llvm/lib/IR/ValueSymbolTable.cpp

   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   while (true) {
  47     // Trim any suffix off and append the next number.
  48     UniqueName.resize(BaseSize);
  49     raw_svector_ostream S(UniqueName);
  50     if (auto *GV = dyn_cast<GlobalValue>(V)) {
  51       // A dot is appended to mark it as clone during ABI demangling so that
  52       // for example "_Z1fv" and "_Z1fv.1" both demangle to "f()", the second
  53       // one being a clone.
  54       // On NVPTX we cannot use a dot because PTX only allows [A-Za-z0-9_$] for
  55       // identifiers. This breaks ABI demangling but at least ptxas accepts and
  56       // compiles the program.
  57       const Module *M = GV->getParent();
  58       if (!(M && Triple(M->getTargetTriple()).isNVPTX()))
  59         S << ".";
  60     }
  61     S << ++LastUnique;
  62
  63     // Try insert the vmap entry with this suffix.
  64     auto IterBool = vmap.insert(std::make_pair(UniqueName.str(), V));
  65     if (IterBool.second)
  66       return &*IterBool.first;
  67   }
  68 }
  69
  70 // Insert a value into the symbol table with the specified name...
  71 //
  72 void ValueSymbolTable::reinsertValue(Value *V) {
  73   assert(V->hasName() && "Can't insert nameless Value into symbol table");
  74
  75   // Try inserting the name, assuming it won't conflict.
  76   if (vmap.insert(V->getValueName())) {
  77     // LLVM_DEBUG(dbgs() << " Inserted value: " << V->getValueName() << ": " <<
  78     // *V << "\n");
  79     return;
  80   }
  81
  82   // Otherwise, there is a naming conflict.  Rename this value.
  83   SmallString<256> UniqueName(V->getName().begin(), V->getName().end());
  84
  85   // The name is too already used, just free it so we can allocate a new name.
  86   MallocAllocator Allocator;
  87   V->getValueName()->Destroy(Allocator);
  88
  89   ValueName *VN = makeUniqueName(V, UniqueName);
  90   V->setValueName(VN);
  91 }
  92
  93 void ValueSymbolTable::removeValueName(ValueName *V) {
  94   // LLVM_DEBUG(dbgs() << " Removing Value: " << V->getKeyData() << "\n");
  95   // Remove the value from the symbol table.
  96   vmap.remove(V);
  97 }
  98
  99 /// createValueName - This method attempts to create a value name and insert
 100 /// it into the symbol table with the specified name.  If it conflicts, it
 101 /// auto-renames the name and returns that instead.
 102 ValueName *ValueSymbolTable::createValueName(StringRef Name, Value *V) {
 103   if (MaxNameSize > -1 && Name.size() > (unsigned)MaxNameSize)
 104     Name = Name.substr(0, std::max(1u, (unsigned)MaxNameSize));
 105
 106   // In the common case, the name is not already in the symbol table.
 107   auto IterBool = vmap.insert(std::make_pair(Name, V));
 108   if (IterBool.second) {
 109     // LLVM_DEBUG(dbgs() << " Inserted value: " << Entry.getKeyData() << ": "
 110     //           << *V << "\n");
 111     return &*IterBool.first;
 112   }
 113
 114   // Otherwise, there is a naming conflict.  Rename this value.
 115   SmallString<256> UniqueName(Name.begin(), Name.end());
 116   return makeUniqueName(V, UniqueName);
 117 }
 118
 119 #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
 120 // dump - print out the symbol table
 121 //
 122 LLVM_DUMP_METHOD void ValueSymbolTable::dump() const {
 123   // dbgs() << "ValueSymbolTable:\n";
 124   for (const auto &I : *this) {
 125     // dbgs() << "  '" << I->getKeyData() << "' = ";
 126     I.getValue()->dump();
 127     // dbgs() << "\n";
 128   }
 129 }
 130 #endif