1 //===- llvm/unittest/IR/VerifierTest.cpp - Verifier unit tests --*- C++ -*-===//
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 #include "llvm/IR/Verifier.h"
10 #include "llvm/IR/Constants.h"
11 #include "llvm/IR/DIBuilder.h"
12 #include "llvm/IR/DerivedTypes.h"
13 #include "llvm/IR/Function.h"
14 #include "llvm/IR/GlobalAlias.h"
15 #include "llvm/IR/GlobalVariable.h"
16 #include "llvm/IR/IRBuilder.h"
17 #include "llvm/IR/Instructions.h"
18 #include "llvm/IR/LLVMContext.h"
19 #include "llvm/IR/Module.h"
20 #include "gtest/gtest.h"
21 
22 namespace llvm {
23 namespace {
24 
25 TEST(VerifierTest, Branch_i1) {
26   LLVMContext C;
27   Module M("M", C);
28   FunctionType *FTy = FunctionType::get(Type::getVoidTy(C), /*isVarArg=*/false);
29   Function *F = Function::Create(FTy, Function::ExternalLinkage, "foo", M);
30   BasicBlock *Entry = BasicBlock::Create(C, "entry", F);
31   BasicBlock *Exit = BasicBlock::Create(C, "exit", F);
32   ReturnInst::Create(C, Exit);
33 
34   // To avoid triggering an assertion in BranchInst::Create, we first create
35   // a branch with an 'i1' condition ...
36 
37   Constant *False = ConstantInt::getFalse(C);
38   BranchInst *BI = BranchInst::Create(Exit, Exit, False, Entry);
39 
40   // ... then use setOperand to redirect it to a value of different type.
41 
42   Constant *Zero32 = ConstantInt::get(IntegerType::get(C, 32), 0);
43   BI->setOperand(0, Zero32);
44 
45   EXPECT_TRUE(verifyFunction(*F));
46 }
47 
48 TEST(VerifierTest, Freeze) {
49   LLVMContext C;
50   Module M("M", C);
51   FunctionType *FTy = FunctionType::get(Type::getVoidTy(C), /*isVarArg=*/false);
52   Function *F = Function::Create(FTy, Function::ExternalLinkage, "foo", M);
53   BasicBlock *Entry = BasicBlock::Create(C, "entry", F);
54   ReturnInst *RI = ReturnInst::Create(C, Entry);
55 
56   IntegerType *ITy = IntegerType::get(C, 32);
57   ConstantInt *CI = ConstantInt::get(ITy, 0);
58 
59   // Valid type : freeze(<2 x i32>)
60   Constant *CV = ConstantVector::getSplat(ElementCount::getFixed(2), CI);
61   FreezeInst *FI_vec = new FreezeInst(CV);
62   FI_vec->insertBefore(RI);
63 
64   EXPECT_FALSE(verifyFunction(*F));
65 
66   FI_vec->eraseFromParent();
67 
68   // Valid type : freeze(float)
69   Constant *CFP = ConstantFP::get(Type::getDoubleTy(C), 0.0);
70   FreezeInst *FI_dbl = new FreezeInst(CFP);
71   FI_dbl->insertBefore(RI);
72 
73   EXPECT_FALSE(verifyFunction(*F));
74 
75   FI_dbl->eraseFromParent();
76 
77   // Valid type : freeze(i32*)
78   PointerType *PT = PointerType::get(ITy, 0);
79   ConstantPointerNull *CPN = ConstantPointerNull::get(PT);
80   FreezeInst *FI_ptr = new FreezeInst(CPN);
81   FI_ptr->insertBefore(RI);
82 
83   EXPECT_FALSE(verifyFunction(*F));
84 
85   FI_ptr->eraseFromParent();
86 
87   // Valid type : freeze(int)
88   FreezeInst *FI = new FreezeInst(CI);
89   FI->insertBefore(RI);
90 
91   EXPECT_FALSE(verifyFunction(*F));
92 
93   FI->eraseFromParent();
94 }
95 
96 TEST(VerifierTest, InvalidRetAttribute) {
97   LLVMContext C;
98   Module M("M", C);
99   FunctionType *FTy = FunctionType::get(Type::getInt32Ty(C), /*isVarArg=*/false);
100   Function *F = Function::Create(FTy, Function::ExternalLinkage, "foo", M);
101   AttributeList AS = F->getAttributes();
102   F->setAttributes(AS.addRetAttribute(
103       C, Attribute::getWithUWTableKind(C, UWTableKind::Default)));
104 
105   std::string Error;
106   raw_string_ostream ErrorOS(Error);
107   EXPECT_TRUE(verifyModule(M, &ErrorOS));
108   EXPECT_TRUE(StringRef(ErrorOS.str()).startswith(
109       "Attribute 'uwtable' does not apply to function return values"));
110 }
111 
112 TEST(VerifierTest, CrossModuleRef) {
113   LLVMContext C;
114   Module M1("M1", C);
115   Module M2("M2", C);
116   Module M3("M3", C);
117   FunctionType *FTy = FunctionType::get(Type::getInt32Ty(C), /*isVarArg=*/false);
118   Function *F1 = Function::Create(FTy, Function::ExternalLinkage, "foo1", M1);
119   Function *F2 = Function::Create(FTy, Function::ExternalLinkage, "foo2", M2);
120   Function *F3 = Function::Create(FTy, Function::ExternalLinkage, "foo3", M3);
121 
122   BasicBlock *Entry1 = BasicBlock::Create(C, "entry", F1);
123   BasicBlock *Entry3 = BasicBlock::Create(C, "entry", F3);
124 
125   // BAD: Referencing function in another module
126   CallInst::Create(F2,"call",Entry1);
127 
128   // BAD: Referencing personality routine in another module
129   F3->setPersonalityFn(F2);
130 
131   // Fill in the body
132   Constant *ConstZero = ConstantInt::get(Type::getInt32Ty(C), 0);
133   ReturnInst::Create(C, ConstZero, Entry1);
134   ReturnInst::Create(C, ConstZero, Entry3);
135 
136   std::string Error;
137   raw_string_ostream ErrorOS(Error);
138   EXPECT_TRUE(verifyModule(M2, &ErrorOS));
139   EXPECT_TRUE(StringRef(ErrorOS.str())
140                   .equals("Global is referenced in a different module!\n"
141                           "i32 ()* @foo2\n"
142                           "; ModuleID = 'M2'\n"
143                           "  %call = call i32 @foo2()\n"
144                           "i32 ()* @foo1\n"
145                           "; ModuleID = 'M1'\n"
146                           "Global is used by function in a different module\n"
147                           "i32 ()* @foo2\n"
148                           "; ModuleID = 'M2'\n"
149                           "i32 ()* @foo3\n"
150                           "; ModuleID = 'M3'\n"));
151 
152   Error.clear();
153   EXPECT_TRUE(verifyModule(M1, &ErrorOS));
154   EXPECT_TRUE(StringRef(ErrorOS.str()).equals(
155       "Referencing function in another module!\n"
156       "  %call = call i32 @foo2()\n"
157       "; ModuleID = 'M1'\n"
158       "i32 ()* @foo2\n"
159       "; ModuleID = 'M2'\n"));
160 
161   Error.clear();
162   EXPECT_TRUE(verifyModule(M3, &ErrorOS));
163   EXPECT_TRUE(StringRef(ErrorOS.str()).startswith(
164       "Referencing personality function in another module!"));
165 
166   // Erase bad methods to avoid triggering an assertion failure on destruction
167   F1->eraseFromParent();
168   F3->eraseFromParent();
169 }
170 
171 TEST(VerifierTest, InvalidVariableLinkage) {
172   LLVMContext C;
173   Module M("M", C);
174   new GlobalVariable(M, Type::getInt8Ty(C), false,
175                      GlobalValue::LinkOnceODRLinkage, nullptr, "Some Global");
176   std::string Error;
177   raw_string_ostream ErrorOS(Error);
178   EXPECT_TRUE(verifyModule(M, &ErrorOS));
179   EXPECT_TRUE(
180       StringRef(ErrorOS.str()).startswith("Global is external, but doesn't "
181                                           "have external or weak linkage!"));
182 }
183 
184 TEST(VerifierTest, InvalidFunctionLinkage) {
185   LLVMContext C;
186   Module M("M", C);
187 
188   FunctionType *FTy = FunctionType::get(Type::getVoidTy(C), /*isVarArg=*/false);
189   Function::Create(FTy, GlobalValue::LinkOnceODRLinkage, "foo", &M);
190   std::string Error;
191   raw_string_ostream ErrorOS(Error);
192   EXPECT_TRUE(verifyModule(M, &ErrorOS));
193   EXPECT_TRUE(
194       StringRef(ErrorOS.str()).startswith("Global is external, but doesn't "
195                                           "have external or weak linkage!"));
196 }
197 
198 TEST(VerifierTest, DetectInvalidDebugInfo) {
199   {
200     LLVMContext C;
201     Module M("M", C);
202     DIBuilder DIB(M);
203     DIB.createCompileUnit(dwarf::DW_LANG_C89, DIB.createFile("broken.c", "/"),
204                           "unittest", false, "", 0);
205     DIB.finalize();
206     EXPECT_FALSE(verifyModule(M));
207 
208     // Now break it by inserting non-CU node to the list of CUs.
209     auto *File = DIB.createFile("not-a-CU.f", ".");
210     NamedMDNode *NMD = M.getOrInsertNamedMetadata("llvm.dbg.cu");
211     NMD->addOperand(File);
212     EXPECT_TRUE(verifyModule(M));
213   }
214   {
215     LLVMContext C;
216     Module M("M", C);
217     DIBuilder DIB(M);
218     auto *CU = DIB.createCompileUnit(dwarf::DW_LANG_C89,
219                                      DIB.createFile("broken.c", "/"),
220                                      "unittest", false, "", 0);
221     new GlobalVariable(M, Type::getInt8Ty(C), false,
222                        GlobalValue::ExternalLinkage, nullptr, "g");
223 
224     auto *F = Function::Create(FunctionType::get(Type::getVoidTy(C), false),
225                                Function::ExternalLinkage, "f", M);
226     IRBuilder<> Builder(BasicBlock::Create(C, "", F));
227     Builder.CreateUnreachable();
228     F->setSubprogram(DIB.createFunction(
229         CU, "f", "f", DIB.createFile("broken.c", "/"), 1, nullptr, 1,
230         DINode::FlagZero,
231         DISubprogram::SPFlagLocalToUnit | DISubprogram::SPFlagDefinition));
232     DIB.finalize();
233     EXPECT_FALSE(verifyModule(M));
234 
235     // Now break it by not listing the CU at all.
236     M.eraseNamedMetadata(M.getOrInsertNamedMetadata("llvm.dbg.cu"));
237     EXPECT_TRUE(verifyModule(M));
238   }
239 }
240 
241 TEST(VerifierTest, MDNodeWrongContext) {
242   LLVMContext C1, C2;
243   auto *Node = MDNode::get(C1, None);
244 
245   Module M("M", C2);
246   auto *NamedNode = M.getOrInsertNamedMetadata("test");
247   NamedNode->addOperand(Node);
248 
249   std::string Error;
250   raw_string_ostream ErrorOS(Error);
251   EXPECT_TRUE(verifyModule(M, &ErrorOS));
252   EXPECT_TRUE(StringRef(ErrorOS.str())
253                   .startswith("MDNode context does not match Module context!"));
254 }
255 
256 TEST(VerifierTest, AttributesWrongContext) {
257   LLVMContext C1, C2;
258   Module M1("M", C1);
259   FunctionType *FTy1 =
260       FunctionType::get(Type::getVoidTy(C1), /*isVarArg=*/false);
261   Function *F1 = Function::Create(FTy1, Function::ExternalLinkage, "foo", M1);
262   F1->setDoesNotReturn();
263 
264   Module M2("M", C2);
265   FunctionType *FTy2 =
266       FunctionType::get(Type::getVoidTy(C2), /*isVarArg=*/false);
267   Function *F2 = Function::Create(FTy2, Function::ExternalLinkage, "foo", M2);
268   F2->copyAttributesFrom(F1);
269 
270   EXPECT_TRUE(verifyFunction(*F2));
271 }
272 
273 } // end anonymous namespace
274 } // end namespace llvm
275