diff options
Diffstat (limited to 'lib/IR/GCOV.cpp')
-rw-r--r-- | lib/IR/GCOV.cpp | 24 |
1 files changed, 18 insertions, 6 deletions
diff --git a/lib/IR/GCOV.cpp b/lib/IR/GCOV.cpp index 8f060d2ac9..522716309a 100644 --- a/lib/IR/GCOV.cpp +++ b/lib/IR/GCOV.cpp @@ -166,9 +166,11 @@ bool GCOVFunction::readGCNO(GCOVBuffer &Buff, GCOV::GCOVVersion Version) { // read line table. while (Buff.readLineTag()) { uint32_t LineTableLength; + // Read the length of this line table. if (!Buff.readInt(LineTableLength)) return false; uint32_t EndPos = Buff.getCursor() + LineTableLength*4; uint32_t BlockNo; + // Read the block number this table is associated with. if (!Buff.readInt(BlockNo)) return false; if (BlockNo >= BlockCount) { errs() << "Unexpected block number: " << BlockNo << " (in " << Name @@ -176,24 +178,34 @@ bool GCOVFunction::readGCNO(GCOVBuffer &Buff, GCOV::GCOVVersion Version) { return false; } GCOVBlock &Block = *Blocks[BlockNo]; - if (!Buff.readInt(Dummy)) return false; // flag - while (Buff.getCursor() != (EndPos - 4)) { + // Read the word that pads the beginning of the line table. This may be a + // flag of some sort, but seems to always be zero. + if (!Buff.readInt(Dummy)) return false; + + // Line information starts here and continues up until the last word. + if (Buff.getCursor() != (EndPos - sizeof(uint32_t))) { StringRef F; + // Read the source file name. if (!Buff.readString(F)) return false; if (Filename != F) { errs() << "Multiple sources for a single basic block: " << Filename << " != " << F << " (in " << Name << ").\n"; return false; } - if (Buff.getCursor() == (EndPos - 4)) break; - while (true) { + // Read lines up to, but not including, the null terminator. + while (Buff.getCursor() < (EndPos - 2 * sizeof(uint32_t))) { uint32_t Line; if (!Buff.readInt(Line)) return false; - if (!Line) break; + // Line 0 means this instruction was injected by the compiler. Skip it. + if (!Line) continue; Block.addLine(Line); } + // Read the null terminator. + if (!Buff.readInt(Dummy)) return false; } - if (!Buff.readInt(Dummy)) return false; // flag + // The last word is either a flag or padding, it isn't clear which. Skip + // over it. + if (!Buff.readInt(Dummy)) return false; } return true; } |