1 //===-- llvm-bcanalyzer.cpp - Byte Code Analyzer --------------------------===//
3 // The LLVM Compiler Infrastructure
5 // This file was developed by Reid Spencer and is distributed under the
6 // University of Illinois Open Source License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This tool may be invoked in the following manner:
11 // llvm-bcanalyzer [options] - Read LLVM bytecode from stdin
12 // llvm-bcanalyzer [options] x.bc - Read LLVM bytecode from the x.bc file
15 // --help - Output information about command line switches
16 // --nodetails - Don't print out detailed informaton about individual
17 // blocks and functions
18 // --dump - Dump low-level bytecode structure in readable format
20 // This tool provides analytical information about a bytecode file. It is
21 // intended as an aid to developers of bytecode reading and writing software. It
22 // produces on std::out a summary of the bytecode file that shows various
23 // statistics about the contents of the file. By default this information is
24 // detailed and contains information about individual bytecode blocks and the
25 // functions in the module. To avoid this more detailed output, use the
26 // -nodetails option to limit the output to just module level information.
27 // The tool is also able to print a bytecode file in a straight forward text
28 // format that shows the containment and relationships of the information in
29 // the bytecode file (-dump option).
31 //===----------------------------------------------------------------------===//
33 #include "llvm/Analysis/Verifier.h"
34 #include "llvm/Bitcode/BitstreamReader.h"
35 #include "llvm/Bytecode/Analyzer.h"
36 #include "llvm/Support/CommandLine.h"
37 #include "llvm/Support/Compressor.h"
38 #include "llvm/Support/ManagedStatic.h"
39 #include "llvm/Support/MemoryBuffer.h"
40 #include "llvm/System/Signals.h"
45 static cl::opt<std::string>
46 InputFilename(cl::Positional, cl::desc("<input bytecode>"), cl::init("-"));
48 static cl::opt<std::string>
49 OutputFilename("-o", cl::init("-"), cl::desc("<output file>"));
51 static cl::opt<bool> NoDetails("nodetails", cl::desc("Skip detailed output"));
52 static cl::opt<bool> Dump("dump", cl::desc("Dump low level bytecode trace"));
53 static cl::opt<bool> Verify("verify", cl::desc("Progressively verify module"));
55 //===----------------------------------------------------------------------===//
56 // Bitcode specific analysis.
57 //===----------------------------------------------------------------------===//
59 static cl::opt<bool> Bitcode("bitcode", cl::desc("Read a bitcode file"));
61 /// CurStreamType - If we can sniff the flavor of this stream, we can produce
68 /// Error - All bitcode analysis errors go through this function, making this a
69 /// good place to breakpoint if debugging.
70 static bool Error(const std::string &Err) {
71 std::cerr << Err << "\n";
75 /// ParseBlock - Read a block, updating statistics, etc.
76 static bool ParseBlock(BitstreamReader &Stream) {
77 unsigned BlockID = Stream.ReadSubBlockID();
79 // TODO: Compute per-block-id stats.
82 if (Stream.EnterSubBlock())
83 return Error("Malformed block record");
85 SmallVector<uint64_t, 64> Record;
87 // Read all the records for this block.
89 if (Stream.AtEndOfStream())
90 return Error("Premature end of bitstream");
92 // Read the code for this record.
93 unsigned AbbrevID = Stream.ReadCode();
96 if (Stream.ReadBlockEnd())
97 return Error("Error at end of block");
99 case bitc::ENTER_SUBBLOCK:
100 if (ParseBlock(Stream))
103 case bitc::DEFINE_ABBREV:
104 Stream.ReadAbbrevRecord();
108 unsigned Code = Stream.ReadRecord(AbbrevID, Record);
109 // TODO: Compute per-blockid/code stats.
116 /// AnalyzeBitcode - Analyze the bitcode file specified by InputFilename.
117 static int AnalyzeBitcode() {
118 // Read the input file.
119 MemoryBuffer *Buffer;
120 if (InputFilename == "-")
121 Buffer = MemoryBuffer::getSTDIN();
123 Buffer = MemoryBuffer::getFile(&InputFilename[0], InputFilename.size());
126 return Error("Error reading '" + InputFilename + "'.");
128 if (Buffer->getBufferSize() & 3)
129 return Error("Bitcode stream should be a multiple of 4 bytes in length");
131 unsigned char *BufPtr = (unsigned char *)Buffer->getBufferStart();
132 BitstreamReader Stream(BufPtr, BufPtr+Buffer->getBufferSize());
135 // Read the stream signature.
137 Signature[0] = Stream.Read(8);
138 Signature[1] = Stream.Read(8);
139 Signature[2] = Stream.Read(4);
140 Signature[3] = Stream.Read(4);
141 Signature[4] = Stream.Read(4);
142 Signature[5] = Stream.Read(4);
144 // Autodetect the file contents, if it is one we know.
145 CurStreamType = UnknownBitstream;
146 if (Signature[0] == 'B' && Signature[1] == 'C' &&
147 Signature[2] == 0x0 && Signature[3] == 0xC &&
148 Signature[4] == 0xE && Signature[5] == 0xD)
149 CurStreamType = LLVMIRBitstream;
151 // Parse the top-level structure. We only allow blocks at the top-level.
152 while (!Stream.AtEndOfStream()) {
153 unsigned Code = Stream.ReadCode();
154 if (Code != bitc::ENTER_SUBBLOCK)
155 return Error("Invalid record at top-level");
157 if (ParseBlock(Stream))
161 // Print a summary of the read file.
163 std::cerr << "Summary of " << InputFilename << ":\n";
164 std::cerr << " Stream type: ";
165 switch (CurStreamType) {
166 default: assert(0 && "Unknown bitstream type");
167 case UnknownBitstream: std::cerr << "unknown\n"; break;
168 case LLVMIRBitstream: std::cerr << "LLVM IR\n"; break;
177 //===----------------------------------------------------------------------===//
178 // Bytecode specific analysis.
179 //===----------------------------------------------------------------------===//
181 int main(int argc, char **argv) {
182 llvm_shutdown_obj X; // Call llvm_shutdown() on exit.
183 cl::ParseCommandLineOptions(argc, argv, " llvm-bcanalyzer file analyzer\n");
185 sys::PrintStackTraceOnErrorSignal();
188 return AnalyzeBitcode();
191 std::ostream *Out = &std::cout; // Default to printing to stdout...
192 std::string ErrorMessage;
193 BytecodeAnalysis bca;
195 /// Determine what to generate
196 bca.detailedResults = !NoDetails;
197 bca.progressiveVerify = Verify;
199 /// Analyze the bytecode file
200 Module* M = AnalyzeBytecodeFile(InputFilename, bca,
201 Compressor::decompressToNewBuffer,
202 &ErrorMessage, (Dump?Out:0));
204 // All that bcanalyzer does is write the gathered statistics to the output
205 PrintBytecodeAnalysis(bca,*Out);
208 std::string verificationMsg;
209 if (verifyModule(*M, ReturnStatusAction, &verificationMsg))
210 std::cerr << "Final Verification Message: " << verificationMsg << "\n";
213 if (Out != &std::cout) {
214 ((std::ofstream*)Out)->close();
218 } catch (const std::string& msg) {
219 std::cerr << argv[0] << ": " << msg << "\n";
221 std::cerr << argv[0] << ": Unexpected unknown exception occurred.\n";