In a very recent change I introduced a --no-export-default flag
but after conferring with others it seems that this feature already
exists in gnu GNU ld and lld in the form the --export-dynamic flag
which is off by default.
This change replaces export-default with export-dynamic and also
changes the default to match the traditional linker behaviour.
Now, by default, only the entry point is exported. If other symbols
are required by the embedder then --export-dynamic or --export can
be used to export all visibility hidden symbols or individual
symbols respectively.
This change touches a lot of tests that were relying on symbols
being exported by default. I imagine it will also effect many
users but do think the change is worth it match of the traditional
behaviour and flag names.
Differential Revision: https://reviews.llvm.org/D52587
llvm-svn: 343265
Add REQUIRES: x86 to pdb-debug-f.s as this is causing the Arm and
AArch64 buildbots to fail as they do not have the x86 backend.
Differential Revision: https://reviews.llvm.org/D52606
llvm-svn: 343196
Summary: The convenience wrapper in STLExtras is available since rL342102.
Reviewers: ruiu, espindola
Subscribers: emaste, arichardson, mgrang, llvm-commits
Differential Revision: https://reviews.llvm.org/D52569
llvm-svn: 343146
Summary:
lld already gives later -z options precedence in getZFlag().
This matches the behavior of ld.bfd and ld.gold, where later options
override earlier ones. (I tested with -z max-page-size and -z stack-size.)
Reviewers: ruiu, espindola, grimar
Reviewed By: ruiu, grimar
Subscribers: grimar, emaste, arichardson, llvm-commits
Differential Revision: https://reviews.llvm.org/D52526
llvm-svn: 343145
Summary:
An AArch64 LE relocation is a positive ("variant 1") offset. This
relocation is used to write the upper 12 bits of a 24-bit offset into an
add instruction:
add x0, x0, :tprel_hi12:v1
The comment in the ARM docs for R_AARCH64_TLSLE_ADD_TPREL_HI12 is:
"Set an ADD immediate field to bits [23:12] of X; check 0 <= X < 2^24."
Reviewers: javed.absar, espindola, ruiu, peter.smith, zatrazz
Reviewed By: ruiu
Subscribers: emaste, arichardson, kristof.beyls, llvm-commits
Differential Revision: https://reviews.llvm.org/D52525
llvm-svn: 343144
This is https://bugs.llvm.org//show_bug.cgi?id=38919.
Currently, LLD may report "unsupported relocation target while parsing debug info"
when parsing the debug information.
At the same time LLD does that for zeroed R_X86_64_NONE relocations,
which obviously has "invalid" targets.
The nature of R_*_NONE relocation assumes them should be ignored.
This patch teaches LLD to stop reporting the debug information parsing errors for them.
Differential revision: https://reviews.llvm.org/D52408
llvm-svn: 343078
This involves adding more generic list of symbol suffixes/prefixes
to ignore for autoexport; adding a few other entries to these lists
as well from the corresponding lists in binutils.
Differential Revision: https://reviews.llvm.org/D52382
llvm-svn: 343070
Don't assume that the IAT chunk will be a DefinedImportData, it can
just as well be a DefinedRegular for gnu import libraries.
Differential Revision: https://reviews.llvm.org/D52381
llvm-svn: 343069
These option control weather or not symbols marked as visibility
default are exported in the output binary.
By default this is true, but emscripten prefers to control the
exported symbol list explicitly at link time and ignore the
symbol attributes.
Differential Revision: https://reviews.llvm.org/D52003
llvm-svn: 343034
When we write a struct to a mmap'ed buffer, we usually use
write16/32/64, but we didn't for VersionDefinitionSection, so
we needed to template that class.
llvm-svn: 343024
Previously, if you invoke lld's `main` more than once in the same process,
the second invocation could fail or produce a wrong result due to a stale
pointer values of the previous run.
Differential Revision: https://reviews.llvm.org/D52506
llvm-svn: 343009
This is a feature that MS link.exe lacks; it currently errors out on
such relocations, just like lld did before.
This allows linking clang.exe for ARM - practically, any image over
16 MB will likely run into the issue.
Differential Revision: https://reviews.llvm.org/D52156
llvm-svn: 342962
Summary:
Currently we are pointing all debug information that refer removed function code
to the beginning of the code section (offset = 0). A debugger may want to
resolve code offset to the debug information, which will collide with offsets
of the live functions.
Moving offsets of dead functions outside code section range.
Reviewers: sbc100
Reviewed By: sbc100
Subscribers: dblaikie, ruiu, alexcrichton, dschuff, aprantl, jgravelle-google, aheejin, sunfish, JDevlieghere, llvm-commits
Differential Revision: https://reviews.llvm.org/D49446
llvm-svn: 342930
Implement final argument precedence if multiple /debug arguments are passed on the command-line to match expected link.exe behavior.
Support /debug:none and emit warning for /debug:fastlink with automatic fallback to /debug:full.
Emit error if last /debug:option is unknown.
Emit warning if last /debugtype:option is unknown.
https://reviews.llvm.org/D50404
llvm-svn: 342894
GNU binutils import libraries aren't the same kind of short import
libraries as link.exe and LLD produce, but are a plain static library
containing .idata section chunks. MSVC link.exe can successfully link
to them.
In order for imports from GNU import libraries to mix properly with the
normal import chunks, the chunks from the existing mechanism needs to
be added into named sections like .idata$2.
These GNU import libraries consist of one header object, a number of
object files, one for each imported function/variable, and one trailer.
Within the import libraries, the object files are ordered alphabetically
in this order. The chunks stemming from these libraries have to be
grouped by what library they originate from and sorted, to make sure
the section chunks for headers and trailers for the lists are ordered
as intended. This is done on all sections named .idata$*, before adding
the synthesized chunks to them.
Differential Revision: https://reviews.llvm.org/D38513
llvm-svn: 342777
Summary:
As for x86_64, the default image base for AArch64 and i386 should be
aligned to a superpage appropriate for the architecture.
On AArch64, this is 2 MiB, on i386 it is 4 MiB.
Reviewers: emaste, grimar, javed.absar, espindola, ruiu, peter.smith, srhines, rprichard
Reviewed By: ruiu, peter.smith
Subscribers: jfb, markj, arichardson, krytarowski, kristof.beyls, llvm-commits
Differential Revision: https://reviews.llvm.org/D50297
llvm-svn: 342746
Non-member functions are generally preferred over member functions
because it is clear that non-member functions don't depend on an
internal state of an object.
llvm-svn: 342695
The PPC64 elf V2 abi defines 2 entry points for a function. There are a few
places we need to calculate the offset from the global entry to the local entry
and how this is done is not straight forward. This patch adds a helper function
mostly for documentation purposes, explaining how the 2 entry points differ and
why we choose one over the other, as well as documenting how the offsets are
encoded into a functions st_other field.
Differential Revision: https://reviews.llvm.org/D52231
llvm-svn: 342603
The access sequence for global variables in the medium and large code models use
2 instructions to add an offset to the toc-pointer. If the offset fits whithin
16-bits then the instruction that sets the high 16 bits is redundant.
This patch adds the --toc-optimize option, (on by default) and enables rewriting
of 2 instruction global variable accesses into 1 when the offset from the
TOC-pointer to the variable (or .got entry) fits in 16 signed bits. eg
addis %r3, %r2, 0 --> nop
addi %r3, %r3, -0x8000 --> addi %r3, %r2, -0x8000
This rewriting can be disabled with the --no-toc-optimize flag
Differential Revision: https://reviews.llvm.org/D49237
llvm-svn: 342602
The __NULL_IMPORT_DESCRIPTOR symbol has two leading underscores on
architectures other than i386 as well; it is not a mangled symbol name.
llvm-svn: 342448
Summary:
For --pack-dyn-relocs=android, finalizeSections calls
LinkerScript::assignAddresses and
AndroidPackedRelocationSection::updateAllocSize in a loop,
where assignAddresses lays out the ELF image, then updateAllocSize
determines the size of the Android packed relocation table by encoding it.
Encoding the table requires knowing the values of relocation addends.
To get the addend of a TLS relocation, updateAllocSize can call getSymVA
on a TLS symbol before setPhdrs has initialized Out::TlsPhdr, producing an
error:
<file> has an STT_TLS symbol but doesn't have an SHF_TLS section
Fix the problem by initializing Out::TlsPhdr immediately after the program
headers are created. The segment's p_vaddr field isn't initialized until
setPhdrs, so use FirstSec->Addr, which is what setPhdrs would use.
FirstSec will typically refer to the .tdata or .tbss output section, whose
(tentative) address was computed by assignAddresses.
Android currently avoids this problem because it uses emutls and doesn't
support ELF TLS. This problem doesn't apply to --pack-dyn-relocs=relr
because SHR_RELR only handles relative relocations without explicit addends
or info.
Fixes https://bugs.llvm.org/show_bug.cgi?id=37841.
Reviewers: ruiu, pcc, chh, javed.absar, espindola
Subscribers: emaste, arichardson, llvm-commits, srhines
Differential Revision: https://reviews.llvm.org/D51671
llvm-svn: 342432
A General-dynamic tls access can be written using a R_PPC64_TLSGD16 relocation
if the target got entry is within 16 bits of the TOC-base. This patch adds
support for R_PPC64_TLSGD16 by relaxing it the same as a R_PPC64_GOT_TLSGD16_LO.
Differential Revision: https://reviews.llvm.org/D52055
llvm-svn: 342411
There are a growing number of places when we either want to read or write an
instruction when handling a half16 relocation type. On big-endian the buffer
pointer is pointing into the middle of the word we want and on little-endian it
is pointing to the start of the word. These 2 helpers are to simplify reading
and writing in these contexts.
Differential Revision: https://reviews.llvm.org/D52115
llvm-svn: 342410
dllimported symbols go through an import stub that's called __imp_ followed by
the name the stub points to. Make that work.
Differential Revision: https://reviews.llvm.org/D52145
llvm-svn: 342401
tolower() has some overhead because current locale is considered (though in lld the default "C" locale is used which does not matter too much). llvm::toLower is more efficient as it compiles to a compare and a conditional jump, as opposed to a libc call if tolower is used.
Disregarding locale also matches gdb's behavior (gdb/minsyms.h):
#define SYMBOL_HASH_NEXT(hash, c) \
((hash) * 67 + TOLOWER ((unsigned char) (c)) - 113)
where TOLOWER (include/safe-ctype.h) is a macro that uses a lookup table under the hood which is similar to llvm::toLower.
Reviewers: ruiu, espindola
Subscribers: emaste, arichardson, llvm-commits
Differential Revision: https://reviews.llvm.org/D52128
llvm-svn: 342342
Previously, lld-link would use a random byte sequence as the PDB GUID. Instead,
use a hash of the PDB file contents.
To not disturb llvm-pdbutil pdb2yaml, the hash generation is an opt-in feature
on InfoStreamBuilder and ldb/COFF/PDB.cpp always sets it.
Since writing the PDB computes this ID which also goes in the exe, the PDB
writing code now must be called before writeBuildId(). writeBuildId() for that
reason is no longer included in the "Code Layout" timer.
Since the PDB GUID is now a function of the PDB contents, the PDB Age is always
set to 1. There was a long comment above loadExistingBuildId (now gone) about
how not changing the GUID and only incrementing the age was important, but
according to the discussion in PR35914 that comment was incorrect.
Differential Revision: https://reviews.llvm.org/D51956
llvm-svn: 342334
For this, add a few toString() calls when printing the "undefined symbol"
diagnostics; toString() already does demangling on Windows hosts.
Also make lld::demangleMSVC() (called by toString(Symbol*)) call LLVM's
microsoftDemangle() instead of UnDecorateSymbolName() so that it works on
non-Windows hosts – this makes both updating tests easier and provides a better
user experience for people doing cross-links.
This doesn't yet do the right thing for symbols starting with __imp_, but that
can be improved in a follow-up.
Differential Revision: https://reviews.llvm.org/D52104
llvm-svn: 342332
Sam Clegg