138
139 const MCContext &getContext() const {
140 return ExternalContext ? *ExternalContext : Context;
141 }
142 MCContext &getContext() {
143 return ExternalContext ? *ExternalContext : Context;
144 }
145
146 const Module *getModule() const { return TheModule; }
147
148 /// Returns the MachineFunction constructed for the IR function \p F.
149 /// Creates a new MachineFunction if none exists yet.
150 MachineFunction &getOrCreateMachineFunction(Function &F);
151
152 /// \brief Returns the MachineFunction associated to IR function \p F if there
153 /// is one, otherwise nullptr.
154 MachineFunction *getMachineFunction(const Function &F) const;
155
156 /// Delete the MachineFunction \p MF and reset the link in the IR Function to
157 /// Machine Function map.
158 void deleteMachineFunctionFor(Function &F);
159
160 /// Add an externally created MachineFunction \p MF for \p F.
161 void insertFunction(const Function &F, std::unique_ptr<MachineFunction> &&MF);
162
163 /// Keep track of various per-module pieces of information for backends
164 /// that would like to do so.
165 template<typename Ty>
166 Ty &getObjFileInfo() {
167 if (ObjFileMMI == nullptr)
168 ObjFileMMI = new Ty(*this);
169 return *static_cast<Ty*>(ObjFileMMI);
170 }
171
172 template<typename Ty>
173 const Ty &getObjFileInfo() const {
174 return const_cast<MachineModuleInfo*>(this)->getObjFileInfo<Ty>();
175 }
176
177 /// Returns true if valid debug info is present.
178 bool hasDebugInfo() const { return DbgInfoAvailable; }
179
180 bool usesMSVCFloatingPoint() const { return UsesMSVCFloatingPoint; }
181
182 void setUsesMSVCFloatingPoint(bool b) { UsesMSVCFloatingPoint = b; }
183
184 /// \name Exception Handling
185 /// \{
186
187 /// Set the call site currently being processed.
188 void setCurrentCallSite(unsigned Site) { CurCallSite = Site; }
189
190 /// Get the call site currently being processed, if any. return zero if
191 /// none.
192 unsigned getCurrentCallSite() { return CurCallSite; }
193
194 /// \}
195}; // End class MachineModuleInfo
196
197class MachineModuleInfoWrapperPass : public ImmutablePass {
198 MachineModuleInfo MMI;
199
200public:
201 static char ID; // Pass identification, replacement for typeid
202 explicit MachineModuleInfoWrapperPass(const LLVMTargetMachine *TM = nullptr);
203
204 explicit MachineModuleInfoWrapperPass(const LLVMTargetMachine *TM,
205 MCContext *ExtContext);
206
207 // Initialization and Finalization
208 bool doInitialization(Module &) override;
209 bool doFinalization(Module &) override;
210
211 MachineModuleInfo &getMMI() { return MMI; }
212 const MachineModuleInfo &getMMI() const { return MMI; }
213};
214
215/// An analysis that produces \c MachineModuleInfo for a module.
216/// This does not produce its own MachineModuleInfo because we need a consistent
217/// MachineModuleInfo to keep ownership of MachineFunctions regardless of
218/// analysis invalidation/clearing. So something outside the analysis
219/// infrastructure must own the MachineModuleInfo.
220class MachineModuleAnalysis : public AnalysisInfoMixin<MachineModuleAnalysis> {
221 friend AnalysisInfoMixin<MachineModuleAnalysis>;
222 static AnalysisKey Key;
223
224 MachineModuleInfo &MMI;
225
226public:
227 class Result {
228 MachineModuleInfo &MMI;
229 Result(MachineModuleInfo &MMI) : MMI(MMI) {}
230 friend class MachineModuleAnalysis;
231
232 public:
233 MachineModuleInfo &getMMI() { return MMI; }
234
235 // MMI owes MCContext. It should never be invalidated.
236 bool invalidate(Module &, const PreservedAnalyses &,
237 ModuleAnalysisManager::Invalidator &) {
238 return false;
239 }
240 };
241
242 MachineModuleAnalysis(MachineModuleInfo &MMI) : MMI(MMI) {}
243
244 /// Run the analysis pass and produce machine module information.
245 Result run(Module &M, ModuleAnalysisManager &);
246};
247
248} // end namespace llvm
249
250#endif // LLVM_CODEGEN_MACHINEMODULEINFO_H
251

source code of llvm/include/llvm/CodeGen/MachineModuleInfo.h