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
~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 bool AppenDot = false;
47 if (auto *GV = dyn_cast<GlobalValue>(V)) {
48 // A dot is appended to mark it as clone during ABI demangling so that
49 // for example "_Z1fv" and "_Z1fv.1" both demangle to "f()", the second
50 // one being a clone.
51 // On NVPTX we cannot use a dot because PTX only allows [A-Za-z0-9_$] for
52 // identifiers. This breaks ABI demangling but at least ptxas accepts and
53 // compiles the program.
54 const Module *M = GV->getParent();
55 if (!(M && Triple(M->getTargetTriple()).isNVPTX()))
56 AppenDot = true;
57 }
58
59 while (true) {
60 // Trim any suffix off and append the next number.
61 UniqueName.resize(BaseSize);
62 raw_svector_ostream S(UniqueName);
63 if (AppenDot)
64 S << ".";
65 S << ++LastUnique;
66
67 // Retry if MaxNameSize has been exceeded.
68 if (MaxNameSize > -1 && UniqueName.size() > (size_t)MaxNameSize) {
69 assert(BaseSize >= UniqueName.size() - (size_t)MaxNameSize &&
70 "Can't generate unique name: MaxNameSize is too small.");
71 BaseSize -= UniqueName.size() - (size_t)MaxNameSize;
72 continue;
73 }
74 // Try insert the vmap entry with this suffix.
75 auto IterBool = vmap.insert(std::make_pair(UniqueName.str(), V));
76 if (IterBool.second)
77 return &*IterBool.first;
78 }
79 }
80
81 // Insert a value into the symbol table with the specified name...
82 //
reinsertValue(Value * V)83 void ValueSymbolTable::reinsertValue(Value *V) {
84 assert(V->hasName() && "Can't insert nameless Value into symbol table");
85
86 // Try inserting the name, assuming it won't conflict.
87 if (vmap.insert(V->getValueName())) {
88 // LLVM_DEBUG(dbgs() << " Inserted value: " << V->getValueName() << ": " <<
89 // *V << "\n");
90 return;
91 }
92
93 // Otherwise, there is a naming conflict. Rename this value.
94 SmallString<256> UniqueName(V->getName().begin(), V->getName().end());
95
96 // The name is too already used, just free it so we can allocate a new name.
97 MallocAllocator Allocator;
98 V->getValueName()->Destroy(Allocator);
99
100 ValueName *VN = makeUniqueName(V, UniqueName);
101 V->setValueName(VN);
102 }
103
removeValueName(ValueName * V)104 void ValueSymbolTable::removeValueName(ValueName *V) {
105 // LLVM_DEBUG(dbgs() << " Removing Value: " << V->getKeyData() << "\n");
106 // Remove the value from the symbol table.
107 vmap.remove(V);
108 }
109
110 /// createValueName - This method attempts to create a value name and insert
111 /// it into the symbol table with the specified name. If it conflicts, it
112 /// auto-renames the name and returns that instead.
createValueName(StringRef Name,Value * V)113 ValueName *ValueSymbolTable::createValueName(StringRef Name, Value *V) {
114 if (MaxNameSize > -1 && Name.size() > (unsigned)MaxNameSize)
115 Name = Name.substr(0, std::max(1u, (unsigned)MaxNameSize));
116
117 // In the common case, the name is not already in the symbol table.
118 auto IterBool = vmap.insert(std::make_pair(Name, V));
119 if (IterBool.second) {
120 // LLVM_DEBUG(dbgs() << " Inserted value: " << Entry.getKeyData() << ": "
121 // << *V << "\n");
122 return &*IterBool.first;
123 }
124
125 // Otherwise, there is a naming conflict. Rename this value.
126 SmallString<256> UniqueName(Name.begin(), Name.end());
127 return makeUniqueName(V, UniqueName);
128 }
129
130 #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
131 // dump - print out the symbol table
132 //
dump() const133 LLVM_DUMP_METHOD void ValueSymbolTable::dump() const {
134 // dbgs() << "ValueSymbolTable:\n";
135 for (const auto &I : *this) {
136 // dbgs() << " '" << I->getKeyData() << "' = ";
137 I.getValue()->dump();
138 // dbgs() << "\n";
139 }
140 }
141 #endif
142