1 //===- ValueSymbolTable.cpp - Implement the ValueSymbolTable class --------===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // This file implements the ValueSymbolTable class for the IR library.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #include "llvm/IR/ValueSymbolTable.h"
15 #include "llvm/ADT/SmallString.h"
16 #include "llvm/ADT/Triple.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 
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, 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     //DEBUG(dbgs() << " Inserted value: " << V->getValueName() << ": " << *V << "\n");
78     return;
79   }
80 
81   // Otherwise, there is a naming conflict.  Rename this value.
82   SmallString<256> UniqueName(V->getName().begin(), V->getName().end());
83 
84   // The name is too already used, just free it so we can allocate a new name.
85   V->getValueName()->Destroy();
86 
87   ValueName *VN = makeUniqueName(V, UniqueName);
88   V->setValueName(VN);
89 }
90 
91 void ValueSymbolTable::removeValueName(ValueName *V) {
92   //DEBUG(dbgs() << " Removing Value: " << V->getKeyData() << "\n");
93   // Remove the value from the symbol table.
94   vmap.remove(V);
95 }
96 
97 /// createValueName - This method attempts to create a value name and insert
98 /// it into the symbol table with the specified name.  If it conflicts, it
99 /// auto-renames the name and returns that instead.
100 ValueName *ValueSymbolTable::createValueName(StringRef Name, Value *V) {
101   // In the common case, the name is not already in the symbol table.
102   auto IterBool = vmap.insert(std::make_pair(Name, V));
103   if (IterBool.second) {
104     //DEBUG(dbgs() << " Inserted value: " << Entry.getKeyData() << ": "
105     //           << *V << "\n");
106     return &*IterBool.first;
107   }
108 
109   // Otherwise, there is a naming conflict.  Rename this value.
110   SmallString<256> UniqueName(Name.begin(), Name.end());
111   return makeUniqueName(V, UniqueName);
112 }
113 
114 #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
115 // dump - print out the symbol table
116 //
117 LLVM_DUMP_METHOD void ValueSymbolTable::dump() const {
118   //dbgs() << "ValueSymbolTable:\n";
119   for (const auto &I : *this) {
120     //dbgs() << "  '" << I->getKeyData() << "' = ";
121     I.getValue()->dump();
122     //dbgs() << "\n";
123   }
124 }
125 #endif
126