ValueSymbolTable.cpp revision 360660 
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/ADT/Triple.h"
16#include "llvm/Config/llvm-config.h"
17#include "llvm/IR/GlobalValue.h"
18#include "llvm/IR/Module.h"
19#include "llvm/IR/Type.h"
20#include "llvm/IR/Value.h"
21#include "llvm/Support/Casting.h"
22#include "llvm/Support/Compiler.h"
23#include "llvm/Support/Debug.h"
24#include "llvm/Support/raw_ostream.h"
25#include <cassert>
26#include <utility>
27
28using namespace llvm;
29
30#define DEBUG_TYPE "valuesymtab"
31
32// Class destructor
33ValueSymbolTable::~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
43ValueName *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, 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//
72void 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  V->getValueName()->Destroy();
87
88  ValueName *VN = makeUniqueName(V, UniqueName);
89  V->setValueName(VN);
90}
91
92void ValueSymbolTable::removeValueName(ValueName *V) {
93  // LLVM_DEBUG(dbgs() << " Removing Value: " << V->getKeyData() << "\n");
94  // Remove the value from the symbol table.
95  vmap.remove(V);
96}
97
98/// createValueName - This method attempts to create a value name and insert
99/// it into the symbol table with the specified name.  If it conflicts, it
100/// auto-renames the name and returns that instead.
101ValueName *ValueSymbolTable::createValueName(StringRef Name, Value *V) {
102  // In the common case, the name is not already in the symbol table.
103  auto IterBool = vmap.insert(std::make_pair(Name, V));
104  if (IterBool.second) {
105    // LLVM_DEBUG(dbgs() << " Inserted value: " << Entry.getKeyData() << ": "
106    //           << *V << "\n");
107    return &*IterBool.first;
108  }
109
110  // Otherwise, there is a naming conflict.  Rename this value.
111  SmallString<256> UniqueName(Name.begin(), Name.end());
112  return makeUniqueName(V, UniqueName);
113}
114
115#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
116// dump - print out the symbol table
117//
118LLVM_DUMP_METHOD void ValueSymbolTable::dump() const {
119  //dbgs() << "ValueSymbolTable:\n";
120  for (const auto &I : *this) {
121    //dbgs() << "  '" << I->getKeyData() << "' = ";
122    I.getValue()->dump();
123    //dbgs() << "\n";
124  }
125}
126#endif
127