This patch simplifies LLVM's lit infrastructure by enforcing an ordering
that a site config is always run before a source-tree config.
A significant amount of the complexity from lit config files arises from
the fact that inside of a source-tree config file, we don't yet know if
the site config has been run. However it is *always* required to run
a site config first, because it passes various variables down through
CMake that the main config depends on. As a result, every config
file has to do a bunch of magic to try to reverse-engineer the location
of the site config file if they detect (heuristically) that the site
config file has not yet been run.
This patch solves the problem by emitting a mapping from source tree
config file to binary tree site config file in llvm-lit.py. Then, during
discovery when we find a config file, we check to see if we have a
target mapping for it, and if so we use that instead.
This mechanism is generic enough that it does not affect external users
of lit. They will just not have a config mapping defined, and everything
will work as normal.
On the other hand, for us it allows us to make many simplifications:
* We are guaranteed that a site config will be executed first
* Inside of a main config, we no longer have to assume that attributes
might not be present and use getattr everywhere.
* We no longer have to pass parameters such as --param llvm_site_config=<path>
on the command line.
* It is future-proof, meaning you don't have to edit llvm-lit.in to add
support for new projects.
* All of the duplicated logic of trying various fallback mechanisms of
finding a site config from the main config are now gone.
One potentially noteworthy thing that was required to implement this
change is that whereas the ninja check targets previously used the first
method to spawn lit, they now use the second. In particular, you can no
longer run lit.py against the source tree while specifying the various
`foo_site_config=<path>` parameters. Instead, you need to run
llvm-lit.py.
Differential Revision: https://reviews.llvm.org/D37756
llvm-svn: 313270
Arg instances can be claimed. After claimed, its `isClaimed` function
returns true. We do not use that notion in lld, so using NoClaim
versions of functions is just confusing. This patch is to just use
hasArg instead of hasArgNoClaim.
llvm-svn: 313187
There are no alises handled by this switch, but getUnaliasesdOption is
preferred way of doing this. This is also consistent with ELF and COFF.
llvm-svn: 313180
This is how the flag is documented in GNU binutils ld; -Bstatic
only applies to -l options after it, until the next -Bdynamic.
Differential Revision: https://reviews.llvm.org/D37794
llvm-svn: 313175
In MinGW configurations (GCC, or clang with a *-windows-gnu target),
the -export directives in the object file contains the undecorated
symbol name, while it is decorated in MSVC configurations. (On the
command line, link.exe takes an undecorated symbol name for the
-export argument though.)
Differential Revision: https://reviews.llvm.org/D37772
llvm-svn: 313174
There is no need to scan over all input sections for relocatable output.
As we do not process or scan relocations anyways.
Patch moves check for Config->Relocatable out to avoid that and also removes
excessive check for isa<EhInputSection> from first for loop.
It is excessive because we handle all of them in a second for loop below.
That all allowed to simplify code.
Differential revision: https://reviews.llvm.org/D37746
llvm-svn: 313127
This should fix the lto bootstrap.
It is somewhat hard to remember about lazy symbols deep down in the
link. It might be worth it replacing them with undefined symbols once
we are done adding files.
llvm-svn: 313103
https://reviews.llvm.org/rL312796 meant that references to garbage collected common symbols would cause a segfault.
This change fixes the behaviour for references to stripped common symbols.
Differential Revision: https://reviews.llvm.org/D37718
llvm-svn: 313086
On i386, the --entry parameter to GNU ld is supposed to be a decorated
symbol name, while it is an undecorated name in link.exe.
Differential Revision: https://reviews.llvm.org/D37710
llvm-svn: 313066
For now LLD does not setup the least-significant bit for microMIPS
symbols. llvm-objdump does not like that. In attempt to fix
sanitizer-x86_64-linux-fast build-bot let's temporarily check the raw
binary file content.
llvm-svn: 313040
The patch implements initial support of microMIPS code linking:
- Handle microMIPS specific relocations.
- Emit both R1-R5 and R6 microMIPS PLT records.
For now linking mixed set of regular and microMIPS object files is not
supported. Also the patch does not handle (setup and clear) the
least-significant bit of an address which is utilized as the ISA mode
bit and allows to make jump between regular and microMIPS code without
any thunks.
Differential revision: https://reviews.llvm.org/D37335
llvm-svn: 313028
Replace OutputSection *Cmd to OutputSection *OS. The Commands vector was
moved to OutputSection but the names of the variables were not. This patch
changes the names to match.
Differential Revision: https://reviews.llvm.org/D37627
llvm-svn: 313015
When given
foobar = ALIGN(., 0x100);
my expectation from what the manual says is that the final address of
foobar will be aligned. It seems that bfd aligns the offset in the
section, which causes some odd results if the section is not 0x100
aligned. Gold aligns the address.
This changes lld to align the final address.
llvm-svn: 312979
/natvis is a new command line option introduced by MSVC 2017.
We eventually have to support it, but for now, let's ignore it so that
we can at least link stuff instead of printing out an error.
Patch by Michael Rickert.
llvm-svn: 312966
We do not use "Shim" as a name of MinGW driver, so rename it MinGW.
I don't think the former dependency list was correct. MinGW driver
depends on COFF.
llvm-svn: 312960
This adds support for passing LTO flags to the MINGW driver
in GNU LD style i.e. -mllvm flag -> /mllvm:flag
Reviewers: ruiu, mstorsjo
Differential Revision: https://reviews.llvm.org/D37712
llvm-svn: 312956
If the sysroot parameter is passed to the clang frontend, clang
already uses it to find libraries and adds -L options for it, but
also passes it on to the linker. Therefore we can get pretty far
by just ignoring it altogether.
Differential Revision: https://reviews.llvm.org/D37707
llvm-svn: 312945
Pass the -verbose option through to the COFF linker, and show the
arguments passed to it. If the -### option is specified, just show
the produced argument list and exit, just like in clang.
Replace the first argument with "lld-link" in order to produce a
correct command line.
Differential Revision: https://reviews.llvm.org/D37706
llvm-svn: 312944
Summary:
In addition to removing a few global variables and functions, I believe
this patch improves code readability a bit in general.
Reviewers: mstorsjo, martell
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D37699
llvm-svn: 312940
When building COFF programs many targets such as mingw prefer
to have a gnu ld frontend. Rather then having a fully fledged
standalone driver we wrap a shim around the LINK driver.
Extra tests were provided by mstorsjo
Reviewers: mstorsjo, ruiu
Differential Revision: https://reviews.llvm.org/D33880
llvm-svn: 312926
'@' is a valid character in file paths, but the linker script tokenizer treats it
as a separate token. This was leading to an unexpected test failure, on our local
builds. This patch changes the test to quote the path to prevent this happening.
An alternative would have been to add '@' to the list of "unquoted tokens" in
ScriptLexer.cpp, but ld.bfd has the same behaviour as the current LLD.
Reviewers: ruiu
Differential Revision: https://reviews.llvm.org/D37689
llvm-svn: 312922
This allows combining --dynamic-list and version scripts too. The
version script controls which symbols are visible, and
--dynamic-list controls which of those are preemptible.
Unlike previous versions, undefined symbols are still considered
preemptible, which was the issue breaking the cfi tests.
This fixes pr34053.
llvm-svn: 312806
to separate commons based on file name patterns. The following linker script
construct does not work because commons are allocated before section placement
is done and the only synthesized BssSection that holds all commons has no file
associated with it:
SECTIONS { .common_0 : { *file0.o(COMMON) }}
This patch changes the allocation of commons to create a section per common
symbol and let the section logic do the layout.
Differential revision: https://reviews.llvm.org/D37489
llvm-svn: 312796
There is no need to check anything excepr that
symbol is not in output.
Previously additional iformation like symbol values
or flags were checked, that was not correct.
For example if we would provide symbol with different
value/visibility/type for case when should not provide
symbol at all, testcase would not fail.
llvm-svn: 312779
REGION_ALIAS(alias, region)
Alias names can be added to existing memory regions created with
the MEMORY command. Each name corresponds to at most one
memory region.
Differential revision: https://reviews.llvm.org/D37477
llvm-svn: 312777
If --dynamic-list is given, only those symbols are preemptible.
This allows combining --dynamic-list and version scripts too. The
version script controls which symbols are visible, and --dynamic-list
controls which of those are preemptible.
This fixes pr34053.
llvm-svn: 312757
It is possible for two modules to have the same name if they are
archive members with the same name, or if we are doing LTO (in which
case all modules will have the name "lto.tmp").
Differential Revision: https://reviews.llvm.org/D37589
llvm-svn: 312744
To support errata patching on AArch64 we need to be able to overwrite
an arbitrary instruction with a branch. For AArch64 it is sufficient to
always write all the bits of the branch instruction and not just the
immediate field. This is safe as the non-immediate bits of the branch
instruction are always the same.
Differential Revision: https://reviews.llvm.org/D36745
llvm-svn: 312727
It is a bit more convinent and helps to simplify logic
of program headers allocation a little.
Differential revision: https://reviews.llvm.org/D34956
llvm-svn: 312711
The default padding for an executable segment is the target trap
instruction which for x86_64 is 0xCC. However, the .eh_frame section
requires the padding to be zero. The code that writes the .eh_frame
section assumes that its segment is zero initialized and does not
explicitly write the zero padding. This does not work when the .eh_frame
section is in the executable segment (for example when using
-no-rosegment).
This patch changes the .eh_frame writing code to explicitly write the
zero padding.
Differential Revision: https://reviews.llvm.org/D37462
llvm-svn: 312706
If using --format=binary with an input file name that has one or more non-ascii
characters in, LLD has undefined behaviour (it crashes on my Windows Debug build)
when calling isalnum with these non-ascii characters. Instead, of calling
std::isalnum, this patch uses an internal version that ignores the locale and
checks a specific subset of characters.
Reviewers: ruiu
Differential Revision: https://reviews.llvm.org/D37331
llvm-svn: 312705
The R_AARCH64_LDST<N>_ABS LO12_NC relocations where N is 8, 16, 32, 64 or
128 have a scaled immediate. For example R_AARCH64_LDST32_ABS_LO12_NC
shifts the calculated value right by 4. If the target symbol + relocation
addend is not aligned properly then bits of the answer will be lost.
This change adds an alignment check to the relocations to make sure the
target of the relocation is aligned properly. This matches the behavior of
GNU ld. The motivation is to catch ODR violations such as a declaration of
extern int foo, but a definition of bool foo as the compiler may use
R_AARCH64_LDST32_ABS_LO12_NC for the former, but not align the destination.
Differential Revision: https://reviews.llvm.org/D37444
llvm-svn: 312637
The fixSectionAlignments() function may alter the alignment of some
OutputSections, this is likely to alter the addresses calculated earlier
in assignAddresses(). By moving the call to fixSectionAlignments() we
make sure that assignAddresses() is consistent with the early calculation
used for RangeThunks and the final call just before writing the image.
Differential Revision: https://reviews.llvm.org/D36739
llvm-svn: 312636
The --symbol-ordering-file path was not being rewritten in the response file when
using --reproduce. This patch adds this to the list of switches that are rewritten,
so that the path is somewhere within the reproducer directory tree.
Reviewers: ruiu
Differential Revision: https://reviews.llvm.org/D37480
llvm-svn: 312626
Previously LLD did not calculate LMAOffset correctly when
AT and MEMORY were used together.
Patch fixes PR34407.
Differential revision: https://reviews.llvm.org/D37469
llvm-svn: 312625
Summary:
Previous would throw warning whenever libxml2 is not installed. Now
only give this warning if merging manifest fails.
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D37240
llvm-svn: 312604
Looks like raw_string_ostream is buffered. If we do not call `flush`
nor `str`, it is not guaranteed that a result string has all characters
that were written to it.
It wasn't failing on buildbots, but I could reproduce the issue on my
Windows workstation.
llvm-svn: 312577
std::vector::insert invalidates all iterators, so it was not safe to do
Script->Opt.Commands.insert(++I, Make(ElfSym::End1));
Script->Opt.Commands.insert(++I, Make(ElfSym::End2));
because after the first line, `I` is no longer valid.
This patch rewrites fixes the issue. I belive the new code without
higher-order functions is a bit more readable than before.
llvm-svn: 312570
Pass BSIZE and SHIFT as a function arguments to the `writeRelocation`
routine. It does not make a sense to have so many `writeRelocation's`
instances.
llvm-svn: 312495
Recently (before r312477) lib/DebugInfo incorrectly handled the case
when debug ranges uses base address of CU. Section index was not
calulcated properly and LLD crashed on provided testcase.
Differential revision: https://reviews.llvm.org/D37297
llvm-svn: 312478
Apply the simplification suggestions that Peter Collingbourne made
during the review at D37368. The returned thunk is cast to the
appropriate type in the SymbolTable, and the constant symbol's body is
not needed directly, so avoid the assignment. NFC
llvm-svn: 312391
If a symbol is locally defined and is DLL imported in another
translation unit, and the object with the locally defined version is
loaded prior to the imported version, then the linker will fail to
resolve the definition of the thunk and return the locally defined
symbol. This will then be attempted to be cast to an import thunk,
which will clearly fail.
Only return the thunk if the symbol is inserted or a thunk is created.
Otherwise, report a duplication error.
llvm-svn: 312386
We have llvm-readobj for dumping CodeView from object files, and
llvm-pdbutil has always been more focused on PDB. However,
llvm-pdbutil has a lot of useful options for summarizing debug
information in aggregate and presenting high level statistical
views. Furthermore, it's arguably better as a testing tool since
we don't have to write tests to conform to a state-machine like
structure where you match multiple lines in succession, each
depending on a previous match. llvm-pdbutil dumps much more
concisely, so it's possible to use single-line matches in many
cases where as with readobj tests you have to use multi-line
matches with an implicit state machine.
Because of this, I'm adding object file support to llvm-pdbutil.
In fact, this mirrors the cvdump tool from Microsoft, which also
supports both object files and pdb files. In the future we could
perhaps rename this tool llvm-cvutil.
In the meantime, this allows us to deep dive into object files
the same way we already can with PDB files.
llvm-svn: 312358
Previously it was called twice for .comment synthetic section.
That created 2 pieces of data, which was deduplicated anyways,
but was not clean.
llvm-svn: 312327
The problem with symbol assignments in implicit linker scripts is that
they can refer synthetic symbols such as _end, _etext or _edata. The
value of these symbols is currently fixed only after all linker script
commands are processed, so these assignments will be using non-final and
hence invalid value.
Rather than fixing the symbol values after all command processing have
finished, we instead change the logic to generate symbol assignment
commands that set the value of these symbols while processing the
commands, this ensures that the value is going to be correct by the time
any reference to these symbol is processed and is equivalent to defining
these symbols explicitly in linker script as BFD ld does.
Differential Revision: https://reviews.llvm.org/D36986
llvm-svn: 312305
writeArchive returned a pair, but the first element of the pair is always
its first argument on failure, so it doesn't make sense to return it from
the function. This patch change the return type so that it does't return it.
Differential Revision: https://reviews.llvm.org/D37313
llvm-svn: 312177
This reverts commit r312171 because it is pointed out that that's not a
correct fix (see https://bugs.llvm.org/show_bug.cgi?id=32674#c14) and
also because it broke buildbots.
llvm-svn: 312174
MSVC link.exe supports nested static libraries. That is, an .a file can
contain other .a file as its member. It is reported that MySQL actually
depends on this feature.
Fixes https://bugs.llvm.org/show_bug.cgi?id=32674
llvm-svn: 312171
Imagine we have archive file with symbols foo and bar.
And script that do foo = 1.
In that case correct behavior is not to fetch symbols from archive but
create absolute symbol.
If we have script zed = foo then symbol foo will be fetched from archive.
Currently we have Opt.ReferencedSymbols list of symbols referenced
by script and create them undefined early. That allows archives fetching logic
to work. That is what LLD already do and it seems everything is fine here.
But during writing D37059 I had to add left side of assignments to
Opt.ReferencedSymbols list because wanted to stop optimizing out
these symbols when LTO is involved (LTO also uses this list).
And testcase from this patch would have fail if we would have it before.
Differential revision: https://reviews.llvm.org/D37208
llvm-svn: 312004
This is PR32429.
We did not mention -fPIC in error about producing dynamic relocation
in readonly segment before. Patch changes that.
Differential revision: https://reviews.llvm.org/D36874
llvm-svn: 312003
Various classes have `Symtab` member variables even though we have
lld::coff::Symtab variable because previous attempts to make COFF lld's
internal structure resemble to ELF's was incomplete. This patch finishes
that job by removing member variables.
llvm-svn: 311938
Summary:
ArgParser created an instance of COFFOptTable on stack to use it to
parser command line arguments. Parsed arguments were then returned from
the function as InputArgList. This was safe because InputArgList referred
only statically-allocated InfoTable.
That is not a safe assumption after https://reviews.llvm.org/D36782,
which changes the type of its internal table from ArrayRef to std::vector.
To make lld work with that patch, we need to keep an instance of
COFFOptTable at least as long as an InputArgList is alive. This patch
does that.
Reviewers: yamaguchi
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D37217
llvm-svn: 311930
Patch by Patricio Villalobos.
I discovered that lld for darwin is generating the wrong code for lazy
bindings in the __stub_helper section (at least for osx 10.12). This is
the way i can reproduce this problem, using this program:
#include <stdio.h>
int main(int argc, char **argv) {
printf("C: printf!\n");
puts("C: puts!\n");
return 0;
}
Then I link it using i have tested it in 3.9, 4.0 and 4.1 versions:
$ clang -c hello.c
$ lld -flavor darwin hello.o -o h1 -lc
When i execute the binary h1 the system gives me the following error:
C: printf!
dyld: lazy symbol binding failed:
BIND_OPCODE_SET_SEGMENT_AND_OFFSET_ULEB
has segment 4 which is too large (0..3)
dyld: BIND_OPCODE_SET_SEGMENT_AND_OFFSET_ULEB has segment 4 which is too
large (0..3)
Trace/BPT trap: 5
Investigating the code, it seems that the problem is that the asm code
generated in the file StubPass.cpp, specifically in the line 323,when it
adds, what it seems an arbitrary number (12) to the offset into the lazy
bind opcodes section, but it should be calculated depending on the
MachONormalizedFileBinaryWrite::lazyBindingInfo result.
I confirmed this bug by patching the code manually in the binary and
writing the right offset in the asm code (__stub_helper).
This patch fixes the content of the atom that contains the assembly code
when the offset is known.
Differential Revision: https://reviews.llvm.org/D35387
llvm-svn: 311734
linker script SECTION rules. This patch extends it to use a fully specified
file name as it appears in --trace output to match agains, i.e,
"<path>/<objname>.o" or "<path>/<libname>.a(<objname>.o)".
Differential Revision: https://reviews.llvm.org/D37031
llvm-svn: 311713
Currently LLD reads the R_MIPS_HI16's addends in the `computeMipsAddend`
function, the R_MIPS_LO16's addends in both `computeMipsAddend` and
`getImplicitAddend` functions. This patch moves reading all addends to
the `getImplicitAddend` function. As a side effect it fixes a "paired"
HI16/LO16 addend calculation if "LO16" part of a pair is not found.
llvm-svn: 311711
Before this patch, lld printed out something like
error: -O: number expected, but got
After this patch, it prints out the same error message like this:
error: -O: number expected, but got ''
Fixes https://bugs.llvm.org/show_bug.cgi?id=34311
llvm-svn: 311681
Currently, LLD checks whether there's enough space for headers by
checking if headers fit below the address of the first allocated
section. However, that's always thue if the binary doesn't start
at zero which means that LLD always emits a segment for headers,
even if no other sections belong to that segment.
This is a problem in cases when linker script is being used with a
non-zero start address when we don't want to make the headers visible
by not leaving enough space for them. This pattern is common in
embedded programming but doesn't work in LLD.
This patch changes the behavior of LLD in case when linker script
is being to match the behavior of BFD ld and gold, which is to only
place headers into a segment when they're covered by some output
section.
Differential Revision: https://reviews.llvm.org/D36256
llvm-svn: 311586
Previously up to 3 errors were reported at once,
with patch we always will report only one,
just like in other linker code.
Differential revision: https://reviews.llvm.org/D37015
llvm-svn: 311537
It was broken from begining, because visibility
attributes were not applied properly to
symbols before this patch.
Differential revision: https://reviews.llvm.org/D36966
llvm-svn: 311536
Code suggested by Rui Ueyama in PR34238 comments.
Previously LTO optimized away symbols referenced from linker script
because did not see that them are used from regular objects.
Patch adds such symbols as undefined earlier, before running LTO,
what sets IsUsedInRegularObj for them and fixes the issue.
Differential revision: https://reviews.llvm.org/D37009
llvm-svn: 311534
Patch by Rafael Espíndola.
This is PR34053.
The implementation is a bit of a hack, given the precise location where
IsPreemtible is set, it cannot be used from
SymbolTable::handleAnonymousVersion.
I could add another method to SymbolTable if you think that would be
better.
Differential Revision: https://reviews.llvm.org/D36499
llvm-svn: 311468
This is PR33097.
Previously when doing relocatable link, all IR symbols were absent
in result object file. Patch makes external symbols to be exported.
Differential revision: https://reviews.llvm.org/D36957
llvm-svn: 311431
Summary: Now that the llvm-mt manifest merging libraries are complete, we may use them to merge manifests instead of needing to shell out to mt.exe.
Subscribers: mgorny, llvm-commits
Differential Revision: https://reviews.llvm.org/D36255
llvm-svn: 311424
This adds support for dumping a summary of module symbols
and CodeView debug chunks. This option prints a table for
each module of all of the symbols that occurred in the module
and the number of times it occurred and total byte size. Then
at the end it prints the totals for the entire file.
Additionally, this patch adds the -jmc (just my code) option,
which suppresses modules which are from external libraries or
linker imports, so that you can focus only on the object files
and libraries that originate from your own source code.
llvm-svn: 311338
hexdump is not part of the GNU coreutils, and so is not required to be able to
build and test LLVM, according to the documentation. This change removes the
dependency on hexdump from a lit test.
Reviewers: grimar
Differential Revision: https://reviews.llvm.org/D36958
llvm-svn: 311335
With fix: explicitly specify ouput format for hexdump tool call.
Original commit message:
[ELF] - Do not forget to fill last bytes of PT_LOADs with trap instructions.
Previously last 4 bytes of executable loads
were not filled with trap instructions,
patch fixes this bug.
Differential revision: https://reviews.llvm.org/D36262
llvm-svn: 311315
Previously we would crash on samples from testcase,
because were trying to access zero pointer to output section.
Differential revision: https://reviews.llvm.org/D36145
llvm-svn: 311311
Previously last 4 bytes of executable loads
were not filled with trap instructions,
patch fixes this bug.
Differential revision: https://reviews.llvm.org/D36262
llvm-svn: 311310
We would previously crash on next script:
MEMORY { name : ORIGIN = .; }
Patch fixes that.
Differential revision: https://reviews.llvm.org/D36138
llvm-svn: 311073
We had a lock to guard BAlloc from being used concurrently, but that
is not very easy to understand. This patch replaces it with a
std::unique_ptr.
llvm-svn: 311056
Clang passes this options to linker. We should ignore them,
anyways they are always enabled by default atm.
Fixes https://bugs.llvm.org/show_bug.cgi?id=34200.
llvm-svn: 310995
When creating an import library from lld, the cases with
Name != ExtName shouldn't end up as a weak alias, but as a real
export of the new name, which is what actually is exported from
the DLL.
This restores the behaviour of renamed exports to what it was in
4.0.
Differential Revision: https://reviews.llvm.org/D36634
llvm-svn: 310992
Since SVN r303491 and r304573, LLD used the COFFImportLibrary
functions from LLVM. These only had two names, Name and ExtName,
which wasn't enough to convey all the details of stdcall functions.
Stdcall functions got the wrong symbol name in the import library
itself in r303491, which is why it was reverted in r304561. When
re-landed and fixed in r304573 (after adding a test in r304572),
the symbol name itself in the import library ended up right, but the
name type of the import library entry was wrong.
This had the effect that linking to the import library succeeded
(contrary to in r303491, where linking to such an import library
failed), but at runtime, the symbol wouldn't be found in the DLL
(since the caller linked to the stdcall decorated name).
Differential Revision: https://reviews.llvm.org/D36545
llvm-svn: 310989
I'm explicitly ignoring the warning by casting to void instead of
deleting the local assignment, because it's confusing to see a
function that fails when its return value evaluates to true.
But when you see that it's a std::error_code, it makes more sense.
llvm-svn: 310965
Previously, our algorithm to compute a build id involved hashing the
executable and storing that as the GUID in the CV Debug Record chunk,
and setting the age to 1.
This breaks down in one very obvious case: a user adds some newlines to
a file, rebuilds, but changes nothing else. This causes new line
information and new file checksums to get written to the PDB, meaning
that the debug info is different, but the generated code would be the
same, so we would write the same build over again with an age of 1.
Anyone using a symbol cache would have a problem now, because the
debugger would open the executable, look at the age and guid, find a
matching PDB in the symbol cache and then load it. It would never copy
the new PDB to the symbol cache.
This patch implements the canonical Windows algorithm for updating
a build id, which is to check the existing executable first, and
re-use an existing GUID while bumping the age if it already
exists.
Differential Revision: https://reviews.llvm.org/D36758
llvm-svn: 310961
GdbIndexSection doesn't need lazy finalization because when an instance
of the class is created, we already know all debug info sections.
We can initialize the instnace in the ctor.
llvm-svn: 310931
Rui Ueyama