This implementation is probably slightly inefficient than before,
but that should be negligible because this is not a performance-
critical pass.
llvm-svn: 296570
I do not fully understand why we had these values in the tests, but
the new value matches what ld.bfd and ld.gold set, so I guess that
was just a mistake.
Differential Revision: https://reviews.llvm.org/D30441
llvm-svn: 296505
This reverts commit r296378.
I am pretty sure this is incorrect. In particular, for just
.cfi_startproc
nop
.cfi_endproc
We now add an extra 4 zeros that neither bfd nor gold add.
llvm-svn: 296503
In other places in LLD, we use write32<E> instead of Elf_Word.
This patch uses the same technique in the hash table classes.
The hash table classes needs improving as they have almost no
comments. We at least need to describe the hash table structure
and why we have to support two different on-disk hash tables
for the same purpose. I'll do that later.
llvm-svn: 296439
Previously, these two functions put their symbols in different queues.
Now that the queues have been merged. So there's no point to keep two
separate functions.
llvm-svn: 296435
That function doesn't use any member of SymbolTableSection, so I
couldn't see a reason to make it a member of that class. The function
takes a SymbolBody, so it is more natural to make it a member of
SymbolBody.
llvm-svn: 296433
Previously, there were three conditions: .symtab, .dynsym or we are
producing a relocatable output. Turned out that the third condition is
the same as the first one. This patch removes that third condition and
simplify code.
llvm-svn: 296431
The previous code was a bit hard to understand because it unnecessarily
distinguished local and non-local symbols. It had NumLocals member
variable, but that variable didn't have a number of local symbols but
had some value that I cannot describe easily.
This patch rewrites SynbolTableSection::finalizeContents and
SymbolTableSection::writeTo to make it easy to understand. NumLocals
member variable has been removed, and writeGlobalSymbols and
writeLocalSymbols have been merged into one function.
There's still a piece of code that I think unnecessary. I'm not removing
that code in this patch, but will do in a follow-up patch.
llvm-svn: 296423
This part of code is hard to understand because NumLocals does not
actually mean the number of local symbols but something else (!).
We need to rewrite. But before that we need to clean it up.
llvm-svn: 296400
Patch by Mark Kettenis.
Currenlty ld.lld does not add a terminator (a CIE with its length field
set to zero) to the .eh_frame sections it generates. While the relevant
standards (the AMD64 SysV ABI and the Linux LSB) are not explicit about
this, such a terminator is expected by some unwinder implementations and
seems to be always emitted by ld.bfd. In addition to that, the Linux LSB
https://refspecs.linuxfoundation.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/ehframechpt.html#EHFRAME
explicitly says that
The .eh_frame section shall contain 1 or more Call Frame Information
(CFI) records.
Currently, if the .eh_frame sections of the input files only contain
terminators, ld.lld emits a zero=sized .eh_frame section
which clearly doesn't meet that requirement.
The diff makes sure a terminator gets added to each .eh_frame section
and adjusts all the relevant tests to account for that. An additional
test isn't needed as these adjustments mean that the existence of the
terminator is tested for by several tests already.
Differential Revision: https://reviews.llvm.org/D30335
llvm-svn: 296378
The list of all input sections was defined in SymbolTable class for a
historical reason. The list itself is not a template. However, because
SymbolTable class is a template, we needed to pass around ELFT to access
the list. This patch moves the list out of the class so that it doesn't
need ELFT.
llvm-svn: 296309
With this we complete the transition out of special output sections,
and with the previous patches it should be possible to merge
OutputSectionBase and OuputSection.
llvm-svn: 296023
With the current design an InputSection is basically anything that
goes directly in a OutputSection. That includes plain input section
but also synthetic sections, so this should probably not be a
template.
llvm-svn: 295993
This change moves the SymbolBodies with isLocal() == true before the global
symbols then calculating NumLocals rather than assuming all locals are
added before globals and the first NumLocals have isLocal() == true. This
permits Thunks to be moved after the pass that adds global symbols from
synthetics to the symbol table.
Differential revision: https://reviews.llvm.org/D30085
llvm-svn: 295650
This patch removes NeedsCopyOrPltAddr and instead add two variables,
NeedsCopy and NeedsPltAddr. This uses one more bit in Symbol class,
but the actual size doesn't increase because we had unused bits.
This should improve code readability.
llvm-svn: 295287
In the target dependent code we already always return a int64_t. In
the target independent code we carefully use uintX_t, which has the
same result given 2 complement rules.
This just simplifies the code to use int64_t everywhere.
llvm-svn: 295263
Unfortunately some consumers of our .o files produced with -r expect
only one section symbol per section. That is true of at least of go's
own linker.
Combining them is a somewhat convoluted process. We have to create a
symbol for every section since we don't know which ones will be
needed. The relocation sections also have to be written first to
handle the Elf_Rel addend.
I did consider a completely different approach:
We could remove the -r special case of relocation sections when
reading. We would instead have a copyRelocs function that is used
instead of scanRelocs. It would create a DynamicReloc for each
relocation and a RelocationSection for each input relocation section.
A complication of such change is that DynamicReloc would have to take
a section index and a input section instead of a symbol since with
-emit-relocs some DynamicReloc would hold relocations referring to the
dynamic symbol table and other to the static symbol table.
That would be a pretty big change, and if we do it it is probably
better to do it as a refactoring.
llvm-svn: 294816
Much of the code in PltSection and IPltSection is similar, we identify
the IPlt by a HeaderSize of 0 and alter our behaviour in the member
functions appropriately:
-Iplt does not have a header
-Iplt always follows after the Plt
Differential Revision: https://reviews.llvm.org/D29664
llvm-svn: 294579
When we need a copy relocation we create a synthetic SHT_NOBITS
section that contains the right amount of ZI and assign it to either
.bss or .rel.ro.bss as appropriate. This allows the dynamic relocation
to be placed on the InputSection, removing the last case where a
dynamic relocation is stored as an offset from the OutputSection. This
has the side effect that we can run assignOffsets() after scanRelocs()
without losing the additional ZI needed for the copy relocations.
Differential Revision: https://reviews.llvm.org/D29637
llvm-svn: 294577
With a synthetic merge section we can have, for example, a single
.rodata section with stings, fixed sized constants and non merge
constants.
I can be simplified further by not setting Entsize, but that is
probably better done is a followup patch.
This should allow some cleanup in the linker script code now that
every output section command maps to just one output section.
llvm-svn: 294005
Thunks are now implemented by redirecting the relocation to the
symbol S, to a symbol TS in a Thunk. The Thunk will transfer control
to S. This has the following implications:
- All the side-effects of Thunks happen within createThunks()
- Thunks are no longer stored in InputSections and Symbols no longer
need to hold a pointer to a Thunk
- The synthetic Thunk sections need to be merged into OutputSections
This implementation is almost a direct conversion of the existing
Thunks with the following exceptions:
- Mips LA25 Thunks are placed before the InputSection that defines
the symbol that needs a Thunk.
- All ARM Thunks are placed at the end of the OutputSection of the
first caller to the Thunk.
Range extension Thunks are not supported yet so it is optimistically
assumed that all Thunks can be reused.
This is a recommit of r293283 with a fixed comparison predicate as
std::merge requires a strict weak ordering.
Differential revision: https://reviews.llvm.org/D29327
llvm-svn: 293757
Thunks are now implemented by redirecting the relocation to the
symbol S, to a symbol TS in a Thunk. The Thunk will transfer control
to S. This has the following implications:
- All the side-effects of Thunks happen within createThunks()
- Thunks are no longer stored in InputSections and Symbols no longer
need to hold a pointer to a Thunk
- The synthetic Thunk sections need to be merged into OutputSections
This implementation is almost a direct conversion of the existing
Thunks with the following exceptions:
- Mips LA25 Thunks are placed before the InputSection that defines
the symbol that needs a Thunk.
- All ARM Thunks are placed at the end of the OutputSection of the
first caller to the Thunk.
Range extension Thunks are not supported yet so it is optimistically
assumed that all Thunks can be reused.
Differential Revision: https://reviews.llvm.org/D29129
llvm-svn: 293283
Mapping symbols allow a mapping symbol aware disassembler to
correctly disassemble the PLT when the code immediately prior to the
PLT is Thumb.
To implement this we add a function to add symbols with local
binding to be defined in SyntheticSymbols.
Differential Revision: https://reviews.llvm.org/D28956
llvm-svn: 293044
Next code crashed under MSVS2015 for me:
this->OutSec->Info = this->Info = 1 + It - Symbols.begin();
Because It was end() and addition of 1 is not allowed.
vector implementation catched and failed that inside:
_Myiter& operator+=(difference_type _Off)
{ // increment by integer
#if _ITERATOR_DEBUG_LEVEL == 2
if (this->_Getcont() == 0
|| this->_Ptr + _Off < ((_Myvec *)this->_Getcont())->_Myfirst
|| ((_Myvec *)this->_Getcont())->_Mylast < this->_Ptr + _Off)
{ // report error
_DEBUG_ERROR("vector iterator + offset out of range");
_SCL_SECURE_OUT_OF_RANGE;
llvm-svn: 292940
Rui Ueyama