This patch adds an implementation of unwinding using PE EH info. It allows to
get almost ideal call stacks on 64-bit Windows systems (except some epilogue
cases, but I believe that they can be fixed with unwind plan disassembly
augmentation in the future).
To achieve the goal the CallFrameInfo abstraction was made. It is based on the
DWARFCallFrameInfo class interface with a few changes to make it less
DWARF-specific.
To implement the new interface for PECOFF object files the class PECallFrameInfo
was written. It uses the next helper classes:
- UnwindCodesIterator helps to iterate through UnwindCode structures (and
processes chained infos transparently);
- EHProgramBuilder with the use of UnwindCodesIterator constructs EHProgram;
- EHProgram is, by fact, a vector of EHInstructions. It creates an abstraction
over the low-level unwind codes and simplifies work with them. It contains
only the information that is relevant to unwinding in the unified form. Also
the required unwind codes are read from the object file only once with it;
- EHProgramRange allows to take a range of EHProgram and to build an unwind row
for it.
So, PECallFrameInfo builds the EHProgram with EHProgramBuilder, takes the ranges
corresponding to every offset in prologue and builds the rows of the resulted
unwind plan. The resulted plan covers the whole range of the function except the
epilogue.
Reviewers: jasonmolenda, asmith, amccarth, clayborg, JDevlieghere, stella.stamenova, labath, espindola
Reviewed By: jasonmolenda
Subscribers: leonid.mashinskiy, emaste, mgorny, aprantl, arichardson, MaskRay, lldb-commits, llvm-commits
Tags: #lldb
Differential Revision: https://reviews.llvm.org/D67347
llvm-svn: 374528
Testing whether a name is mangled or not is extremely cheap and can be
done by looking at the first two characters. Mangled knows how to do
it. On the flip side, many call sites that currently pass in an
is_mangled determination do not know how to correctly do it (for
example, they leave out Swift mangling prefixes).
This patch removes this entry point and just forced Mangled to
determine the mangledness of a string itself.
Differential Revision: https://reviews.llvm.org/D68674
llvm-svn: 374180
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
Summary:
This is a redo of D68069 because I reverted it due to some concerns that were now addressed along with the new comments that @labath added.
I found a case where the main android binary (app_process32) had thumb code at its entry point but no entry in the symbol table indicating this. This made lldb set a 4 byte breakpoint at that address (we default to arm code) instead of a 2 byte one (like we should for thumb).
The big deal with this is that the expression evaluator uses the entry point as a way to know when a JITed expression has finished executing by putting a breakpoint there. Because of this, evaluating expressions on certain android devices (Google Pixel something) made the process crash.
This was fixed by checking this specific situation when we parse the symbol table and add an artificial symbol for this 2 byte range and indicating that it's arm thumb.
I created 2 unit tests for this, one to check that now we know that the entry point is arm thumb, and the other to make sure we didn't change the behaviour for arm code.
I also run the following on the command line with the `app_process32` where I found the issue:
**Before:**
```
(lldb) dis -s 0x1640 -e 0x1644
app_process32[0x1640]: .long 0xf0004668 ; unknown opcode
```
**After:**
```
(lldb) dis -s 0x1640 -e 0x1644
app_process32`:
app_process32[0x1640] <+0>: mov r0, sp
app_process32[0x1642]: andeq r0, r0, r0
```
Reviewers: clayborg, labath, wallace, espindola
Reviewed By: labath
Subscribers: labath, lldb-commits, MaskRay, kristof.beyls, arichardson, emaste, srhines
Tags: #lldb
Differential Revision: https://reviews.llvm.org/D68533
llvm-svn: 374132
This makes parsing the symbol table of clang marginally faster. (Hashtable versus tree).
Differential Revision: https://reviews.llvm.org/D68605
llvm-svn: 374084
The symtab parser in ObjectFileMachO has logic to coalesce debug (STAB)
and non-debug symbols, based on the address and the symbol name for
static (STSYM) and global symbols (GSYM) respectively. It makes the
assumption that the debug variant is always encountered first. Rather
than creating a second entry in the symbol table for the non-debug
symbol, the latter gets merged into the existing debug symbol.
This breaks when the linker emits the non-debug symbol first. We'd end
up with two entries in the symbol table, each containing part of the
information LLDB relies on. Indeed, commenting out the merging logic
breaks the test suite spectacularly.
This patch solves that problem by always parsing the debug symbols
first. This guarantees that the assumption for merging holds.
I'm not particularly happy with adding a lambda, but after numerous
attempts this is the best solution I could come up with. The symtab
parsing logic is pretty complex in that it touches a lot of things. I've
experienced first hand that it's very easy to break things. I believe
this approach strikes a balance between fixing the issue while limiting
the risk of regressions.
Differential revision: https://reviews.llvm.org/D68536
llvm-svn: 373994
Summary:
If the .symtab section is stripped from the binary it might be that
there's a .gnu_debugdata section which contains a smaller .symtab in
order to provide enough information to create a backtrace with function
names or to set and hit a breakpoint on a function name.
This change looks for a .gnu_debugdata section in the ELF object file.
The .gnu_debugdata section contains a xz-compressed ELF file with a
.symtab section inside. Symbols from that compressed .symtab section
are merged with the main object file's .dynsym symbols (if any).
In addition we always load the .dynsym even if there's a .symtab
section.
For example, the Fedora and RHEL operating systems strip their binaries
but keep a .gnu_debugdata section. While gdb already can read this
section, LLDB until this patch couldn't. To test this patch on a
Fedora or RHEL operating system, try to set a breakpoint on the "help"
symbol in the "zip" binary. Before this patch, only GDB can set this
breakpoint; now LLDB also can do so without installing extra debug
symbols:
lldb /usr/bin/zip -b -o "b help" -o "r" -o "bt" -- -h
The above line runs LLDB in batch mode and on the "/usr/bin/zip -h"
target:
(lldb) target create "/usr/bin/zip"
Current executable set to '/usr/bin/zip' (x86_64).
(lldb) settings set -- target.run-args "-h"
Before the program starts, we set a breakpoint on the "help" symbol:
(lldb) b help
Breakpoint 1: where = zip`help, address = 0x00000000004093b0
Once the program is run and has hit the breakpoint we ask for a
backtrace:
(lldb) r
Process 10073 stopped
* thread #1, name = 'zip', stop reason = breakpoint 1.1
frame #0: 0x00000000004093b0 zip`help
zip`help:
-> 0x4093b0 <+0>: pushq %r12
0x4093b2 <+2>: movq 0x2af5f(%rip), %rsi ; + 4056
0x4093b9 <+9>: movl $0x1, %edi
0x4093be <+14>: xorl %eax, %eax
Process 10073 launched: '/usr/bin/zip' (x86_64)
(lldb) bt
* thread #1, name = 'zip', stop reason = breakpoint 1.1
* frame #0: 0x00000000004093b0 zip`help
frame #1: 0x0000000000403970 zip`main + 3248
frame #2: 0x00007ffff7d8bf33 libc.so.6`__libc_start_main + 243
frame #3: 0x0000000000408cee zip`_start + 46
In order to support the .gnu_debugdata section, one has to have LZMA
development headers installed. The CMake section, that controls this
part looks for the LZMA headers and enables .gnu_debugdata support by
default if they are found; otherwise or if explicitly requested, the
minidebuginfo support is disabled.
GDB supports the "mini debuginfo" section .gnu_debugdata since v7.6
(2013).
Reviewers: espindola, labath, jankratochvil, alexshap
Reviewed By: labath
Subscribers: rnkovacs, wuzish, shafik, emaste, mgorny, arichardson, hiraditya, MaskRay, lldb-commits
Tags: #lldb, #llvm
Differential Revision: https://reviews.llvm.org/D66791
llvm-svn: 373891
This file really suffered from the Great Reformat. I'm adding a few
early returns to give the deeply nested code some more breathing room.
llvm-svn: 373778
Backing out because SymbolFile/Breakpad/symtab.test is failing and it seems to be a legit issue. Will investigate.
This reverts commit 72153f95ee4c1b52d2f4f483f0ea4f650ec863be.
llvm-svn: 373687
Summary:
I found a case where the main android binary (app_process32) had thumb code at its entry point but no entry in the symbol table indicating this. This made lldb set a 4 byte breakpoint at that address (we default to arm code) instead of a 2 byte one (like we should for thumb).
The big deal with this is that the expression evaluator uses the entry point as a way to know when a JITed expression has finished executing by putting a breakpoint there. Because of this, evaluating expressions on certain android devices (Google Pixel something) made the process crash.
This was fixed by checking this specific situation when we parse the symbol table and add an artificial symbol for this 2 byte range and indicating that it's arm thumb.
I created 2 unit tests for this, one to check that now we know that the entry point is arm thumb, and the other to make sure we didn't change the behaviour for arm code.
I also run the following on the command line with the `app_process32` where I found the issue:
**Before:**
```
(lldb) dis -s 0x1640 -e 0x1644
app_process32[0x1640]: .long 0xf0004668 ; unknown opcode
```
**After:**
```
(lldb) dis -s 0x1640 -e 0x1644
app_process32`:
app_process32[0x1640] <+0>: mov r0, sp
app_process32[0x1642]: andeq r0, r0, r0
```
Reviewers: clayborg, labath, wallace, espindola
Subscribers: srhines, emaste, arichardson, kristof.beyls, MaskRay, lldb-commits
Tags: #lldb
Differential Revision: https://reviews.llvm.org/D68069
llvm-svn: 373680
Summary:
This patch converts FileSystem::Open from this prototype:
Status
Open(File &File, const FileSpec &file_spec, ...);
to this one:
llvm::Expected<std::unique_ptr<File>>
Open(const FileSpec &file_spec, ...);
This is beneficial on its own, as llvm::Expected is a more modern
and recommended error type than Status. It is also a necessary step
towards https://reviews.llvm.org/D67891, and further developments
for lldb_private::File.
Reviewers: JDevlieghere, jasonmolenda, labath
Reviewed By: labath
Subscribers: mgorny, lldb-commits
Tags: #lldb
Differential Revision: https://reviews.llvm.org/D67996
llvm-svn: 373003
Add a test case for the change from SVN r372657, and for the
preexisting ARM identification.
Add a missing ArchDefinitionEntry for PECOFF/arm64, and tweak
the ArmNt case to set the architecture to armv7 (ArmNt never ran
on anything lower than that). (This avoids a case where
ArchSpec::MergeFrom would override the arch from arm to armv7 and
ArchSpec::CoreUpdated would reset the OS to unknown at the same time.)
Differential Revision: https://reviews.llvm.org/D67951
llvm-svn: 372741
The PECOFF object file plugin uses the dbghelp API, but doesn't
specify that it has to be linked in anywhere.
Current MSVC based builds have probably succeeded, as other parts
in LLDB have had a "#pragma comment(lib, "dbghelp.lib")", but there's
currently no such pragma in the PECOFF plugin.
The "#pragma comment(lib, ...)" approach doesn't work in MinGW mode
(unless the compiler is given the -fms-extensions option, and even
then, it's only supported by clang/lld, not by GCC/binutils), thus
add it to be linked via CMake. (The other parts of LLDB that use
dbghelp are within _MSC_VER ifdefs.)
Differential Revision: https://reviews.llvm.org/D67885
llvm-svn: 372587
Summary:
This change ensures that the .dynsym section will be parsed even when there's already is a .symtab.
It is motivated because of minidebuginfo (https://sourceware.org/gdb/current/onlinedocs/gdb/MiniDebugInfo.html#MiniDebugInfo).
There it says:
Keep all the function symbols not already in the dynamic symbol table.
That means the .symtab embedded inside the .gnu_debugdata does NOT contain the symbols from .dynsym. But in order to put a breakpoint on all symbols we need to load both. I hope this makes sense.
My other patch D66791 implements support for minidebuginfo, that's why I need this change.
Reviewers: labath, espindola, alexshap
Subscribers: JDevlieghere, emaste, arichardson, MaskRay, lldb-commits
Tags: #lldb
Differential Revision: https://reviews.llvm.org/D67390
llvm-svn: 371599
The function had the same name as one of the member function, so
it was just copied to all classes so that the lookup works. We
could also give the function a more better and unique name
(because it's actually printing the register value and writing
to the stream, not writing to the register).
Also removes the unused return value.
llvm-svn: 370854
Summary: The fields that aren't useful for us right now are simply ignored.
Reviewers: amccarth, markmentovai
Subscribers: rnk, lldb-commits
Differential Revision: https://reviews.llvm.org/D66633
llvm-svn: 369892
On macOS one Mach-O slice can contain multiple load commands: One load
command for being loaded into a macOS process and one load command for
being loaded into a macCatalyst process. This patch adds support for
the new load command and makes sure ObjectFileMachO returns the
Architecture that matches the Module.
Differential Revision: https://reviews.llvm.org/D66626
llvm-svn: 369814
Now that we've moved to C++14, we no longer need the llvm::make_unique
implementation from STLExtras.h. This patch is a mechanical replacement
of (hopefully) all the llvm::make_unique instances across the monorepo.
Differential revision: https://reviews.llvm.org/D66259
llvm-svn: 368933
Summary:
In an attempt to make file-address-based lookups more predictable, in D55998
we started ignoring sections which would result in file address
overlaps. It turns out this was too aggressive because thread-local
sections typically will have file addresses which apear to overlap
regular data/code. This does not cause a problem at runtime because
thread-local sections are loaded into memory using special logic, but it
can cause problems for lldb when trying to lookup objects by their file
address.
This patch changes ObjectFileELF to permit thread-local sections to
overlap regular ones by essentially giving them a separate address
space. It also makes them more symmetrical to regular sections by
creating container sections from PT_TLS segments.
Simultaneously, the patch changes the regular file address lookup logic
to ignore sections with the thread-specific bit set. I believe this is
what the users looking up file addresses would typically expect, as
looking up thread-local data generally requires more complex logic (e.g.
DWARF has a special opcode for that).
Reviewers: clayborg, jingham, MaskRay
Subscribers: emaste, aprantl, arichardson, lldb-commits
Differential Revision: https://reviews.llvm.org/D65282
llvm-svn: 368010
Summary:
The contents of the gnu_debuglink section were passed through the
GetDebugSymbolFilePaths interface, which was more generic than needed.
As the only class implementing this function is ObjectFileELF, we can
modify the function to return just a single FileSpec (instead of a
list). Also, since the SymbolVendorELF already assumes ELF object files,
we don't have to make this method available on the generic ObjectFile
interface -- instead we can put it on ObjectFileELF directly.
This change also makes is so that if the Module has an explicit symbol
file spec set, we disregard the value the value of the debug link
(instead of doing a secondary lookup using that). I think it makes sense
to honor the users wishes if he had explicitly set the symbol file spec,
and this seems to be consistent with what SymbolVendorMacOSX is doing
(SymbolVendorMacOSX.cpp:125).
The main reason for making these changes is to make the treatment of
build-ids and debug links simpler in the follow-up patch.
Reviewers: clayborg, jankratochvil, mgorny, espindola
Subscribers: emaste, arichardson, MaskRay, lldb-commits
Differential Revision: https://reviews.llvm.org/D65560
llvm-svn: 367824
Summary:
On the heels of D62934, this patch uses the same approach to introduce
llvm RTTI support to the ObjectFile hierarchy. It also replaces the
existing uses of GetPluginName doing run-time type checks with
llvm::dyn_cast and friends.
This formally introduces new dependencies from some other plugins to
ObjectFile plugins. However, I believe this is fine because:
- these dependencies were already kind of there, and the only reason
we could get away with not modeling them explicitly was because the
code was relying on magically knowing what will GetPluginName() return
for a particular kind of object files.
- the dependencies themselves are logical (it makes sense for
SymbolVendorELF to depend on ObjectFileELF), or at least don't
actively get in the way (the JitLoaderGDB->MachO thing).
- they don't introduce any new dependency loops as ObjectFile plugins
don't depend on any other plugins
Reviewers: xiaobai, JDevlieghere, espindola
Subscribers: emaste, mgorny, arichardson, MaskRay, lldb-commits
Differential Revision: https://reviews.llvm.org/D65450
llvm-svn: 367413
This time, the warning pointed to an actual problem, because the
coff_opt_header structure contained a std::vector. I guess this happened
to work because the all-zero state was a valid representation of an
empty vector, but its not a good idea to rely on that.
I remove the memset, and have the structure clear its members in the
constructor instead.
llvm-svn: 367299
This patch replaces explicit calls to log::Printf with the new LLDB_LOGF
macro. The macro is similar to LLDB_LOG but supports printf-style format
strings, instead of formatv-style format strings.
So instead of writing:
if (log)
log->Printf("%s\n", str);
You'd write:
LLDB_LOG(log, "%s\n", str);
This change was done mechanically with the command below. I replaced the
spurious if-checks with vim, since I know how to do multi-line
replacements with it.
find . -type f -name '*.cpp' -exec \
sed -i '' -E 's/log->Printf\(/LLDB_LOGF\(log, /g' "{}" +
Differential revision: https://reviews.llvm.org/D65128
llvm-svn: 366936
Just delete the memset as the ELFHeader constructor already
zero-initializes the object. Also clean up the ObjectFileELF
constructors/desctructors while I'm in there.
llvm-svn: 366692
The new DriverKit user-land kernel drivers in macOS 10.15 / Catalina
do not have a main() function or an LC_MAIN load command. lldb uses
the address of main() as the return address for inferior function
calls; it puts a breakpoint on main, runs the inferior function call,
and when the main() breakpoint is hit, lldb knows unambiguously that
the inferior function call ran to completion - no other function calls
main.
This change hoists the logic for finding the "entry address" from
ThreadPlanCallFunction to Target. It changes the logic to first
try to get the entry address from the main executable module,
but if that module does not have one, it will iterate through all
modules looking for an entry address.
The patch also adds code to ObjectFileMachO to use dyld's
_dyld_start function as an entry address.
<rdar://problem/52343958>
Differential Revision: https://reviews.llvm.org/D64897
llvm-svn: 366493
Instead of having to write FileSpecList::Append(FileSpec(args)) you can
now call FileSpecList::EmplaceBack(args), similar to
std::vector<>::emplace_back.
llvm-svn: 366489
With this style, a compressed section is indicated by a "z" in the section
name, instead of a section header flag. This patch consists of two small tweaks:
- use an llvm Decompressor method in order to properly detect compressed sections
- make sure we recognise .zdebug_info (and friends) when classifying section types.
llvm-svn: 365654
Summary: This patch modernizes the GetSDKVersion API and hopefully prevents problems such as the ones discovered in D61218.
Reviewers: aprantl, jasonmolenda, clayborg
Reviewed By: aprantl, clayborg
Subscribers: clayborg, labath, lldb-commits
Tags: #lldb
Differential Revision: https://reviews.llvm.org/D61233
llvm-svn: 365090
operator new doesn't return a null pointer, even if one turns off
exceptions (it calls std::terminate instead). Therefore, all of this is
dead code.
llvm-svn: 364744
Summary:
NFC = [[ https://llvm.org/docs/Lexicon.html#nfc | Non functional change ]]
This commit is the result of modernizing the LLDB codebase by using
`nullptr` instread of `0` or `NULL`. See
https://clang.llvm.org/extra/clang-tidy/checks/modernize-use-nullptr.html
for more information.
This is the command I ran and I to fix and format the code base:
```
run-clang-tidy.py \
-header-filter='.*' \
-checks='-*,modernize-use-nullptr' \
-fix ~/dev/llvm-project/lldb/.* \
-format \
-style LLVM \
-p ~/llvm-builds/debug-ninja-gcc
```
NOTE: There were also changes to `llvm/utils/unittest` but I did not
include them because I felt that maybe this library shall be updated in
isolation somehow.
NOTE: I know this is a rather large commit but it is a nobrainer in most
parts.
Reviewers: martong, espindola, shafik, #lldb, JDevlieghere
Reviewed By: JDevlieghere
Subscribers: arsenm, jvesely, nhaehnle, hiraditya, JDevlieghere, teemperor, rnkovacs, emaste, kubamracek, nemanjai, ki.stfu, javed.absar, arichardson, kbarton, jrtc27, MaskRay, atanasyan, dexonsmith, arphaman, jfb, jsji, jdoerfert, lldb-commits, llvm-commits
Tags: #lldb, #llvm
Differential Revision: https://reviews.llvm.org/D61847
llvm-svn: 361484
Summary:
First part of a fix for JITed code debugging. This has been a regression from 5.0 to 6.0 and it's is still reproducible on current master: https://bugs.llvm.org/show_bug.cgi?id=36209
The address of the breakpoint site is corrupt: the 0x4 value we end up with, looks like an offset on a zero base address. When we parse the ELF section headers from the JIT descriptor, the load address for the text section we find in `header.sh_addr` is correct.
The bug manifests in `VMAddressProvider::GetVMRange(const ELFSectionHeader &)` (follow it from `ObjectFileELF::CreateSections()`). Here we think the object type was `eTypeObjectFile` and unleash some extra logic [1] which essentially overwrites the address with a zero value.
The object type is deduced from the ELF header's `e_type` in `ObjectFileELF::CalculateType()`. It never returns `eTypeJIT`, because the ELF header has no representation for it [2]. Instead the in-memory ELF object states `ET_REL`, which leads to `eTypeObjectFile`. This is what we get from `lli` at least since 3.x. (Might it be better to write `ET_EXEC` on the JIT side instead? In fact, relocations were already applied at this point, so "Relocatable" is not quite exact.)
So, this patch proposes to set `eTypeJIT` explicitly whenever we read from a JIT descriptor. In `ObjectFileELF::CreateSections()` we can then call `GetType()`, which returns the explicit value or otherwise falls back to `CalculateType()`.
LLDB then sets the breakpoint successfully. Next step: debug info.
```
Process 1056 stopped
* thread #1, name = 'lli', stop reason = breakpoint 1.2
frame #0: 0x00007ffff7ff7000 JIT(0x3ba2030)`jitbp()
JIT(0x3ba2030)`jitbp:
-> 0x7ffff7ff7000 <+0>: pushq %rbp
0x7ffff7ff7001 <+1>: movq %rsp, %rbp
0x7ffff7ff7004 <+4>: movabsq $0x7ffff7ff6000, %rdi ; imm = 0x7FFFF7FF6000
0x7ffff7ff700e <+14>: movabsq $0x7ffff6697e80, %rcx ; imm = 0x7FFFF6697E80
```
[1] It was first introduced with https://reviews.llvm.org/D38142#change-lF6csxV8HdlL, which has also been the original breaking change. The code has changed a lot since then.
[2] ELF object types: https://github.com/llvm/llvm-project/blob/2d2277f5/llvm/include/llvm/BinaryFormat/ELF.h#L110
Reviewers: labath, JDevlieghere, bkoropoff, clayborg, espindola, alexshap, stella.stamenova
Reviewed By: labath, clayborg
Subscribers: probinson, emaste, aprantl, arichardson, MaskRay, AlexDenisov, yurydelendik, lldb-commits
Tags: #lldb
Differential Revision: https://reviews.llvm.org/D61611
llvm-svn: 360354
Summary:
According to [C128] "Virtual functions should specify exactly one
of `virtual`, `override`, or `final`", I've added override where a
virtual function is overriden but the explicit `override` keyword
was missing. Whenever both `virtual` and `override` were specified,
I removed `virtual`. As C.128 puts it:
> [...] writing more than one of these three is both redundant and
> a potential source of errors.
I anticipate a discussion about whether or not to add `override` to
destructors but I went for it because of an example in [ISOCPP1000].
Let me repeat the comment for you here:
Consider this code:
```
struct Base {
virtual ~Base(){}
};
struct SubClass : Base {
~SubClass() {
std::cout << "It works!\n";
}
};
int main() {
std::unique_ptr<Base> ptr = std::make_unique<SubClass>();
}
```
If for some odd reason somebody removes the `virtual` keyword from the
`Base` struct, the code will no longer print `It works!`. So adding
`override` to destructors actively protects us from accidentally
breaking our code at runtime.
[C128]: https://github.com/isocpp/CppCoreGuidelines/blob/master/CppCoreGuidelines.md#c128-virtual-functions-should-specify-exactly-one-of-virtual-override-or-final
[ISOCPP1000]: https://github.com/isocpp/CppCoreGuidelines/issues/1000#issuecomment-476951555
Reviewers: teemperor, JDevlieghere, davide, shafik
Reviewed By: teemperor
Subscribers: kwk, arphaman, kadircet, lldb-commits
Tags: #lldb
Differential Revision: https://reviews.llvm.org/D61440
llvm-svn: 359868
Summary:
When we want to compare a ConstString against a string literal (or any other non-ConstString),
we currently have to explicitly turn the other string into a ConstString. This makes sense as
comparing ConstStrings against each other is only a fast pointer comparison.
However, currently we (rather incorrectly) use in several places in LLDB temporary ConstStrings when
we just want to compare a given ConstString against a hardcoded value, for example like this:
```
if (extension != ConstString(".oat") && extension != ConstString(".odex"))
```
Obviously this kind of defeats the point of ConstStrings. In the comparison above we would
construct two temporary ConstStrings every time we hit the given code. Constructing a
ConstString is relatively expensive: we need to go to the StringPool, take a read and possibly
an exclusive write-lock and then look up our temporary string in the string map of the pool.
So we do a lot of heavy work for essentially just comparing a <6 characters in two strings.
I initially wanted to just fix these issues by turning the temporary ConstString in static variables/
members, but that made the code much less readable. Instead I propose to add a new overload
for the ConstString comparison operator that takes a StringRef. This comparison operator directly
compares the ConstString content against the given StringRef without turning the StringRef into
a ConstString.
This means that the example above can look like this now:
```
if (extension != ".oat" && extension != ".odex")
```
It also no longer has to unlock/lock two locks and call multiple functions in other TUs for constructing
the temporary ConstString instances. Instead this should end up just being a direct string comparison
of the two given strings on most compilers.
This patch also directly updates all uses of temporary and short ConstStrings in LLDB to use this new
comparison operator. It also adds a some unit tests for the new and old comparison operator.
Reviewers: #lldb, JDevlieghere, espindola, amccarth
Reviewed By: JDevlieghere, amccarth
Subscribers: amccarth, clayborg, JDevlieghere, emaste, arichardson, MaskRay, lldb-commits
Tags: #lldb
Differential Revision: https://reviews.llvm.org/D60667
llvm-svn: 359281
D59433 and D60501 changed the way UUIDs are computed from minidump
files. This was done to synchronize the U(G)UID representation with the
native tools of given platforms, but it created a mismatch between
minidumps and breakpad files.
This updates the breakpad algorithm to match the one found in minidumps,
and also adds a couple of tests which should fail if these two ever get
out of sync. Incidentally, this means that the module id in the breakpad
files is almost identical to our notion of UUIDs, so the computation
algorithm can be somewhat simplified.
llvm-svn: 358500
A lot of comments in LLDB are surrounded by an ASCII line to delimit the
begging and end of the comment.
Its use is not really consistent across the code base, sometimes the
lines are longer, sometimes they are shorter and sometimes they are
omitted. Furthermore, it looks kind of weird with the 80 column limit,
where the comment actually extends past the line, but not by much.
Furthermore, when /// is used for Doxygen comments, it looks
particularly odd. And when // is used, it incorrectly gives the
impression that it's actually a Doxygen comment.
I assume these lines were added to improve distinguishing between
comments and code. However, given that todays editors and IDEs do a
great job at highlighting comments, I think it's worth to drop this for
the sake of consistency. The alternative is fixing all the
inconsistencies, which would create a lot more churn.
Differential revision: https://reviews.llvm.org/D60508
llvm-svn: 358135
Summary:
This patch adds support for parsing STACK CFI records from breakpad
files. The expressions specifying the values of registers are not
parsed.The idea is that these will be handed off to the postfix
expression -> dwarf compiler, once it is extracted from the internals of
the NativePDB plugin.
Reviewers: clayborg, amccarth, markmentovai
Subscribers: aprantl, lldb-commits
Differential Revision: https://reviews.llvm.org/D60268
llvm-svn: 357975
Previously we would classify all STACK records into a single bucket.
This is not really helpful, because there are three distinct types of
records beginning with the token "STACK" (STACK CFI INIT, STACK CFI,
STACK WIN). To be consistent with how we're treating other records, we
should classify these as three different record types.
It also implements the logic to put "STACK CFI INIT" and "STACK CFI"
records into the same "section" of the breakpad file, as they are meant
to be read together (similar to how FUNC and LINE records are treated).
The code which performs actual parsing of these records will come in a
separate patch.
llvm-svn: 357691
My apologies for the large patch. With the exception of ConstString.h
itself it was entirely produced by sed.
ConstString has exactly one const char * data member, so passing a
ConstString by reference is not any more efficient than copying it by
value. In both cases a single pointer is passed. But passing it by
value makes it harder to accidentally return the address of a local
object.
(This fixes rdar://problem/48640859 for the Apple folks)
Differential Revision: https://reviews.llvm.org/D59030
llvm-svn: 355553
Summary:
This file implements some general purpose data structures, and so it
belongs to the Utility module.
Reviewers: zturner, jingham, JDevlieghere, clayborg, espindola
Subscribers: emaste, mgorny, javed.absar, arichardson, MaskRay, lldb-commits
Differential Revision: https://reviews.llvm.org/D58970
llvm-svn: 355509
Summary:
These functions should always return the opposite of the
`Triple{Environment,OS,Vendor}WasSpecified` functions. Unspecified unknown is
the same as unspecified, which is why one set of functions should give us what
we want. It's possible to have specified unknown, which is why we can't just
rely on checking the enum values of vendor/os/environment. We must also ensure
that the names of these are empty and not "unknown".
Differential Revision: https://reviews.llvm.org/D58653
llvm-svn: 354933
Split the recognition into NetBSD executables & shared libraries
and core(5) files.
Introduce new owner type: "NetBSD-CORE", as core(5) files are not tagged
in the same way as regular NetBSD executables.
Stop using incorrectly ABI_TAG and ABI_SIZE. Introduce IDENT_TAG,
IDENT_DECSZ, IDENT_NAMESZ and PROCINFO.
The new values detect correctly the NetBSD images.
The patch has been originally written by Kamil Rytarowski. I've added
tests and applied minor code changes per review. The work has been
sponsored by the NetBSD Foundation.
Differential Revision: https://reviews.llvm.org/D42870
llvm-svn: 354466
COFF files are modelled in lldb as having one big container section
spanning the entire module image, with the actual sections being
subsections of that. In this model, the base address is simply the
address of the first byte of that section.
This also removes the hack where ObjectFilePECOFF was using the
m_file_offset field to communicate this information. Using file offset
for this purpose is completely wrong, as that is supposed to indicate
where is this ObjectFile located in the file on disk. This field is only
meaningful for fat binaries, and should normally be 0.
Both PDB plugins have been updated to use GetBaseAddress instead of
GetFileOffset.
llvm-svn: 354258
Summary:
This is a preparatory step to enable adding extra unwind strategies by
symbol file plugins. This has been discussed on the lldb-dev mailing
list: <http://lists.llvm.org/pipermail/lldb-dev/2019-February/014703.html>.
Reviewers: jasonmolenda, clayborg, espindola
Subscribers: lemo, emaste, lldb-commits, arichardson
Differential Revision: https://reviews.llvm.org/D58129
llvm-svn: 354033
Summary:
This is coming from the discussion in D55356 (the most interesting part
happened on the mailing list, so it isn't reflected on the review page).
In short the issue is that lldb assumes that all bytes of a module image
in memory will be backed by a "section". This isn't the case for PECOFF
files because the initial bytes of the module image will contain the
file header, which does not correspond to any normal section in the
file. In particular, this means it is not possible to implement
GetBaseAddress function for PECOFF files, because that's supposed point
to the first byte of that header.
If my (limited) understanding of how PECOFF files work is correct, then
the OS is expecded to load the entire module into one continuous chunk
of memory. The address of that chunk (+/- ASLR) is given by the "image
base" field in the COFF header, and it's size by "image size". All of
the COFF sections are then loaded into this range.
If that's true, then we can model this behavior in lldb by creating a
"container" section to represent the entire module image, and then place
other sections inside that. This would make be consistent with how MachO
and ELF files are modelled (except that those can have multiple
top-level containers as they can be loaded into multiple discontinuous
chunks of memory).
This change required a small number of fixups in the PDB plugins, which
assumed a certain order of sections within the object file (which
obivously changes now). I fix this by changing the lookup code to use
section IDs (which are unchanged) instead of indexes. This has the nice
benefit of removing spurious -1s in the plugins as the section IDs in
the pdbs match the 1-based section IDs in the COFF plugin.
Besides making the implementation of GetBaseAddress possible, this also
improves the lookup of addresses in the gaps between the object file
sections, which will now be correctly resolved as belonging to the
object file.
Reviewers: zturner, amccarth, stella.stamenova, clayborg, lemo
Reviewed By: clayborg, lemo
Subscribers: JDevlieghere, abidh, lldb-commits
Tags: #lldb
Differential Revision: https://reviews.llvm.org/D56537
llvm-svn: 353916
The `ap` suffix is a remnant of lldb's former use of auto pointers,
before they got deprecated. Although all their uses were replaced by
unique pointers, some variables still carried the suffix.
In r353795 I removed another auto_ptr remnant, namely redundant calls to
::get for unique_pointers. Jim justly noted that this is a good
opportunity to clean up the variable names as well.
I went over all the changes to ensure my find-and-replace didn't have
any undesired side-effects. I hope I didn't miss any, but if you end up
at this commit doing a git blame on a weirdly named variable, please
know that the change was unintentional.
llvm-svn: 353912
Apparently there are multiple places where MSVC complains about
instantiations with extended aligment. I think it's better to define
`_ENABLE_EXTENDED_ALIGNED_STORAGE` as suggested by the error message.
I don't have access to a Windows machine so this is all speculative.
llvm-svn: 353778
Unlike std::make_unique, which is only available since C++14,
std::make_shared is available since C++11. Not only is std::make_shared
a lot more readable compared to ::reset(new), it also performs a single
heap allocation for the object and control block.
Differential revision: https://reviews.llvm.org/D57990
llvm-svn: 353764
instead of returning the UUID through by-ref argument and a boolean
value indicating success, we can just return it directly. Since the UUID
class already has an invalid state, it can be used to denote the failure
without the additional bool.
llvm-svn: 353714
LLDB testsuite fails when built by GCC8 on:
LLDB :: SymbolFile/DWARF/find-basic-namespace.cpp
This is because this code in LLDB codebase has undefined behavior:
#include <algorithm>
#include <string.h>
// lldb/source/Plugins/ObjectFile/Mach-O/ObjectFileMachO.cpp:1731
static struct section_64 {
char sectname[16];
char segname[16];
} sect64 = { {'_','_','a','p','p','l','e','_','n','a','m','e','s','p','a','c'}, "__DWARF" };
int main() {
return std::min<size_t>(strlen(sect64.sectname), sizeof(sect64.sectname));
}
It has been discussed as a (false) bugreport to GCC:
wrong-code: LLDB testcase fails: SymbolFile/DWARF/find-basic-namespace.cpp
https://bugzilla.redhat.com/show_bug.cgi?id=1672436
Differential Revision: https://reviews.llvm.org/D57781
llvm-svn: 353280
The two records aren't used by anything yet, but this part can be
separated out easily, so I am comitting it separately to simplify
reviews of the followup patch.
llvm-svn: 352507
Summary:
This addresses the issues raised in D56844. It removes the accessors from the
breakpad record structures by making the fields public. Also, I refactor the
UUID parsing code to remove hard-coded constants.
Reviewers: lemo
Subscribers: clayborg, lldb-commits
Differential Revision: https://reviews.llvm.org/D57037
llvm-svn: 352021
This patch extends SymbolFileBreakpad::AddSymbols to include the symbols
from the FUNC records too. These symbols come from the debug info and
have a size associated with them, so they are given preference in case
there is a PUBLIC record for the same address.
To achieve this, I first pre-process the symbols into a temporary
DenseMap, and then insert the uniqued symbols into the module's symtab.
Reviewers: clayborg, lemo, zturner
Reviewed By: clayborg
Subscribers: lldb-commits
Differential Revision: https://reviews.llvm.org/D56590
llvm-svn: 351781
to reflect the new license.
We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.
Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.
llvm-svn: 351636
Summary:
This centralizes parsing of breakpad records, which was previously
spread out over ObjectFileBreakpad and SymbolFileBreakpad.
For each record type X there is a separate breakpad::XRecord class, and
an associated parse function. The classes just store the information in
the breakpad records in a more accessible form. It is up to the users to
determine what to do with that data.
This separation also made it possible to write some targeted tests for
the parsing code, which was previously unaccessible, so I write a couple
of those too.
Reviewers: clayborg, lemo, zturner
Reviewed By: clayborg
Subscribers: mgorny, fedor.sergeev, lldb-commits
Differential Revision: https://reviews.llvm.org/D56844
llvm-svn: 351541
The code was assuming that the elf file will have a PT_LOAD segment
starting from the first byte of the file. While this is true for files
generated by most linkers (it's a way of saving space), it is not a
requirement. And files not satisfying this constraint can still be
perfectly executable. yaml2obj is one of the tools which produces files
like this.
This patch relaxes the check in ObjectFileELF to take the address of the
first PT_LOAD segment as the base address of the object (instead of the
one with the offset 0). Since the PT_LOAD segments are supposed to be
sorted according to the VM address, this entry will also be the one with
the lowest VM address.
If we ever run into files which don't have the PT_LOAD segments sorted,
we can easily change this code to return the lowest VM address as the
base address (if that is the correct thing to do for these files).
llvm-svn: 350923
If a section name is exactly 8 bytes long (or has been truncated to 8
bytes), it will not contain the terminating nul character. This means
reading the name as a c string will pick up random data following the
name field (which happens to be the section vm size).
This fixes the name computation to avoid out-of-bounds access and adds a
test.
Reviewers: zturner, stella.stamenova
Subscribers: lldb-commits
Differential Revision: https://reviews.llvm.org/D56124
llvm-svn: 350809
Summary:
The concept of a base address was already present in the implementation
(it's needed for computing section load addresses properly), but it was
never exposed through this function. This fixes that.
llvm-svn: 350804
Summary:
This is the result of the discussion in D55356, where it was suggested
as a solution to representing the addresses that logically belong to a
module in memory, but are not a part of any of its sections.
The ELF PT_LOAD segments are similar to the MachO "load commands",
except that the relationship between them and the object file sections
is a bit weaker. While in the MachO case, the sections belonging to a
specific segment are placed directly inside it in the object file
logical structur, in the ELF case, the sections and segments form two
separate hierarchies. This means that it is in theory possible to create
an elf file where only a part of a section would belong to some segment
(and another part to a different one). However, I am not aware of any
tool which would produce such a file (and most tools will have problems
ingesting them), so this means it is still possible to follow the MachO
model and make sections children of the PT_LOAD segments.
In case we run into (corrupt?) files with overlapping sections, I have
added code (and tests) which adjusts the sizes and/or drops the offending
sections in order to present a reasonable image to the upper layers of
LLDB. This is mostly done for completeness, as I don't anticipate
running into this situation in the real world. However, if we do run
into it, and the current behavior is not suitable for some reason, we
can implement this logic differently.
Reviewers: clayborg, jankratochvil, krytarowski, joerg, espindola
Subscribers: emaste, arichardson, lldb-commits
Differential Revision: https://reviews.llvm.org/D55998
llvm-svn: 350742
Summary:
This patch allows ObjectFileBreakpad to parse the contents of Breakpad
files into sections. This sounds slightly odd at first, but in essence
its not too different from how other object files handle things. For
example in elf files, the symtab section consists of a number of
"records", where each record represents a single symbol. The same is
true for breakpad's PUBLIC section, except in this case, the records will be
textual instead of binary.
To keep sections contiguous, I create a new section every time record
type changes. Normally, the breakpad processor will group all records of
the same type in one block, but the format allows them to be intermixed,
so in general, the "object file" may contain multiple sections with the
same record type.
Reviewers: clayborg, zturner, lemo, markmentovai, amccarth
Subscribers: lldb-commits
Differential Revision: https://reviews.llvm.org/D55434
llvm-svn: 350511
Summary:
instead of returning the architecture through by-ref argument and a
boolean value indicating success, we can just return the ArchSpec
directly. Since the ArchSpec already has an invalid state, it can be
used to denote the failure without the additional bool.
Reviewers: clayborg, zturner, espindola
Subscribers: emaste, arichardson, JDevlieghere, lldb-commits
Differential Revision: https://reviews.llvm.org/D56129
llvm-svn: 350291
Prior to this there were 3 places that were duplicating the logic to detect if a section can/should be loaded and some were doing things a bit differently. Now it is all centralized in one place and it is done correctly.
llvm-svn: 349926
Summary:
The first section header does not define a real section. Instead it is
used for various elf extensions. This patch skips creation of a section
for index 0.
This has one furtunate side-effect, in that it allows us to use the section
header index as the Section ID (where 0 is also invalid). This way, we
can get rid of a lot of spurious +1s in the ObjectFileELF code.
Reviewers: clayborg, krytarowski, joerg, espindola
Subscribers: emaste, lldb-commits, arichardson
Differential Revision: https://reviews.llvm.org/D55757
llvm-svn: 349498
Summary:
This patch attempts to move as much code as possible out of the
CreateSections function to make room for future improvements there. Some
of this may be slightly over-engineered (VMAddressProvider), but I
wanted to keep the logic of this function very simple, because once I
start taking segment headers into acount (as discussed in D55356), the
function is going to grow significantly.
While in there, I also added tests for various bits of functionality.
This should be NFC, except that I changed the order of hac^H^Heuristicks
for determining section type slightly. Previously, name-based deduction
(.symtab -> symtab) would take precedence over type-based (SHT_SYMTAB ->
symtab) one. In fact we would assert if we ran into a .text section with
type SHT_SYMTAB. Though unlikely to matter in practice, this order
seemed wrong to me, so I have inverted it.
Reviewers: clayborg, krytarowski, espindola
Subscribers: emaste, arichardson, lldb-commits
Differential Revision: https://reviews.llvm.org/D55706
llvm-svn: 349268
This patch simplifies boolean expressions acorss LLDB. It was generated
using clang-tidy with the following command:
run-clang-tidy.py -checks='-*,readability-simplify-boolean-expr' -format -fix $PWD
Differential revision: https://reviews.llvm.org/D55584
llvm-svn: 349215
Move code into a separate function, and replace the if-else chain with
llvm::StringSwitch.
A slight behavioral change is that now I use the section flags
(SHF_TLS) instead of the section name to set the thread-specific
property. There is no explanation in the original commit introducing
this (r153537) as to why that was done this way, but the new behavior
should be more correct.
llvm-svn: 348936
Kadir Cetinkaya