Summary:
This uses one less word on 64-bit platforms, so should be a strict
improvement. This change also lets us get rid of llvm::CachedHash.
Reviewers: rafael, timshen
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D25646
llvm-svn: 284502
Both gold and ld accepts integers instead of named constants
for PHDRS.
Patch adds support for that.
Differential revision: https://reviews.llvm.org/D25549
llvm-svn: 284470
Summary:
Reclaiming the name 'CachedHashString' will let us add a type with that
name that owns its value.
Reviewers: timshen
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D25644
llvm-svn: 284434
This is not particularly efficient, but does avoid exposing Comdat*
out of LTO.h.
I will send a patch for review with a more efficient interface that
should map nicely to a bitcode symbol table.
llvm-svn: 284413
The R_ARM_TARGET2 relocation is used in ARM exception tables to encode
a data dependency that will only be dereferenced by code in the
run-time support library. In a similar way to R_ARM_TARGET1 the
handling of the relocation is target specific, it maps to one of
R_ARM_ABS32, R_ARM_REL32 or R_ARM_GOT_PREL. The choice depends on the
run-time library. R_ARM_GOT_PREL is used for linux and BSD,
R_ARM_ABS32 and R_ARM_REL32 are used for bare-metal.
The command line option --target2=<target> can be used to select the
relocation used for R_ARM_TARGET2. The default is R_ARM_GOT_PREL.
Differential revision: https://reviews.llvm.org/D25684
llvm-svn: 284404
skip() and skip(StringRef) were overloaded functions that
have different semantics. This patch rename one of the functions
to avoid function overloading.
llvm-svn: 284396
In continue of D25555, this patch fixes possible crash when
we have multiple SHT_MIPS_REGINFO or SHT_MIPS_ABIFLAGS sections.
yaml2obj was used to produce such objects.
Differential revision: https://reviews.llvm.org/D25609
llvm-svn: 284376
It was requested on review for https://reviews.llvm.org/D25090 to add testcase in lld.
Spec says (http://www.sco.com/developers/gabi/1998-04-29/ch4.eheader.html) :
e_shnum
This member holds the number of entries in the section header table.
Thus the product of e_shentsize and e_shnum gives the section header table's size in bytes.
If a file has no section header table, e_shnum holds the value zero.
In case revealed, broken input did not contain zero in this field.
LLD then could crash when proccessed sections (returned array has incorrect size):
template <class ELFT> void SharedFile<ELFT>::parseSoName() {
...
for (const Elf_Shdr &Sec : Obj.sections()) {
...
llvm-svn: 284375
Most functions that return StringRef should check their return values,
so I'm planning on marking StringRef [[nodiscard]]. This requires
splitting up functions like next() that are sometimes just used for
side effects.
llvm-svn: 284363
While the toStringRef API almost certainly ends up populating the
SmallString here, the correct way to use this API is to use the return
value.
llvm-svn: 284361
This is 30646.
PT_OPENBSD_RANDOMIZE
The array element specifies the location and size of a part of the memory image of the program that must be filled with random data before any code in the object is executed. The memory region specified by a segment of this type may overlap the region specified by a PT_GNU_RELRO segment, in which case the intersection will be filled with random data before being marked read-only.
Reference links:
http://man.openbsd.org/OpenBSD-current/man5/elf.5c494713c45
Differential revision: https://reviews.llvm.org/D25469
llvm-svn: 284234
Issue was revealed by AFl and I was able to generate such object using yaml2obj.
When object has more than one SHT_MIPS_OPTIONS,
each except the last one is destroyed after placing into Sections array.
Sections array contains dead pointers finally. LLD may crash then.
Differential revision: https://reviews.llvm.org/D25555
llvm-svn: 284227
-z wxneeded creates a PHDR PT_OPENBSD_WXNEEDED.
PT_OPENBSD_WXNEEDED
The array element specifies that a process executing this file may need to be able to map or protect memory regions as simultaneously executable and writable. If the system is unable or unwilling to permit that for this executable then it may fail immediately. This segment type is meaningful only for executable files and is ignored in other objects.
http://man.openbsd.org/OpenBSD-current/man5/elf.5
Differential revision: https://reviews.llvm.org/D25472
llvm-svn: 284226
Previously we would fail to synthesise a __start_ or __stop_ symbol if
there existed a definition in a DSO. Instead, we would try to link against
the DSO definition. This became possible after D23552 when linking against
lld-produced DSOs but could in principle also occur when linking against
DSOs produced by other linkers.
Not only does it seem more likely that a user would expect the resolved
definition to be local to the executable, but if a __start_ or __stop_
symbol was synthesised by the linker, it is effectively impossible to link
against correctly from a non-PIC executable in a read-only section. Neither
a PLT nor a copy relocation would give us the right semantics here. The only
way the link could succeed is if the executable provided its own synthetic
definition of the symbol.
The fix is to also synthesise the definition if the only definition comes
from a DSO. Since this is what the addOptionalSynthetic function does,
switch to using that function.
Fixes PR30680.
Differential Revision: https://reviews.llvm.org/D25544
llvm-svn: 284168
Previously, we supported only SHF_COMPRESSED sections because it's
new and it's the ELF standard. But there are object files compressed
in the GNU style out there, so we had to support it.
Sections compressed in the GNU style start with ".zdebug_" and
contain different headers than the ELF standard's one. In this
patch, getRawCompressedData is responsible to handle it.
A tricky thing about GNU-style compressed sections is that we have
to rename them when creating output sections. ".zdebug_" prefix
implies the section is compressed. We need to rename ".zdebug_"
".debug" because our output sections are not compressed.
We do that in this patch.
llvm-svn: 284068
r283984 introduced a problem of too many warning messages being shown
when -ffunction-sections and -fdata-sections were used in conjunction
with --gc-sections linker flag and debugging information present. This
happens because lot of relocations from .debug_line section may become
invalid in such case. The newer fix doesn't show any warning message but
zeroes OutSec pointer in createInputSectionList() to avoid crash, when
relocations are written
llvm-svn: 284010
Following the lazy reference might bring in an object file that depends
on bitcode files that weren't part of the LTO step.
Differential Revision: https://reviews.llvm.org/D25461
llvm-svn: 283989
I don't really understand why we get a larger .rodata section only
on this bot. I guess it may be picking up a library which contains
a .rodata. I removed the specific values since their values are not
important for this test case.
llvm-svn: 283931
This part was splitted from D25016.
When sh_info value was set in the way that non-local symbol was treated as local, lld
was asserting, patch fixes that.
Differential revision: https://reviews.llvm.org/D25371
llvm-svn: 283859
Before the default was whatever number hardware_concurrency() returned.
Users can specify the number of threads via --lto-jobs=X option.
llvm-svn: 283787
Sometimes the very first PT_LOAD segment, created by lld, can be empty.
This happens when (all conditions met):
- Linker script is used
- First section in ELF image is not RO
- Not enough space for program headers.
Differential revision: https://reviews.llvm.org/D25330
llvm-svn: 283760
With fix: commit changes from InputFiles.cpp too.
Original commit message:
We have following code in lld, that truncates the alignment value to 32 bit. Big alignment in this case
may give result 0 and crash later.
template <class ELFT>
CommonInputSection<ELFT>::CommonInputSection(std::vector<DefinedCommon *> Syms)
: InputSection<ELFT>(nullptr, &Hdr, "") {
....
for (DefinedCommon *Sym : Syms) {
this->Alignment = std::max<uintX_t>(this->Alignment, Sym->Alignment);
...
}
}
Patch fixes the issue.
Differential revision: https://reviews.llvm.org/D25235
llvm-svn: 283738
.ARM.exidx sections have a reverse dependency on the section they have
a SHF_LINK_ORDER dependency on. In other words a .ARM.exidx section is
live only if the executable section it describes is live. We implement
this with a reverse dependency field in InputSection.
Adding the dependency to InputSection is the simplest implementation
but it could be moved out to a separate map if it were found to decrease
performance for non ARM targets.
Differential revision: https://reviews.llvm.org/D25234
llvm-svn: 283734
We have following code in lld, that truncates the alignment value to 32 bit. Big alignment in this case
may give result 0 and crash later.
template <class ELFT>
CommonInputSection<ELFT>::CommonInputSection(std::vector<DefinedCommon *> Syms)
: InputSection<ELFT>(nullptr, &Hdr, "") {
....
for (DefinedCommon *Sym : Syms) {
this->Alignment = std::max<uintX_t>(this->Alignment, Sym->Alignment);
...
}
}
Patch fixes the issue.
Differential revision: https://reviews.llvm.org/D25235
llvm-svn: 283733
Absolute local symbols with name staring from ".L" were reason of crash.
The same could happen when using some broken inputs found by AFL.
Patch fixes that.
Differential revision: https://reviews.llvm.org/D25365
llvm-svn: 283731
Justin Lebar