This is for PR36716 and
this enables emitting STT_FILE symbols.
Output size affect is minor:
lld binary size changes from 52,883,408 to 52,949,400
clang binary size changes from 83,136,456 to 83,219,600
Differential revision: https://reviews.llvm.org/D45261
llvm-svn: 329557
Currently there are a few odd things about the warning about symbols
that cannot be ordered. This patch fixes:
* When there is an undefined symbol that resolves to a shared file, we
were printing the location of the undefined reference.
* If there are multiple comdats, we were reporting them all.
llvm-svn: 329371
Added checks to test that we do not produce
output where VA of sections overruns the address
space available.
Differential revision: https://reviews.llvm.org/D43820
llvm-svn: 329063
It generally does not matter much where we place sections ordered
by --symbol-ordering-file relative to other sections. But if the
ordered sections are hot (which is the case already for some users
of --symbol-ordering-file, and is increasingly more likely to be
the case once profile-guided section layout lands) and the target
has limited-range branches, it is beneficial to place the ordered
sections in the middle of the output section in order to decrease
the likelihood that a range extension thunk will be required to call
a hot function from a cold function or vice versa.
That is what this patch does. After D44966 it reduces the size of
Chromium for Android's .text section by 60KB.
Differential Revision: https://reviews.llvm.org/D44969
llvm-svn: 328905
This patch fixes an issue introduced in r328810 which made the algorithm
to always run the loop O(n^2) times, though we can break early. The
output remains the same.
llvm-svn: 328811
There are no reasons for them to be STV_DEFAULT,
recently bfd did the same change.
Differential revision: https://reviews.llvm.org/D44566
llvm-svn: 327983
This patch adds changes to start supporting the Power 64-Bit ELF V2 ABI.
This includes:
- Changing the ElfSym::GlobalOffsetTable to be named .TOC.
- Creating a GotHeader so the first entry in the .got is .TOC.
- Setting the e_flags to be 1 for ELF V1 and 2 for ELF V2
Differential Revision: https://reviews.llvm.org/D44483
llvm-svn: 327871
This is the same as 327248 except Arm defining _GLOBAL_OFFSET_TABLE_ to
be the base of the .got section as some existing code is relying upon it.
For most Targets the _GLOBAL_OFFSET_TABLE_ symbol is expected to be at
the start of the .got.plt section so that _GLOBAL_OFFSET_TABLE_[0] =
reserved value that is by convention the address of the dynamic section.
Previously we had defined _GLOBAL_OFFSET_TABLE_ as either the start or end
of the .got section with the intention that the .got.plt section would
follow the .got. However this does not always hold with the current
default section ordering so _GLOBAL_OFFSET_TABLE_[0] may not be consistent
with the reserved first entry of the .got.plt.
X86, X86_64 and AArch64 will use the .got.plt. Arm, Mips and Power use .got
Fixes PR36555
Differential Revision: https://reviews.llvm.org/D44259
llvm-svn: 327823
This change broke ARM code that expects to be able to add
_GLOBAL_OFFSET_TABLE_ to the result of an R_ARM_REL32.
I will provide a reproducer on llvm-commits.
llvm-svn: 327688
This is an option to print out a table of symbols and filenames.
The output format of this option is the same as GNU, so that it can be
processed by the same scripts as before after migrating from GNU to lld.
This option is mildly useful; we can live without it. But it is pretty
convenient sometimes, and it can be implemented in 50 lines of code, so
I think lld should support this option.
Differential Revision: https://reviews.llvm.org/D44336
llvm-svn: 327565
This is part of PR36515.
With some linkerscripts it is possible to get file offset overlaps
and overflows. Currently LLD checks overlaps in checkNoOverlappingSections().
And also we allow broken output with --no-inhibit-exec.
Problem is that sometimes final offset of sections is completely broken
and we calculate output file size wrong and might crash.
Patch implements check to verify that there is no output section
which offset exceeds file size.
Differential revision: https://reviews.llvm.org/D43819
llvm-svn: 327376
the start of the .got.plt section so that _GLOBAL_OFFSET_TABLE_[0] =
reserved value that is by convention the address of the dynamic section.
Previously we had defined _GLOBAL_OFFSET_TABLE_ as either the start or end
of the .got section with the intention that the .got.plt section would
follow the .got. However this does not always hold with the current
default section ordering so _GLOBAL_OFFSET_TABLE_[0] may not be consistent
with the reserved first entry of the .got.plt.
X86, X86_64, Arm and AArch64 will use the .got.plt. Mips and Power use .got
Fixes PR36555
Differential Revision: https://reviews.llvm.org/D44259
llvm-svn: 327248
It was raised during the review of D43819.
LLD usually use [X, Y] for reporting ranges, like below:
"relocation R_386_16 out of range: 65536 is not in [0, 65535]"
Patch changes rangeToString() to do the same.
Differential revision: https://reviews.llvm.org/D44207
llvm-svn: 326918
Summary:
I originally tried to simplify code and then noticed that lld doesn't
do what it tells to the user by warn(). It says "unable to order
discarded symbol" but it actually can for sections eliminated by ICF.
With this patch, lld doesn't sort such sections.
Reviewers: jhenderson, rafael
Subscribers: emaste, arichardson, llvm-commits
Differential Revision: https://reviews.llvm.org/D44180
llvm-svn: 326911
Previously, we didn't try to make effort to put .note sections next
to each other in the output file, so two .note sections were likely
to be stored to two separate NOTE segments. That's undesirable because
we should create as few segments as possible in general.
Differential Revision: https://reviews.llvm.org/D43858
llvm-svn: 326410
This should resolve the issue that lld build fails in some hosts
that uses case-insensitive file system.
Differential Revision: https://reviews.llvm.org/D43788
llvm-svn: 326339
Imagine that we have sections A, B, C, where A == C and
symbol ordering file containing symbols: symC, symB, symA
Previously because of ICF it was possible that final order would be
B, A or B, C. That violates order specified in ordering file.
Patch changes that.
Differential revision: https://reviews.llvm.org/D43234
llvm-svn: 326179
This fixes pr36475.
I think this code can be simplified a bit, but I would like to check
in the more direct fix if we are in agreement on the direction and
then refactor.
This is not something that bfd does. The issue is not noticed in bfd
because it keeps fewer sections from the linkerscript in the output.
The reasons why it seems reasonable to do this:
- As George noticed, we would still keep the flags if the output
section had both an empty synthetic section and a regular section
- We need an heuristic to find the flags of output sections. Using the
flags of a synthetic section that would have been there seems a
reasonable heuristic.
llvm-svn: 326137
MIPS ABIs require that if an executable file uses non-PIC model, the
EI_ABIVERSION entry in the ELF header should be incremented from 0 to 1.
That allows obsoleted / limited dynamic linkers refuse to link them.
llvm-svn: 325890
This continues direction started in D43069.
We can keep sections that are explicitly assigned to segment in script.
It helps to simplify code.
Differential revision: https://reviews.llvm.org/D43571
llvm-svn: 325887
We sometimes need to iterate over input sections for a given
output section. It is not very convinent because we have to iterate
over section descriptions.
Patch introduces getInputSections helper, it simplifies things.
Differential revision: https://reviews.llvm.org/D43574
llvm-svn: 325763
There are a number of different situations when symbols are requested
to be ordered in the --symbol-ordering-file that cannot be ordered for
some reason. To assist with identifying these symbols, and either
tidying up the order file, or the inputs, a number of warnings have
been added. As some users may find these warnings unhelpful, due to how
they use the symbol ordering file, a switch has also been added to
disable these warnings.
The cases where we now warn are:
* Entries in the order file that don't correspond to any symbol in the input
* Undefined symbols
* Absolute symbols
* Symbols imported from shared objects
* Symbols that are discarded, due to e.g. --gc-sections or /DISCARD/ linker script sections
* Multiple of the same entry in the order file
Reviewed by: rafael, ruiu
Differential Revision: https://reviews.llvm.org/D42475
llvm-svn: 325125
We sort inside output sections, so all the sections we see should be
InputSectionBase.
I noticed the patch adding callgraph based section ordering used this
type and changing this separately makes the merge easier.
llvm-svn: 325094
When decompressing a compressed debug section, we drop SHF_COMPRESSED
flag but we didn't drop "z" in ".zdebug" section name. This patch does
that for consistency.
This change also fixes the issue that .zdebug_gnu_pubnames are not
dropped when we are creating a .gdb_index section.
llvm-svn: 324949
This is a bit more verbose, but it has a few advantages.
The logic on what to do with special sections like .init_array is not
duplicated. Before we would need keep isKnownNonreorderableSection in
sync.
I think with this the call graph based sorting can be implemented by
"just" returning a new order from buildSectionOrder.
llvm-svn: 324744
This is PR35740 which now crashes
because we remove unused synthetic sections incorrectly.
We can keep input section description and corresponding output
section live even if it must be empty and dead.
This results in a crash because SHF_LINK_ORDER handling code
tries to access first section which is nullptr in this case.
Patch fixes the issue.
Differential revision: https://reviews.llvm.org/D42681
llvm-svn: 324463
In lld this was the only use of Config->Static where it meant anything
else other than "use .a instead of .so".
If a program turns out to not use any dynamic libraries, we should
produce the same result with and without -static.
llvm-svn: 324421
