+
+bool InternalState::hasZeroForFileOffset(const ld::Section* sect)
+{
+ switch ( sect->type() ) {
+ case ld::Section::typeZeroFill:
+ case ld::Section::typeTLVZeroFill:
+ return _options.optimizeZeroFill();
+ case ld::Section::typePageZero:
+ case ld::Section::typeStack:
+ case ld::Section::typeTentativeDefs:
+ return true;
+ default:
+ break;
+ }
+ return false;
+}
+
+uint64_t InternalState::pageAlign(uint64_t addr)
+{
+ const uint64_t alignment = _options.segmentAlignment();
+ return ((addr+alignment-1) & (-alignment));
+}
+
+uint64_t InternalState::pageAlign(uint64_t addr, uint64_t pageSize)
+{
+ return ((addr+pageSize-1) & (-pageSize));
+}
+
+void InternalState::setSectionSizesAndAlignments()
+{
+ for (std::vector<ld::Internal::FinalSection*>::iterator sit = sections.begin(); sit != sections.end(); ++sit) {
+ ld::Internal::FinalSection* sect = *sit;
+ if ( sect->type() == ld::Section::typeAbsoluteSymbols ) {
+ // absolute symbols need their finalAddress() to their value
+ for (std::vector<const ld::Atom*>::iterator ait = sect->atoms.begin(); ait != sect->atoms.end(); ++ait) {
+ const ld::Atom* atom = *ait;
+ (const_cast<ld::Atom*>(atom))->setSectionOffset(atom->objectAddress());
+ }
+ }
+ else {
+ uint16_t maxAlignment = 0;
+ uint64_t offset = 0;
+ for (std::vector<const ld::Atom*>::iterator ait = sect->atoms.begin(); ait != sect->atoms.end(); ++ait) {
+ const ld::Atom* atom = *ait;
+ bool pagePerAtom = false;
+ uint32_t atomAlignmentPowerOf2 = atom->alignment().powerOf2;
+ uint32_t atomModulus = atom->alignment().modulus;
+ if ( _options.pageAlignDataAtoms() && ( strncmp(atom->section().segmentName(), "__DATA", 6) == 0) ) {
+ // most objc sections cannot be padded
+ bool contiguousObjCSection = ( strncmp(atom->section().sectionName(), "__objc_", 7) == 0 );
+ if ( strcmp(atom->section().sectionName(), "__objc_const") == 0 )
+ contiguousObjCSection = false;
+ if ( strcmp(atom->section().sectionName(), "__objc_data") == 0 )
+ contiguousObjCSection = false;
+ switch ( atom->section().type() ) {
+ case ld::Section::typeUnclassified:
+ case ld::Section::typeTentativeDefs:
+ case ld::Section::typeZeroFill:
+ if ( contiguousObjCSection )
+ break;
+ pagePerAtom = true;
+ if ( atomAlignmentPowerOf2 < 12 ) {
+ atomAlignmentPowerOf2 = 12;
+ atomModulus = 0;
+ }
+ break;
+ default:
+ break;
+ }
+ }
+ if ( atomAlignmentPowerOf2 > maxAlignment )
+ maxAlignment = atomAlignmentPowerOf2;
+ // calculate section offset for this atom
+ uint64_t alignment = 1 << atomAlignmentPowerOf2;
+ uint64_t currentModulus = (offset % alignment);
+ uint64_t requiredModulus = atomModulus;
+ if ( currentModulus != requiredModulus ) {
+ if ( requiredModulus > currentModulus )
+ offset += requiredModulus-currentModulus;
+ else
+ offset += requiredModulus+alignment-currentModulus;
+ }
+ // LINKEDIT atoms are laid out later
+ if ( sect->type() != ld::Section::typeLinkEdit ) {
+ (const_cast<ld::Atom*>(atom))->setSectionOffset(offset);
+ offset += atom->size();
+ if ( pagePerAtom ) {
+ offset = (offset + 4095) & (-4096); // round up to end of page
+ }
+ }
+ if ( (atom->scope() == ld::Atom::scopeGlobal)
+ && (atom->definition() == ld::Atom::definitionRegular)
+ && (atom->combine() == ld::Atom::combineByName)
+ && ((atom->symbolTableInclusion() == ld::Atom::symbolTableIn)
+ || (atom->symbolTableInclusion() == ld::Atom::symbolTableInAndNeverStrip)) ) {
+ this->hasWeakExternalSymbols = true;
+ if ( _options.warnWeakExports() )
+ warning("weak external symbol: %s", atom->name());
+ }
+ }
+ sect->size = offset;
+ // section alignment is that of a contained atom with the greatest alignment
+ sect->alignment = maxAlignment;
+ // unless -sectalign command line option overrides
+ if ( _options.hasCustomSectionAlignment(sect->segmentName(), sect->sectionName()) )
+ sect->alignment = _options.customSectionAlignment(sect->segmentName(), sect->sectionName());
+ // each atom in __eh_frame has zero alignment to assure they pack together,
+ // but compilers usually make the CFIs pointer sized, so we want whole section
+ // to start on pointer sized boundary.
+ if ( sect->type() == ld::Section::typeCFI )
+ sect->alignment = 3;
+ if ( sect->type() == ld::Section::typeTLVDefs )
+ this->hasThreadLocalVariableDefinitions = true;
+ }
+ }
+
+ // <rdar://problem/24221680> All __thread_data and __thread_bss sections must have same alignment
+ uint8_t maxThreadAlign = 0;
+ for (ld::Internal::FinalSection* sect : sections) {
+ if ( (sect->type() == ld::Section::typeTLVInitialValues) || (sect->type() == ld::Section::typeTLVZeroFill) ) {
+ if ( sect->alignment > maxThreadAlign )
+ maxThreadAlign = sect->alignment;
+ }
+ }
+ for (ld::Internal::FinalSection* sect : sections) {
+ if ( (sect->type() == ld::Section::typeTLVInitialValues) || (sect->type() == ld::Section::typeTLVZeroFill) ) {
+ sect->alignment = maxThreadAlign;
+ }
+ }
+
+}
+
+uint64_t InternalState::assignFileOffsets()
+{
+ const bool log = false;
+ const bool hiddenSectionsOccupyAddressSpace = ((_options.outputKind() != Options::kObjectFile)
+ && (_options.outputKind() != Options::kPreload));
+ const bool segmentsArePageAligned = (_options.outputKind() != Options::kObjectFile);
+
+ uint64_t address = 0;
+ const char* lastSegName = "";
+ uint64_t floatingAddressStart = _options.baseAddress();
+ bool haveFixedSegments = false;
+
+ // mark all sections as not having an address yet
+ for (std::vector<ld::Internal::FinalSection*>::iterator it = sections.begin(); it != sections.end(); ++it) {
+ ld::Internal::FinalSection* sect = *it;
+ sect->alignmentPaddingBytes = 0;
+ sect->address = ULLONG_MAX;
+ }
+
+ // first pass, assign addresses to sections in segments with fixed start addresses
+ if ( log ) fprintf(stderr, "Fixed address segments:\n");
+ for (std::vector<ld::Internal::FinalSection*>::iterator it = sections.begin(); it != sections.end(); ++it) {
+ ld::Internal::FinalSection* sect = *it;
+ if ( ! _options.hasCustomSegmentAddress(sect->segmentName()) )
+ continue;
+ haveFixedSegments = true;
+ if ( segmentsArePageAligned ) {
+ if ( strcmp(lastSegName, sect->segmentName()) != 0 ) {
+ address = _options.customSegmentAddress(sect->segmentName());
+ lastSegName = sect->segmentName();
+ }
+ }
+ // adjust section address based on alignment
+ uint64_t unalignedAddress = address;
+ uint64_t alignment = (1 << sect->alignment);
+ address = ( (unalignedAddress+alignment-1) & (-alignment) );
+
+ // update section info
+ sect->address = address;
+ sect->alignmentPaddingBytes = (address - unalignedAddress);
+
+ // sanity check size
+ if ( ((address + sect->size) > _options.maxAddress()) && (_options.outputKind() != Options::kObjectFile)
+ && (_options.outputKind() != Options::kStaticExecutable) )
+ throwf("section %s (address=0x%08llX, size=%llu) would make the output executable exceed available address range",
+ sect->sectionName(), address, sect->size);
+
+ if ( log ) fprintf(stderr, " address=0x%08llX, hidden=%d, alignment=%02d, section=%s,%s\n",
+ sect->address, sect->isSectionHidden(), sect->alignment, sect->segmentName(), sect->sectionName());
+ // update running totals
+ if ( !sect->isSectionHidden() || hiddenSectionsOccupyAddressSpace )
+ address += sect->size;
+
+ // if TEXT segment address is fixed, then flow other segments after it
+ if ( strcmp(sect->segmentName(), "__TEXT") == 0 ) {
+ floatingAddressStart = address;
+ }
+ }
+
+ // second pass, assign section addresses to sections in segments that are ordered after a segment with a fixed address
+ if ( haveFixedSegments && !_options.segmentOrder().empty() ) {
+ if ( log ) fprintf(stderr, "After Fixed address segments:\n");
+ lastSegName = "";
+ ld::Internal::FinalSection* lastSect = NULL;
+ for (std::vector<ld::Internal::FinalSection*>::iterator it = sections.begin(); it != sections.end(); ++it) {
+ ld::Internal::FinalSection* sect = *it;
+ if ( (sect->address == ULLONG_MAX) && _options.segmentOrderAfterFixedAddressSegment(sect->segmentName()) ) {
+ address = lastSect->address + lastSect->size;
+ if ( (strcmp(lastSegName, sect->segmentName()) != 0) && segmentsArePageAligned ) {
+ // round up size of last segment
+ address = pageAlign(address, _options.segPageSize(lastSegName));
+ }
+ // adjust section address based on alignment
+ uint64_t unalignedAddress = address;
+ uint64_t alignment = (1 << sect->alignment);
+ address = ( (unalignedAddress+alignment-1) & (-alignment) );
+ sect->alignmentPaddingBytes = (address - unalignedAddress);
+ sect->address = address;
+ if ( log ) fprintf(stderr, " address=0x%08llX, hidden=%d, alignment=%02d, section=%s,%s\n",
+ sect->address, sect->isSectionHidden(), sect->alignment, sect->segmentName(), sect->sectionName());
+ // update running totals
+ if ( !sect->isSectionHidden() || hiddenSectionsOccupyAddressSpace )
+ address += sect->size;
+ }
+ lastSegName = sect->segmentName();
+ lastSect = sect;
+ }
+ }
+
+ // last pass, assign addresses to remaining sections
+ address = floatingAddressStart;
+ lastSegName = "";
+ ld::Internal::FinalSection* overlappingFixedSection = NULL;
+ ld::Internal::FinalSection* overlappingFlowSection = NULL;
+ ld::Internal::FinalSection* prevSect = NULL;
+ if ( log ) fprintf(stderr, "Regular layout segments:\n");
+ for (std::vector<ld::Internal::FinalSection*>::iterator it = sections.begin(); it != sections.end(); ++it) {
+ ld::Internal::FinalSection* sect = *it;
+ if ( sect->address != ULLONG_MAX )
+ continue;
+ if ( (_options.outputKind() == Options::kPreload) && (sect->type() == ld::Section::typeMachHeader) ) {
+ sect->alignmentPaddingBytes = 0;
+ continue;
+ }
+ if ( segmentsArePageAligned ) {
+ if ( strcmp(lastSegName, sect->segmentName()) != 0 ) {
+ // round up size of last segment if needed
+ if ( *lastSegName != '\0' ) {
+ address = pageAlign(address, _options.segPageSize(lastSegName));
+ }
+ // set segment address based on end of last segment
+ address = pageAlign(address);
+ lastSegName = sect->segmentName();
+ }
+ }
+
+ // adjust section address based on alignment
+ uint64_t unalignedAddress = address;
+ uint64_t alignment = (1 << sect->alignment);
+ address = ( (unalignedAddress+alignment-1) & (-alignment) );
+
+ // update section info
+ sect->address = address;
+ sect->alignmentPaddingBytes = (address - unalignedAddress);
+
+ // <rdar://problem/21994854> if first section is more aligned than segment, move segment start up to match
+ if ( (prevSect != NULL) && (prevSect->type() == ld::Section::typeFirstSection) && (strcmp(prevSect->segmentName(), sect->segmentName()) == 0) ) {
+ assert(prevSect->size == 0);
+ if ( prevSect->address != sect->address ) {
+ prevSect->alignmentPaddingBytes += (sect->address - prevSect->address);
+ prevSect->address = sect->address;
+ }
+ }
+
+ // sanity check size
+ if ( ((address + sect->size) > _options.maxAddress()) && (_options.outputKind() != Options::kObjectFile)
+ && (_options.outputKind() != Options::kStaticExecutable) )
+ throwf("section %s (address=0x%08llX, size=%llu) would make the output executable exceed available address range",
+ sect->sectionName(), address, sect->size);
+
+ // sanity check it does not overlap a fixed address segment
+ for (std::vector<ld::Internal::FinalSection*>::iterator sit = sections.begin(); sit != sections.end(); ++sit) {
+ ld::Internal::FinalSection* otherSect = *sit;
+ if ( ! _options.hasCustomSegmentAddress(otherSect->segmentName()) )
+ continue;
+ if ( otherSect->size == 0 )
+ continue;
+ if ( sect->size == 0 )
+ continue;
+ if ( sect->address > otherSect->address ) {
+ if ( (otherSect->address+otherSect->size) > sect->address ) {
+ overlappingFixedSection = otherSect;
+ overlappingFlowSection = sect;
+ }
+ }
+ else {
+ if ( (sect->address+sect->size) > otherSect->address ) {
+ overlappingFixedSection = otherSect;
+ overlappingFlowSection = sect;
+ }
+ }
+ }
+
+ if ( log ) fprintf(stderr, " address=0x%08llX, size=0x%08llX, hidden=%d, alignment=%02d, padBytes=%d, section=%s,%s\n",
+ sect->address, sect->size, sect->isSectionHidden(), sect->alignment, sect->alignmentPaddingBytes,
+ sect->segmentName(), sect->sectionName());
+ // update running totals
+ if ( !sect->isSectionHidden() || hiddenSectionsOccupyAddressSpace )
+ address += sect->size;
+ prevSect = sect;
+ }
+ if ( overlappingFixedSection != NULL ) {
+ fprintf(stderr, "Section layout:\n");
+ for (std::vector<ld::Internal::FinalSection*>::iterator it = sections.begin(); it != sections.end(); ++it) {
+ ld::Internal::FinalSection* sect = *it;
+ //if ( sect->isSectionHidden() )
+ // continue;
+ fprintf(stderr, " address:0x%08llX, alignment:2^%d, size:0x%08llX, padBytes:%d, section:%s/%s\n",
+ sect->address, sect->alignment, sect->size, sect->alignmentPaddingBytes,
+ sect->segmentName(), sect->sectionName());
+
+ }
+ throwf("Section (%s/%s) overlaps fixed address section (%s/%s)",
+ overlappingFlowSection->segmentName(), overlappingFlowSection->sectionName(),
+ overlappingFixedSection->segmentName(), overlappingFixedSection->sectionName());
+ }
+
+
+ // third pass, assign section file offsets
+ uint64_t fileOffset = 0;
+ lastSegName = "";
+ if ( log ) fprintf(stderr, "All segments with file offsets:\n");
+ for (std::vector<ld::Internal::FinalSection*>::iterator it = sections.begin(); it != sections.end(); ++it) {
+ ld::Internal::FinalSection* sect = *it;
+ if ( hasZeroForFileOffset(sect) ) {
+ // fileoff of zerofill sections is moot, but historically it is set to zero
+ sect->fileOffset = 0;
+
+ // <rdar://problem/10445047> align file offset with address layout
+ fileOffset += sect->alignmentPaddingBytes;
+ }
+ else {
+ // page align file offset at start of each segment
+ if ( segmentsArePageAligned && (*lastSegName != '\0') && (strcmp(lastSegName, sect->segmentName()) != 0) ) {
+ fileOffset = pageAlign(fileOffset, _options.segPageSize(lastSegName));
+ }
+ lastSegName = sect->segmentName();
+
+ // align file offset with address layout
+ fileOffset += sect->alignmentPaddingBytes;
+
+ // update section info
+ sect->fileOffset = fileOffset;
+
+ // update running total
+ fileOffset += sect->size;
+ }
+
+ if ( log ) fprintf(stderr, " fileoffset=0x%08llX, address=0x%08llX, hidden=%d, size=%lld, alignment=%02d, section=%s,%s\n",
+ sect->fileOffset, sect->address, sect->isSectionHidden(), sect->size, sect->alignment,
+ sect->segmentName(), sect->sectionName());
+ }
+
+#if 0
+ // for encrypted iPhoneOS apps
+ if ( _options.makeEncryptable() ) {
+ // remember end of __TEXT for later use by load command
+ for (std::vector<ld::Internal::FinalSection*>::iterator it = state.sections.begin(); it != state.sections.end(); ++it) {
+ ld::Internal::FinalSection* sect = *it;
+ if ( strcmp(sect->segmentName(), "__TEXT") == 0 ) {
+ _encryptedTEXTendOffset = pageAlign(sect->fileOffset + sect->size);
+ }
+ }
+ }
+#endif
+
+ // return total file size
+ return fileOffset;
+}
+
+static char* commatize(uint64_t in, char* out)
+{
+ char* result = out;
+ char rawNum[30];
+ sprintf(rawNum, "%llu", in);
+ const int rawNumLen = strlen(rawNum);
+ for(int i=0; i < rawNumLen-1; ++i) {
+ *out++ = rawNum[i];
+ if ( ((rawNumLen-i) % 3) == 1 )
+ *out++ = ',';
+ }
+ *out++ = rawNum[rawNumLen-1];
+ *out = '\0';
+ return result;
+}
+
+static void printTime(const char* msg, uint64_t partTime, uint64_t totalTime)
+{
+ static uint64_t sUnitsPerSecond = 0;
+ if ( sUnitsPerSecond == 0 ) {
+ struct mach_timebase_info timeBaseInfo;
+ if ( mach_timebase_info(&timeBaseInfo) != KERN_SUCCESS )
+ return;
+ sUnitsPerSecond = 1000000000ULL * timeBaseInfo.denom / timeBaseInfo.numer;
+ }
+ if ( partTime < sUnitsPerSecond ) {
+ uint32_t milliSecondsTimeTen = (partTime*10000)/sUnitsPerSecond;
+ uint32_t milliSeconds = milliSecondsTimeTen/10;
+ uint32_t percentTimesTen = (partTime*1000)/totalTime;
+ uint32_t percent = percentTimesTen/10;
+ fprintf(stderr, "%24s: % 4d.%d milliseconds (% 4d.%d%%)\n", msg, milliSeconds, milliSecondsTimeTen-milliSeconds*10, percent, percentTimesTen-percent*10);
+ }
+ else {
+ uint32_t secondsTimeTen = (partTime*10)/sUnitsPerSecond;
+ uint32_t seconds = secondsTimeTen/10;
+ uint32_t percentTimesTen = (partTime*1000)/totalTime;
+ uint32_t percent = percentTimesTen/10;
+ fprintf(stderr, "%24s: % 4d.%d seconds (% 4d.%d%%)\n", msg, seconds, secondsTimeTen-seconds*10, percent, percentTimesTen-percent*10);
+ }
+}
+
+
projects / apple / ld64.git / blobdiff