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
28 using namespace llvm;
29
30 #define DEBUG_TYPE "valuesymtab"
31
32 // Class destructor
~ValueSymbolTable()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
makeUniqueName(Value * V,SmallString<256> & UniqueName)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 //
reinsertValue(Value * V)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 V->getValueName()->Destroy();
87
88 ValueName *VN = makeUniqueName(V, UniqueName);
89 V->setValueName(VN);
90 }
91
removeValueName(ValueName * V)92 void 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.
createValueName(StringRef Name,Value * V)101 ValueName *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 //
dump() const118 LLVM_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