This is the function equivalent of a copy relocation.
Since functions are expected to change sizes, we cannot use copy
relocations. In situations where one would be needed, what is done
instead is:
* Create a plt entry
* Output an undefined symbol whose addr is the plt entry.
The dynamic linker makes sure any shared library uses the plt entry as
the function address.
llvm-svn: 260224
Summary:
LLVM3.3 (and earlier) would fail to include a relocation section in
the group that the section it was relocating is in. Object files
affected by this issue have been encountered in the wild when using LLD.
This would result in a siutation like:
Section {
Index: 5
Name: .text._Z3fooIiEvv (6)
Type: SHT_PROGBITS (0x1)
Flags [ (0x206)
SHF_ALLOC (0x2)
SHF_EXECINSTR (0x4)
SHF_GROUP (0x200)
]
Address: 0x0
Offset: 0x48
Size: 5
Link: 0
Info: 0
AddressAlignment: 1
EntrySize: 0
}
Section {
Index: 6
Name: .rela.text._Z3fooIiEvv (1)
Type: SHT_RELA (0x4)
Flags [ (0x0)
]
Address: 0x0
Offset: 0x3F0
Size: 24
Link: 8
Info: 5
AddressAlignment: 8
EntrySize: 24
}
In LLD, during symbol resolution, we discard the section containing the
weak symbol, but this amounts to replacing it with
InputSection<ELFT>::Discarded.
When we later saw the corresponding relocation section, we would then
end up pusing onto InputSection<ELFT>::Discarded.RelocSections, which is
bogus.
Reviewers: ruiu, rafael
Subscribers: llvm-commits, Bigcheese
Differential Revision: http://reviews.llvm.org/D16898
llvm-svn: 259831
If object files are drawn from archive files, the error message should
be something like "conflict symbols in foo.a(bar.o) and baz.o" instead
of "conflict symbols in bar.o and baz.o". This patch implements that.
llvm-svn: 259475
Main executable did not export symbols that exist both in the main executable and in DSOs before this patch.
Symbols from object files that override symbols in DSO should be added to .dynsym table.
Differential revision: http://reviews.llvm.org/D16405
llvm-svn: 258672
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
--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
Fix: Added missed input file.
Initial commit message:
[ELF/AArch64] - Implemented R_AARCH64_TLSIE_ADR_GOTTPREL_PAGE21 and R_AARCH64_TLSIE_LD64_GOTTPREL_LO12_NC relocations
* R_AARCH64_TLSIE_ADR_GOTTPREL_PAGE21 is calculated as Page(G(GTPREL(S+A))) – Page(P), set an ADRP immediate field to bits [32:12] of X; check –2^32 ≤ X < 2^32;
* R_AARCH64_TLSIE_LD64_GOTTPREL_LO12_NC is calculated as G(GTPREL(S+A)), set an LD offset field to bits [11:3] of X. No overflow check; check that X&7 = 0.
Differential revision: http://reviews.llvm.org/D16117
llvm-svn: 257596
On Windows different versions of 'sed' work in different text/binary
mode by default. If default mode is text, sed produces corrupted binary
files. Unfortunately there is no standard command line option to select
the mode. Some 'sed' support '-b' to switch to binary mode, while other
ones support '--text' option and does not have '-b' option at all.
llvm-svn: 257471
On MIPS O32 ABI, _gp_disp is a magic symbol designates offset between
start of function and gp pointer into GOT. To make seal with such symbol
we add new method addIgnoredStrong(). It adds ignored symbol with global
binding to prevent the symbol substitution. The addIgnored call is not
enough here because this call adds a weak symbol which might be
substituted by symbol from shared library.
Differential Revision: http://reviews.llvm.org/D16084
llvm-svn: 257449
R_AARCH64_TSTBR14 is calculated as S+A-P,
Set the immediate field of a TBZ/TBNZ instruction to bits [15:2] of X; check -2^15 ≤ X < 2^15
Differential revision: http://reviews.llvm.org/D15824
llvm-svn: 257334
R_AARCH64_CONDBR19 is calculated as S+A-P,
Set the immediate field of a conditional branch instruction to bits [20:2] of X; check -2^20 ≤ X< 2^20.
Afaik there is no document for AARCH64 instruction encoding from official for unknown reason, so
I used gold source code and next link as a reference for implementation: http://kitoslab-eng.blogspot.ru/2012/10/armv8-aarch64-instruction-encoding.html. From which is clear that immediate field of a conditional branch instruction is 5 bits off. That is proved by output which is is equal to gold/bfd now.
Differential revision: http://reviews.llvm.org/D15809
llvm-svn: 257333
In this patch, all symbols are resolved normally and then wrap options
are applied. Renaming is implemented by mutating `Body` pointers of
Symbols. (As a result, Symtab.find(SymbolName)->getName() may return
a string that's different from SymbolName, but that is by design.
I designed the symbol and the symbol table to allow this kind of
operations.)
http://reviews.llvm.org/D15896
llvm-svn: 257075
@indntpoff is similar to @gotntpoff, but for use in position dependent code. While @gotntpoff resolves to GOT slot address relative to the
start of the GOT in the movl or addl instructions, @indntpoff resolves to the
absolute GOT slot address. ("ELF Handling For Thread-Local Storage", Ulrich Drepper).
Differential revision: http://reviews.llvm.org/D15494
llvm-svn: 255884
R_X86_64_SIZE64/R_X86_64_SIZE32 relocations were introduced in 0.98v of "System V Application Binary Interface x86-64" (http://www.x86-64.org/documentation/abi.pdf).
Calculation for them is Z + A, where:
Z - Represents the size of the symbol whose index resides in the relocation entry.
A - Represents the addend used to compute the value of the relocatable field.
Differential revision: http://reviews.llvm.org/D15335
llvm-svn: 255332
Implement the TLS relocation optimization for 32-bit x86 that is described in
"ELF Handling For Thread-Local Storage" by Ulrich Drepper, chapter 5,
"IA-32 Linker Optimizations". Specifically, this patch implements these
optimizations: LD->LE, GD->IE, GD->LD, and IE->LE.
Differential revision: http://reviews.llvm.org/D15292
llvm-svn: 255103
"Ulrich Drepper, ELF Handling For Thread-Local Storage" (5.5 x86-x64 linker optimizations, http://www.akkadia.org/drepper/tls.pdf) shows how GD can be optimized to IE.
This patch implements the optimization.
Differential revision: http://reviews.llvm.org/D15000
llvm-svn: 254713
ABI specifies the allowed range for these relocations as 2^(n-1) <= X < 2^n.
The patch fixes checks and introduces precise tests for these relocations.
Differential revision: http://reviews.llvm.org/D14957
llvm-svn: 254146
Rafael Espindola