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* Split the creation of program headers in a few steps.Rafael Espindola2016-02-101-1/+5
| | | | | | | | | | | | | | | | | | | | | | | | IMHO this makes the code easier to read and should help with linker scripts. This is strongly based on D16575. The main differences are: We record a range of sections, not every section in a program header. scanHeaders takes case of deciding what goes in every program header, including PT_GNU_RELRO We create dummy sections for the start of the file With this, program header creation has 3 isolated stages: Map sections to program headers. Assign addresses to *sections* Looking at sections find the address and size of each program header. Thanks to George Rimar for the initial version. llvm-svn: 260453
* Use a SymbolBody to represent the personality.Rafael Espindola2016-02-101-1/+1
| | | | | | | | NFC, just more in line with the rest of lld. Thanks to Rui for the suggestion. llvm-svn: 260380
* ELF: Make EHOutputSection::readEntryLength a non-member function.Rui Ueyama2016-02-051-1/+0
| | | | | | This function did not use any fields of the class. llvm-svn: 259946
* Centralize most calls to setUsedInDynamicReloc.Rafael Espindola2016-02-051-1/+1
| | | | llvm-svn: 259887
* ELF: Make names for TLS module indices shorter.Rui Ueyama2016-02-051-3/+3
| | | | | | | | | | The previous names contained "Local" and "Current", but what we are handling is always local and current, so they were redundant. TlsIndex comes from "tls_index" struct that Ulrich Drepper is using in this document to describe this data structure in GOT. llvm-svn: 259852
* Do not round uintX_t to uint32_t.Rui Ueyama2016-02-041-1/+1
| | | | | | On 64-bit computers, this value can be larger than UINT32_MAX. llvm-svn: 259847
* Avoid code duplication when creating dynamic relocations.Rafael Espindola2016-02-041-6/+40
| | | | | | | | | | | | | | | | | Another case where we currently have almost duplicated code is the creation of dynamic relocations. First to decide if we need one, then to decide what to write. This patch fixes it by passing more information from the relocation scan to the section writing code. This is the same idea used for r258723. I actually think it should be possible to simplify this further by reordering things a bit in the writer. For example, we should be able to represent almost every position in the file with an OutputSeciton and offset. When writing it out we then just need to add the offset to the OutputSection VA. llvm-svn: 259829
* Add comments.Rui Ueyama2016-02-021-0/+8
| | | | llvm-svn: 259460
* ELF: Teach SymbolBody about how to get its addresses.Rui Ueyama2016-02-011-6/+0
| | | | | | | | | | | | | Previously, the methods to get symbol addresses were somewhat scattered in many places. You can use getEntryAddr returns the address of the symbol, but if you want to get the GOT address for the symbol, you needed to call Out<ELFT>::Got->getEntryAddr(Sym). This change adds new functions, getVA, getGotVA, getGotPltVA, and getPltVA to SymbolBody, so that you can use SymbolBody as the central place to ask about symbols. http://reviews.llvm.org/D16710 llvm-svn: 259404
* Merge identical strings.Rafael Espindola2016-01-291-12/+14
| | | | | | | | | | | This avoids the need to have reserve and addString in sync. We avoid hashing the global symbols again. This means that we don't merge a global symbol that has the same name as some other string, but that doesn't seem very common. The string table size is the same in clang an scylladb with or without hashing global symbols again. llvm-svn: 259136
* Remove another case of almost duplicated code.Rafael Espindola2016-01-271-5/+0
| | | | | | | Were had very similar code for deciding to keep a local symbol and for actually writing it. llvm-svn: 258958
* Remove redundant variable.Rafael Espindola2016-01-271-2/+1
| | | | llvm-svn: 258940
* Avoid almost duplication in .dynamic finalize and write.Rafael Espindola2016-01-251-4/+17
| | | | | | | | | | | | | There are a few cases where we have almost duplicated code. This patches fixes the simplest: the finalize and write of dynamic section. Right now they have to have exactly the same structure to decide if a DT_* entry is needed and then to actually write it. We cannot just write it to a std::vector in the first pass since addresses have not been computed yet. llvm-svn: 258723
* [ELF] Avoid unnecessary global variable.Sean Silva2016-01-231-4/+0
| | | | | | | | | | Summary: It looks like this snuck through in r256143/D15383. Reviewers: ruiu, grimar Differential Revision: http://reviews.llvm.org/D16500 llvm-svn: 258599
* [ELF][MIPS] Initial support of MIPS local GOT entriesSimon Atanasyan2016-01-211-1/+8
| | | | | | | | | | | | | | | | | | | | | | | | Some MIPS relocation (for now R_MIPS_GOT16) requires creation of GOT entries for symbol not included in the dynamic symbol table. They are local symbols and non-local symbols with 'local' visibility. Local GOT entries occupy continuous block between GOT header and regular GOT entries. The patch adds initial support for handling local GOT entries. The main problem is allocating local GOT entries for local symbols. Such entries should be initialized by high 16-bit of the symbol value. In ideal world there should be no duplicated entries with the same values. But at the moment of the `Writer::scanRelocs` call we do not know a value of the symbol. In this patch we create new local GOT entry for each relocation against local symbol, though we can exhaust GOT quickly. That needs to be optimized later. When we calculate relocation we know a final symbol value and request local GOT entry index. To do that we maintain map between addresses and local GOT entry indexes. If we start to calculate relocations in parallel we will have to serialize access to this map. Differential Revision: http://reviews.llvm.org/D16324 llvm-svn: 258388
* Delete dead code.Rafael Espindola2016-01-181-4/+0
| | | | llvm-svn: 258078
* Reapply r257753 with fix:George Rimar2016-01-151-0/+44
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Added check for terminator CIE/FDE which has zero data size. void EHOutputSection<ELFT>::addSectionAux( ... // If CIE/FDE data length is zero then Length is 4, this // shall be considered a terminator and processing shall end. if (Length == 4) break; ... After this "Bug 25923 - lld/ELF2 linked application crashes if exceptions were used." is fixed for me. Self link of clang also works. Initial commit message: [ELF] - implemented --eh-frame-hdr command line option. --eh-frame-hdr Request creation of ".eh_frame_hdr" section and ELF "PT_GNU_EH_FRAME" segment header. Both gold and the GNU linker support an option --eh-frame-hdr which tell them to construct a header for all the .eh_frame sections. This header is placed in a section named .eh_frame_hdr and also in a PT_GNU_EH_FRAME segment. At runtime the unwinder can find all the PT_GNU_EH_FRAME segments by calling dl_iterate_phdr. This section contains a lookup table for quick binary search of FDEs. Detailed info can be found here: http://www.airs.com/blog/archives/462 Differential revision: http://reviews.llvm.org/D15712 llvm-svn: 257889
* Update for LLVM function name change.Rui Ueyama2016-01-141-4/+0
| | | | llvm-svn: 257801
* Revert r257753: "[ELF] - implemented --eh-frame-hdr command line option."Rui Ueyama2016-01-141-40/+0
| | | | | | This reverts commit r257753 because we cannot link Clang with this patch. llvm-svn: 257797
* [ELF] - implemented --eh-frame-hdr command line option.George Rimar2016-01-141-0/+40
| | | | | | | | | | | | | | --eh-frame-hdr Request creation of ".eh_frame_hdr" section and ELF "PT_GNU_EH_FRAME" segment header. Both gold and the GNU linker support an option --eh-frame-hdr which tell them to construct a header for all the .eh_frame sections. This header is placed in a section named .eh_frame_hdr and also in a PT_GNU_EH_FRAME segment. At runtime the unwinder can find all the PT_GNU_EH_FRAME segments by calling dl_iterate_phdr. This section contains a lookup table for quick binary search of FDEs. Detailed info can be found here: http://www.airs.com/blog/archives/462 Differential revision: http://reviews.llvm.org/D15712 llvm-svn: 257753
* ELF: Improve performance of string table construction.Rui Ueyama2016-01-071-10/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | String tables in unstripped executable files are fairly large in size. For example, lld's executable file is about 34.4 MB in my environment, and of which 3.5 MB is the string table. Efficiency of string table construction matters. Previously, the string table was built in an inefficient way. We used StringTableBuilder to build that and enabled string tail merging, although tail merging is not effective for the symbol table (you can only make the string table 0.3% smaller for lld.) Tail merging is computation intensive task and slow. This patch eliminates string tail merging. I changed the way of adding strings to the string table in this patch too. Previously, strings were added using add() and the same strings were then passed to getOffset() to get their offsets in the string table. In this way, getOffset() needs to look up a hash table to get offsets for given strings. This is a violation of "we look up the symbol table (or a hash table) only once for each symbol" dogma of the new LLD's design. Hash table lookup for long C++ mangled names is slow. I eliminated that lookup in this patch. In total, this patch improves link time of lld itself about 12% (3.50 seconds -> 3.08 seconds.) llvm-svn: 257017
* Use RoundUpToAlignment instead of writing the expression to round up.Rui Ueyama2016-01-061-1/+1
| | | | | | | The original code might be more readable than the new one if you remember the expression. Otherwise the new one is probably better. llvm-svn: 256995
* Define align() and use that instead of RoundUpToAlignment().Rui Ueyama2016-01-061-0/+4
| | | | | | The name "RoundUpToAlignment" is too long compared to what it does. llvm-svn: 256993
* Simplify MipsReginfoInputSection.Rui Ueyama2016-01-061-1/+1
| | | | | | | MipsReginfoInputSection is basically just a container of Elf_Mips_Reginfo struct. This patch makes that struct directly accessible from others. llvm-svn: 256984
* Do not use SpecificBumpPtrAllocator to create output sections.Rui Ueyama2015-12-261-1/+1
| | | | | | | | The number of output sections is usually limited, so the cost of allocating them is not a bottleneck. This patch simplifies the code by removing the allocators. llvm-svn: 256437
* Use virtual function instead of hand-written type dispatch.Rui Ueyama2015-12-261-5/+6
| | | | | | | | OutputSectionBase already has virtual member functions. This patch makes addSection() a virtual function to remove code from Writer::createSections(). llvm-svn: 256436
* Move a function to a file where it is used.Rui Ueyama2015-12-251-2/+1
| | | | llvm-svn: 256410
* Move function to the file where it is used.Rafael Espindola2015-12-231-1/+0
| | | | llvm-svn: 256348
* Split Undefined and UndefinedElf.Rafael Espindola2015-12-221-1/+0
| | | | | | | | | | | | | | | | | | | | | | I am working on adding LTO support to the new ELF lld. In order to do that, it will be necessary to represent defined and undefined symbols that are not from ELF files. One way to do it is to change the symbol hierarchy to look like Defined : SymbolBody Undefined : SymbolBody DefinedElf<ELFT> : Defined UndefinedElf<ELFT> : Undefined Another option would be to use bogus Elf_Sym, but I think that is getting a bit too hackish. This patch does the Undefined/UndefinedElf. Split. The next one will do the Defined/DefinedElf split. llvm-svn: 256289
* Simplify types. NFC.Rafael Espindola2015-12-211-2/+2
| | | | llvm-svn: 256197
* [ELF] - fixed not properly handled @GOTTPOFF relocation against local symbolsGeorge Rimar2015-12-211-1/+2
| | | | | | | | | | | | | | This patch changes sequence of applying relocations, moving tls optimized relocation handling code before code for other locals. Without that change relocation @GOTTPOFF against local symbol caused runtime error ("unrecognized reloc ..."). That change also should fix other tls optimized relocations, but I did not check them, that's a field for another patch. R_X86_64_GOTTPOFF relocations against locals can be found when linking against libc.a(malloc.o): 000000000036 000600000016 R_X86_64_GOTTPOFF 0000000000000000 libc_tsd_MALLOC - 4 000000000131 000600000016 R_X86_64_GOTTPOFF 0000000000000000 libc_tsd_MALLOC - 4 Differential revision: http://reviews.llvm.org/D15581 llvm-svn: 256145
* [ELF] - Implemented R_*_IRELATIVE relocations for x86, x64 targets.George Rimar2015-12-211-0/+2
| | | | | | | | | | | This relocation is similar to R_*_RELATIVE except that the value used in this relocation is the program address returned by the function, which takes no arguments, at the address of the result of the corresponding R_*_RELATIVE relocation as specified in the processor-specific ABI. The purpose of this relocation to avoid name lookup for locally defined STT_GNU_IFUNC symbols at load-time. More info can be found in ifunc.txt from https://sites.google.com/site/x32abi/documents. Differential revision: http://reviews.llvm.org/D15235 llvm-svn: 256144
* [ELF] - R_386_GOTOFF relocation implemented.George Rimar2015-12-211-0/+4
| | | | | | | | | | | R_386_GOTOFF is calculated as S + A - GOT, where: S - Represents the value of the symbol whose index resides in the relocation entry. A - Represents the addend used to compute the value of the relocatable field. GOT - Represents the address of the global offset table. Differential revision: http://reviews.llvm.org/D15383 llvm-svn: 256143
* [ELF][MIPS] MIPS .reginfo sections handlingSimon Atanasyan2015-12-201-0/+15
| | | | | | | | | | | | | | | | | | | | | MIPS .reginfo section provides information on the registers used by the code in the object file. Linker should collect this information and write .reginfo section in the output file. This section contains a union of used registers masks taken from input .reginfo sections and final value of the `_gp` symbol. For details see the "Register Information" section in Chapter 4 in the following document: ftp://www.linux-mips.org/pub/linux/mips/doc/ABI/mipsabi.pdf The patch implements .reginfo sections handling with a couple missed features: a) it does not put output .reginfo section into the separate REGINFO segment; b) it does not merge `ri_cprmask` masks from input section. These features will be implemented later. Differential Revision: http://reviews.llvm.org/D15669 llvm-svn: 256119
* [ELF] - implement support of extended length field for CIE/FDE records of ↵George Rimar2015-12-171-0/+2
| | | | | | | | | | | | eh_frame. Ian Lance Taylor writes: "Read 4 bytes. If they are not 0xffffffff, they are the length of the CIE or FDE record. Otherwise the next 64 bits holds the length, and this is a 64-bit DWARF format. This is like .debug_frame." (http://www.airs.com/blog/archives/460), that also consistent with spec (https://refspecs.linuxfoundation.org/LSB_3.0.0/LSB-PDA/LSB-PDA/ehframechpt.html). Patch implements support of described extended length field and also adds few more checks for safety. Differential revision: http://reviews.llvm.org/D15532 llvm-svn: 255883
* Renamed addLocalModelTlsIndex() -> addCurrentModuleTlsIndex(), NFC.George Rimar2015-12-071-1/+1
| | | | | | (per discussion with Michael Spencer) llvm-svn: 254896
* [ELF] - Implemented some GD, LD and IE TLS access models for x86 target.George Rimar2015-12-021-0/+1
| | | | | | | | | Main aim of the patch to introduce basic support for TLS access models for x86 target. Models using @tlsgd, @tlsldm and @gotntpoff are implemented. Differential revision: http://reviews.llvm.org/D15060 llvm-svn: 254500
* [ELF] - Fixed bug leading to miss of tls relocation when @tlsgd and ↵George Rimar2015-12-011-1/+2
| | | | | | | | | | | | | | | | | @gottpoff relocations were used at the same time. Combination of @tlsgd and @gottpoff at the same time leads to miss of R_X86_64_TPOFF64 dynamic relocation. Patch fixes that. @tlsgd(%rip) - Allocate two contiguous entries in the GOT to hold a tls index structure (for passing to tls get addr). @gottpoff(%rip) - Allocate one GOT entry to hold a variable offset in initial TLS block (relative to TLS block end, %fs:0). The same situation can be observed for x86 (probably others too, not sure) with corresponding for that target relocations: @tlsgd, @gotntpoff. Differential revision: http://reviews.llvm.org/D15105 llvm-svn: 254443
* Reapply r254428.George Rimar2015-12-011-3/+4
| | | | | | | | | | | | | | | | | | | Fix was: uint32_t getLocalTlsIndexVA() { return getVA() + LocalTlsIndexOff; } => uint32_t getLocalTlsIndexVA() { return Base::getVA() + LocalTlsIndexOff; } Both works for my MSVS. Original commit message: [ELF] - Refactor of tls_index implementation for tls local dynamic model. Patch contains the next 2 changes: 1) static variable Out<ELFT>::LocalModuleTlsIndexOffset moved to Out<ELFT>::Got. At fact there is no meaning for it to be separated from GOT class because at each place of using it anyways needs to call GOT`s getVA(). Also it is impossible to have that offset and not have GOT. 2) addLocalModuleTlsIndex -> addLocalModelTlsIndex (word "Module" changed to "Model"). Not sure was it a mistype or not but I think that update is closer to Urlich terminology. Differential revision: http://reviews.llvm.org/D15113 llvm-svn: 254433
* revert r254428 [ELF] - Refactor of tls_index implementation for tls local ↵George Rimar2015-12-011-4/+3
| | | | | | | | | | | | | | dynamic model. It failed buildbot: http://lab.llvm.org:8011/builders/llvm-clang-lld-x86_64-scei-ps4-ubuntu-fast/builds/3782/steps/build/logs/stdio Target.cpp In file included from /home/buildbot/Buildbot/Slave/llvm-clang-lld-x86_64-scei-ps4-ubuntu-fast/llvm.src/tools/lld/ELF/Target.cpp:20: /home/buildbot/Buildbot/Slave/llvm-clang-lld-x86_64-scei-ps4-ubuntu-fast/llvm.src/tools/lld/ELF/OutputSections.h:136:42: error: use of undeclared identifier 'getVA' uint32_t getLocalTlsIndexVA() { return getVA() + LocalTlsIndexOff; } llvm-svn: 254432
* [ELF] - Refactor of tls_index implementation for tls local dynamic model.George Rimar2015-12-011-3/+4
| | | | | | | | | | Patch contains the next 2 changes: 1) static variable Out<ELFT>::LocalModuleTlsIndexOffset moved to Out<ELFT>::Got. At fact there is no meaning for it to be separated from GOT class because at each place of using it anyways needs to call GOT`s getVA(). Also it is impossible to have that offset and not have GOT. 2) addLocalModuleTlsIndex -> addLocalModelTlsIndex (word "Module" changed to "Model"). Not sure was it a mistype or not but I think that update is closer to Urlich terminology. Differential revision: http://reviews.llvm.org/D15113 llvm-svn: 254428
* [ELF] - Split RelocationSection<ELFT>::writeTo function.George Rimar2015-11-301-0/+3
| | | | | | | | Splitted writeTo to separate tls relocs handling stuff which is too long for one method now. NFC. Differential revision: http://reviews.llvm.org/D15012 llvm-svn: 254309
* Reapply r254098.George Rimar2015-11-251-1/+2
| | | | | | | | | Fix is (OutputSections.cpp): for (std::pair<const SymbolBody *, size_t> &I : Entries) { => for (std::pair<const SymbolBody *, unsigned> &I : Entries) { llvm-svn: 254105
* Revert r254098 as it seems broke build bot.George Rimar2015-11-251-2/+1
| | | | | | http://lab.llvm.org:8011/builders/llvm-clang-lld-x86_64-scei-ps4-ubuntu-fast/builds/3555 llvm-svn: 254103
* [ELF] - Lazy relocations support for x86 target.George Rimar2015-11-251-1/+2
| | | | | | | | | | | Patch implements lazy relocations for x86. One of features of x86 is that executable files and shared object files have separate procedure linkage tables. So patch implements both cases. Detailed information about instructions used can be found in http://docs.oracle.com/cd/E19620-01/805-3050/chapter6-1235/index.html (search: x86: Procedure Linkage Table). Differential revision: http://reviews.llvm.org/D14955 llvm-svn: 254098
* [ELF2] - Implemented R_X86_64_GOTTPOFF relocationGeorge Rimar2015-11-131-0/+1
| | | | | | | | Generates single GOT entry, R_X86_64_TPOFF64 is added to RelaDyn. Differential revision: http://reviews.llvm.org/D14621 llvm-svn: 253049
* [elf2] Implement global dynamic tls.Michael J. Spencer2015-11-131-2/+2
| | | | llvm-svn: 252979
* [ELF2] Add mandatory .dynamic section entries on MIPS.Igor Kudrin2015-11-121-0/+12
| | | | | | | | | | | | | | | | | | | | | The MIPS target requires specific dynamic section entries to be defined. * DT_MIPS_RLD_VERSION and DT_MIPS_FLAGS store predefined values. * DT_MIPS_BASE_ADDRESS holds base VA. * DT_MIPS_LOCAL_GOTNO holds the number of local GOT entries. * DT_MIPS_SYMTABNO holds the number of .dynsym entries. * DT_MIPS_GOTSYM holds the index of the .dynsym entry which corresponds to the first entry of the global part of GOT. * DT_MIPS_RLD_MAP holds the address of the reserved space in the data segment. * DT_MIPS_PLTGOT points to the .got.plt section if it exists. * DT_PLTGOT holds the address of the GOT section. See "Dynamic Section" in Chapter 5 in the following document for detailed description: ftp://www.linux-mips.org/pub/linux/mips/doc/ABI/mipsabi.pdf Differential revision: http://reviews.llvm.org/D14450 llvm-svn: 252857
* Add support for processing .eh_frame.Rafael Espindola2015-11-111-1/+43
| | | | | | | | | | | | | This adds support for: * Uniquing CIEs * Dropping FDEs that point to dropped sections It drops 657 488 bytes from the .eh_frame of a Release+Asserts clang. The link time impact is smallish. Linking clang with a Release+Asserts lld goes from 0.488064805 seconds to 0.504763060 seconds (1.034 X slower). llvm-svn: 252790
* Remove const from a few places. NFC.Rafael Espindola2015-11-111-1/+1
| | | | | | This just reduces the noise from an upcoming patch. llvm-svn: 252737
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