1 //===- llvm-extract.cpp - LLVM function extraction utility ----------------===//
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 utility changes the input module to only contain a single function,
11 // which is primarily used for debugging transformations.
12 //
13 //===----------------------------------------------------------------------===//
14
15 #include "llvm/ADT/SetVector.h"
16 #include "llvm/ADT/SmallPtrSet.h"
17 #include "llvm/Bitcode/BitcodeWriterPass.h"
18 #include "llvm/IR/DataLayout.h"
19 #include "llvm/IR/IRPrintingPasses.h"
20 #include "llvm/IR/LLVMContext.h"
21 #include "llvm/IR/Module.h"
22 #include "llvm/IRReader/IRReader.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/Regex.h"
29 #include "llvm/Support/Signals.h"
30 #include "llvm/Support/SourceMgr.h"
31 #include "llvm/Support/SystemUtils.h"
32 #include "llvm/Support/ToolOutputFile.h"
33 #include "llvm/Transforms/IPO.h"
34 #include <memory>
35 using namespace llvm;
36
37 // InputFilename - The filename to read from.
38 static cl::opt<std::string>
39 InputFilename(cl::Positional, cl::desc("<input bitcode file>"),
40 cl::init("-"), cl::value_desc("filename"));
41
42 static cl::opt<std::string>
43 OutputFilename("o", cl::desc("Specify output filename"),
44 cl::value_desc("filename"), cl::init("-"));
45
46 static cl::opt<bool>
47 Force("f", cl::desc("Enable binary output on terminals"));
48
49 static cl::opt<bool>
50 DeleteFn("delete", cl::desc("Delete specified Globals from Module"));
51
52 // ExtractFuncs - The functions to extract from the module.
53 static cl::list<std::string>
54 ExtractFuncs("func", cl::desc("Specify function to extract"),
55 cl::ZeroOrMore, cl::value_desc("function"));
56
57 // ExtractRegExpFuncs - The functions, matched via regular expression, to
58 // extract from the module.
59 static cl::list<std::string>
60 ExtractRegExpFuncs("rfunc", cl::desc("Specify function(s) to extract using a "
61 "regular expression"),
62 cl::ZeroOrMore, cl::value_desc("rfunction"));
63
64 // ExtractAlias - The alias to extract from the module.
65 static cl::list<std::string>
66 ExtractAliases("alias", cl::desc("Specify alias to extract"),
67 cl::ZeroOrMore, cl::value_desc("alias"));
68
69
70 // ExtractRegExpAliases - The aliases, matched via regular expression, to
71 // extract from the module.
72 static cl::list<std::string>
73 ExtractRegExpAliases("ralias", cl::desc("Specify alias(es) to extract using a "
74 "regular expression"),
75 cl::ZeroOrMore, cl::value_desc("ralias"));
76
77 // ExtractGlobals - The globals to extract from the module.
78 static cl::list<std::string>
79 ExtractGlobals("glob", cl::desc("Specify global to extract"),
80 cl::ZeroOrMore, cl::value_desc("global"));
81
82 // ExtractRegExpGlobals - The globals, matched via regular expression, to
83 // extract from the module...
84 static cl::list<std::string>
85 ExtractRegExpGlobals("rglob", cl::desc("Specify global(s) to extract using a "
86 "regular expression"),
87 cl::ZeroOrMore, cl::value_desc("rglobal"));
88
89 static cl::opt<bool>
90 OutputAssembly("S",
91 cl::desc("Write output as LLVM assembly"), cl::Hidden);
92
main(int argc,char ** argv)93 int main(int argc, char **argv) {
94 // Print a stack trace if we signal out.
95 sys::PrintStackTraceOnErrorSignal();
96 PrettyStackTraceProgram X(argc, argv);
97
98 LLVMContext &Context = getGlobalContext();
99 llvm_shutdown_obj Y; // Call llvm_shutdown() on exit.
100 cl::ParseCommandLineOptions(argc, argv, "llvm extractor\n");
101
102 // Use lazy loading, since we only care about selected global values.
103 SMDiagnostic Err;
104 std::unique_ptr<Module> M;
105 M.reset(getLazyIRFileModule(InputFilename, Err, Context));
106
107 if (!M.get()) {
108 Err.print(argv[0], errs());
109 return 1;
110 }
111
112 // Use SetVector to avoid duplicates.
113 SetVector<GlobalValue *> GVs;
114
115 // Figure out which aliases we should extract.
116 for (size_t i = 0, e = ExtractAliases.size(); i != e; ++i) {
117 GlobalAlias *GA = M->getNamedAlias(ExtractAliases[i]);
118 if (!GA) {
119 errs() << argv[0] << ": program doesn't contain alias named '"
120 << ExtractAliases[i] << "'!\n";
121 return 1;
122 }
123 GVs.insert(GA);
124 }
125
126 // Extract aliases via regular expression matching.
127 for (size_t i = 0, e = ExtractRegExpAliases.size(); i != e; ++i) {
128 std::string Error;
129 Regex RegEx(ExtractRegExpAliases[i]);
130 if (!RegEx.isValid(Error)) {
131 errs() << argv[0] << ": '" << ExtractRegExpAliases[i] << "' "
132 "invalid regex: " << Error;
133 }
134 bool match = false;
135 for (Module::alias_iterator GA = M->alias_begin(), E = M->alias_end();
136 GA != E; GA++) {
137 if (RegEx.match(GA->getName())) {
138 GVs.insert(&*GA);
139 match = true;
140 }
141 }
142 if (!match) {
143 errs() << argv[0] << ": program doesn't contain global named '"
144 << ExtractRegExpAliases[i] << "'!\n";
145 return 1;
146 }
147 }
148
149 // Figure out which globals we should extract.
150 for (size_t i = 0, e = ExtractGlobals.size(); i != e; ++i) {
151 GlobalValue *GV = M->getNamedGlobal(ExtractGlobals[i]);
152 if (!GV) {
153 errs() << argv[0] << ": program doesn't contain global named '"
154 << ExtractGlobals[i] << "'!\n";
155 return 1;
156 }
157 GVs.insert(GV);
158 }
159
160 // Extract globals via regular expression matching.
161 for (size_t i = 0, e = ExtractRegExpGlobals.size(); i != e; ++i) {
162 std::string Error;
163 Regex RegEx(ExtractRegExpGlobals[i]);
164 if (!RegEx.isValid(Error)) {
165 errs() << argv[0] << ": '" << ExtractRegExpGlobals[i] << "' "
166 "invalid regex: " << Error;
167 }
168 bool match = false;
169 for (auto &GV : M->globals()) {
170 if (RegEx.match(GV.getName())) {
171 GVs.insert(&GV);
172 match = true;
173 }
174 }
175 if (!match) {
176 errs() << argv[0] << ": program doesn't contain global named '"
177 << ExtractRegExpGlobals[i] << "'!\n";
178 return 1;
179 }
180 }
181
182 // Figure out which functions we should extract.
183 for (size_t i = 0, e = ExtractFuncs.size(); i != e; ++i) {
184 GlobalValue *GV = M->getFunction(ExtractFuncs[i]);
185 if (!GV) {
186 errs() << argv[0] << ": program doesn't contain function named '"
187 << ExtractFuncs[i] << "'!\n";
188 return 1;
189 }
190 GVs.insert(GV);
191 }
192 // Extract functions via regular expression matching.
193 for (size_t i = 0, e = ExtractRegExpFuncs.size(); i != e; ++i) {
194 std::string Error;
195 StringRef RegExStr = ExtractRegExpFuncs[i];
196 Regex RegEx(RegExStr);
197 if (!RegEx.isValid(Error)) {
198 errs() << argv[0] << ": '" << ExtractRegExpFuncs[i] << "' "
199 "invalid regex: " << Error;
200 }
201 bool match = false;
202 for (Module::iterator F = M->begin(), E = M->end(); F != E;
203 F++) {
204 if (RegEx.match(F->getName())) {
205 GVs.insert(&*F);
206 match = true;
207 }
208 }
209 if (!match) {
210 errs() << argv[0] << ": program doesn't contain global named '"
211 << ExtractRegExpFuncs[i] << "'!\n";
212 return 1;
213 }
214 }
215
216 // Materialize requisite global values.
217 if (!DeleteFn)
218 for (size_t i = 0, e = GVs.size(); i != e; ++i) {
219 GlobalValue *GV = GVs[i];
220 if (GV->isMaterializable()) {
221 std::string ErrInfo;
222 if (GV->Materialize(&ErrInfo)) {
223 errs() << argv[0] << ": error reading input: " << ErrInfo << "\n";
224 return 1;
225 }
226 }
227 }
228 else {
229 // Deleting. Materialize every GV that's *not* in GVs.
230 SmallPtrSet<GlobalValue *, 8> GVSet(GVs.begin(), GVs.end());
231 for (auto &G : M->globals()) {
232 if (!GVSet.count(&G) && G.isMaterializable()) {
233 std::string ErrInfo;
234 if (G.Materialize(&ErrInfo)) {
235 errs() << argv[0] << ": error reading input: " << ErrInfo << "\n";
236 return 1;
237 }
238 }
239 }
240 for (auto &F : *M) {
241 if (!GVSet.count(&F) && F.isMaterializable()) {
242 std::string ErrInfo;
243 if (F.Materialize(&ErrInfo)) {
244 errs() << argv[0] << ": error reading input: " << ErrInfo << "\n";
245 return 1;
246 }
247 }
248 }
249 }
250
251 // In addition to deleting all other functions, we also want to spiff it
252 // up a little bit. Do this now.
253 PassManager Passes;
254 Passes.add(new DataLayoutPass(M.get())); // Use correct DataLayout
255
256 std::vector<GlobalValue*> Gvs(GVs.begin(), GVs.end());
257
258 Passes.add(createGVExtractionPass(Gvs, DeleteFn));
259 if (!DeleteFn)
260 Passes.add(createGlobalDCEPass()); // Delete unreachable globals
261 Passes.add(createStripDeadDebugInfoPass()); // Remove dead debug info
262 Passes.add(createStripDeadPrototypesPass()); // Remove dead func decls
263
264 std::string ErrorInfo;
265 tool_output_file Out(OutputFilename.c_str(), ErrorInfo, sys::fs::F_None);
266 if (!ErrorInfo.empty()) {
267 errs() << ErrorInfo << '\n';
268 return 1;
269 }
270
271 if (OutputAssembly)
272 Passes.add(createPrintModulePass(Out.os()));
273 else if (Force || !CheckBitcodeOutputToConsole(Out.os(), true))
274 Passes.add(createBitcodeWriterPass(Out.os()));
275
276 Passes.run(*M.get());
277
278 // Declare success.
279 Out.keep();
280
281 return 0;
282 }
283