Works on this dependency chain:
ArrayRef.h ->
Hashing.h -> --CUT--
Host.h ->
StringMap.h / StringRef.h
ArrayRef is very popular, but Host.h is rarely needed. Move the
IsBigEndianHost constant to SwapByteOrder.h. Clients of that header are
more likely to need it.
llvm-svn: 375316
Summary:
Also changes the wasm YAML format to reflect the possibility of having
multiple return types and to put the returns after the params for
consistency with the binary encoding.
Reviewers: aheejin, sbc100
Subscribers: dschuff, jgravelle-google, hiraditya, sunfish, arphaman, rupprecht, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D69156
llvm-svn: 375283
This fixes the second part of PR42407.
For files with dwarf debug info, it manually loads and iterates
.debug_info to find the declared location of variables, to allow
reporting them. (This matches the corresponding code in the ELF
linker.)
For functions, it uses the existing getFileLineDwarf which uses
LLVMSymbolizer for translating addresses to file lines.
In object files with codeview debug info, only the source location
of duplicate functions is printed. (And even there, only for the
first input file. The getFileLineCodeView function requires the
object file to be fully loaded and initialized to properly resolve
source locations, but duplicate symbols are reported at a stage when
the second object file isn't fully loaded yet.)
Differential Revision: https://reviews.llvm.org/D68975
llvm-svn: 375218
This updates some more places using `%T` to use `%/T` for path normalization.
If this does not work, this and r375126 should be reverted together.
llvm-svn: 375131
Summary:
Glob support was improved to accept `\` as an escape character in r375051, but reverted as r375052 due to a failure in this test on Windows.
The reason this failure seems Windows specific is because the path separator `\` is currently being relied on to be interpreted literally instead of as an escape character. Per documentation on linker input section wildcard patterns, this seems to be a bug in lld accepting `\` as a literal instead of an escape character.
For example:
```
SECTIONS{ .foo :{ /path/to/foo.o(.foo) }} # OK: standard UNIX path
SECTIONS{ .foo :{ C:/path/to/foo.o(.foo) }} # OK: windows accepts slashes in either direction
SECTIONS{ .foo :{ C:\\path\\to\\foo.o(.foo) }} # OK: escape character used to match a literal \
SECTIONS{ .foo :{ C:\path\to\foo.o(.foo) }} # BAD: this actually matches the path C:pathtofoo.o(.foo)
```
This avoids the problem in the test by using `%/T` in place of `%T` to normalize the path separator to `/`, which windows should also accept.
This patch just fixes the test, and glob support will be be relanded separately.
For a sample buildbot error, see: http://lab.llvm.org:8011/builders/clang-x64-windows-msvc/builds/11578/steps/stage%201%20check/logs/stdio
Reviewers: evgeny777, ruiu, MaskRay, espindola
Reviewed By: ruiu, MaskRay
Subscribers: emaste, arichardson, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D69074
llvm-svn: 375126
Undefined symbols in WebAssembly can come with custom `import-module`
and `import-field` attributes. However when reading symbols from
bitcode object files during LTO those curtom attributes are not
available.
Once we compile the LTO object and read in the symbol table from the
object file we have access to these custom attributes. In this case,
when undefined symbols are added and a symbol already exists in the
SymbolTable we can't simple return it, we may need to update the
symbol's attributes.
Fixes: PR43211
Differential Revision: https://reviews.llvm.org/D68959
llvm-svn: 375081
Fix a bug where were not handling relocations against weakly undefined
data symbol. Add a test for this case. Also ensure that the weak
references to data symbols are not pulled in from archive files by
default (but are if `-u <name>` is added to the command line).
Fixes: PR43696
Differential Revision: https://reviews.llvm.org/D69073
llvm-svn: 375077
Summary:
WebAssembly memories are zero-initialized, so when module does not
import its memory initializing .bss sections is guaranteed to be a
no-op. To reduce binary size and initialization time, .bss sections
are simply not emitted into the final binary unless the memory is
imported.
Reviewers: sbc100
Subscribers: dschuff, jgravelle-google, aheejin, sunfish, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D68965
llvm-svn: 374940
This makes use of it slightly clearer, and makes it match the
same construct in the lld ELF linker.
Differential Revision: https://reviews.llvm.org/D68935
llvm-svn: 374869
Summary:
- Expand the "Name" column past 13 characters when any of the section names are longer. Current behavior is a staggard output instead of a nice table if a single name is longer.
- Only print the required number of hex chars for addresses (i.e. 8 characters for 32-bit, 16 characters for 64-bit)
- Fix trailing spaces
Reviewers: grimar, jhenderson, espindola
Reviewed By: grimar
Subscribers: emaste, sbc100, arichardson, aheejin, seiya, llvm-commits, MaskRay
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D68730
llvm-svn: 374795
A common pattern in Windows is to have all your precompiled headers
use an object named stdafx.obj. If you've got a project with many
different static libs, you might use a separate PCH for each one of
these.
During the final link step, a file from A might reference the PCH
object from A, but it will have the same name (stdafx.obj) as any
other PCH from another project. The only difference will be the
path. For example, A might be A/stdafx.obj while B is B/stdafx.obj.
The existing algorithm checks only the filename that was passed on
the command line (or stored in archive), but this is insufficient in
the case where relative paths are used, because depending on the
command line object file / library order, it might find the wrong
PCH object first resulting in a signature mismatch.
The fix here is to simply check whether the absolute path of the
PCH object (which is stored in the input obj file for the file that
references the PCH) *ends with* the full relative path of whatever
is specified on the command line (or is in the archive).
Differential Revision: https://reviews.llvm.org/D66431
llvm-svn: 374442
The only condition that isecLoc becomes null is
Out::bufferStart == nullptr,
isec->getParent()->offset == 0, and
isec->outSecOff == 0.
We can check the first condition only once.
llvm-svn: 374332
isecLoc there can be null, but at the same time isec->getSize() may
be non-null. It is UB to offset a nullptr.The most straight-forward fix
here appears to perform casts+normal integral arithmetics.
FAIL: lld :: ELF/invalid/invalid-relocation-aarch64.test (1158 of 2217)
******************** TEST 'lld :: ELF/invalid/invalid-relocation-aarch64.test' FAILED ********************
Script:
--
: 'RUN: at line 2'; /b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm_build_ubsan/bin/yaml2obj /b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm-project/lld/test/ELF/invalid/invalid-relocation-aarch64.test -o /b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm_build_ubsan/tools/lld/test/ELF/invalid/Output/invalid-relocation-aarch64.test.tmp.o
: 'RUN: at line 3'; not /b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm_build_ubsan/bin/ld.lld /b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm_build_ubsan/tools/lld/test/ELF/invalid/Output/invalid-relocation-aarch64.test.tmp.o -o /dev/null 2>&1 | /b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm_build_ubsan/bin/FileCheck /b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm-project/lld/test/ELF/invalid/invalid-relocation-aarch64.test
--
Exit Code: 1
Command Output (stderr):
--
/b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm-project/lld/test/ELF/invalid/invalid-relocation-aarch64.test:4:10: error: CHECK: expected string not found in input
# CHECK: error: unknown relocation (1024) against symbol foo
^
<stdin>:1:1: note: scanning from here
/b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm-project/lld/ELF/Target.cpp💯41: runtime error: applying non-zero offset 24 to null pointer
^
<stdin>:1:118: note: possible intended match here
/b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm-project/lld/ELF/Target.cpp💯41: runtime error: applying non-zero offset 24 to null pointer
^
--
********************
Testing: 0.. 10.. 20.. 30.. 40.. 50.
FAIL: lld :: ELF/invalid/invalid-relocation-x64.test (1270 of 2217)
******************** TEST 'lld :: ELF/invalid/invalid-relocation-x64.test' FAILED ********************
Script:
--
: 'RUN: at line 2'; /b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm_build_ubsan/bin/yaml2obj /b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm-project/lld/test/ELF/invalid/invalid-relocation-x64.test -o /b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm_build_ubsan/tools/lld/test/ELF/invalid/Output/invalid-relocation-x64.test.tmp1.o
: 'RUN: at line 3'; echo ".global foo; foo:" > /b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm_build_ubsan/tools/lld/test/ELF/invalid/Output/invalid-relocation-x64.test.tmp2.s
: 'RUN: at line 4'; /b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm_build_ubsan/bin/llvm-mc /b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm_build_ubsan/tools/lld/test/ELF/invalid/Output/invalid-relocation-x64.test.tmp2.s -o /b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm_build_ubsan/tools/lld/test/ELF/invalid/Output/invalid-relocation-x64.test.tmp2.o -filetype=obj -triple x86_64-pc-linux
: 'RUN: at line 5'; not /b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm_build_ubsan/bin/ld.lld /b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm_build_ubsan/tools/lld/test/ELF/invalid/Output/invalid-relocation-x64.test.tmp1.o /b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm_build_ubsan/tools/lld/test/ELF/invalid/Output/invalid-relocation-x64.test.tmp2.o -o /dev/null 2>&1 | /b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm_build_ubsan/bin/FileCheck /b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm-project/lld/test/ELF/invalid/invalid-relocation-x64.test
--
Exit Code: 1
Command Output (stderr):
--
/b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm-project/lld/test/ELF/invalid/invalid-relocation-x64.test:6:10: error: CHECK: expected string not found in input
# CHECK: error: unknown relocation (152) against symbol foo
^
<stdin>:1:1: note: scanning from here
/b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm-project/lld/ELF/Target.cpp💯41: runtime error: applying non-zero offset 24 to null pointer
^
<stdin>:1:118: note: possible intended match here
/b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm-project/lld/ELF/Target.cpp💯41: runtime error: applying non-zero offset 24 to null pointer
^
--
********************
Testing: 0.. 10.. 20.. 30.. 40.. 50.. 60.. 70.. 80.. 90..
Testing Time: 20.73s
********************
Failing Tests (2):
lld :: ELF/invalid/invalid-relocation-aarch64.test
lld :: ELF/invalid/invalid-relocation-x64.test
llvm-svn: 374329
Similar to D67323, but for COFF. Many lld/COFF/ files already use
`namespace lld { namespace coff {`. Only a few need changing.
Reviewed By: ruiu
Differential Revision: https://reviews.llvm.org/D68772
llvm-svn: 374314
GNU ld looks for a number of other patterns than just lib<name>.dll.a
and lib<name>.a.
GNU ld does support linking directly against a DLL without using an
import library. If that's the only match for a -l argument, point out
that the user needs to use an import library, instead of leaving the
user with a puzzling message about the -l argument not being found
at all.
Also convert an existing case of fatal() into error().
Differential Revision: https://reviews.llvm.org/D68689
llvm-svn: 374292
This pattern matches the ELF implementation add if also useful as
part of a planned change where running `mark` more than once is needed.
Differential Revision: https://reviews.llvm.org/D68749
llvm-svn: 374275
David added the JamCRC implementation in r246590. More recently, Eugene
added a CRC-32 implementation in r357901, which falls back to zlib's
crc32 function if present.
These checksums are essentially the same, so having multiple
implementations seems unnecessary. This replaces the CRC-32
implementation with the simpler one from JamCRC, and implements the
JamCRC interface in terms of CRC-32 since this means it can use zlib's
implementation when available, saving a few bytes and potentially making
it faster.
JamCRC took an ArrayRef<char> argument, and CRC-32 took a StringRef.
This patch changes it to ArrayRef<uint8_t> which I think is the best
choice, and simplifies a few of the callers nicely.
Differential revision: https://reviews.llvm.org/D68570
llvm-svn: 374148
Fixes assert in addLinkerModuleCoffGroup() when using by-ordinal imports
only.
Patch by Stefan Schmidt.
Differential revision: https://reviews.llvm.org/D68352
llvm-svn: 374140
The combination of the two flags doesn't make sense. And other linkers
seem to just ignore --export-dynamic if --relocatable is given, but
we probably should report it as an error to let users know that is
an invalid combination.
Fixes https://bugs.llvm.org/show_bug.cgi?id=43552
Differential Revision: https://reviews.llvm.org/D68441
llvm-svn: 374022
This makes it clear `ELF/**/*.cpp` files define things in the `lld::elf`
namespace and simplifies `elf::foo` to `foo`.
Reviewed By: atanasyan, grimar, ruiu
Differential Revision: https://reviews.llvm.org/D68323
llvm-svn: 373885
This allows us to delete `using namespace llvm::support::endian` and
simplify D68323. This change adds runtime config->endianness check but
the overhead should be negligible.
Reviewed By: ruiu
Differential Revision: https://reviews.llvm.org/D68561
llvm-svn: 373884
Before, SecToClusters[*] was used to track the belonged cluster.
During a merge (From -> Into), every element of From has to be updated.
Use a union-find set to speed up this use case.
Also, replace `std::vector<int> Sections;` with a doubly-linked
pointers: int Next, Prev;
Reviewed By: Bigcheese
Differential Revision: https://reviews.llvm.org/D46228
llvm-svn: 373708
This patch adds /reproduce:<path> option to lld/COFF. This is an
lld-specific option, so we can name it freely. I chose /reproduce
over other names (e.g. /lldlinkrepro) for consistency with other lld
ports.
Differential Revision: https://reviews.llvm.org/D68381
llvm-svn: 373704
This reverts commit r371729 because /linkrepro option also exists
in Microsoft link.exe and their linker takes not a filename but a
directory name as an argument for /linkrepro.
Differential Revision: https://reviews.llvm.org/D68378
llvm-svn: 373703
Summary:
rL371826 rearranged some output from llvm-objdump for GNU objdump compatability, but there still seem to be some more.
I think this rearrangement is a little closer. Overview of the ordering which matches GNU objdump:
* Archive headers
* File headers
* Section headers
* Symbol table
* Dwarf debugging
* Relocations (if `--disassemble` is not used)
* Section contents
* Disassembly
Reviewers: jhenderson, justice_adams, grimar, ychen, espindola
Reviewed By: jhenderson
Subscribers: aprantl, emaste, arichardson, jrtc27, atanasyan, seiya, llvm-commits, MaskRay
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D68066
llvm-svn: 373671
Our .interp section is not a SyntheticSection. As a result, it terminates the
loop in removeUnusedSyntheticSections(). This has at least two consequences:
- The synthetic .bss and .bss.rel.ro sections are always present in
dynamically linked executables, even when they are not needed.
- The synthetic .ARM.exidx (and possibly other) sections are always present
in partitions other than the last one, even when not needed.
.ARM.exidx in particular is problematic because it assumes that its
list of code sections is non-empty in getLinkOrderDep(), which can
lead to a crash if the partition does not have any code sections.
Fix these problems by moving the creation of the .interp sections to the
top of createSyntheticSections(). While here, make the code a little less
error-prone by changing the add() lambdas to take a SyntheticSection instead
of an InputSectionBase.
Differential Revision: https://reviews.llvm.org/D68256
llvm-svn: 373347
Merging SHF_LINK_ORDER sections can affect semantics if the sh_link
fields point to different sections.
Specifically, for SHF_LINK_ORDER sections, the sh_link field acts as a reverse
dependency from the linked section, causing the SHF_LINK_ORDER section to
be included if the linked section is included. Merging sections with different
sh_link fields will cause the entire contents of the SHF_LINK_ORDER section
to be associated with a single (arbitrarily chosen) output section, whereas the
correct semantics are for the individual pieces of the SHF_LINK_ORDER section
to be associated with their linked output sections. As a result we can end up
incorrectly dropping SHF_LINK_ORDER section contents or including the wrong
section contents, depending on which linked sections were chosen.
Differential Revision: https://reviews.llvm.org/D68094
llvm-svn: 373255
For the following two cases, we currently suppress the symbols. This
patch emits them (compatible with GNU as).
* `test2_a = undef`: if `undef` is otherwise unused.
* `.hidden hidden`: if `hidden` is unused. This is the main point of the
patch, because omitting the symbol would cause a linker semantic
difference.
It causes a behavior change that is not compatible with GNU as:
.weakref foo1, bar1
When neither foo1 nor bar1 is used, we now emit bar1, which is arguably
more consistent.
Another change is that we will emit .TOC. for .TOC.@tocbase . For this
directive, suppressing .TOC. can be seen as a size optimization, but we
choose to drop it for simplicity and consistency.
llvm-svn: 373168
Instead of returning an optional, just return the input string if
demangling fails, as that's what all callers use anyway.
Differential Revision: https://reviews.llvm.org/D68015
llvm-svn: 373077
This avoids a few lines of boilerplate of dealing with C string
allocations.
Add a testcase for a case where demangling shouldn't happen.
Differential Revision: https://reviews.llvm.org/D68014
llvm-svn: 373076
Fixes PR43461 (regression caused by D67504)
The partition field of a SECTIONS-specified section is not set after
D67504. The 0 value affects findSection() which checks if the partition
field is 1.
So `Out::initArray = findSection(".init_array")` is null, and
DT_INIT_ARRAYSZ is not set.
Reviewed By: peter.smith
Differential Revision: https://reviews.llvm.org/D68087
llvm-svn: 372996
Summary:
The following patch avoids segfaulting if the section list is empty when writing a mach-o MH_OBJECT. I ran into this case from a more complicated example trying to dead_strip while using '-r' in lld.
I'm not sure if having empty sections is a legal mach-o, but it does seem that other llvm-binutils tools can ingest such a boring object with out issue. Would it be better to emit an error, emit a warning, or do nothing? It seems that adding a warning diagnostic might be helpful to users, as I did not expect to have a section-less object when the linker was done.
Reviewers: kledzik, ruiu
Subscribers: llvm-commits, jrm
Tags: #lld, #llvm
Differential Revision: https://reviews.llvm.org/D67735
llvm-svn: 372995
The R_MIPS_JALR relocation denotes jalr/jr instructions in position
independent code. Both these instructions take a target's address from
the $25 register. If offset to the target symbol fits into the 18-bits,
it's more efficient to replace jalr/jr by bal/b instructions.
Differential Revision: https://reviews.llvm.org/D68057
llvm-svn: 372951
D64906 allows PT_LOAD to have overlapping p_offset ranges. In the
default R RX RW RW layout + -z noseparate-code case, we do not tail pad
segments when transiting to another segment. This can save at most
3*maxPageSize bytes.
a) Before D64906, we tail pad R, RX and the first RW.
b) With -z separate-code, we tail pad R and RX, but not the first RW (RELRO).
In some cases, b) saves one file page. In some cases, b) wastes one
virtual memory page. The waste is a concern on Fuchsia. Because it uses
compressed binaries, it doesn't benefit from the saved file page.
This patch adds -z separate-loadable-segments to restore the behavior before
D64906. It can affect section addresses and can thus be used as a
debugging mechanism (see PR43214 and ld.so partition bug in
crbug.com/998712).
Reviewed By: jakehehrlich, ruiu
Differential Revision: https://reviews.llvm.org/D67481
llvm-svn: 372807
Summary:
When support for ThinLTO was first added to lld, the options that
control it were prefixed with --plugin-opt= for compatibility with
an existing implementation as a linker plugin. This change enables
shorter versions of the options to be used, as follows:
New Existing
-thinlto-emit-imports-files --plugin-opt=thinlto-emit-imports-files
-thinlto-index-only --plugin-opt=thinlto-index-only
-thinlto-index-only= --plugin-opt=thinlto-index-only=
-thinlto-object-suffix-replace= --plugin-opt=thinlto-object-suffix-replace=
-thinlto-prefix-replace= --plugin-opt=thinlto-prefix-replace=
-lto-obj-path= --plugin-opt=obj-path=
The options with the --plugin-opt= prefix have been retained as aliases
for the shorter variants so that they continue to be accepted.
Reviewers: tejohnson, ruiu, espindola
Reviewed By: ruiu
Subscribers: emaste, arichardson, MaskRay, steven_wu, dexonsmith, arphaman, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D67782
llvm-svn: 372798
When /DISCARD/ is used on an input section, that input section may have
a .ARM.exidx metadata section that depends on it. As the discard handling
comes after the .ARM.exidx synthetic section is created we need to make
sure that we account for the case where the .ARM.exidx output section
should be removed because there are no more live input sections.
Differential Revision: https://reviews.llvm.org/D67848
llvm-svn: 372781
D67504 removed uses of `assigned` from OutputSection::addSection, which
makes `assigned` purely used in processSectionCommands() and its
callees. By replacing its references with `parent`, we can remove
`assigned`.
Reviewed By: grimar
Differential Revision: https://reviews.llvm.org/D67531
llvm-svn: 372735
Fixes PR38748
mergeSections() calls getOutputSectionName() to get output section
names. Two MergeInputSections may be merged even if they are made
different by SECTIONS commands.
This patch moves mergeSections() after processSectionCommands() and
addOrphanSections() to fix the issue. The new pass is renamed to
OutputSection::finalizeInputSections().
processSectionCommands() and addorphanSections() are changed to add
sections to InputSectionDescription::sectionBases.
finalizeInputSections() merges MergeInputSections and migrates
`sectionBases` to `sections`.
For the -r case, we drop an optimization that tries keeping sh_entsize
non-zero. This is for the simplicity of addOrphanSections(). The
updated merge-entsize2.s reflects the change.
Reviewed By: grimar
Differential Revision: https://reviews.llvm.org/D67504
llvm-svn: 372734
In case of linking binary blobs which do not have any ELF headers, we can
deduce MIPS ABI ELF header flags from an `emulation` option.
Patch by Kyle Evans.
llvm-svn: 372513
Summary:
If st_link(A)=B, and A has the SHF_LINK_ORDER flag, we may dereference
a null pointer if B is garbage collected (PR43147):
1. In Wrter.cpp:compareByFilePosition, `aOut->sectionIndex` or `bOut->sectionIndex`
2. In OutputSections::finalize, `d->getParent()->sectionIndex`
Simply error and bail out to avoid null pointer dereferences. ld.bfd has
a similar error:
sh_link of section `.bar' points to discarded section `.foo0' of `a.o'
ld.bfd is more permissive in that it just checks whether the linked-to
section of the first input section is discarded. This is likely because
it sets sh_link of the output section according to the first input
section.
Reviewed By: grimar
Differential Revision: https://reviews.llvm.org/D67761
llvm-svn: 372400
copy-rel-abs.s uses llvm-objdump to generate output that's then run
through FileCheck. llvm-objdump prints the file path at the top of the
file, which means that any build path that contains 'zed' will get
false-matched. Ensure that 'zed' is only matched after the 'SYMBOL
TABLE:' output, preventing this from failing if your build directory is
~/build/sanitized-xxx/, or similar.
llvm-svn: 372351
Summary:
This was always the intended behavior, but had not been
implemented. This ordering is important for Emscripten when generating
.mem files while compiling to JS, since only zeros at the end of
initialized memory can be dropped.
Fixes https://github.com/emscripten-core/emscripten/issues/8999
Reviewers: sbc100
Subscribers: dschuff, jgravelle-google, aheejin, sunfish, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D67736
llvm-svn: 372284
D67284 introduced ARMErrataFix.cpp which was derived from
AArch64ErrataFix.cpp. There were some useful refactoring changes made to
ARMErrataFix.cpp made as part of the review. This change applies the
relevant changes back to AArch64ErrataFix.cpp.
Main changes are:
- Old style variable names in comments like IS, are now new style isec.
- Simplify init() collection of mappingSymbols to always start with a code
mapping symbol.
- Simplify logic in mergeCmp().
- Fix one 80 column overflow caused by IS -> isec transformation.
Differential Revision: https://reviews.llvm.org/D67622
llvm-svn: 372094
Provide a missing initializer to get rid of warning provoking buildbot
failures.
error: missing field 'rel' initializer
[-Werror,-Wmissing-field-initializers]
llvm-svn: 371970
The --fix-cortex-a8 option implements a linker workaround for the
coretex-a8 erratum 657417. A summary of the erratum conditions is:
- A 32-bit Thumb-2 branch instruction B.w, Bcc.w, BL, BLX spans two
4KiB regions.
- The destination of the branch is to the first 4KiB region.
- The instruction before the branch is a 32-bit Thumb-2 non-branch
instruction.
The linker fix is to redirect the branch to a patch not in the first
4KiB region. The patch forwards the branch on to its target.
The cortex-a8, is an old CPU, with the first implementation of this
workaround in ld.bfd appearing in 2009. The cortex-a8 has been used in
early Android Phones and there are some critical applications that still
need to run on a cortex-a8 that have the erratum. The patch is applied
roughly 10 times on LLD and 20 on Clang when they are built with
--fix-cortex-a8 on an Arm system.
The formal erratum description is avaliable in the ARM Core Cortex-A8
(AT400/AT401) Errata Notice document. This is available from Arm on
request but it seems to be findable via a web search.
Differential Revision: https://reviews.llvm.org/D67284
llvm-svn: 371965
If there is no readonly section, we map:
* The ELF header at imageBase+maxPageSize
* Program headers at imageBase+maxPageSize+sizeof(Ehdr)
* The first section .text at imageBase+maxPageSize+sizeof(Ehdr)+sizeof(program headers)
Due to the interaction between Writer<ELFT>::fixSectionAlignments and
LinkerScript::allocateHeaders,
`alignDown(p_vaddr(R PT_LOAD)) = alignDown(p_vaddr(RX PT_LOAD))`.
The RX PT_LOAD will override the R PT_LOAD at runtime, which is not ideal:
```
// PHDR at 0x401034, should be 0x400034
PHDR 0x000034 0x00401034 0x00401034 0x000a0 0x000a0 R 0x4
// R PT_LOAD contains just Ehdr and program headers.
// At 0x401000, should be 0x400000
LOAD 0x000000 0x00401000 0x00401000 0x000d4 0x000d4 R 0x1000
LOAD 0x0000d4 0x004010d4 0x004010d4 0x00001 0x00001 R E 0x1000
```
* createPhdrs allocates the headers to the R PT_LOAD.
* fixSectionAlignments assigns `imageBase+maxPageSize+sizeof(Ehdr)+sizeof(program headers)` (formula: `alignTo(dot, maxPageSize) + dot % config->maxPageSize`) to addrExpr of .text
* allocateHeaders computes the minimum address among SHF_ALLOC sections, i.e. addr(.text)
* allocateHeaders sets address of ELF header to `addr(.text)-sizeof(Ehdr)-sizeof(program headers) = imageBase+maxPageSize`
The main observation is that when the SECTIONS command is not used, we
don't have to call allocateHeaders. This requires an assumption that
the presence of PT_PHDR and addresses of headers can be decided
regardless of address information.
This may seem natural because dot is not manipulated by a linker script.
The other thing is that we have to drop the special rule for -T<section>
in `getInitialDot`. If -Ttext is smaller than the image base, the headers
will not be allocated with the old behavior (allocateHeaders is called)
but always allocated with the new behavior.
The behavior change is not a problem. Whether and where headers are
allocated can vary among linkers, or ld.bfd across different versions
(--enable-separate-code or not). It is thus advised to use a linker
script with the PHDRS command to have a consistent behavior across
linkers. If PT_PHDR is needed, an explicit --image-base can be a simpler
alternative.
Differential Revision: https://reviews.llvm.org/D67325
llvm-svn: 371957
This is useful for enforcing that builds are independent of the
environment; it can be used when all system library paths are added
via /libpath: already. It's similar ot cl.exe's /X flag.
Since it should also affect %LINK% (the other caller of
`Process::GetEnv` in lld/COFF), the early-option-parsing needs
to move around a bit. The options are:
- Add a manual loop over the argv ArrayRef and look for "/lldignoreenv".
This repeats the name of the flag in both Options.td and in
DriverUtils.cpp.
- Add yet another table.ParseArgs() call just for /lldignoreenv before
adding %LINK%.
- Use the existing early ParseArgs() that's there for --rsp-quoting and use
it for /lldignoreenv for %LINK% as well. This means --rsp-quoting
and /lldignoreenv can't be passed via %LINK%.
I went with the third approach.
Differential Revision: https://reviews.llvm.org/D67456
llvm-svn: 371852
from thin archives.
Currently lld adds the archive name to MemoryBufferRef identifiers in order to
ensure they are unique. For thin archives, since the file name is already unique and we
want to keep the original path to the file, don't add the archive name.
Differential Revision: https://reviews.llvm.org/D67295
llvm-svn: 371778
ICF is performed after EhInputSections and MergeInputSections were
eliminated from inputSections. Every element of inputSections is an
InputSection.
llvm-svn: 371744
This makes lld-link behave like ld.lld. I don't see a reason for
the two drivers to have different behavior here.
While here, also make lld-link add a version.txt to the tar, like
ld.lld does.
Differential Revision: https://reviews.llvm.org/D67461
llvm-svn: 371729
-z undefs is the inverse of -z defs. It allows unresolved references
from object files. This can be used to cancel --no-undefined or -z defs.
Reviewed By: ruiu
Differential Revision: https://reviews.llvm.org/D67479
llvm-svn: 371715
Martin Storsjo