LLVM 19.0.0git
ModuleSymbolTable.cpp
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1//===- ModuleSymbolTable.cpp - symbol table for in-memory IR --------------===//
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// This class represents a symbol table built from in-memory IR. It provides
10// access to GlobalValues and should only be used if such access is required
11// (e.g. in the LTO implementation).
12//
13//===----------------------------------------------------------------------===//
14
16#include "RecordStreamer.h"
17#include "llvm/ADT/STLExtras.h"
18#include "llvm/ADT/StringRef.h"
20#include "llvm/IR/Function.h"
21#include "llvm/IR/GlobalAlias.h"
22#include "llvm/IR/GlobalValue.h"
24#include "llvm/IR/InlineAsm.h"
25#include "llvm/IR/Module.h"
26#include "llvm/MC/MCAsmInfo.h"
27#include "llvm/MC/MCContext.h"
28#include "llvm/MC/MCInstrInfo.h"
34#include "llvm/MC/MCSymbol.h"
41#include "llvm/Support/SMLoc.h"
45#include <algorithm>
46#include <cassert>
47#include <cstdint>
48#include <memory>
49#include <string>
50
51using namespace llvm;
52using namespace object;
53
55 if (FirstMod)
56 assert(FirstMod->getTargetTriple() == M->getTargetTriple());
57 else
58 FirstMod = M;
59
60 for (GlobalValue &GV : M->global_values())
61 SymTab.push_back(&GV);
62
64 SymTab.push_back(new (AsmSymbols.Allocate())
65 AsmSymbol(std::string(Name), Flags));
66 });
67}
68
69static void
72 // This function may be called twice, once for ModuleSummaryIndexAnalysis and
73 // the other when writing the IR symbol table. If parsing inline assembly has
74 // caused errors in the first run, suppress the second run.
75 if (M.getContext().getDiagHandlerPtr()->HasErrors)
76 return;
77 StringRef InlineAsm = M.getModuleInlineAsm();
78 if (InlineAsm.empty())
79 return;
80
81 std::string Err;
82 const Triple TT(M.getTargetTriple());
83 const Target *T = TargetRegistry::lookupTarget(TT.str(), Err);
84 assert(T && T->hasMCAsmParser());
85
86 std::unique_ptr<MCRegisterInfo> MRI(T->createMCRegInfo(TT.str()));
87 if (!MRI)
88 return;
89
90 MCTargetOptions MCOptions;
91 std::unique_ptr<MCAsmInfo> MAI(T->createMCAsmInfo(*MRI, TT.str(), MCOptions));
92 if (!MAI)
93 return;
94
95 std::unique_ptr<MCSubtargetInfo> STI(
96 T->createMCSubtargetInfo(TT.str(), "", ""));
97 if (!STI)
98 return;
99
100 std::unique_ptr<MCInstrInfo> MCII(T->createMCInstrInfo());
101 if (!MCII)
102 return;
103
104 std::unique_ptr<MemoryBuffer> Buffer(
105 MemoryBuffer::getMemBuffer(InlineAsm, "<inline asm>"));
107 SrcMgr.AddNewSourceBuffer(std::move(Buffer), SMLoc());
108
109 MCContext MCCtx(TT, MAI.get(), MRI.get(), STI.get(), &SrcMgr);
110 std::unique_ptr<MCObjectFileInfo> MOFI(
111 T->createMCObjectFileInfo(MCCtx, /*PIC=*/false));
112 MOFI->setSDKVersion(M.getSDKVersion());
113 MCCtx.setObjectFileInfo(MOFI.get());
114 RecordStreamer Streamer(MCCtx, M);
115 T->createNullTargetStreamer(Streamer);
116
117 std::unique_ptr<MCAsmParser> Parser(
118 createMCAsmParser(SrcMgr, MCCtx, Streamer, *MAI));
119
120 std::unique_ptr<MCTargetAsmParser> TAP(
121 T->createMCAsmParser(*STI, *Parser, *MCII, MCOptions));
122 if (!TAP)
123 return;
124
125 MCCtx.setDiagnosticHandler([&](const SMDiagnostic &SMD, bool IsInlineAsm,
126 const SourceMgr &SrcMgr,
127 std::vector<const MDNode *> &LocInfos) {
128 M.getContext().diagnose(
129 DiagnosticInfoSrcMgr(SMD, M.getName(), IsInlineAsm, /*LocCookie=*/0));
130 });
131
132 // Module-level inline asm is assumed to use At&t syntax (see
133 // AsmPrinter::doInitialization()).
134 Parser->setAssemblerDialect(InlineAsm::AD_ATT);
135
136 Parser->setTargetParser(*TAP);
137 if (Parser->Run(false))
138 return;
139
140 Init(Streamer);
141}
142
144 const Module &M,
146 initializeRecordStreamer(M, [&](RecordStreamer &Streamer) {
147 Streamer.flushSymverDirectives();
148
149 for (auto &KV : Streamer) {
150 StringRef Key = KV.first();
151 RecordStreamer::State Value = KV.second;
152 // FIXME: For now we just assume that all asm symbols are executable.
154 switch (Value) {
156 llvm_unreachable("NeverSeen should have been replaced earlier");
159 break;
161 break;
166 break;
170 break;
174 }
176 }
177 });
178
179 // In ELF, object code generated for x86-32 and some code models of x86-64 may
180 // reference the special symbol _GLOBAL_OFFSET_TABLE_ that is not used in the
181 // IR. Record it like inline asm symbols.
182 Triple TT(M.getTargetTriple());
183 if (!TT.isOSBinFormatELF() || !TT.isX86())
184 return;
185 auto CM = M.getCodeModel();
186 if (TT.getArch() == Triple::x86 || CM == CodeModel::Medium ||
187 CM == CodeModel::Large) {
188 AsmSymbol("_GLOBAL_OFFSET_TABLE_",
191 }
192}
193
195 const Module &M, function_ref<void(StringRef, StringRef)> AsmSymver) {
196 initializeRecordStreamer(M, [&](RecordStreamer &Streamer) {
197 for (auto &KV : Streamer.symverAliases())
198 for (auto &Alias : KV.second)
199 AsmSymver(KV.first->getName(), Alias);
200 });
201}
202
204 if (isa<AsmSymbol *>(S)) {
205 OS << cast<AsmSymbol *>(S)->first;
206 return;
207 }
208
209 auto *GV = cast<GlobalValue *>(S);
210 if (GV->hasDLLImportStorageClass())
211 OS << "__imp_";
212
213 Mang.getNameWithPrefix(OS, GV, false);
214}
215
217 if (isa<AsmSymbol *>(S))
218 return cast<AsmSymbol *>(S)->second;
219
220 auto *GV = cast<GlobalValue *>(S);
221
223 if (GV->isDeclarationForLinker())
225 else if (GV->hasHiddenVisibility() && !GV->hasLocalLinkage())
227 if (const GlobalVariable *GVar = dyn_cast<GlobalVariable>(GV)) {
228 if (GVar->isConstant())
230 }
231 if (const GlobalObject *GO = GV->getAliaseeObject())
232 if (isa<Function>(GO) || isa<GlobalIFunc>(GO))
234 if (isa<GlobalAlias>(GV))
236 if (GV->hasPrivateLinkage())
238 if (!GV->hasLocalLinkage())
240 if (GV->hasCommonLinkage())
242 if (GV->hasLinkOnceLinkage() || GV->hasWeakLinkage() ||
243 GV->hasExternalWeakLinkage())
245
246 if (GV->getName().starts_with("llvm."))
248 else if (auto *Var = dyn_cast<GlobalVariable>(GV)) {
249 if (Var->getSection() == "llvm.metadata")
251 }
252
253 return Res;
254}
unsigned const MachineRegisterInfo * MRI
for(const MachineOperand &MO :llvm::drop_begin(OldMI.operands(), Desc.getNumOperands()))
std::string Name
static void initializeRecordStreamer(const Module &M, function_ref< void(RecordStreamer &)> Init)
Module.h This file contains the declarations for the Module class.
assert(ImpDefSCC.getReg()==AMDGPU::SCC &&ImpDefSCC.isDef())
This file contains some templates that are useful if you are working with the STL at all.
raw_pwrite_stream & OS
Diagnostic information for SMDiagnostic reporting.
const GlobalObject * getAliaseeObject() const
Definition: Globals.cpp:380
Context object for machine code objects.
Definition: MCContext.h:82
void setObjectFileInfo(const MCObjectFileInfo *Mofi)
Definition: MCContext.h:413
void setDiagnosticHandler(DiagHandlerTy DiagHandler)
Definition: MCContext.h:409
void getNameWithPrefix(raw_ostream &OS, const GlobalValue *GV, bool CannotUsePrivateLabel) const
Print the appropriate prefix and the specified global variable's name.
Definition: Mangler.cpp:120
static std::unique_ptr< MemoryBuffer > getMemBuffer(StringRef InputData, StringRef BufferName="", bool RequiresNullTerminator=true)
Open the specified memory range as a MemoryBuffer.
static void CollectAsmSymvers(const Module &M, function_ref< void(StringRef, StringRef)> AsmSymver)
Parse inline ASM and collect the symvers directives that are defined in the current module.
std::pair< std::string, uint32_t > AsmSymbol
void printSymbolName(raw_ostream &OS, Symbol S) const
uint32_t getSymbolFlags(Symbol S) const
static void CollectAsmSymbols(const Module &M, function_ref< void(StringRef, object::BasicSymbolRef::Flags)> AsmSymbol)
Parse inline ASM and collect the symbols that are defined or referenced in the current module.
A Module instance is used to store all the information related to an LLVM module.
Definition: Module.h:65
const std::string & getTargetTriple() const
Get the target triple which is a string describing the target host.
Definition: Module.h:297
A discriminated union of two or more pointer types, with the discriminator in the low bit of the poin...
Definition: PointerUnion.h:118
iterator_range< const_symver_iterator > symverAliases()
Instances of this class encapsulate one diagnostic report, allowing printing to a raw_ostream as a ca...
Definition: SourceMgr.h:281
Represents a location in source code.
Definition: SMLoc.h:23
This owns the files read by a parser, handles include stacks, and handles diagnostic wrangling.
Definition: SourceMgr.h:31
unsigned AddNewSourceBuffer(std::unique_ptr< MemoryBuffer > F, SMLoc IncludeLoc)
Add a new source buffer to this source manager.
Definition: SourceMgr.h:144
T * Allocate(size_t num=1)
Allocate space for an array of objects without constructing them.
Definition: Allocator.h:437
StringRef - Represent a constant reference to a string, i.e.
Definition: StringRef.h:50
Target - Wrapper for Target specific information.
Triple - Helper class for working with autoconf configuration names.
Definition: Triple.h:44
LLVM Value Representation.
Definition: Value.h:74
An efficient, type-erasing, non-owning reference to a callable.
This class implements an extremely fast bulk output stream that can only output to a stream.
Definition: raw_ostream.h:52
#define llvm_unreachable(msg)
Marks that the current location is not supposed to be reachable.
This is an optimization pass for GlobalISel generic memory operations.
Definition: AddressRanges.h:18
SourceMgr SrcMgr
Definition: Error.cpp:24
MCAsmParser * createMCAsmParser(SourceMgr &, MCContext &, MCStreamer &, const MCAsmInfo &, unsigned CB=0)
Create an MCAsmParser instance for parsing assembly similar to gas syntax.
Definition: AsmParser.cpp:6451
static const Target * lookupTarget(StringRef Triple, std::string &Error)
lookupTarget - Lookup a target based on a target triple.