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/Analysis/Verifier.h"
18 #include "llvm/Bitcode/ReaderWriter.h"
19 #include "llvm/IR/LLVMContext.h"
20 #include "llvm/IR/Module.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/ManagedStatic.h"
26 #include "llvm/Support/PrettyStackTrace.h"
27 #include "llvm/Support/Signals.h"
28 #include "llvm/Support/SourceMgr.h"
29 #include "llvm/Support/SystemUtils.h"
30 #include "llvm/Support/ToolOutputFile.h"
31 using namespace llvm;
32
33 static cl::list<std::string>
34 InputFilenames(cl::Positional,
35 cl::desc("<input bitcode files>"));
36
37 static cl::opt<std::string>
38 OutputFilename("o", cl::desc("Override output filename"), cl::init("-"),
39 cl::value_desc("filename"));
40
41 static cl::opt<bool>
42 OutputAssembly("S",
43 cl::desc("Write output as LLVM assembly"), cl::Hidden);
44
45 namespace {
46 class StripAttributes : public ModulePass {
47 public:
48 static char ID;
49
StripAttributes()50 StripAttributes() : ModulePass(ID) {
51 }
52
runOnFunction(Function & F)53 bool runOnFunction(Function &F) {
54 // Remove any target-cpu and/or target-features attributes from each
55 // Function or Function declaration.
56 if (F.hasFnAttribute("target-cpu") ||
57 F.hasFnAttribute("target-features")) {
58
59 AttrBuilder B;
60 B.addAttribute("target-cpu").addAttribute("target-features");
61 AttributeSet ToStrip = AttributeSet::get(F.getContext(),
62 AttributeSet::FunctionIndex, B);
63 F.removeAttributes(AttributeSet::FunctionIndex, ToStrip);
64 return true;
65 }
66 return false;
67 }
68
69 // We have to use a ModulePass, since a FunctionPass only gets run on
70 // defined Functions (and not declared Functions).
runOnModule(Module & M)71 virtual bool runOnModule(Module &M) {
72 bool Changed = false;
73 for (Module::iterator I = M.begin(), E = M.end(); I != E; ++I) {
74 Changed |= runOnFunction(*I);
75 }
76 return Changed;
77 }
78 };
79
createStripAttributePass()80 llvm::ModulePass * createStripAttributePass() {
81 return new StripAttributes();
82 }
83 }
84
85
86 char StripAttributes::ID = 0;
87 static RegisterPass<StripAttributes> RPSA("StripAttributes",
88 "Strip Function Attributes Pass");
89
90
LoadFile(const char * argv0,const std::string & FN,LLVMContext & Context)91 static inline std::auto_ptr<Module> LoadFile(const char *argv0,
92 const std::string &FN,
93 LLVMContext& Context) {
94 SMDiagnostic Err;
95 Module* Result = ParseIRFile(FN, Err, Context);
96 if (Result) {
97 return std::auto_ptr<Module>(Result); // Load successful!
98 }
99
100 Err.print(argv0, errs());
101 return std::auto_ptr<Module>();
102 }
103
104
main(int argc,char ** argv)105 int main(int argc, char **argv) {
106 // Print a stack trace if we signal out.
107 sys::PrintStackTraceOnErrorSignal();
108 PrettyStackTraceProgram X(argc, argv);
109
110 LLVMContext &Context = getGlobalContext();
111 llvm_shutdown_obj Y; // Call llvm_shutdown() on exit.
112 cl::ParseCommandLineOptions(argc, argv, "strip function attribute pass\n");
113
114 std::string ErrorMessage;
115
116 std::auto_ptr<Module> M(LoadFile(argv[0], InputFilenames[0], Context));
117 if (M.get() == 0) {
118 errs() << argv[0] << ": error loading file '"
119 << InputFilenames[0] << "'\n";
120 return 1;
121 }
122
123 // Perform the actual function attribute stripping.
124 PassManager PM;
125 PM.add(createStripAttributePass());
126 PM.run(*M.get());
127
128 std::string ErrorInfo;
129 tool_output_file Out(OutputFilename.c_str(), ErrorInfo,
130 sys::fs::F_Binary);
131 if (!ErrorInfo.empty()) {
132 errs() << ErrorInfo << '\n';
133 return 1;
134 }
135
136 if (verifyModule(*M)) {
137 errs() << argv[0] << ": stripped module is broken!\n";
138 return 1;
139 }
140
141 if (OutputAssembly) {
142 Out.os() << *M;
143 } else if (!CheckBitcodeOutputToConsole(Out.os(), true)) {
144 WriteBitcodeToFile(M.get(), Out.os());
145 }
146
147 Out.keep();
148
149 return 0;
150 }
151