Unverified Commit ec42d547 authored by Jacek Caban's avatar Jacek Caban Committed by GitHub
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[lld][COFF][NFC] Factor out exception table sorting. (#72518) 

This is a preparation for ARM64EC support, which needs to sort both ARM
and x86_64 tables separately.
parent a67b85ef

lld/COFF/Writer.cpp

+41 −29
Original line number Diff line number Diff line
@@ -247,7 +247,8 @@ private: 
  void writeBuildId();

  void writePEChecksum();

  void sortSections();

  void sortExceptionTable();

  template <typename T> void sortExceptionTable(Chunk *first, Chunk *last);

  void sortExceptionTables();

  void sortCRTSectionChunks(std::vector<Chunk *> &chunks);

  void addSyntheticIdata();

  void sortBySectionOrder(std::vector<Chunk *> &chunks);
@@ -751,7 +752,7 @@ void Writer::run() { 
    }

    writeSections();

    prepareLoadConfig();

    sortExceptionTable();

    sortExceptionTables();



    // Fix up the alignment in the TLS Directory's characteristic field,

    // if a specific alignment value is needed
@@ -2164,41 +2165,52 @@ void Writer::writeBuildId() { 
}



// Sort .pdata section contents according to PE/COFF spec 5.5.

void Writer::sortExceptionTable() {

  if (!firstPdata)

    return;

  llvm::TimeTraceScope timeScope("Sort exception table");

template <typename T>

void Writer::sortExceptionTable(Chunk *first, Chunk *last) {

  // We assume .pdata contains function table entries only.

  auto bufAddr = [&](Chunk *c) {

    OutputSection *os = ctx.getOutputSection(c);

    return buffer->getBufferStart() + os->getFileOff() + c->getRVA() -

           os->getRVA();

  };

  uint8_t *begin = bufAddr(firstPdata);

  uint8_t *end = bufAddr(lastPdata) + lastPdata->getSize();

  if (ctx.config.machine == AMD64) {

    struct Entry { ulittle32_t begin, end, unwind; };

    if ((end - begin) % sizeof(Entry) != 0) {

      fatal("unexpected .pdata size: " + Twine(end - begin) +

            " is not a multiple of " + Twine(sizeof(Entry)));

    }

    parallelSort(

        MutableArrayRef<Entry>((Entry *)begin, (Entry *)end),

        [](const Entry &a, const Entry &b) { return a.begin < b.begin; });

    return;

  }

  if (ctx.config.machine == ARMNT || ctx.config.machine == ARM64) {

    struct Entry { ulittle32_t begin, unwind; };

    if ((end - begin) % sizeof(Entry) != 0) {

  uint8_t *begin = bufAddr(first);

  uint8_t *end = bufAddr(last) + last->getSize();

  if ((end - begin) % sizeof(T) != 0) {

    fatal("unexpected .pdata size: " + Twine(end - begin) +

            " is not a multiple of " + Twine(sizeof(Entry)));

          " is not a multiple of " + Twine(sizeof(T)));

  }

    parallelSort(

        MutableArrayRef<Entry>((Entry *)begin, (Entry *)end),

        [](const Entry &a, const Entry &b) { return a.begin < b.begin; });

    return;



  parallelSort(MutableArrayRef<T>(reinterpret_cast<T *>(begin),

                                  reinterpret_cast<T *>(end)),

               [](const T &a, const T &b) { return a.begin < b.begin; });

}



// Sort .pdata section contents according to PE/COFF spec 5.5.

void Writer::sortExceptionTables() {

  llvm::TimeTraceScope timeScope("Sort exception table");



  struct EntryX64 {

    ulittle32_t begin, end, unwind;

  };

  struct EntryArm {

    ulittle32_t begin, unwind;

  };



  switch (ctx.config.machine) {

  case AMD64:

    if (firstPdata)

      sortExceptionTable<EntryX64>(firstPdata, lastPdata);

    break;

  case ARMNT:

  case ARM64:

    if (firstPdata)

      sortExceptionTable<EntryArm>(firstPdata, lastPdata);

    break;

  default:

    if (firstPdata)

      lld::errs() << "warning: don't know how to handle .pdata.\n";

    break;

  }

}



// The CRT section contains, among other things, the array of function