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* Follow aliases when determining if a symbol is thumb.Rafael Espindola2014-04-221-2/+1
| | | | | | This fixes pr19484. llvm-svn: 206917
* Add parens to appease GCC warning.David Blaikie2014-04-191-4/+4
| | | | llvm-svn: 206678
* Compress debug sections only when beneficial.David Blaikie2014-04-181-2/+6
| | | | | | | | | Both ZLIB and the debug info compressed section header ("ZLIB" + the size of the uncompressed data) take some constant overhead so in some cases the compressed data is actually larger than the uncompressed data. In these cases, just don't compress or rename the section at all. llvm-svn: 206659
* Update the fragments of symbols in compressed sections.David Blaikie2014-04-181-0/+21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | While unnamed relocations are already cached in side tables in ELFObjectWriter::RecordRelocation, symbols still need their fragments updated to refer to the newly compressed fragment (even if that fragment isn't big enough to fit the offset). Even though we only create temporary symbols in debug info sections this comes up in 32 bit builds where even temporary symbols in mergeable sections (such as debug_str) have to be emitted as named symbols. I tried a few other ways to do this but they all didn't work for various reasons: 1) Canonicalize the MCSymbolData in RecordRelocation, nulling out the Fragment (so it didn't have to be updated by CompressDebugSection). This doesn't work because some code relies on symbols having fragments to indicate that they're defined, I think. 2) Canonicalize the MCSymbolData in RecordRelocation to be "first fragment + absolute offset" so it would be cheaper to just test and update the fragment in CompressDebugSections. This doesn't work because the offset computed in RecordRelocation isn't that of the symbol's fragment, it's the passed in fragment (I haven't figured out what that fragment is - perhaps it's the location where the relocation is to be written). And if the fragment offset has to be computed only for this use we might as well just do it when we need to, in CompressDebugSection. I also added an assert to help catch this a bit more clearly, even though it is UB. The test case improvements would either assert fail and/or valgrind vail without the fix, even if they wouldn't necessarily fail the FileCheck output. llvm-svn: 206653
* Add range access to MCAssembler's symbol collection.David Blaikie2014-04-181-16/+14
| | | | llvm-svn: 206631
* [C++11] More 'nullptr' conversion or in some cases just using a boolean ↵Craig Topper2014-04-131-2/+2
| | | | | | check instead of comparing to nullptr. llvm-svn: 206129
* Format fixes for r205990David Blaikie2014-04-111-5/+12
| | | | llvm-svn: 206078
* Don't lose the thumb bit by using relocations with sections.Rafael Espindola2014-04-111-0/+7
| | | | | | This fixes a regression from r205076. llvm-svn: 206047
* Reimplement debug info compression by compressing the whole section, rather ↵David Blaikie2014-04-101-0/+114
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | than a fragment. To support compressing the debug_line section that contains multiple fragments (due, I believe, to variation in choices of line table encoding depending on the size of instruction ranges in the actual program code) we needed to support compressing multiple MCFragments in a single pass. This patch implements that behavior by mutating the post-relaxed and relocated section to be the compressed form of its former self, including renaming the section. This is a more flexible (and less invasive, to a degree) implementation that will allow for other features such as "use compression only if it's smaller than the uncompressed data". Compressing debug_frame would be a possible further extension to this work, but I've left it for now. The hurdle there is alignment sections - which might require going as far as to refactor MCAssembler.cpp:writeFragment to handle writing to a byte buffer or an MCObjectWriter (there's already a virtual call there, so it shouldn't add substantial compile-time cost) which could in turn involve refactoring MCAsmBackend::writeNopData to use that same abstraction... which involves touching all the backends. This would remove the limited handling of fragment writing seen in ELFObjectWriter.cpp:getUncompressedData which would be nice - but it's more invasive. I did discover that I (perhaps obviously) don't need to handle relocations when I rewrite the fragments - since the relocations have already been applied and computed (and stored into ELFObjectWriter::Relocations) by this stage (necessarily, because we need to have written any immediate values or assembly-time relocations into the data already before we compress it, which we have). The test case doesn't necessarily cover that in detail - I can add more test coverage if that's preferred. llvm-svn: 205990
* Work around gold bug http://sourceware.org/PR16794.Rafael Espindola2014-04-021-0/+5
| | | | llvm-svn: 205416
* Completely rewrite ELFObjectWriter::RecordRelocation.Rafael Espindola2014-03-291-160/+226
| | | | | | | | | | | | | | | | | | | I started trying to fix a small issue, but this code has seen a small fix too many. The old code was fairly convoluted. Some of the issues it had: * It failed to check if a symbol difference was in the some section when converting a relocation to pcrel. * It failed to check if the relocation was already pcrel. * The pcrel value computation was wrong in some cases (relocation-pc.s) * It was missing quiet a few cases where it should not convert symbol relocations to section relocations, leaving the backends to patch it up. * It would not propagate the fact that it had changed a relocation to pcrel, requiring a quiet nasty work around in ARM. * It was missing comments. llvm-svn: 205076
* Remove another unused argument.Rafael Espindola2014-03-271-6/+3
| | | | llvm-svn: 204961
* Remove unused argument.Rafael Espindola2014-03-271-1/+1
| | | | llvm-svn: 204956
* Correctly propagates st_size.Rafael Espindola2014-03-271-7/+6
| | | | | | This also finally removes a bogus call to AliasedSymbol. llvm-svn: 204883
* Correctly detect if a symbol uses a reserved section index or not.Rafael Espindola2014-03-261-3/+5
| | | | | | | The logic was incorrect for variables, causing them to end up in the wrong section if the section had an index >= 0xff00. llvm-svn: 204771
* Create .symtab_shndxr only when needed.Rafael Espindola2014-03-251-86/+120
| | | | | | | | | | | | | | | | | | | | | | | We need .symtab_shndxr if and only if a symbol references a section with an index >= 0xff00. The old code was trying to figure out if the section was needed ahead of time, making it a fairly dependent on the code actually writing the table. It was also somewhat conservative and would create the section in cases where it was not needed. If I remember correctly, the old structure was there so that the sections were created in the same order gas creates them. That was valuable when MC's support for ELF was new and we tested with elf-dump.py. This patch refactors the symbol table creation to another class and makes it obvious that .symtab_shndxr is really only created when we are about to output a reference to a section index >= 0xff00. While here, also improve the tests to use macros. One file is one section short of needing .symtab_shndxr, the second one has just the right number. llvm-svn: 204769
* Use Endian.h to simplify this code a bit.Rafael Espindola2014-03-251-104/+64
| | | | | | | While at it, factor some logic into FragmentWriter. This will allow more code to be factored out of the fairly large ELFObjectWriter. llvm-svn: 204765
* Propagate section from base to derived symbol.Rafael Espindola2014-03-241-18/+19
| | | | | | | | | | | | We were already propagating the section in a = b With this patch we also propagate it for a = b + 1 llvm-svn: 204581
* Propagate types from symbol to aliases.Rafael Espindola2014-03-231-1/+22
| | | | | | | | | | | | | | | | | | | | | | | This is similar, but not identical to what gas does. The logic in MC is to just compute the symbol table after parsing the entire file. GAS is mixed, given .type b, @object a = b b: .type b, @function It will propagate the change and make 'a' a function. Given .type b, @object b: a = b .type b, @function the type of 'a' is still object. Since we do the computation in the end, we produce a function in both cases. llvm-svn: 204555
* Fix the value computation inRafael Espindola2014-03-211-23/+31
| | | | | | | | | | sym_a: sym_d = sym_a + 1 This is the smallest fix I was able to extract from what got reverted in r204203. llvm-svn: 204527
* Reapply 'ARM IAS: support .thumb_set'Saleem Abdulrasool2014-03-201-4/+11
| | | | | | | Re-apply the change after it was reverted to do conflicts due to another change being reverted. llvm-svn: 204306
* Look through variables when computing relocations.Rafael Espindola2014-03-201-5/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Given bar = foo + 4 .long bar MC would eat the 4. GNU as includes it in the relocation. The rule seems to be that a variable that defines a symbol is used in the relocation and one that does not define a symbol is evaluated and the result included in the relocation. Fixing this unfortunately required some other changes: * Since the variable is now evaluated, it would prevent the ELF writer from noticing the weakref marker the elf streamer uses. This patch then replaces that with a VariantKind in MCSymbolRefExpr. * Using VariantKind then requires us to look past other VariantKind to see .weakref bar,foo call bar@PLT doing this also fixes zed = foo +2 call zed@PLT so that is a good thing. * Looking past VariantKind means that the relocation selection has to use the fixup instead of the target. This is a reboot of the previous fixes for MC. I will watch the sanitizer buildbot and wait for a build before adding back the previous fixes. llvm-svn: 204294
* Revert "Add back r203962, r204028 and r204059."Rafael Espindola2014-03-191-58/+39
| | | | | | This reverts commit r204178. llvm-svn: 204203
* Add back r203962, r204028 and r204059.Rafael Espindola2014-03-181-39/+58
| | | | | | | | This reverts commit r204137. This includes a fix for handling aliases of aliases. llvm-svn: 204178
* Revert r203962 and two revisions depending on it: r204028 and r204059.Alexander Kornienko2014-03-181-58/+39
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The revision I'm reverting breaks handling of transitive aliases. This blocks us and breaks sanitizer bootstrap: http://lab.llvm.org:8011/builders/sanitizer-x86_64-linux-bootstrap/builds/2651 (and checked locally by Alexey). This revision is the result of: svn merge -r204059:204058 -r204028:204027 -r203962:203961 . + the regression test added to test/MC/ELF/alias.s Another way to reproduce the regression with clang: $ cat q.c void a1(); void a2() __attribute__((alias("a1"))); void a3() __attribute__((alias("a2"))); void a1() {} $ ~/work/llvm-build/bin/clang-3.5-good -c q.c && mv q.o good.o && \ ~/work/llvm-build/bin/clang-3.5-bad -c q.c && mv q.o bad.o && \ objdump -t good.o bad.o good.o: file format elf64-x86-64 SYMBOL TABLE: 0000000000000000 l df *ABS* 0000000000000000 q.c 0000000000000000 l d .text 0000000000000000 .text 0000000000000000 l d .data 0000000000000000 .data 0000000000000000 l d .bss 0000000000000000 .bss 0000000000000000 l d .comment 0000000000000000 .comment 0000000000000000 l d .note.GNU-stack 0000000000000000 .note.GNU-stack 0000000000000000 l d .eh_frame 0000000000000000 .eh_frame 0000000000000000 g F .text 0000000000000006 a1 0000000000000000 g F .text 0000000000000006 a2 0000000000000000 g F .text 0000000000000006 a3 bad.o: file format elf64-x86-64 SYMBOL TABLE: 0000000000000000 l df *ABS* 0000000000000000 q.c 0000000000000000 l d .text 0000000000000000 .text 0000000000000000 l d .data 0000000000000000 .data 0000000000000000 l d .bss 0000000000000000 .bss 0000000000000000 l d .comment 0000000000000000 .comment 0000000000000000 l d .note.GNU-stack 0000000000000000 .note.GNU-stack 0000000000000000 l d .eh_frame 0000000000000000 .eh_frame 0000000000000000 g F .text 0000000000000006 a1 0000000000000000 g F .text 0000000000000006 a2 0000000000000000 g .text 0000000000000000 a3 llvm-svn: 204137
* ARM IAS: support .thumb_setSaleem Abdulrasool2014-03-171-2/+8
| | | | | | | | | | | | | | This performs the equivalent of a .set directive in that it creates a symbol which is an alias for another symbol or value which may possibly be yet undefined. This directive also has the added property in that it marks the aliased symbol as being a thumb function entry point, in the same way that the .thumb_func directive does. The current implementation fails one test due to an unrelated issue. Functions within .thumb sections are not marked as thumb_func. The result is that the aliasee function is not valued correctly. llvm-svn: 204059
* Consider the base pointer for setting the symbol type.Rafael Espindola2014-03-171-2/+3
| | | | | | | | | | | | | | This is really a consistency fix. Since given a = b we propagate the information, we should propagate it too given a = b + (1 - 1) Fixes pr19145. llvm-svn: 204028
* Correctly handle an ELF symbol defined with "a = b + expr".Rafael Espindola2014-03-141-37/+49
| | | | | | | | | We were marking the symbol as absolute instead of computing b's offset + the expression value. This fixes pr19126. llvm-svn: 203962
* [C++11] Add 'override' keyword to virtual methods that override their base ↵Craig Topper2014-03-081-10/+8
| | | | | | class. llvm-svn: 203340
* Replace OwningPtr<T> with std::unique_ptr<T>.Ahmed Charles2014-03-061-2/+1
| | | | | | | | | | This compiles with no changes to clang/lld/lldb with MSVC and includes overloads to various functions which are used by those projects and llvm which have OwningPtr's as parameters. This should allow out of tree projects some time to move. There are also no changes to libs/Target, which should help out of tree targets have time to move, if necessary. llvm-svn: 203083
* doesSectionRequireSymbols is meaningless on ELF, remove.Rafael Espindola2014-02-061-3/+0
| | | | | | | | | | | | | | | | | | | | This is a nop. doesSectionRequireSymbols is only used from isSymbolLinkerVisible. isSymbolLinkerVisible only use from ELF was in if (!Asm.isSymbolLinkerVisible(Symbol) && !Symbol.isUndefined()) return false; if (Symbol.isTemporary()) return false; If the symbol is a temporary this code returns false and it is irrelevant if we take the first if or not. If the symbol is not a temporary, Asm.isSymbolLinkerVisible returns true without ever calling doesSectionRequireSymbols. This was an horrible leftover from when support for ELF was first added. llvm-svn: 200894
* Force emit a relocation for @gnu_indirect_function symbols so that the indirectRoman Divacky2014-01-081-1/+1
| | | | | | resolution works. llvm-svn: 198780
* In the ELFWriter when writing aliased (.set) symbols dont blindlyRoman Divacky2014-01-071-1/+36
| | | | | | | | | | | | take type from the new symbol but merge them so that the type is never "downgraded". This is probably quite rare, except for IFUNC symbols which we used to misassemble, losing the IFUNC type. Fixes #18372. llvm-svn: 198706
* MC: Fatally error if subtraction operand is badDavid Majnemer2014-01-061-0/+6
| | | | | | | | | Instead of crashing, raise an error when a subtraction expression involves an undefined symbol. This fixes PR18375. llvm-svn: 198590
* [mc] Fix ELF st_other flag.Logan Chien2013-12-051-2/+1
| | | | | | | | | | | | ELF_Other_Weakref and ELF_Other_ThumbFunc seems to be LLVM internal ELF symbol flags. These should not be emitted to object file. This commit defines ELF_STO_Shift for the target-defined flags for st_other, and increase the value of ELF_Other_Shift to 16. llvm-svn: 196440
* Move the STT_FILE symbols out of the normal symbol table processing forJoerg Sonnenberger2013-10-291-8/+26
| | | | | | | ELF. They can overlap with the other symbols, e.g. if a source file "foo.c" contains a function "foo" with a static variable "c". llvm-svn: 193569
* MC: Support multiple sections with the same name in the same comdat groupDavid Blaikie2013-10-221-8/+11
| | | | | | Code review by Eric Christopher and Rafael Espindola. llvm-svn: 193209
* WhitespaceDavid Blaikie2013-10-221-2/+2
| | | | llvm-svn: 193194
* Provide basic type safety for array_pod_sort comparators.Benjamin Kramer2013-09-221-5/+4
| | | | | | | | This makes using array_pod_sort significantly safer. The implementation relies on function pointer casting but that should be safe as we're dealing with void* here. llvm-svn: 191175
* Put ELF COMDAT relocations into the relevant COMDAT group.Tim Northover2013-07-101-2/+9
| | | | | | | | Patch from Игорь Пашев (I do hope we support utf-8 commit messages; I also hope he'll forgive me for transliterating it as Igor Pashev in case things go horribly wrong). llvm-svn: 186034
* Remove MCELFObjectTargetWriter::adjustFixupOffset hackUlrich Weigand2013-05-151-3/+0
| | | | | | | | Now that PowerPC no longer uses adjustFixupOffset, and no other back-end (ever?) did, we can remove the infrastructure itself (incidentally addressing a FIXME to that effect). llvm-svn: 181895
* Commit the right files for r176762. Sigh.Nick Lewycky2013-03-091-3/+3
| | | | llvm-svn: 176763
* ELF symbol table field st_other support, Jack Carter2013-02-191-3/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | excluding visibility bits. Generic STO handling at the Target level. The st_other field of the ELF symbol table is one byte in size. The first 2 bytes are used for generic visibility and are currently handled by llvm. The other six bits are processor specific and need to be set at the target level. A couple of notes: The new static methods for accessing and setting the "other" flags in include/llvm/MC/MCELF.h match the style guide and not the other methods in the file. I don't like the inconsistency, but feel I should follow the prescribed lowerUpper() convention. STO_ value definitions are not specified in gnu land as consistently as the STT_ and STB_ fields. Probably because the latter were defined in a standards doc and the former defined partially in code. I have stuck with the full byte definition of the flags. Contributer: Zoran Jovanovic llvm-svn: 175561
* This patch just fixes up various llvm formattingJack Carter2013-02-121-1/+2
| | | | | | | | | | violations such as tabs, blanks at eol and long lines. llvm-svn: 175007
* Link .ARM.exidx with corresponding text section.Logan Chien2013-02-051-0/+18
| | | | | | | | The sh_link in the ELF section header of .ARM.exidx should be filled with the section index of the corresponding text section. llvm-svn: 174372
* This patch reworks how llvm targets set Jack Carter2013-01-301-8/+6
| | | | | | | | | | | | | | | | | | | | | | | | and update ELF header e_flags. Currently gathering information such as symbol, section and data is done by collecting it in an MCAssembler object. From MCAssembler and MCAsmLayout objects ELFObjectWriter::WriteObject() forms and streams out the ELF object file. This patch just adds a few members to the MCAssember class to store and access the e_flag settings. It allows for runtime additions to the e_flag by assembler directives. The standalone assembler can get to MCAssembler from getParser().getStreamer().getAssembler(). This patch is the generic infrastructure and will be followed by patches for ARM and Mips for their target specific use. Contributer: Jack Carter llvm-svn: 173882
* This is a resubmittal. For some reason it broke the bots yesterdayJack Carter2013-01-181-0/+2
| | | | | | | | | | | | | | | | | | | | | | but I cannot reproduce the problem and have scrubed my sources and even tested with llvm-lit -v --vg. Support for Mips register information sections. Mips ELF object files have a section that is dedicated to register use info. Some of this information such as the assumed Global Pointer value is used by the linker in relocation resolution. The register info file is .reginfo in o32 and .MIPS.options in 64 and n32 abi files. This patch contains the changes needed to create the sections, but leaves the actual register accounting for a future patch. Contributer: Jack Carter llvm-svn: 172847
* Remove redundant 'llvm::' qualificationsDmitri Gribenko2013-01-131-1/+1
| | | | llvm-svn: 172358
* Make the contents of encoded sections SmallVector<char, N> instead ofEli Bendersky2012-12-071-8/+8
| | | | | | | | | | | SmallString. This makes it possible to use the length-erased SmallVectorImpl in the interface without imposing buffer size. Thus, the size of MCInstFragment is back down since a preallocated 8-byte contents buffer is enough. It would be generally a good idea to rid all the fragments of SmallString as contents, because a vector just makes more sense. llvm-svn: 169644
* Added Mapping Symbols for ARM ELFTim Northover2012-12-071-1/+1
| | | | | | | | | | Before this patch, when you objdump an LLVM-compiled file, objdump tried to decode data-in-code sections as if they were code. This patch adds the missing Mapping Symbols, as defined by "ELF for the ARM Architecture" (ARM IHI 0044D). Patch based on work by Greg Fitzgerald. llvm-svn: 169609
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