1 //===- ValueSymbolTable.cpp - Implement the ValueSymbolTable class --------===// 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 file implements the ValueSymbolTable class for the IR library. 10 // 11 //===----------------------------------------------------------------------===// 12 13 #include "llvm/IR/ValueSymbolTable.h" 14 #include "llvm/ADT/SmallString.h" 15 #include "llvm/Config/llvm-config.h" 16 #include "llvm/IR/GlobalValue.h" 17 #include "llvm/IR/Module.h" 18 #include "llvm/IR/Type.h" 19 #include "llvm/IR/Value.h" 20 #include "llvm/Support/Casting.h" 21 #include "llvm/Support/Compiler.h" 22 #include "llvm/Support/Debug.h" 23 #include "llvm/Support/raw_ostream.h" 24 #include "llvm/TargetParser/Triple.h" 25 #include <cassert> 26 #include <utility> 27 28 using namespace llvm; 29 30 #define DEBUG_TYPE "valuesymtab" 31 32 // Class destructor 33 ValueSymbolTable::~ValueSymbolTable() { 34 #ifndef NDEBUG // Only do this in -g mode... 35 for (const auto &VI : vmap) 36 dbgs() << "Value still in symbol table! Type = '" 37 << *VI.getValue()->getType() << "' Name = '" << VI.getKeyData() 38 << "'\n"; 39 assert(vmap.empty() && "Values remain in symbol table!"); 40 #endif 41 } 42 43 ValueName *ValueSymbolTable::makeUniqueName(Value *V, 44 SmallString<256> &UniqueName) { 45 unsigned BaseSize = UniqueName.size(); 46 bool AppenDot = false; 47 if (auto *GV = dyn_cast<GlobalValue>(V)) { 48 // A dot is appended to mark it as clone during ABI demangling so that 49 // for example "_Z1fv" and "_Z1fv.1" both demangle to "f()", the second 50 // one being a clone. 51 // On NVPTX we cannot use a dot because PTX only allows [A-Za-z0-9_$] for 52 // identifiers. This breaks ABI demangling but at least ptxas accepts and 53 // compiles the program. 54 const Module *M = GV->getParent(); 55 if (!(M && Triple(M->getTargetTriple()).isNVPTX())) 56 AppenDot = true; 57 } 58 59 while (true) { 60 // Trim any suffix off and append the next number. 61 UniqueName.resize(BaseSize); 62 raw_svector_ostream S(UniqueName); 63 if (AppenDot) 64 S << "."; 65 S << ++LastUnique; 66 67 // Retry if MaxNameSize has been exceeded. 68 if (MaxNameSize > -1 && UniqueName.size() > (size_t)MaxNameSize) { 69 assert(BaseSize >= UniqueName.size() - (size_t)MaxNameSize && 70 "Can't generate unique name: MaxNameSize is too small."); 71 BaseSize -= UniqueName.size() - (size_t)MaxNameSize; 72 continue; 73 } 74 // Try insert the vmap entry with this suffix. 75 auto IterBool = vmap.insert(std::make_pair(UniqueName.str(), V)); 76 if (IterBool.second) 77 return &*IterBool.first; 78 } 79 } 80 81 // Insert a value into the symbol table with the specified name... 82 // 83 void ValueSymbolTable::reinsertValue(Value *V) { 84 assert(V->hasName() && "Can't insert nameless Value into symbol table"); 85 86 // Try inserting the name, assuming it won't conflict. 87 if (vmap.insert(V->getValueName())) { 88 // LLVM_DEBUG(dbgs() << " Inserted value: " << V->getValueName() << ": " << 89 // *V << "\n"); 90 return; 91 } 92 93 // Otherwise, there is a naming conflict. Rename this value. 94 SmallString<256> UniqueName(V->getName().begin(), V->getName().end()); 95 96 // The name is too already used, just free it so we can allocate a new name. 97 MallocAllocator Allocator; 98 V->getValueName()->Destroy(Allocator); 99 100 ValueName *VN = makeUniqueName(V, UniqueName); 101 V->setValueName(VN); 102 } 103 104 void ValueSymbolTable::removeValueName(ValueName *V) { 105 // LLVM_DEBUG(dbgs() << " Removing Value: " << V->getKeyData() << "\n"); 106 // Remove the value from the symbol table. 107 vmap.remove(V); 108 } 109 110 /// createValueName - This method attempts to create a value name and insert 111 /// it into the symbol table with the specified name. If it conflicts, it 112 /// auto-renames the name and returns that instead. 113 ValueName *ValueSymbolTable::createValueName(StringRef Name, Value *V) { 114 if (MaxNameSize > -1 && Name.size() > (unsigned)MaxNameSize) 115 Name = Name.substr(0, std::max(1u, (unsigned)MaxNameSize)); 116 117 // In the common case, the name is not already in the symbol table. 118 auto IterBool = vmap.insert(std::make_pair(Name, V)); 119 if (IterBool.second) { 120 // LLVM_DEBUG(dbgs() << " Inserted value: " << Entry.getKeyData() << ": " 121 // << *V << "\n"); 122 return &*IterBool.first; 123 } 124 125 // Otherwise, there is a naming conflict. Rename this value. 126 SmallString<256> UniqueName(Name.begin(), Name.end()); 127 return makeUniqueName(V, UniqueName); 128 } 129 130 #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP) 131 // dump - print out the symbol table 132 // 133 LLVM_DUMP_METHOD void ValueSymbolTable::dump() const { 134 // dbgs() << "ValueSymbolTable:\n"; 135 for (const auto &I : *this) { 136 // dbgs() << " '" << I->getKeyData() << "' = "; 137 I.getValue()->dump(); 138 // dbgs() << "\n"; 139 } 140 } 141 #endif 142