The Thumb BL and BLX instructions on older Arm Architectures such as v5 and
v6 have a constrained encoding J1 and J2 must equal 1, later Architectures
relaxed this restriction allowing J1 and J2 to be used to calculate a larger
immediate.
This patch adds support for the old encoding, it is used when the build
attributes for the input objects only contain older architectures.
Differential Revision: https://reviews.llvm.org/D50076
llvm-svn: 340159
LEB compression breaks debug info so we don't want to enable
it by default, even at high optimization levels.
Differential Revision: https://reviews.llvm.org/D50729
llvm-svn: 340073
Summary:
This prefix was added in r333421, and it changed our dumper output to
say things like "CVRegEAX" instead of just "EAX". That's a functional
change that I'd rather avoid.
I tested GCC, Clang, and MSVC, and all of them support #pragma
push_macro. They don't issue warnings whem the macro is not defined
either.
I don't have a Mac so I can't test the real termios.h header, but I
looked at the termios.h sources online and looked for other conflicts.
I saw only the CR* macros, so those are the ones we work around.
Reviewers: zturner, JDevlieghere
Subscribers: hiraditya, llvm-commits
Differential Revision: https://reviews.llvm.org/D50851
llvm-svn: 339907
Summary: This makes it conform to what the comment says. Otherwise when getErrPlace() is called afterwards, cast<InputSection>(D) will cause incompatible cast as MergeInputSection is not a subclass of InputSection.
Reviewers: ruiu, grimar, espindola, pcc
Reviewed By: grimar
Subscribers: emaste, arichardson, llvm-commits
Differential Revision: https://reviews.llvm.org/D50742
llvm-svn: 339904
This patch solves 2 problems:
1) It adds a test to check the line below:
https://github.com/llvm-mirror/lld/blob/master/ELF/InputFiles.cpp#L334
Test case contains SHT_GROUP section with a broken (0xFF) flag.
2) The patch fixes the case when we silently accepted such broken groups
in the case when there were no other objects with the same group signature.
llvm-svn: 339765
We have a dead piece of code there which is impossible to trigger
using regular objects I believe.
Patch removes it and adds a test case showing how this condition
can be triggered with use of a broken object and crash the linker.
llvm-svn: 339680
The code involved was simply dead. `IgnoreAll` value is used in
`maybeReportUndefined` only which is never called for -r.
And at the same time `IgnoreAll` was set only for -r.
llvm-svn: 339672
That piece of code is really very old and "protected"
from TLS relocations against symbol in non-allocatable sections.
It is useless because normally non-alloc sections have relocations
with allocatable targets, but not the reverse.
And so the code was simply dead.
llvm-svn: 339553
It turns out that postThunkContents() is only used for
sorting symbols in .symtab.
Though we can instead move the logic to SymbolTableBaseSection::finalizeContents(),
postpone calling it and then get rid of postThunkContents completely.
Differential revision: https://reviews.llvm.org/D49547
llvm-svn: 339413
We have a crash issue when handling the empty -defsym.
For parsing this option we are using ScriptParser class which is used
generally for reading the linker script. For empty defsym case, we
pass the empty memory buffer and crash in the place removed in https://reviews.llvm.org/rL336436.
But reverting of the above patch would not help here (we would still crash but a bit later). And
even after fixing the crash we would report something like
"lld.exe: error: -defsym:1: unexpected EOF"
It is probably not the appropriate message because mentions EOF.
I think the issue should be handled on a higher level like this patch does.
So we do not want to pass the empty memory buffer first of all I believe.
Differential revision: https://reviews.llvm.org/D50498
llvm-svn: 339412
Patch by PkmX.
This patch makes lld recognize RISC-V target and implements basic
relocation for RV32/RV64 (and RVC). This should be necessary for static
linking ELF applications.
The ABI documentation for RISC-V can be found at:
https://github.com/riscv/riscv-elf-psabi-doc/blob/master/riscv-elf.md.
Note that the documentation is far from complete so we had to figure out
some details from bfd.
The patch should be pretty straightforward. Some highlights:
- A new relocation Expr R_RISCV_PC_INDIRECT is added. This is needed as
the low part of a PC-relative relocation is linked to the corresponding
high part (auipc), see:
https://github.com/riscv/riscv-elf-psabi-doc/blob/master/riscv-elf.md#pc-relative-symbol-addresses
- LLVM's MC support for RISC-V is very incomplete (we are working on
this), so tests are given in objectyaml format with the original
assembly included in the comments. Once we have complete support for
RISC-V in MC, we can switch to llvm-as/llvm-objdump.
- We don't support linker relaxation for now as it requires greater
changes to lld that is beyond the scope of this patch. Once this is
accepted we can start to work on adding relaxation to lld.
Differential Revision: https://reviews.llvm.org/D39322
llvm-svn: 339364
link.exe ignores REL32 relocations on 32-bit x86, as well as relocations
against non-function symbols such as labels. This makes lld do the same.
Differential Revision: https://reviews.llvm.org/D50430
llvm-svn: 339345
This is a larger patch. This relocation has irregular immediate
masks that require a lookup to find the correct mask.
Differential Revision: https://reviews.llvm.org/D50450
llvm-svn: 339332
Adding all libcall symbols to the link can have undesired consequences.
For example, the libgcc implementation of __sync_val_compare_and_swap_8
on 32-bit ARM pulls in an .init_array entry that aborts the program if
the Linux kernel does not support 64-bit atomics, which would prevent
the program from running even if it does not use 64-bit atomics.
This change makes it so that we only add libcall symbols to the
link before LTO if we have to, i.e. if the symbol's definition is in
bitcode. Any other required libcall symbols will be added to the link
after LTO when we add the LTO object file to the link.
Differential Revision: https://reviews.llvm.org/D50475
llvm-svn: 339301
If /subsystem:windows is passed, link.exe only looks for WinMain and wWinMain,
and if /subsystem:console is passed it only looks for main and wmain. lld-link
used to look for all 4 in both cases. This patch makes lld-link match
link.exe's behavior.
This requires that the subsystem is known by the time findDefaultEntry() gets
called. findDefaultEntry() is called before the main link loop, so that the
loop can mark the entry point as undefined. That means inferSubsystem() has to
be called above the main loop as well. This in turn means /subsystem: from
.drectve sections only has an effect on entry point inference for obj files
passed to lld-link directly (and not in obj files found later in .lib files).
link.exe seems to ignore /subsystem: for obj files from lib files completely
(while in lld it's ignored only for entry point detection but it still
overrides /subsystem: flags passed on the command line for the value that gets
written in the output file).
Also, if the subsytem isn't needed (e.g. when only writing a /def: lib file and
not writing a coff file), link.exe doesn't complain if the subsystem isn't
known, so both subsystem and entry point handling should be below the early
return lld has for that case.
Fixes PR36523.
https://reviews.llvm.org/D50316
llvm-svn: 339165
Summary: To be consistent with other files where only SignExtend64 is used.
Reviewers: ruiu, espindola
Subscribers: emaste, arichardson, llvm-commits
Differential Revision: https://reviews.llvm.org/D50366
llvm-svn: 339083
Summary:
The issue with the python path is that the path to python on Windows can contain spaces. To make the tests always work, the path to python needs to be surrounded by quotes.
This is a companion change to: https://reviews.llvm.org/D50206
Reviewers: asmith, zturner, espindola
Subscribers: emaste, sbc100, arichardson, aheejin, steven_wu, dexonsmith, llvm-commits
Differential Revision: https://reviews.llvm.org/D50282
llvm-svn: 339075
GNU ld's manual says that TARGET(foo) is basically an alias for
`--format foo` where foo is a BFD target name such as elf64-x86-64.
Unlike GNU linkers, lld doesn't allow arbitrary BFD target name for
--format. We accept only "default", "elf" or "binary". This makes
situation a bit tricky because we can't simply make TARGET an alias for
--target.
A quick code search revealed that the usage number of TARGET is very
small, and the only meaningful usage is to switch to the binary mode.
Thus, in this patch, we handle only TARGET(elf.*) and TARGET(binary).
Differential Revision: https://reviews.llvm.org/D48153
llvm-svn: 339060
MinGW configurations don't use associative comdats, as GNU ld doesn't
support that. Instead they produce normal comdats named .text$sym,
.xdata$sym and .pdata$sym.
GNU ld doesn't discard any comdats starting with .xdata or .pdata,
even if --gc-sections is used (while it does discard other unreferenced
comdats), regardless of what symbol name is used after the $ separator.
For LLD, treat any such comdat as implicitly associative to the base
symbol. This requires maintaining a map from symbol name to section
number, but that is only maintained when the MinGW flag has been
enabled.
Differential Revision: https://reviews.llvm.org/D49700
llvm-svn: 339058
It's not an error if a common symbol (uninitialized data, with alignment
specified via the aligncomm directive) is replaced with a regular
one with initialized data (with alignment specified via the section
chunk).
Differential Revision: https://reviews.llvm.org/D50268
llvm-svn: 339049
--export now implies --undefined
This is really a requirement from emscripten but I think it
makes sense in general too.
Differential Revision: https://reviews.llvm.org/D50287
llvm-svn: 339047
During copy relocation of a variable defined in a DSO, if a TLS variable in that DSO happens to have the same st_value, it would also be copied. This was unnecessary because the addresses of TLS variables are relative to TLS segment. They don't interfere with non-TLS variables.
This copying behavior can be harmful in the following scenario:
For function-scope thread-local variables with non-trivial constructors,
they have guard variables. In the case of x86_64 general-dynamic model:
template <int N>
void foo() {
thread_local std::string a;
}
GOT[n] R_X86_64_DTPMOD64 guard variable for a
GOT[n+1] R_X86_64_DTPOFF64 guard variable for a
GOT[n+2] R_X86_64_DTPMOD64 a
GOT[n+3] R_X86_64_DTPOFF64 a
a and its guard variable are both represented as TLS variables, which
should be within the same module. If one is copy relocated to the main
module while the other is not, their module ID will mismatch and can
cause access without prior construction.
Reviewers: ruiu, espindola
Subscribers: emaste, arichardson, llvm-commits
Differential Revision: https://reviews.llvm.org/D50289
llvm-svn: 339042
Some parts of the code changed are a bit old. I found traces in 2016.
Initiall commits has test cases and perhaps reasonable comments.
For example, we had segfaults earlier and had the code to fix them.
Now, in 2018, I think it is excessive to have these parts, because
we do not have segfaults and our code was changed a lot (softly saying).
I reviewed the current sources and I think that at this point of the
execution flow, we should never face with
the conditions checked and so I removing them in this patch.
This helps to cleanup the code.
llvm-svn: 339003
Add a test for the R_ARM_THM_JUMP11 relocation to an undefined symbol. We
have to use yaml2obj as llvm-mc relaxes the narrow branch to a b.w which
uses the R_ARM_THM_JUMP24 relocation instead.
Differential Revision: https://reviews.llvm.org/D50234
llvm-svn: 338999
Summary:
Optimization remark format is slightly changed by LLVM patch D49412.
One test is fixed with expected messages changed.
Frankly speaking I have not tested this change yet. I will test when manage to setup the project.
Reviewers: xbolva00, espindola
Reviewed By: xbolva00
Subscribers: emaste, arichardson, steven_wu, dexonsmith
Differential Revision: https://reviews.llvm.org/D50242
llvm-svn: 338970
This simplifies the code a bit.
It is NFC except that it removes early exit for Count == 0
which does not seem to be useful (we have no such tests either).
Differential revision: https://reviews.llvm.org/D49136
llvm-svn: 338953
This matches the behavior of the ELF linker where -u/--undefined
means symbols will get pulled in from archives but won't result
in link error if they are missing.
Also, don't actually great symbol table entries for the undefined
symbols, again matching more closely the ELF linker.
This also results in simplification of the code.
Differential Revision: https://reviews.llvm.org/D50279
llvm-svn: 338938
LinkerDriver::inferSubsystem() used to do Symtab->findUnderscore("WinMain"),
but WinMain is stdcall in 32-bit and is hence is called _WinMain@16. Instead,
Symtab->findMangle(mangle("WinMain")) needs to be called.
But since LinkerDriver::inferSubsystem() and LinkerDriver::findDefaultEntry()
both need to call this, introduce a common helper function for this and call it
from both places. (Also call it for "main" for consistency, even though
findUnderscore() is enough for main since that's __cdecl on 32-bit).
This also exposed a bug for /nodefaultlib entrypoint inference: The code here
called findMangle(Sym) instead of findMangle(mangle(Sym)), again doing the
wrong thing on 32-bit. Fix that too.
While here, make Driver::mangle() a static free function.
https://reviews.llvm.org/D50184
llvm-svn: 338877
In according to the comment, undefined symbol should never reach there.
So, should be able to remove the check. I am assuming this is NFC.
llvm-svn: 338723
It does not seem that this code is alive.
I seems was needed previously but we fixed it.
If it is still needed, it needs new tests,
but for now I do not know how to trigger it,
and so I removed it.
llvm-svn: 338713
Some lit tests that call llvm-ar use the 'r' flag. If the target archive
already exists and is in a corrupt state, this can cause the test to fail. We
have added 'rm -f' calls before the llvm-ar calls to increase the
robustness of the tests.
Differential revision: https://reviews.llvm.org/D49184
llvm-svn: 338705
Patch by Konstantin Schwarz!
If more than a single output section is added to a PT_LOAD header,
only the first section should set the LMAOffset of the segment.
Otherwise, we get a load-address overlap error
Differential revision: https://reviews.llvm.org/D50133
llvm-svn: 338697
Patch by Konstantin Schwarz!
If both the MemRegion and LMARegion are set for an output section in
a linker script, we should only increase the LMARegion if it is
different from the MemRegion. Otherwise, we reserve the memory twice.
Differential revision: https://reviews.llvm.org/D50065
llvm-svn: 338684
Patch by Konstantin Schwarz!
The condition to create a new phdr must also check the usage of "AT>"
linker script command, and create a new PT_LOAD header if a new LMARegion is used.
This fixes PR38307
Differential revision: https://reviews.llvm.org/D50052
llvm-svn: 338679
This was useful for LTO bringup in lld-link while lld couldn't write PDBs. Now
that it can, this should no longer be needed. Hopefully the flag is obscure
enough and recent enough, that nobody uses it – but if somebody should use it,
they should be able to just stop passing it and things should continue to work.
https://reviews.llvm.org/D50139
llvm-svn: 338615
This reverts commit r338596 because it contained a functional change.
The patch accidentally replaced StringRef::startswith with the exact match.
llvm-svn: 338600
Some test setups run tests in a read-only path, which means that opening the
default output path (a.out) for write will fail. This change adds appropriate -o
flags so the tests will not fail spuriously.
llvm-svn: 338440
If any of our inputs are bitcode files, the LTO code generator may create
references to certain library functions that might not be explicit in the
bitcode file's symbol table. If any of those library functions are defined
in a bitcode file in an archive member, we need to arrange to use LTO to
compile those archive members by adding them to the link beforehand.
Differential Revision: https://reviews.llvm.org/D50017
llvm-svn: 338434
This patch does the same thing as r338153 for COFF.
Note that this patch affects only the order of log messages.
The output file is already deterministic.
Differential Revision: https://reviews.llvm.org/D50023
llvm-svn: 338406
The Tag_ABI_VFP_args build attribute controls the procedure call standard
used for floating point parameters on ARM. The values are:
0 - Base AAPCS (FP Parameters passed in Core (Integer) registers
1 - VFP AAPCS (FP Parameters passed in FP registers)
2 - Toolchain specific (Neither Base or VFP)
3 - Compatible with all (No use of floating point parameters)
If the Tag_ABI_VFP_args build attribute is missing it has an implicit value
of 0.
We use the attribute in two ways:
- Detect a clash in calling convention between Base, VFP and Toolchain.
we follow ld.bfd's lead and do not error if there is a clash between an
implicit Base AAPCS caused by a missing attribute. Many projects
including the hard-float (VFP AAPCS) version of glibc contain assembler
files that do not use floating point but do not have Tag_ABI_VFP_args.
- Set the EF_ARM_ABI_FLOAT_SOFT or EF_ARM_ABI_FLOAT_HARD ELF header flag
for Base or VFP AAPCS respectively. This flag is used by some ELF
loaders.
References:
- Addenda to, and Errata in, the ABI for the ARM Architecture for
Tag_ABI_VFP_args
- Elf for the ARM Architecture for ELF header flags
Fixes PR36009
Differential Revision: https://reviews.llvm.org/D49993
llvm-svn: 338377
Summary:
This adds an LLD flag to mark executable LOAD segments execute-only for AArch64 targets.
In AArch64 the expectation is that code is execute-only compatible, so this just adds a linker option to enforce this.
Patch by: ivanlozano (Ivan Lozano)
Reviewers: srhines, echristo, peter.smith, eugenis, javed.absar, espindola, ruiu
Reviewed By: ruiu
Subscribers: dokyungs, emaste, arichardson, kristof.beyls, llvm-commits
Differential Revision: https://reviews.llvm.org/D49456
llvm-svn: 338271
The xxHash64 function has been made unsigned-char-independent, so
we can reland this change now.
Original commit message:
> The icf-safe.s test currently fails on 32-bit platforms because it uses
> the --print-icf-sections flag and depends on the output appearing in
> a specific order. However, this flag causes the output to depend on
> the order of the sections in the Sections array, which depends on the
> hash values returned from hash_combine, which happen to be different
> for that test between 32-bit and 64-bit platforms.
>
> This change makes the output deterministic by using xxHash64 instead of
> hash_combine.
Differential Revision: https://reviews.llvm.org/D49877
llvm-svn: 338153
The icf-safe.s test currently fails on 32-bit platforms because it uses
the --print-icf-sections flag and depends on the output appearing in
a specific order. However, this flag causes the output to depend on
the order of the sections in the Sections array, which depends on the
hash values returned from hash_combine, which happen to be different
for that test between 32-bit and 64-bit platforms.
This change makes the output deterministic by using xxHash64 instead of
hash_combine.
Differential Revision: https://reviews.llvm.org/D49877
llvm-svn: 338088
Discard them unless they have been associated by other means (yet
uimplemented).
According to MS link.exe, such sections are illegal, but MinGW setups
use them in their take on associative comdats.
This avoids leaving references to the bogus SectionChunk* PendingComdat,
which cannot be dereferenced.
This fixes PR38183.
Differential Revision: https://reviews.llvm.org/D49653
llvm-svn: 338064
Patch by Andrew Kelley.
Previously, running lld::coff::link() twice in the same process would
access stale pointers because of these global variables not being reset.
After this patch, lld::coff::link() can be called any number of times,
just like its ELF and MACH-O counterparts.
Differential Revision: https://reviews.llvm.org/D49856
llvm-svn: 338042
We are already ICF'ing these sections as a unit with their dependent
sections, so they don't need to be considered for ICF individually.
This change also "fixes" slowness caused by our quadratic-in-group-size
relocation segregation algorithm on 32-bit ARM platforms with unwind
data and ICF on rodata. In this scenario almost every function's
.ARM.exidx is identical except for the targets of the relocations
that refer to the function and its .ARM.extab, which causes almost
all of the program's .ARM.exidx sections to be initially added to the
same class, which causes us to compare every such section with every
other such section.
Differential Revision: https://reviews.llvm.org/D49716
llvm-svn: 337967
Previously, the error messages didn't contain symbol name because we
didn't read a symbol name for these error messages.
Differential Revision: https://reviews.llvm.org/D49762
llvm-svn: 337863
If we fail to merge a secondary GOT with the primary GOT but so far only
one merged GOT has been created (the primary one), the final element in
MergedGots is the primary GOT. Thus we should not try to merge with this
final element passing IsPrimary=false, since this will ignore the fact
that the destination GOT does in fact need a header, and those extra two
entries can be enough to allow the merge to incorrectly occur. Instead
we should check for this case before attempting the second merge.
Patch by James Clarke.
Differential revision: https://reviews.llvm.org/D49422
llvm-svn: 337810
The gold behaviour with regard to --keep-unique is arguably a bug.
I also noticed a bug in my patch, which is that we mislink the
following program with --icf=safe by merging f3 and f4:
void f1() {}
void f2() {}
__attribute__((weak)) void* f3() { return f1; }
__attribute__((weak)) void* f4() { return f2; }
int main() {
printf("%p %p\n", f3(), f4());
}
llvm-svn: 337729
Signed values for the FDE PC addr were not correctly handled in
readFdeAddr(). If the value is negative and the type of the value is
smaller than 64 bits, the FDE PC addr overflow error would be
incorrectly triggered.
Fixed readFdeAddr() to properly handle signed values by sign extending
where appropriate.
Differential Revision: https://reviews.llvm.org/D49557
llvm-svn: 337683
Under --icf=all we now only apply KeepUnique to non-executable
address-significant sections. This has the effect of making --icf=all
mean unsafe ICF for executable sections and safe ICF for non-executable
sections.
With this change the meaning of the KeepUnique bit changes to
"does the current ICF mode (together with the --keep-unique and
--ignore-data-address-equality flags) require this section to be
kept unique".
Differential Revision: https://reviews.llvm.org/D49626
llvm-svn: 337640
The only restriction is that we cannot merge more than one KeepUnique
section together. This matches gold's behaviour and reduces code size
when using --icf=safe.
Differential Revision: https://reviews.llvm.org/D49622
llvm-svn: 337638
lld currently prepends the absolute path to itself to every diagnostic it
emits. This path can be longer than the diagnostic, and makes the actual error
message hard to read.
There isn't a good reason for printing this path: if you want to know which lld
you're running, pass -v to clang – chances are that if you're unsure of this,
you're not only unsure when it errors out. Some people want an indication that
the diagnostic is from the linker though, so instead print just the basename of
the linker's path.
Before:
```
$ out/bin/clang -target x86_64-unknown-linux -x c++ /dev/null -fuse-ld=lld
/Users/thakis/src/llvm-mono/out/bin/ld.lld: error: cannot open crt1.o: No such file or directory
/Users/thakis/src/llvm-mono/out/bin/ld.lld: error: cannot open crti.o: No such file or directory
/Users/thakis/src/llvm-mono/out/bin/ld.lld: error: cannot open crtbegin.o: No such file or directory
/Users/thakis/src/llvm-mono/out/bin/ld.lld: error: unable to find library -lgcc
/Users/thakis/src/llvm-mono/out/bin/ld.lld: error: unable to find library -lgcc_s
/Users/thakis/src/llvm-mono/out/bin/ld.lld: error: unable to find library -lc
/Users/thakis/src/llvm-mono/out/bin/ld.lld: error: unable to find library -lgcc
/Users/thakis/src/llvm-mono/out/bin/ld.lld: error: unable to find library -lgcc_s
/Users/thakis/src/llvm-mono/out/bin/ld.lld: error: cannot open crtend.o: No such file or directory
/Users/thakis/src/llvm-mono/out/bin/ld.lld: error: cannot open crtn.o: No such file or directory
clang: error: linker command failed with exit code 1 (use -v to see invocation)
```
After:
```
$ out/bin/clang -target x86_64-unknown-linux -x c++ /dev/null -fuse-ld=lld
ld.lld: error: cannot open crt1.o: No such file or directory
ld.lld: error: cannot open crti.o: No such file or directory
ld.lld: error: cannot open crtbegin.o: No such file or directory
ld.lld: error: unable to find library -lgcc
ld.lld: error: unable to find library -lgcc_s
ld.lld: error: unable to find library -lc
ld.lld: error: unable to find library -lgcc
ld.lld: error: unable to find library -lgcc_s
ld.lld: error: cannot open crtend.o: No such file or directory
ld.lld: error: cannot open crtn.o: No such file or directory
clang: error: linker command failed with exit code 1 (use -v to see invocation)
```
https://reviews.llvm.org/D49189
llvm-svn: 337634
If a binary is stripped, which can remove discardable sections (except
for the .reloc section, which also is marked as discardable as it isn't
loaded at runtime, only read by the loader), the .reloc section should
be first of them, in order not to create gaps in the image.
Previously, binaries with relocations were broken if they were stripped
by GNU binutils strip. Trying to execute such binaries produces an error
about "xx is not a valid win32 application".
This fixes GNU binutils bug 23348.
Prior to SVN r329370 (which didn't intend to have functional changes),
the code for moving discardable sections to the end didn't clearly
express how other discardable sections should be ordered compared to
.reloc, but the change retained the exact same end result as before.
After SVN r329370, the code (and comments) more clearly indicate that
it tries to make the .reloc section the absolutely last one; this patch
changes that.
This matches how GNU binutils ld sorts .reloc compared to dwarf debug
info sections.
Differential Revision: https://reviews.llvm.org/D49351
Signed-off-by: Martin Storsjö <martin@martin.st>
llvm-svn: 337598
For dwarf debug info, an executable normally either contains the debug
info, or it is stripped out. To reduce the storage needed (slightly)
for the debug info kept separately from the released, stripped binaries,
one can choose to only copy the debug data from the original executable
(essentially the reverse of the strip operation), producing a file with
only debug info.
When copying the debug data from an executable with GNU objcopy,
the build id and debug directory need to reside in a separate section,
as this will be kept while the rest of the .rdata section is removed.
Differential Revision: https://reviews.llvm.org/D49352
llvm-svn: 337526
This patch changes relative path for source files in obj files to
absolute path in PDB when linking with added flag.
I will make obj file generated by clang-cl independent from build
directory for chromium build. But I don't want to confuse visual studio
debugger or require additional configuration. To attain this goal, I
added flag to convert relative source file path in obj to absolute path
when emitting PDB.
By removing absolute path from obj files, we can share build cache
between chromium developers even when they are doing debug build.
That will make build time faster.
More context:
https://bugs.chromium.org/p/chromium/issues/detail?id=712796https://groups.google.com/a/chromium.org/forum/#!topic/chromium-dev/5HXSVX-7fPc
llvm-svn: 337439
Dwarf debug info contains some data that contains absolute addresses.
Since these sections are discardable and aren't loaded at runtime,
there's no point in adding base relocations for them.
This makes sure that after stripping out dwarf debug info, there are no
base relocations that point to nonexistent sections.
Differential Revision: https://reviews.llvm.org/D49350
llvm-svn: 337438
Currently, getFdePC() returns uint64_t. Its because the following
encodings might use 8 bytes: DW_EH_PE_absptr and DW_EH_PE_udata8.
But caller assigns returned value to uint32_t field:
https://github.com/llvm-mirror/lld/blob/master/ELF/SyntheticSections.cpp#L508
Value is used for building .eh_frame_hdr section.
We use DW_EH_PE_sdata4 encoding for building it at this moment:
https://github.com/llvm-mirror/lld/blob/master/ELF/SyntheticSections.cpp#L2545
And that means that an overflow issue might happen if
DW_EH_PE_absptr/DW_EH_PE_udata8 address encodings are present
in .eh_frame. In that case, before this patch, we silently would
truncate the address and produced broken .eh_frame_hdr section.
It would be not hard to support real 64-bit values for
DW_EH_PE_absptr/DW_EH_PE_udata8 encodings, but it is
unclear if it is usefull and if we should do it.
Since nobody faced/reported it, int this patch I only implement
a check to stop producing broken output silently for now.
llvm-svn: 337382
This is a part of ttps://bugs.llvm.org//show_bug.cgi?id=38119
We produce broken ELF header now when the number of output sections is >= SHN_LORESERVE (0xff00).
ELF spec says (http://www.sco.com/developers/gabi/2003-12-17/ch4.eheader.html):
e_shnum:
If the number of sections is greater than or equal to SHN_LORESERVE (0xff00), this member has the value zero
and the actual number of section header table entries is contained in the sh_size field of the section header at index 0.
(Otherwise, the sh_size member of the initial entry contains 0.)
e_shstrndx
If the section name string table section index is greater than or equal to SHN_LORESERVE (0xff00), this member has the
value SHN_XINDEX (0xffff) and the actual index of the section name string table section is contained in the sh_link field of
the section header at index 0. (Otherwise, the sh_link member of the initial entry contains 0.)
We did not set these fields correctly earlier. The patch fixes the issue.
Differential revision: https://reviews.llvm.org/D49371
llvm-svn: 337363
Peter Smith