lib/VMCore/ValueSymbolTable.cpp

   1 //===-- ValueSymbolTable.cpp - Implement the ValueSymbolTable class -------===//
   2 //
   3 //                     The LLVM Compiler Infrastructure
   4 //
   5 // This file was developed by the LLVM research group.  It is distributed under
   6 // the University of Illinois Open Source License. See LICENSE.TXT for details.
   7 //
   8 //===----------------------------------------------------------------------===//
   9 //
  10 // This file implements the ValueSymbolTable class for the VMCore library.
  11 //
  12 //===----------------------------------------------------------------------===//
  13
  14 #include "llvm/GlobalValue.h"
  15 #include "llvm/Type.h"
  16 #include "llvm/ValueSymbolTable.h"
  17 #include "llvm/ADT/StringExtras.h"
  18 #include <algorithm>
  19 #include <iostream>
  20
  21 using namespace llvm;
  22
  23 #define DEBUG_SYMBOL_TABLE 0
  24 #define DEBUG_ABSTYPE 0
  25
  26 // Class destructor
  27 ValueSymbolTable::~ValueSymbolTable() {
  28 #ifndef NDEBUG   // Only do this in -g mode...
  29   bool LeftoverValues = true;
  30   for (iterator VI = vmap.begin(), VE = vmap.end(); VI != VE; ++VI)
  31     if (!isa<Constant>(VI->second) ) {
  32       std::cerr << "Value still in symbol table! Type = '"
  33                 << VI->second->getType()->getDescription() << "' Name = '"
  34                 << VI->first << "'\n";
  35       LeftoverValues = false;
  36     }
  37   assert(LeftoverValues && "Values remain in symbol table!");
  38 #endif
  39 }
  40
  41 // getUniqueName - Given a base name, return a string that is either equal to
  42 // it (or derived from it) that does not already occur in the symbol table for
  43 // the specified type.
  44 //
  45 std::string ValueSymbolTable::getUniqueName(const std::string &BaseName) const {
  46   std::string TryName = BaseName;
  47   const_iterator End = vmap.end();
  48
  49   // See if the name exists
  50   while (vmap.find(TryName) != End)            // Loop until we find a free
  51     TryName = BaseName + utostr(++LastUnique); // name in the symbol table
  52   return TryName;
  53 }
  54
  55
  56 // lookup a value - Returns null on failure...
  57 //
  58 Value *ValueSymbolTable::lookup(const std::string &Name) const {
  59   const_iterator VI = vmap.find(Name);
  60   if (VI != vmap.end())                   // We found the symbol
  61     return const_cast<Value*>(VI->second);
  62   return 0;
  63 }
  64
  65 // Strip the symbol table of its names.
  66 //
  67 bool ValueSymbolTable::strip() {
  68   bool RemovedSymbol = false;
  69   for (iterator VI = vmap.begin(), VE = vmap.end(); VI != VE; ) {
  70     Value *V = VI->second;
  71     ++VI;
  72     if (!isa<GlobalValue>(V) || cast<GlobalValue>(V)->hasInternalLinkage()) {
  73       // Set name to "", removing from symbol table!
  74       V->setName("");
  75       RemovedSymbol = true;
  76     }
  77   }
  78   return RemovedSymbol;
  79 }
  80
  81 // Insert a value into the symbol table with the specified name...
  82 //
  83 void ValueSymbolTable::insert(Value* V) {
  84   assert(V && "Can't insert null Value into symbol table!");
  85   assert(V->hasName() && "Can't insert nameless Value into symbol table");
  86
  87   // Check to see if there is a naming conflict.  If so, rename this type!
  88   std::string UniqueName = getUniqueName(V->getName());
  89
  90 #if DEBUG_SYMBOL_TABLE
  91   dump();
  92   std::cerr << " Inserting value: " << UniqueName << ": " << V->dump() << "\n";
  93 #endif
  94
  95   // Insert the vmap entry
  96   vmap.insert(make_pair(UniqueName, V));
  97 }
  98
  99 // Remove a value
 100 bool ValueSymbolTable::erase(Value *V) {
 101   assert(V->hasName() && "Value doesn't have name!");
 102   iterator Entry = vmap.find(V->getName());
 103   if (Entry == vmap.end())
 104     return false;
 105
 106 #if DEBUG_SYMBOL_TABLE
 107   dump();
 108   std::cerr << " Removing Value: " << Entry->second->getName() << "\n";
 109 #endif
 110
 111   // Remove the value from the plane...
 112   vmap.erase(Entry);
 113   return true;
 114 }
 115
 116
 117 // rename - Given a value with a non-empty name, remove its existing entry
 118 // from the symbol table and insert a new one for Name.  This is equivalent to
 119 // doing "remove(V), V->Name = Name, insert(V)",
 120 //
 121 bool ValueSymbolTable::rename(Value *V, const std::string &name) {
 122   assert(V && "Can't rename a null Value");
 123   assert(V->hasName() && "Can't rename a nameless Value");
 124   assert(!V->getName().empty() && "Can't rename an Value with null name");
 125   assert(V->getName() != name && "Can't rename a Value with same name");
 126   assert(!name.empty() && "Can't rename a named Value with a null name");
 127
 128   // Find the name
 129   iterator VI = vmap.find(V->getName());
 130
 131   // If we didn't find it, we're done
 132   if (VI == vmap.end())
 133     return false;
 134
 135   // Remove the old entry.
 136   vmap.erase(VI);
 137
 138   // See if we can insert the new name.
 139   VI = vmap.lower_bound(name);
 140
 141   // Is there a naming conflict?
 142   if (VI != vmap.end() && VI->first == name) {
 143     V->Name = getUniqueName( name);
 144     vmap.insert(make_pair(V->Name, V));
 145   } else {
 146     V->Name = name;
 147     vmap.insert(VI, make_pair(name, V));
 148   }
 149
 150   return true;
 151 }
 152
 153 // DumpVal - a std::for_each function for dumping a value
 154 //
 155 static void DumpVal(const std::pair<const std::string, Value *> &V) {
 156   std::cerr << "  '" << V.first << "' = ";
 157   V.second->dump();
 158   std::cerr << "\n";
 159 }
 160
 161 // dump - print out the symbol table
 162 //
 163 void ValueSymbolTable::dump() const {
 164   std::cerr << "ValueSymbolTable:\n";
 165   for_each(vmap.begin(), vmap.end(), DumpVal);
 166 }