llvm-6502/lib/IR/GCOV.cpp
Yuchen Wu cbbd20879e Fixed llvm-cov to count edges instead of blocks.
This was a fundamental flaw in llvm-cov where it treated the values in
the GCDA files as block counts instead of edge counts. This created
incorrect line counts when branching was present. Instead, the edge
counts should be summed to obtain the correct block count.

The fix was tested using custom test files as well as single source
files from the test-suite directory. The behaviour can be verified by
reading the GCOV documentation that describes the GCDA spec ("ARC_COUNTS
gives the counter values for those arcs that are instrumented") and the
header description provided by GCOVProfiling.cpp ("instruments the code
that runs to records (sic) the edges between blocks that run and emit a
complementary "gcda" file on exit").

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@193299 91177308-0d34-0410-b5e6-96231b3b80d8
2013-10-24 01:51:04 +00:00

282 lines
9.0 KiB
C++

//===- GCOVr.cpp - LLVM coverage tool -------------------------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// GCOV implements the interface to read and write coverage files that use
// 'gcov' format.
//
//===----------------------------------------------------------------------===//
#include "llvm/Support/GCOV.h"
#include "llvm/ADT/OwningPtr.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/Support/Format.h"
#include "llvm/Support/MemoryObject.h"
#include "llvm/Support/system_error.h"
using namespace llvm;
//===----------------------------------------------------------------------===//
// GCOVFile implementation.
/// ~GCOVFile - Delete GCOVFile and its content.
GCOVFile::~GCOVFile() {
DeleteContainerPointers(Functions);
}
/// isGCDAFile - Return true if Format identifies a .gcda file.
static bool isGCDAFile(GCOV::GCOVFormat Format) {
return Format == GCOV::GCDA_402 || Format == GCOV::GCDA_404;
}
/// isGCNOFile - Return true if Format identifies a .gcno file.
static bool isGCNOFile(GCOV::GCOVFormat Format) {
return Format == GCOV::GCNO_402 || Format == GCOV::GCNO_404;
}
/// read - Read GCOV buffer.
bool GCOVFile::read(GCOVBuffer &Buffer) {
GCOV::GCOVFormat Format = Buffer.readGCOVFormat();
if (Format == GCOV::InvalidGCOV)
return false;
unsigned i = 0;
while (1) {
GCOVFunction *GFun = NULL;
if (isGCDAFile(Format)) {
// Use existing function while reading .gcda file.
assert(i < Functions.size() && ".gcda data does not match .gcno data");
GFun = Functions[i];
} else if (isGCNOFile(Format)) {
GFun = new GCOVFunction();
Functions.push_back(GFun);
}
if (!GFun || !GFun->read(Buffer, Format))
break;
++i;
}
return true;
}
/// dump - Dump GCOVFile content on standard out for debugging purposes.
void GCOVFile::dump() {
for (SmallVectorImpl<GCOVFunction *>::iterator I = Functions.begin(),
E = Functions.end(); I != E; ++I)
(*I)->dump();
}
/// collectLineCounts - Collect line counts. This must be used after
/// reading .gcno and .gcda files.
void GCOVFile::collectLineCounts(FileInfo &FI) {
for (SmallVectorImpl<GCOVFunction *>::iterator I = Functions.begin(),
E = Functions.end(); I != E; ++I)
(*I)->collectLineCounts(FI);
}
//===----------------------------------------------------------------------===//
// GCOVFunction implementation.
/// ~GCOVFunction - Delete GCOVFunction and its content.
GCOVFunction::~GCOVFunction() {
DeleteContainerPointers(Blocks);
}
/// read - Read a function from the buffer. Return false if buffer cursor
/// does not point to a function tag.
bool GCOVFunction::read(GCOVBuffer &Buff, GCOV::GCOVFormat Format) {
if (!Buff.readFunctionTag())
return false;
Buff.readInt(); // Function header length
Ident = Buff.readInt();
Buff.readInt(); // Checksum #1
if (Format != GCOV::GCNO_402 && Format != GCOV::GCDA_402)
Buff.readInt(); // Checksum #2
Name = Buff.readString();
if (Format == GCOV::GCNO_402 || Format == GCOV::GCNO_404)
Filename = Buff.readString();
if (Format == GCOV::GCDA_402 || Format == GCOV::GCDA_404) {
Buff.readArcTag();
uint32_t i = 0;
uint32_t Count = Buff.readInt() / 2;
// This for loop adds the counts for each block. A second nested loop is
// required to combine the edge counts that are contained in the GCDA file.
for (uint32_t Line = 0; i < Count; ++Line) {
GCOVBlock &Block = *Blocks[Line];
for (size_t Edge = 0, End = Block.getNumEdges(); Edge < End; ++Edge) {
assert(i < Count && "Unexpected number of Edges!");
Block.addCount(Buff.readInt64());
++i;
}
}
return true;
}
LineNumber = Buff.readInt();
// read blocks.
bool BlockTagFound = Buff.readBlockTag();
(void)BlockTagFound;
assert(BlockTagFound && "Block Tag not found!");
uint32_t BlockCount = Buff.readInt();
for (uint32_t i = 0, e = BlockCount; i != e; ++i) {
Buff.readInt(); // Block flags;
Blocks.push_back(new GCOVBlock(i));
}
// read edges.
while (Buff.readEdgeTag()) {
uint32_t EdgeCount = (Buff.readInt() - 1) / 2;
uint32_t BlockNo = Buff.readInt();
assert(BlockNo < BlockCount && "Unexpected Block number!");
for (uint32_t i = 0, e = EdgeCount; i != e; ++i) {
Blocks[BlockNo]->addEdge(Buff.readInt());
Buff.readInt(); // Edge flag
}
}
// read line table.
while (Buff.readLineTag()) {
uint32_t LineTableLength = Buff.readInt();
uint32_t EndPos = Buff.getCursor() + LineTableLength*4;
uint32_t BlockNo = Buff.readInt();
assert(BlockNo < BlockCount && "Unexpected Block number!");
GCOVBlock *Block = Blocks[BlockNo];
Buff.readInt(); // flag
while (Buff.getCursor() != (EndPos - 4)) {
StringRef Filename = Buff.readString();
if (Buff.getCursor() == (EndPos - 4)) break;
while (uint32_t L = Buff.readInt())
Block->addLine(Filename, L);
}
Buff.readInt(); // flag
}
return true;
}
/// dump - Dump GCOVFunction content on standard out for debugging purposes.
void GCOVFunction::dump() {
outs() << "===== " << Name << " @ " << Filename << ":" << LineNumber << "\n";
for (SmallVectorImpl<GCOVBlock *>::iterator I = Blocks.begin(),
E = Blocks.end(); I != E; ++I)
(*I)->dump();
}
/// collectLineCounts - Collect line counts. This must be used after
/// reading .gcno and .gcda files.
void GCOVFunction::collectLineCounts(FileInfo &FI) {
for (SmallVectorImpl<GCOVBlock *>::iterator I = Blocks.begin(),
E = Blocks.end(); I != E; ++I)
(*I)->collectLineCounts(FI);
}
//===----------------------------------------------------------------------===//
// GCOVBlock implementation.
/// ~GCOVBlock - Delete GCOVBlock and its content.
GCOVBlock::~GCOVBlock() {
Edges.clear();
DeleteContainerSeconds(Lines);
}
void GCOVBlock::addLine(StringRef Filename, uint32_t LineNo) {
GCOVLines *&LinesForFile = Lines[Filename];
if (!LinesForFile)
LinesForFile = new GCOVLines();
LinesForFile->add(LineNo);
}
/// collectLineCounts - Collect line counts. This must be used after
/// reading .gcno and .gcda files.
void GCOVBlock::collectLineCounts(FileInfo &FI) {
for (StringMap<GCOVLines *>::iterator I = Lines.begin(),
E = Lines.end(); I != E; ++I)
I->second->collectLineCounts(FI, I->first(), Counter);
}
/// dump - Dump GCOVBlock content on standard out for debugging purposes.
void GCOVBlock::dump() {
outs() << "Block : " << Number << " Counter : " << Counter << "\n";
if (!Edges.empty()) {
outs() << "\tEdges : ";
for (SmallVectorImpl<uint32_t>::iterator I = Edges.begin(), E = Edges.end();
I != E; ++I)
outs() << (*I) << ",";
outs() << "\n";
}
if (!Lines.empty()) {
outs() << "\tLines : ";
for (StringMap<GCOVLines *>::iterator LI = Lines.begin(),
LE = Lines.end(); LI != LE; ++LI) {
outs() << LI->first() << " -> ";
LI->second->dump();
outs() << "\n";
}
}
}
//===----------------------------------------------------------------------===//
// GCOVLines implementation.
/// collectLineCounts - Collect line counts. This must be used after
/// reading .gcno and .gcda files.
void GCOVLines::collectLineCounts(FileInfo &FI, StringRef Filename,
uint64_t Count) {
for (SmallVectorImpl<uint32_t>::iterator I = Lines.begin(),
E = Lines.end(); I != E; ++I)
FI.addLineCount(Filename, *I, Count);
}
/// dump - Dump GCOVLines content on standard out for debugging purposes.
void GCOVLines::dump() {
for (SmallVectorImpl<uint32_t>::iterator I = Lines.begin(),
E = Lines.end(); I != E; ++I)
outs() << (*I) << ",";
}
//===----------------------------------------------------------------------===//
// FileInfo implementation.
/// print - Print source files with collected line count information.
void FileInfo::print(StringRef gcnoFile, StringRef gcdaFile) {
for (StringMap<LineCounts>::iterator I = LineInfo.begin(), E = LineInfo.end();
I != E; ++I) {
StringRef Filename = I->first();
outs() << " -: 0:Source:" << Filename << "\n";
outs() << " -: 0:Graph:" << gcnoFile << "\n";
outs() << " -: 0:Data:" << gcdaFile << "\n";
LineCounts &L = LineInfo[Filename];
OwningPtr<MemoryBuffer> Buff;
if (error_code ec = MemoryBuffer::getFileOrSTDIN(Filename, Buff)) {
errs() << Filename << ": " << ec.message() << "\n";
return;
}
StringRef AllLines = Buff.take()->getBuffer();
uint32_t i = 0;
while (!AllLines.empty()) {
if (L.find(i) != L.end()) {
if (L[i] == 0)
outs() << " #####:";
else
outs() << format("%9lu:", L[i]);
} else {
outs() << " -:";
}
std::pair<StringRef, StringRef> P = AllLines.split('\n');
if (AllLines != P.first)
outs() << format("%5u:", i+1) << P.first;
outs() << "\n";
AllLines = P.second;
++i;
}
}
}