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/Module.h"
20 #include "llvm/IR/Verifier.h"
21 #include "llvm/IRReader/IRReader.h"
22 #include "llvm/Pass.h"
23 #include "llvm/PassManager.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
runOnFunction(Function & F)54 bool runOnFunction(Function &F) {
55 // Remove any target-cpu and/or target-features attributes from each
56 // Function or Function declaration.
57 if (F.hasFnAttribute("target-cpu") ||
58 F.hasFnAttribute("target-features")) {
59
60 AttrBuilder B;
61 B.addAttribute("target-cpu").addAttribute("target-features");
62 AttributeSet ToStrip = AttributeSet::get(F.getContext(),
63 AttributeSet::FunctionIndex, B);
64 F.removeAttributes(AttributeSet::FunctionIndex, ToStrip);
65 return true;
66 }
67 return false;
68 }
69
70 // We have to use a ModulePass, since a FunctionPass only gets run on
71 // defined Functions (and not declared Functions).
runOnModule(Module & M)72 virtual bool runOnModule(Module &M) {
73 bool Changed = false;
74 for (Module::iterator I = M.begin(), E = M.end(); I != E; ++I) {
75 Changed |= runOnFunction(*I);
76 }
77 return Changed;
78 }
79 };
80
createStripAttributePass()81 llvm::ModulePass * createStripAttributePass() {
82 return new StripAttributes();
83 }
84 }
85
86
87 char StripAttributes::ID = 0;
88 static RegisterPass<StripAttributes> RPSA("StripAttributes",
89 "Strip Function Attributes Pass");
90
91
LoadFile(const char * argv0,const std::string & FN,LLVMContext & Context)92 static inline std::unique_ptr<Module> LoadFile(const char *argv0,
93 const std::string &FN,
94 LLVMContext& Context) {
95 SMDiagnostic Err;
96 Module* Result = ParseIRFile(FN, Err, Context);
97 if (Result) {
98 return std::unique_ptr<Module>(Result); // Load successful!
99 }
100
101 Err.print(argv0, errs());
102 return std::unique_ptr<Module>();
103 }
104
105
main(int argc,char ** argv)106 int main(int argc, char **argv) {
107 // Print a stack trace if we signal out.
108 sys::PrintStackTraceOnErrorSignal();
109 PrettyStackTraceProgram X(argc, argv);
110
111 LLVMContext &Context = getGlobalContext();
112 llvm_shutdown_obj Y; // Call llvm_shutdown() on exit.
113 cl::ParseCommandLineOptions(argc, argv, "strip function attribute pass\n");
114
115 std::string ErrorMessage;
116
117 std::unique_ptr<Module> M(LoadFile(argv[0], InputFilenames[0], Context));
118 if (M.get() == 0) {
119 errs() << argv[0] << ": error loading file '"
120 << InputFilenames[0] << "'\n";
121 return 1;
122 }
123
124 // Perform the actual function attribute stripping.
125 PassManager PM;
126 PM.add(createStripAttributePass());
127 PM.run(*M.get());
128
129 std::string ErrorInfo;
130 tool_output_file Out(OutputFilename.c_str(), ErrorInfo,
131 sys::fs::F_None);
132 if (!ErrorInfo.empty()) {
133 errs() << ErrorInfo << '\n';
134 return 1;
135 }
136
137 if (verifyModule(*M)) {
138 errs() << argv[0] << ": stripped module is broken!\n";
139 return 1;
140 }
141
142 if (OutputAssembly) {
143 Out.os() << *M;
144 } else if (!CheckBitcodeOutputToConsole(Out.os(), true)) {
145 WriteBitcodeToFile(M.get(), Out.os());
146 }
147
148 Out.keep();
149
150 return 0;
151 }
152