Remove the is_mangled flag from Mangled and Symbol

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

Remove the is_mangled flag from Mangled and Symbol

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

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Unify the two CRC implementations

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 prese

Unify the two CRC implementations

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

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Explicitly set entry point arch when it's thumb [Second Try]

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 @la

Explicitly set entry point arch when it's thumb [Second Try]

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

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[lldb][ELF] Read symbols from .gnu_debugdata sect.

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
o

[lldb][ELF] Read symbols from .gnu_debugdata sect.

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

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Revert "Explicitly set entry point arch when it's thumb"

Backing out because SymbolFile/Breakpad/symtab.test is failing and it seems to be a legit issue. Will investigate.

This reverts commit 72153

Revert "Explicitly set entry point arch when it's thumb"

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

show more ...

Explicitly set entry point arch when it's thumb

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 th

Explicitly set entry point arch when it's thumb

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

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Revert "[LLDB][ELF] Load both, .symtab and .dynsym sections"

This reverts commit 3a4781bbf4f39a25562b4c61c9a9ab2483a96b41.

llvm-svn: 371625

Revert "[LLDB][ELF] Fixup for comments in D67390"

This reverts commit 813f05915d29904878d926f9849ca3dbe78096af.

llvm-svn: 371624

[LLDB][ELF] Fixup for comments in D67390

llvm-svn: 371600

[LLDB][ELF] Load both, .symtab and .dynsym sections

Summary:
This change ensures that the .dynsym section will be parsed even when there's already is a .symtab.

It is motivated because of minidebug

[LLDB][ELF] Load both, .symtab and .dynsym sections

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

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[LLDB] Migrate llvm::make_unique to std::make_unique

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

[LLDB] Migrate llvm::make_unique to std::make_unique

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

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ObjectFileELF: Remove NT_*** constants

llvm now has definitions of those in BinaryFormat/ELF.h. Use those
instead.

llvm-svn: 368159

ObjectFileELF: permit thread-local sections with overlapping file addresses

Summary:
In an attempt to make file-address-based lookups more predictable, in D55998
we started ignoring sections which w

ObjectFileELF: permit thread-local sections with overlapping file addresses

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

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ObjectFile[ELF]: Refactor gnu_debuglink interface

Summary:
The contents of the gnu_debuglink section were passed through the
GetDebugSymbolFilePaths interface, which was more generic than needed.
As

ObjectFile[ELF]: Refactor gnu_debuglink interface

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

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Add llvm-style RTTI to ObjectFile hierarchy

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
existi

Add llvm-style RTTI to ObjectFile hierarchy

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

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ObjectFileELF: Use llvm::JamCRC to refactor CRC32 computation

Reviewed By: labath

Differential Revision: https://reviews.llvm.org/D65318

llvm-svn: 367090

[Logging] Replace Log::Printf with LLDB_LOG macro (NFC)

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 for

[Logging] Replace Log::Printf with LLDB_LOG macro (NFC)

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

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ELF: Fix a "memset clearing object of non-trivial type" warning

Just delete the memset as the ELFHeader constructor already
zero-initializes the object. Also clean up the ObjectFileELF
constructors/

ELF: Fix a "memset clearing object of non-trivial type" warning

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

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ObjectFileELF: Add support for gnu-style compressed sections

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

ObjectFileELF: Add support for gnu-style compressed sections

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

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Recognise debug_types.dwo as a debug info section

This is a preparatory patch to allow reading type units from dwo files.

llvm-svn: 363146

[lldb] NFC modernize codebase with modernize-use-nullptr

Summary:
NFC = [[ https://llvm.org/docs/Lexicon.html#nfc | Non functional change ]]

This commit is the result of modernizing the LLDB codeba

[lldb] NFC modernize codebase with modernize-use-nullptr

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

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Simplify ArchSpec::IsMIPS()

llvm-svn: 360865

[JITLoaderGDB] Set eTypeJIT for objects read from JIT descriptors

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

[JITLoaderGDB] Set eTypeJIT for objects read from JIT descriptors

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

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Allow direct comparison of ConstString against StringRef

Summary:
When we want to compare a ConstString against a string literal (or any other non-ConstString),
we currently have to explicitly turn

Allow direct comparison of ConstString against StringRef

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

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[NFC] Remove ASCII lines from comments

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

[NFC] Remove ASCII lines from comments

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

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