1 /*
2 * Copyright 2013, The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 #include "llvm/Bitcode/ReaderWriter.h"
18 #include "llvm/IR/LLVMContext.h"
19 #include "llvm/IR/LegacyPassManager.h"
20 #include "llvm/IR/Module.h"
21 #include "llvm/IR/Verifier.h"
22 #include "llvm/IRReader/IRReader.h"
23 #include "llvm/Pass.h"
24 #include "llvm/Support/CommandLine.h"
25 #include "llvm/Support/FileSystem.h"
26 #include "llvm/Support/ManagedStatic.h"
27 #include "llvm/Support/PrettyStackTrace.h"
28 #include "llvm/Support/Signals.h"
29 #include "llvm/Support/SourceMgr.h"
30 #include "llvm/Support/SystemUtils.h"
31 #include "llvm/Support/ToolOutputFile.h"
32 using namespace llvm;
33
34 static cl::list<std::string>
35 InputFilenames(cl::Positional,
36 cl::desc("<input bitcode files>"));
37
38 static cl::opt<std::string>
39 OutputFilename("o", cl::desc("Override output filename"), cl::init("-"),
40 cl::value_desc("filename"));
41
42 static cl::opt<bool>
43 OutputAssembly("S",
44 cl::desc("Write output as LLVM assembly"), cl::Hidden);
45
46 namespace {
47 class StripAttributes : public ModulePass {
48 public:
49 static char ID;
50
StripAttributes()51 StripAttributes() : ModulePass(ID) {
52 }
53
getAnalysisUsage(llvm::AnalysisUsage & AU) const54 virtual void getAnalysisUsage(llvm::AnalysisUsage &AU) const override {
55 AU.setPreservesAll();
56 }
57
runOnFunction(Function & F)58 bool runOnFunction(Function &F) {
59 // Remove any target-cpu and/or target-features attributes from each
60 // Function or Function declaration.
61 if (F.hasFnAttribute("target-cpu") ||
62 F.hasFnAttribute("target-features")) {
63
64 AttrBuilder B;
65 B.addAttribute("target-cpu").addAttribute("target-features");
66 AttributeSet ToStrip = AttributeSet::get(F.getContext(),
67 AttributeSet::FunctionIndex, B);
68 F.removeAttributes(AttributeSet::FunctionIndex, ToStrip);
69 return true;
70 }
71 return false;
72 }
73
74 // We have to use a ModulePass, since a FunctionPass only gets run on
75 // defined Functions (and not declared Functions).
runOnModule(Module & M)76 virtual bool runOnModule(Module &M) {
77 bool Changed = false;
78 for (Module::iterator I = M.begin(), E = M.end(); I != E; ++I) {
79 Changed |= runOnFunction(*I);
80 }
81 return Changed;
82 }
83 };
84
createStripAttributePass()85 llvm::ModulePass * createStripAttributePass() {
86 return new StripAttributes();
87 }
88 }
89
90
91 char StripAttributes::ID = 0;
92 static RegisterPass<StripAttributes> RPSA("StripAttributes",
93 "Strip Function Attributes Pass");
94
95
LoadFile(const char * argv0,const std::string & FN,LLVMContext & Context)96 static inline std::unique_ptr<Module> LoadFile(const char *argv0,
97 const std::string &FN,
98 LLVMContext& Context) {
99 SMDiagnostic Err;
100 std::unique_ptr<Module> Result = parseIRFile(FN, Err, Context);
101 if (Result) {
102 return Result; // Load successful!
103 }
104
105 Err.print(argv0, errs());
106 return std::unique_ptr<Module>();
107 }
108
109
main(int argc,char ** argv)110 int main(int argc, char **argv) {
111 // Print a stack trace if we signal out.
112 sys::PrintStackTraceOnErrorSignal(argv[0]);
113 PrettyStackTraceProgram X(argc, argv);
114
115 LLVMContext Context;
116 llvm_shutdown_obj Y; // Call llvm_shutdown() on exit.
117 cl::ParseCommandLineOptions(argc, argv, "strip function attribute pass\n");
118
119 std::string ErrorMessage;
120
121 std::unique_ptr<Module> M(LoadFile(argv[0], InputFilenames[0], Context));
122 if (M.get() == 0) {
123 errs() << argv[0] << ": error loading file '"
124 << InputFilenames[0] << "'\n";
125 return 1;
126 }
127
128 // Perform the actual function attribute stripping.
129 legacy::PassManager PM;
130 PM.add(createStripAttributePass());
131 PM.run(*M.get());
132
133 std::error_code EC;
134 tool_output_file Out(OutputFilename.c_str(), EC,
135 sys::fs::F_None);
136 if (EC) {
137 errs() << EC.message() << '\n';
138 return 1;
139 }
140
141 if (verifyModule(*M)) {
142 errs() << argv[0] << ": stripped module is broken!\n";
143 return 1;
144 }
145
146 if (OutputAssembly) {
147 Out.os() << *M;
148 } else if (!CheckBitcodeOutputToConsole(Out.os(), true)) {
149 WriteBitcodeToFile(M.get(), Out.os());
150 }
151
152 Out.keep();
153
154 return 0;
155 }
156