This function is a predicate that a given relocation can be relaxed.
The previous name implied that it returns true if a given relocation
has already been optimized away.
llvm-svn: 259128
In many situations, we don't want to exit at the first error even in the
process model. For example, it is better to report all undefined symbols
rather than reporting the first one that the linker picked up randomly.
In order to handle such errors, we don't need to wrap everything with
ErrorOr (thanks for David Blaikie for pointing this out!) Instead, we
can set a flag to record the fact that we found an error and keep it
going until it reaches a reasonable checkpoint.
This idea should be applicable to other places. For example, we can
ignore broken relocations and check for errors after visiting all relocs.
In this patch, I rename error to fatal, and introduce another version of
error which doesn't call exit. That function instead sets HasError to true.
Once HasError becomes true, it stays true, so that we know that there
was an error if it is true.
I think introducing a non-noreturn error reporting function is by itself
a good idea, and it looks to me that this also provides a gradual path
towards lld-as-a-library (or at least embed-lld-to-your-program) without
sacrificing code readability with lots of ErrorOr's.
http://reviews.llvm.org/D16641
llvm-svn: 259069
In InputSection.cpp it was possible to dereference null.
Had to change signature of relocateTlsOptimize to accept pointer instead of reference.
Differential revision: http://reviews.llvm.org/D16466
llvm-svn: 258508
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
MIPS ABI has relocations like R_MIPS_JALR which is just a hint for
linker to make some code optimization. Such relocations should not be
handled as a regular ones and lead to say dynamic relocation creation.
The patch introduces new virtual `Target::isHintReloc` method, overrides
it in the `MipsTargetInfo` class and calls it in the `Writer<ELFT>::scanRelocs`
method.
Differential Revision: http://reviews.llvm.org/D16193
llvm-svn: 257798
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
* 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: 257588
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
R_X86_64_PLT32 is handled in the same way as R_X86_64_PC32 by
relocateOne(), so this function does not seems to be needed.
Without this code, all tests still pass.
http://reviews.llvm.org/D15971
llvm-svn: 257203
All non-trivial relocation decisions need explanations like this
to help readers understand not only how relocations are handled but
why they are handled these ways. This is a start.
llvm-svn: 257119
Summary: This will allow us to remove the AMDGPU support from old ELF.
Reviewers: rafael, ruiu
Differential Revision: http://reviews.llvm.org/D15895
llvm-svn: 257023
The R_MIPS_GPREL16 / R_MIPS_GPREL32 relocations use the following
expressions for calculations:
```
local symbol: S + A + GP0 - GP
global symbol: S + A - GP
GP - Represents the final gp value, i.e. _gp symbol
GP0 - Represents the gp value used to create the relocatable object
```
The GP0 value is taken from the .reginfo data section defined by an object
file. To implement that I keep a reference to `MipsReginfoInputSection`
in the `ObjectFile` class. This reference is used by the
`ObjectFile::getMipsGp0` method to return the GP0 value.
Differential Revision: http://reviews.llvm.org/D15760
llvm-svn: 256416
The patch adds support for R_MIPS_PC16, R_MIPS_PC19_S2, R_MIPS_PC21_S2,
R_MIPS_PC26_S2, R_MIPS_PCHI16, R_MIPS_PCLO16 relocations handling.
llvm-svn: 256172
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
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
@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
The `R_MIPS_JALR` is a relocation generated by gcc and gas. This
relocation points to the `jalr` instruction which might be optimized and
converted to the `b` instruction under some conditions.
Now we just ignore this relocation and keep instructions unchanged.
llvm-svn: 255453
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
If R_386_PLT32 relocation is applied against symbol that can not be preempted then it can be resolved statically.
Patch implements it for x86 target.
Differential revision: http://reviews.llvm.org/D15376
llvm-svn: 255233
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
