1 //===-- TypeFinder.cpp - Implement the TypeFinder 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 TypeFinder class for the IR library.
11 //
12 //===----------------------------------------------------------------------===//
13
14 #include "llvm/IR/TypeFinder.h"
15 #include "llvm/ADT/SmallVector.h"
16 #include "llvm/IR/BasicBlock.h"
17 #include "llvm/IR/DerivedTypes.h"
18 #include "llvm/IR/Function.h"
19 #include "llvm/IR/Metadata.h"
20 #include "llvm/IR/Module.h"
21 using namespace llvm;
22
run(const Module & M,bool onlyNamed)23 void TypeFinder::run(const Module &M, bool onlyNamed) {
24 OnlyNamed = onlyNamed;
25
26 // Get types from global variables.
27 for (Module::const_global_iterator I = M.global_begin(),
28 E = M.global_end(); I != E; ++I) {
29 incorporateType(I->getType());
30 if (I->hasInitializer())
31 incorporateValue(I->getInitializer());
32 }
33
34 // Get types from aliases.
35 for (Module::const_alias_iterator I = M.alias_begin(),
36 E = M.alias_end(); I != E; ++I) {
37 incorporateType(I->getType());
38 if (const Value *Aliasee = I->getAliasee())
39 incorporateValue(Aliasee);
40 }
41
42 // Get types from functions.
43 SmallVector<std::pair<unsigned, MDNode *>, 4> MDForInst;
44 for (Module::const_iterator FI = M.begin(), E = M.end(); FI != E; ++FI) {
45 incorporateType(FI->getType());
46
47 for (const Use &U : FI->operands())
48 incorporateValue(U.get());
49
50 // First incorporate the arguments.
51 for (Function::const_arg_iterator AI = FI->arg_begin(),
52 AE = FI->arg_end(); AI != AE; ++AI)
53 incorporateValue(&*AI);
54
55 for (Function::const_iterator BB = FI->begin(), E = FI->end();
56 BB != E;++BB)
57 for (BasicBlock::const_iterator II = BB->begin(),
58 E = BB->end(); II != E; ++II) {
59 const Instruction &I = *II;
60
61 // Incorporate the type of the instruction.
62 incorporateType(I.getType());
63
64 // Incorporate non-instruction operand types. (We are incorporating all
65 // instructions with this loop.)
66 for (User::const_op_iterator OI = I.op_begin(), OE = I.op_end();
67 OI != OE; ++OI)
68 if (*OI && !isa<Instruction>(OI))
69 incorporateValue(*OI);
70
71 // Incorporate types hiding in metadata.
72 I.getAllMetadataOtherThanDebugLoc(MDForInst);
73 for (unsigned i = 0, e = MDForInst.size(); i != e; ++i)
74 incorporateMDNode(MDForInst[i].second);
75
76 MDForInst.clear();
77 }
78 }
79
80 for (Module::const_named_metadata_iterator I = M.named_metadata_begin(),
81 E = M.named_metadata_end(); I != E; ++I) {
82 const NamedMDNode *NMD = &*I;
83 for (unsigned i = 0, e = NMD->getNumOperands(); i != e; ++i)
84 incorporateMDNode(NMD->getOperand(i));
85 }
86 }
87
clear()88 void TypeFinder::clear() {
89 VisitedConstants.clear();
90 VisitedTypes.clear();
91 StructTypes.clear();
92 }
93
94 /// incorporateType - This method adds the type to the list of used structures
95 /// if it's not in there already.
incorporateType(Type * Ty)96 void TypeFinder::incorporateType(Type *Ty) {
97 // Check to see if we've already visited this type.
98 if (!VisitedTypes.insert(Ty).second)
99 return;
100
101 SmallVector<Type *, 4> TypeWorklist;
102 TypeWorklist.push_back(Ty);
103 do {
104 Ty = TypeWorklist.pop_back_val();
105
106 // If this is a structure or opaque type, add a name for the type.
107 if (StructType *STy = dyn_cast<StructType>(Ty))
108 if (!OnlyNamed || STy->hasName())
109 StructTypes.push_back(STy);
110
111 // Add all unvisited subtypes to worklist for processing
112 for (Type::subtype_reverse_iterator I = Ty->subtype_rbegin(),
113 E = Ty->subtype_rend();
114 I != E; ++I)
115 if (VisitedTypes.insert(*I).second)
116 TypeWorklist.push_back(*I);
117 } while (!TypeWorklist.empty());
118 }
119
120 /// incorporateValue - This method is used to walk operand lists finding types
121 /// hiding in constant expressions and other operands that won't be walked in
122 /// other ways. GlobalValues, basic blocks, instructions, and inst operands are
123 /// all explicitly enumerated.
incorporateValue(const Value * V)124 void TypeFinder::incorporateValue(const Value *V) {
125 if (const auto *M = dyn_cast<MetadataAsValue>(V)) {
126 if (const auto *N = dyn_cast<MDNode>(M->getMetadata()))
127 return incorporateMDNode(N);
128 if (const auto *MDV = dyn_cast<ValueAsMetadata>(M->getMetadata()))
129 return incorporateValue(MDV->getValue());
130 return;
131 }
132
133 if (!isa<Constant>(V) || isa<GlobalValue>(V)) return;
134
135 // Already visited?
136 if (!VisitedConstants.insert(V).second)
137 return;
138
139 // Check this type.
140 incorporateType(V->getType());
141
142 // If this is an instruction, we incorporate it separately.
143 if (isa<Instruction>(V))
144 return;
145
146 // Look in operands for types.
147 const User *U = cast<User>(V);
148 for (Constant::const_op_iterator I = U->op_begin(),
149 E = U->op_end(); I != E;++I)
150 incorporateValue(*I);
151 }
152
153 /// incorporateMDNode - This method is used to walk the operands of an MDNode to
154 /// find types hiding within.
incorporateMDNode(const MDNode * V)155 void TypeFinder::incorporateMDNode(const MDNode *V) {
156 // Already visited?
157 if (!VisitedMetadata.insert(V).second)
158 return;
159
160 // Look in operands for types.
161 for (unsigned i = 0, e = V->getNumOperands(); i != e; ++i) {
162 Metadata *Op = V->getOperand(i);
163 if (!Op)
164 continue;
165 if (auto *N = dyn_cast<MDNode>(Op)) {
166 incorporateMDNode(N);
167 continue;
168 }
169 if (auto *C = dyn_cast<ConstantAsMetadata>(Op)) {
170 incorporateValue(C->getValue());
171 continue;
172 }
173 }
174 }
175