* Do script driven layout only if SECTIONS section exist.
Initial commit message:
[ELF] - Implemented basic location counter support.
This patch implements location counter support.
It also separates assign addresses for sections to assignAddressesScript() if it scipt exists.
Main testcase is test/ELF/linkerscript-locationcounter.s, It contains some work with location counter. It is basic now.
Implemented location counter assignment and '+' operations.
Patch by myself with LOTS of comments and design suggestions from Rui Ueyama.
Differential revision: http://reviews.llvm.org/D18499
llvm-svn: 266526
Parallelism level can be chosen using the new --lto-jobs=K option
where K is the number of threads used for CodeGen. It currently
defaults to 1.
llvm-svn: 266484
This patch implements location counter support.
It also separates assign addresses for sections to assignAddressesScript() if it scipt exists.
Main testcase is test/ELF/linkerscript-locationcounter.s, It contains some work with location counter. It is basic now.
Implemented location counter assignment and '+' operations.
Patch by myself with LOTS of comments and design suggestions from Rui Ueyama.
Differential revision: http://reviews.llvm.org/D18499
llvm-svn: 266457
The _gp_disp symbol designates offset between start of function and 'gp'
pointer into GOT. The following code is a typical MIPS function preamble
used to setup $gp register:
lui $gp, %hi(_gp_disp)
addi $gp, $gp, %lo(_gp_disp)
To calculate R_MIPS_HI16 / R_MIPS_LO16 relocations results we use
the following formulas:
%hi(_gp - P + A)
%lo(_gp - P + A + 4),
where _gp is a value of _gp symbol, A is addend, and P current address.
The R_MIPS_LO16 relocation references _gp_disp symbol is always the second
instruction. That is why we need four byte adjustments. The patch assigns
R_PC type for R_MIPS_LO16 relocation and adjusts its addend by 4. That fix
R_MIPS_LO16 calculation.
For details see p. 4-19 at ftp://www.linux-mips.org/pub/linux/mips/doc/ABI/mipsabi.pdf
Differential Revision: http://reviews.llvm.org/D19115
llvm-svn: 266368
We never need to iterate over the K,V pairs, so we can avoid copying the
key as MapVector does.
This is a small speedup on most benchmarks.
llvm-svn: 266364
The DenseMap doesn't store hash results. This means that when it is
resized it has to recompute them.
This patch is a small hack that wraps the StringRef in a struct that
remembers the hash value. That way we can be sure it is only hashed
once.
llvm-svn: 266357
That was removed in r266304, but leads to warnings by Clang.
Thanks to Rafael Espíndola for pointing on that.
Though I think change was legal from point of C++.
llvm-svn: 266306
They are unnecessary, as the dynamic loader can apply the original relocations
directly. This was also resulting in the creation of copy relocations in PIEs.
Differential Revision: http://reviews.llvm.org/D19089
llvm-svn: 266273
This patch implements the --dynamic-list option, which adds a list of
global symbol that either should not be bounded by default definition
when creating shared libraries, or add in dynamic symbol table in the
case of creating executables.
The patch modifies the ScriptParserBase class to use a list of Token
instead of StringRef, which contains information if the token is a
quoted or unquoted strings. It is used to use a faster search for
exact match symbol name.
The input file follow a similar format of linker script with some
simplifications (it does not have scope or node names). It leads
to a simplified parser define in DynamicList.{cpp,h}.
Different from ld/gold neither glob pattern nor mangled names
(extern 'C++') are currently supported.
llvm-svn: 266227
Previously each archive file was reported no matter were it's member used or not,
like:
lib/libLLVMSupport.a
Now lld prints line for each used internal file, like:
lib/libLLVMSupport.a(lib/Support/CMakeFiles/LLVMSupport.dir/StringSaver.cpp.o)
lib/libLLVMSupport.a(lib/Support/CMakeFiles/LLVMSupport.dir/Host.cpp.o)
lib/libLLVMSupport.a(lib/Support/CMakeFiles/LLVMSupport.dir/ConvertUTF.c.o)
That should be consistent with what gold do.
This fixes PR27243.
Differential revision: http://reviews.llvm.org/D19011
llvm-svn: 266220
This simplifies the code by allowing us to remove the visibility argument
to functions that create synthetic symbols.
The only functional change is that the visibility of the MIPS "_gp" symbol
is now hidden. Because this symbol is defined in every executable or DSO, it
would be difficult to observe a visibility change here.
Differential Revision: http://reviews.llvm.org/D19033
llvm-svn: 266208
We need to ensure that the address of an undefined weak symbol evaluates to
zero. We were getting this right for non-PIC executables (where the symbol
can be evaluated directly) and for DSOs (where we emit a symbolic relocation
for these symbols, as they are preemptible). But we weren't getting it right
for PIEs. Probably the simplest way to ensure that these symbols evaluate
to zero is by not creating a relocation in .got for them.
Differential Revision: http://reviews.llvm.org/D19044
llvm-svn: 266161
With this patch we use the first scan over the relocations to remember
the information we found about them: will them be relaxed, will a plt be
used, etc.
With that the actual relocation application becomes much simpler. That
is particularly true for the interfaces in Target.h.
This unfortunately means that we now do two passes over relocations for
non SHF_ALLOC sections. I think this can be solved by factoring out the
code that scans a single relocation. It can then be used both as a scan
that record info and for a dedicated direct relocation of non SHF_ALLOC
sections.
I also think it is possible to reduce the number of enum values by
representing a target with just an OutputSection and an offset (which
can be from the start or end).
This should unblock adding features like relocation optimizations.
llvm-svn: 266158
The _gp* family of symbols is defined as an offset in .got, and it is
not at all clear what should happen when .got is not defined.
This will allow some simplifications on how these symbols are handled.
llvm-svn: 266063
It is possible to have FDEs with duplicate PCs if ICF was able to merge
functions with FDEs, or if the input files for some reason contained duplicate
FDEs. We previously weren't handling this correctly when producing the
contents of the .eh_frame_hdr section; we were dropping entries and leaving
null entries at the end of the section, which confused consumers of unwind
data, such as the backtrace() function.
Fix the bug by setting the FDE count to the number of FDEs actually emitted
into .eh_frame_hdr, rather than the number of FDEs in .eh_frame.
Differential Revision: http://reviews.llvm.org/D18911
llvm-svn: 265957
Ismail Donmez