Commit Graph

7186 Commits

Author SHA1 Message Date
Shafik Yaghmour
4f14c17df7 [LLDB] Remove uneeded CopyType from BlockPointerSyntheticFrontEnd
BlockPointerSyntheticFrontEnd does a CopyType which results in it copying the type
back into its own context. This will result in a call to ASTImporterDelegate::setOrigin
with &decl->getASTContext() == origin.ctx this can result in an infinite recursion
later on in ASTImporter since it will attempt to find the decl in its origin which will be itself.

Differential Revision: https://reviews.llvm.org/D96366
2021-02-09 16:11:28 -08:00
Michał Górny
bd03f6df51 [lldb] [Process/FreeBSDRemote] Introduce powerpc support
Introduce a minimal support for the 32-bit powerpc platform.  This
includes support for GPR and FPR registers.  I also needed to add
software breakpoint opcode for PPC32/PPC64 (big endian), and to fix
offsets in RegisterInfos_powerpc.h (used only by FreeBSD register
context to be globally unique rather than relative to each struct).

Differential Revision: https://reviews.llvm.org/D95947
2021-02-09 21:10:45 +01:00
Dave Lee
2309392449 [lldb] Inline invariant params to AppleThreadPlanStepThrough (NFC)
These two `AppleThreadPlanStepThrough` thread plans have parameterized behavior
that is unutilized. To make their interface and implementation simpler, this
change inlines those outside parameters.

Differential Revision: https://reviews.llvm.org/D96276
2021-02-09 08:03:51 -08:00
Michał Górny
8244fc505d [lldb] [Process/FreeBSDRemote] Introduce mips64 support
Introduce mips64 support to match the legacy FreeBSD plugin. Similarly
to the legacy plugin, the code does not support FPU registers at the
moment.  The support for them will be submitted separately as it
requires changes to the register context shared by both plugins.

This also includes software single-stepping support that is moved from
the Linux plugin into a common Utility class.  The FreeBSD code also
starts explicitly ignoring EINVAL from PT_CLEARSTEP since this is easier
to implement than checking whether hardware single-stepping were used.

Differential Revision: https://reviews.llvm.org/D95802
2021-02-08 18:27:26 +01:00
Muhammad Omair Javaid
8561ad9296 Use remote regnums in expedited list, value regs and invalidate regs
Native register descriptions in LLDB specify lldb register numbers in
value_regs and invalidate_regs lists. These register numbers may not
match with Process gdb-remote register numbers which are generated by
native process after counting all registers in its register sets.

It was coincidentally not causing any problems as we never came across
a native target with dynamically changing register sets and register
numbers generated by counter matched with LLDB native register numbers.
This came up while testing target AArch64 SVE which can choose register
sets based on underlying hardware.

This patch fixes this behavior and always tries to use remote register
numbers while reading/writing registers over gdb-remote protocol.

Reviewed By: labath

Differential Revision: https://reviews.llvm.org/D77043
2021-02-08 14:09:15 +05:00
Djordje Todorovic
9abd8c1a4c [elf-core] Improve reading memory from core file
This patch tries to improve memory-read from core files
(in order to improve disassembly functionality).

I am using RHEL 7.7 (linux kernel 3.10) and for a lot of cases,
I was not able to disassemble some functions from backtrace when
debugging crashes from core files. It outputs some dummy code.

The cause of the problem was the fact we are returning all the zeros
from ProcessElfCore::ReadMemory() that is being called within
Disassembler::ParseInstructions() and it disassembles some dummy
opcodes from the buffer returned. Therefore, we are removing zero
bytes filling (padding) completely.

Differential Revision: https://reviews.llvm.org/D93939
2021-02-08 00:14:32 -08:00
Michał Górny
9d029362d1 [lldb] [Process/FreeBSDRemote] Introduce arm (32-bit) support
Introduce a NativeRegisterContextFreeBSD for 32-bit ARM platform.
This includes support for GPR + VFP registers as exposed by FreeBSD's
ptrace(2) API.  Hardware breakpoints or watchpoints are not supported
due to missing kernel support.  The code is roughly based on the arm64
context.

It also includes an override for GetSoftwareBreakpointTrapOpcode() based
on the matching code in the PlatformFreeBSD plugin.

Differential Revision: https://reviews.llvm.org/D95696
2021-01-31 19:52:08 +01:00
Michał Górny
f43c0707f6 [lldb] [Process/FreeBSDRemote] Introduce arm64 support
Introduce arm64 support in the FreeBSDRemote plugin.  The code
is roughly based on Linux and reuses the same POSIX RegisterInfos
(but the buffers need to be a few bytes larger due to stricter struct
member alignment in FreeBSD structures -- luckily, they do not affect
the actual member offsets).  It supports reading and writing
general-purpose and FPU registers.  SVE and hardware watchpoint support
is missing due to the limitations of FreeBSD ptrace(2) API.

Differential Revision: https://reviews.llvm.org/D95297
2021-01-31 19:52:08 +01:00
Raphael Isemann
e2a1a718bb [lldb] Add move_iterator to supported template list
Identical to previous commits that just add a standard library template to the
supported template list and test it. Adding this rather obscure class to the
template list is mostly caused by the std::deque test unexpectedly referencing
this type when testing against newer libc++ versions on macOS.

Fixes TestQueueFromStdModule and TestQueueFromStdModule on macOS.
Fixes rdar://73213589
2021-01-27 13:52:42 +01:00
Raphael Isemann
48e09faa94 [lldb][NFC] Another attempt to fix GCC 5.x compilation
37510f69b4 tried to fix GCC 5.x compilation
by making the enum which is used as a unordered_map key unscoped. However it
seems that in GCC 5.x, enum keys are not supported *at all* in unordered_maps
(at least that's what some trial&error on godbolt tells me). This updates the
workaround to just use an int until GCC 5.x support is dropped.
2021-01-26 19:13:12 +01:00
Duncan P. N. Exon Smith
8b6aedc4c9 ExpressionParser: Migrate to FileEntryRef in ParseInternal, NFC
Migrate to the `FileEntryRef` overload of `SourceManager::createFileID`
(using `FileManager::getOptionalFileRef`) in
`ClangExpressionParser::ParseInternal`.

No functionality change here.

Differential Revision: https://reviews.llvm.org/D92957
2021-01-25 16:38:42 -08:00
Pedro Tammela
532e4203c5 [lldb/Lua] add support for Lua function breakpoint
Adds support for running a Lua function when a breakpoint is hit.

Example:
   breakpoint command add -s lua -F abc

The above runs the Lua function 'abc' passing 2 arguments. 'frame', 'bp_loc' and 'extra_args'.

A third parameter 'extra_args' is only present when there is structured data
declared in the command line.

Example:
   breakpoint command add -s lua -F abc -k foo -v bar

Differential Revision: https://reviews.llvm.org/D93649
2021-01-25 23:40:57 +00:00
Walter Erquinigo
4bb6244871 [ThreadPlan] fix exec on Linux 2021-01-25 11:30:48 -08:00
Muhammad Omair Javaid
2fd4d923a8 [LLDB] Define AUXV_AT_HWCAP2 in AuxVector.h
This patch defines AUXV_AT_HWCAP2 for accessing Aux extensions.
2021-01-25 20:48:16 +05:00
Muhammad Omair Javaid
b45020cf63 [LLDB] Remove leftovers and typos from RegisterInfos_arm64_sve.h
This patch removes a couple of left-overs and a typo from
RegisterInfos_arm64_sve.h and RegisterInfoPOSIX_arm64.h.
2021-01-25 20:48:15 +05:00
David Blaikie
78d41a1295 lldb: Add support for printing variables with DW_AT_ranges on DW_TAG_subprograms
Finishing out the support (to the best of my knowledge/based on current
testing running the whole check-lldb with a clang forcibly using
DW_AT_ranges on all DW_TAG_subprograms) for this feature.

Differential Revision: https://reviews.llvm.org/D94064
2021-01-24 18:39:06 -08:00
Augusto Noronha
2afaf072f5 Implement vAttachOrWait
Implements the required functions on gdb-remote so the '--include-existing' flag of process attach works correctly on Linux.

Reviewed By: labath, clayborg

Differential Revision: https://reviews.llvm.org/D94672
2021-01-24 21:30:09 +01:00
Shafik Yaghmour
dc057e87f6 [LLDB] Fix how ObjCBOOLSummaryProvider deals with BOOL
ObjCBOOLSummaryProvider was incorrectly treating BOOL as unsigned and this is now fixed.
Also adding tests for one bit bit-fields of BOOL and unsigned char.
2021-01-22 10:05:24 -08:00
Raphael Isemann
37510f69b4 [lldb][NFC] Fix build with GCC<6
GCC/libstdc++ before 6.1 can't handle scoped enums as unordered_map keys. LLVM
(and some build) bots officially support some GCC 5.x versions, so this patch
just makes the enum unscoped until we can require GCC 6.x.
2021-01-21 15:04:41 +01:00
Raphael Isemann
99b7b41edf [lldb][import-std-module] Do some basic file checks before trying to import a module
Currently when LLDB has enough data in the debug information to import the `std` module,
it will just try to import it. However when debugging libraries where the sources aren't
available anymore, importing the module will generate a confusing diagnostic that
the module couldn't be built.

For the fallback mode (where we retry failed expressions with the loaded module), this
will cause the second expression to fail with a module built error instead of the
actual parsing issue in the user expression.

This patch adds checks that ensures that we at least have any source files in the found
include paths before we try to import the module. This prevents the module from being
loaded in the situation described above which means we don't emit the bogus 'can't
import module' diagnostic and also don't waste any time retrying the expression in the
fallback mode.

For the unit tests I did some refactoring as they now require a VFS with the files in it
and not just the paths. The Python test just builds a binary with a fake C++ module,
then deletes the module before debugging.

Fixes rdar://73264458

Reviewed By: JDevlieghere

Differential Revision: https://reviews.llvm.org/D95096
2021-01-21 12:32:51 +01:00
Hans Wennborg
8ba442bc21 Revert "Following up on PR48517, fix handling of template arguments that refer"
Combined with 'da98651 - Revert "DR2064:
decltype(E) is only a dependent', this change (5a391d3) caused verifier
errors when building Chromium. See https://crbug.com/1168494#c1 for a
reproducer.

Additionally it reverts changes that were dependent on this one, see
below.

> Following up on PR48517, fix handling of template arguments that refer
> to dependent declarations.
>
> Treat an id-expression that names a local variable in a templated
> function as being instantiation-dependent.
>
> This addresses a language defect whereby a reference to a dependent
> declaration can be formed without any construct being value-dependent.
> Fixing that through value-dependence turns out to be problematic, so
> instead this patch takes the approach (proposed on the core reflector)
> of allowing the use of pointers or references to (but not values of)
> dependent declarations inside value-dependent expressions, and instead
> treating template arguments as dependent if they evaluate to a constant
> involving such dependent declarations.
>
> This ends up affecting a bunch of OpenMP tests, due to OpenMP
> imprecisely handling instantiation-dependent constructs, bailing out
> early instead of processing dependent constructs to the extent possible
> when handling the template.
>
> Previously committed as 8c1f2d15b8, and
> reverted because a dependency commit was reverted.

This reverts commit 5a391d38ac.

It also restores clang/test/SemaCXX/coroutines.cpp to its state before
da986511fb.

Revert "[c++20] P1907R1: Support for generalized non-type template arguments of scalar type."

> Previously committed as 9e08e51a20, and
> reverted because a dependency commit was reverted. This incorporates the
> following follow-on commits that were also reverted:
>
> 7e84aa1b81 by Simon Pilgrim
> ed13d8c667 by me
> 95c7b6cadb by Sam McCall
> 430d5d8429 by Dave Zarzycki

This reverts commit 4b574008ae.

Revert "[msabi] Mangle a template argument referring to array-to-pointer decay"

> [msabi] Mangle a template argument referring to array-to-pointer decay
> applied to an array the same as the array itself.
>
> This follows MS ABI, and corrects a regression from the implementation
> of generalized non-type template parameters, where we "forgot" how to
> mangle this case.

This reverts commit 18e093faf7.
2021-01-20 15:55:35 +01:00
Muhammad Omair Javaid
e448ad787e [LLDB] Add support to resize SVE registers at run-time
This patch builds on previously submitted SVE patches regarding expedited
register set and per thread register infos. (D82853 D82855 and D82857)

We need to resize SVE register based on value received in expedited list.
Also we need to resize SVE registers when we write vg register using
register write vg command. The resize will result in a updated offset
for all of fpr and sve register set. This offset will be configured
in native register context by RegisterInfoInterface and will also be
be updated on client side in GDBRemoteRegisterContext.

A follow up patch will provide a API test to verify this change.

Reviewed By: labath

Differential Revision: https://reviews.llvm.org/D82863
2021-01-19 15:01:32 +05:00
Richard Smith
4b574008ae [c++20] P1907R1: Support for generalized non-type template arguments of scalar type.
Previously committed as 9e08e51a20, and
reverted because a dependency commit was reverted. This incorporates the
following follow-on commits that were also reverted:

7e84aa1b81 by Simon Pilgrim
ed13d8c667 by me
95c7b6cadb by Sam McCall
430d5d8429 by Dave Zarzycki
2021-01-18 21:05:01 -08:00
Muhammad Omair Javaid
b9993fcbf5 DynamicRegisterInfo calculate offsets in separate function
This patch pull offset calculation logic out of DynamicRegisterInfo::Finalize
into a separate function. We are going to call this function whenever we
update SVE register sizes.

Reviewed By: labath

Differential Revision: https://reviews.llvm.org/D94008
2021-01-15 16:21:18 +05:00
Muhammad Omair Javaid
4fd77668b2 [LLDB] Add per-thread register infos shared pointer in gdb-remote
In gdb-remote process we have register infos defind as a refernce object of
GDBRemoteDynamicRegisterInfo class. In past register infos have remained
constant througout the life time of a process.

This has changed after AArch64 SVE support where register infos will have
per-thread configuration. SVE registers will have per-thread size and can
be updated while running. This patch aims to build up for that support by
changing GDBRemoteDynamicRegisterInfo reference to a shared pointer deinfed
per-thread.

Reviewed By: labath

Differential Revision: https://reviews.llvm.org/D82857
2021-01-15 16:11:17 +05:00
Joseph Tremoulet
85dfcaadc5 [LLDB] MinidumpParser: Prefer executable module even at higher address
When a program maps one of its own modules for reading, and then
crashes, breakpad can emit two entries for that module in the
ModuleList.  We have logic to identify this case by checking permissions
on mapped memory regions and report just the module with an executable
region.  As currently written, though, the check is asymmetric -- the
entry with the executable region must be the second one encountered for
the preference to kick in.

This change makes the logic symmetric, so that the first-encountered
module will similarly be preferred if it has an executable region but
the second-encountered module does not.  This happens for example when
the module in question is the executable itself, which breakpad likes to
report first -- we need to ignore the other entry for that module when
we see it later, even though it may be mapped at a lower virtual
address.

Reviewed By: clayborg

Differential Revision: https://reviews.llvm.org/D94629
2021-01-14 13:17:57 -05:00
Pavel Labath
4b284b9ca8 [lldb] Fix TestPlatformProcessConnect.py
The test was marked as remote-only, which means it was run ~never, and
accumulated various problems. This commit modifies the test to run
locally and includes a couple of other fixes necessary to make it run:
- moves the "invoke" method into the "Base" test class
- adds []'s around the IP address in a couple more places to make things
  work with IPv6

The test is now marked as skipped when running the remote test suite. It
would be possible to make it run both locally and remotely, but this
would require writing a lot special logic for the remote case, and that
is not worth it.
2021-01-14 09:49:19 +01:00
Augusto Noronha
2bbf724fee Implement vAttachWait in lldb-server
This commit vAttachWait in lldb-server, so --waitfor can be used on
Linux

Reviewed By: labath, clayborg

Differential Revision: https://reviews.llvm.org/D93895
2021-01-14 09:25:15 +01:00
Philip Pfaffe
7ad54d1938 [lldb][wasm] Parse DWO section names
Mirror ELF section parsing to support DWARF section names for
debug fission.

Reviewed By: labath

Differential Revision: https://reviews.llvm.org/D93621
2021-01-14 08:45:02 +01:00
Raphael Isemann
b0dc54e08a [lldb][NFC] Refactor setup code for Clang diagnostics 2021-01-08 14:26:04 +01:00
Jonas Devlieghere
57e0cd3562 [lldb] Make DoReadMemory a protected method.
DoReadMemory is LLDB's internal implementation and shouldn't be called
directly.

Differential revision: https://reviews.llvm.org/D94284
2021-01-07 21:06:36 -08:00
Jonas Devlieghere
f2e05855de [lldb] Access the ModuleList through iterators where possible (NFC)
Replace uses of GetModuleAtIndexUnlocked and
GetModulePointerAtIndexUnlocked with the ModuleIterable and
ModuleIterableNoLocking where applicable.

Differential revision: https://reviews.llvm.org/D94271
2021-01-07 21:06:36 -08:00
Luís Marques
15f5971150 [LLDB][RISCV] Add RISC-V ArchSpec and rv32/rv64 variant detection
Adds the RISC-V ArchSpec bits contributed by @simoncook as part of D62732,
plus logic to distinguish between riscv32 and riscv64 based on ELF class.

The patch follows the implementation approach previously used for MIPS.
It defines RISC-V architecture subtypes and inspects the ELF header,
namely the ELF class, to detect the right subtype.

Differential Revision: https://reviews.llvm.org/D86292
2021-01-07 23:02:55 +00:00
David Blaikie
274afac9a1 lldb: Add support for DW_AT_ranges on DW_TAG_subprograms
gcc already produces debug info with this form
-freorder-block-and-partition
clang produces this sort of thing with -fbasic-block-sections and with a
coming-soon tweak to use ranges in DWARFv5 where they can allow greater
reuse of debug_addr than the low/high_pc forms.

This fixes the case of breaking on a function name, but leaves broken
printing a variable - a follow-up commit will add that and improve the
test case to match.

Differential Revision: https://reviews.llvm.org/D94063
2021-01-07 14:28:03 -08:00
David Spickett
801c7866e6 [lldb][ARM/AArch64] Update disasm flags to latest v8.7a ISA
Add optional memory tagging extension on AArch64.

Use isAArch64() instead of listing the AArch64 triples,
which fixes us not recognising aarch64_be.

Reviewed By: omjavaid

Differential Revision: https://reviews.llvm.org/D94084
2021-01-07 10:51:47 +00:00
Pedro Tammela
d853bd7a4e [lldb/Lua] add support for multiline scripted breakpoints
1 - Partial Statements

The interpreter loop runs every line it receives, so partial
Lua statements are not being handled properly. This is a problem for
multiline breakpoint scripts since the interpreter loop, for this
particular case, is just an abstraction to a partially parsed function
body declaration.

This patch addresses this issue and as a side effect improves the
general Lua interpreter loop as well. It's now possible to write partial
statements in the 'script' command.

Example:
   (lldb) script
   >>>   do
   ..>   local a = 123
   ..>   print(a)
   ..>   end
   123

The technique implemented is the same as the one employed by Lua's own REPL implementation.
Partial statements always errors out with the '<eof>' tag in the error
message.

2 - CheckSyntax in Lua.h

In order to support (1), we need an API for just checking the syntax of string buffers.

3 - Multiline scripted breakpoints

Finally, with all the base features implemented this feature is
straightforward. The interpreter loop behaves exactly the same, the
difference is that it will aggregate all Lua statements into the body of
the breakpoint function. An explicit 'quit' statement is needed to exit the
interpreter loop.

Example:
   (lldb) breakpoint command add -s lua
   Enter your Lua command(s). Type 'quit' to end.
   The commands are compiled as the body of the following Lua function
   function (frame, bp_loc, ...) end
   ..> print(456)
   ..> a = 123
   ..> quit

Differential Revision: https://reviews.llvm.org/D93481
2021-01-07 00:31:36 +00:00
Jorge Gorbe Moya
a39b19821b Make DWARFUnit use the dwo_id from the DWARF5 CU header.
In split DWARF v5 files, the DWO id is no longer in the DW_AT_GNU_dwo_id
attribute. It's in the CU header instead. This change makes lldb look in
both places.

Differential Revision: https://reviews.llvm.org/D93444
2021-01-05 16:40:37 -08:00
Michał Górny
d5317b41c5 [Process/NetBSD] Copy changes from FreeBSDRemote and reformat
Copy changes, including:

- NativeProcessNetBSD::GetLoadedModuleFileSpec()
  and NativeProcessNetBSD::GetFileLoadAddress() methods

- split x86 register sets by CPU extensions

- use offset/size-based register reading/writing

Differential Revision: https://reviews.llvm.org/D93541
2021-01-02 19:15:12 +01:00
Peter Collingbourne
7e5a187de3 CrashReason: Add MTE tag check faults to the list of crash reasons.
As of Linux 5.10, the kernel may report either of the two following
crash reasons:
- SEGV_MTEAERR: async MTE tag check fault
- SEGV_MTESERR: sync MTE tag check fault

Teach LLDB about them.

Differential Revision: https://reviews.llvm.org/D93495
2020-12-29 14:36:50 -08:00
Arthur Eubanks
6283d2aa51 Revert "[LLDB] Unbreak the build after recent clang changes"
This reverts commit 430d5d8429.

Depends on a reverted change.
2020-12-22 10:34:04 -08:00
Andy Yankovsky
1432ae57bf [lldb] Add SBType::GetEnumerationIntegerType method
Add a method for getting the enumeration underlying type.

Differential revision: https://reviews.llvm.org/D93696
2020-12-22 10:08:22 -08:00
Andy Yankovsky
e17a00fc87 [lldb] Add SBType::IsScopedEnumerationType method
Add a method to check if the type is a scoped enumeration (i.e. "enum
class/struct").

Differential revision: https://reviews.llvm.org/D93690
2020-12-22 10:08:21 -08:00
Jonas Devlieghere
5c1c8443eb [lldb] Abstract scoped timer logic behind LLDB_SCOPED_TIMER (NFC)
This patch introduces a LLDB_SCOPED_TIMER macro to hide the needlessly
repetitive creation of scoped timers in LLDB. It's similar to the
LLDB_LOG(F) macro.

Differential revision: https://reviews.llvm.org/D93663
2020-12-22 09:10:27 -08:00
Michał Górny
bd2e83333e [lldb] [Process/FreeBSDRemote] Remove anonymous namespace 2020-12-21 22:26:54 +01:00
Pavel Labath
3f3ab03ab7 [lldb] Remove anonymous namespace from NativeRegisterContextLinux_x86_64
Use "static" instead.
2020-12-21 20:39:05 +01:00
David Zarzycki
430d5d8429 [LLDB] Unbreak the build after recent clang changes
9e08e51a20 introduced a new enum case.
2020-12-18 07:54:36 -05:00
Michał Górny
835f8de850 [lldb] [Process/FreeBSDRemote] Use RegSetKind consistently [NFC]
Use RegSetKind enum for register sets everything, rather than int.
Always spell it as 'RegSetKind', without unnecessary 'enum'.  Add
missing switch case.  While at it, use uint32_t for regnums
consistently.

Differential Revision: https://reviews.llvm.org/D93450
2020-12-17 18:01:46 +01:00
Michał Górny
9ead4e7b4a [lldb] [Process/FreeBSDRemote] Replace GetRegisterSetCount()
Replace the wrong code in GetRegisterSetCount() with a constant return.
The original code passed register index in place of register set index,
effectively getting always true.  Correcting the code to check for
register set existence is not possible as LLDB supports only eliminating
last register sets.  Just return the full number for now which should
be NFC.

Differential Revision: https://reviews.llvm.org/D93396
2020-12-17 18:01:14 +01:00
Raphael Isemann
b8338983e6 [lldb] Add std::array to the supported template list of the CxxModuleHandler
Identical to the other patches that add STL containers to the supported
templated list.
2020-12-17 11:47:58 +01:00
Raphael Isemann
722247c812 [lldb] Unify the two CreateTypedef implementations in TypeSystemClang
To get LLDB one step closer to fulfil the software redundancy requirements of
modern aircrafts, we apparently decided to have two separately maintained
implementations of `CreateTypedef` in TypeSystemClang. Let's pass on the idea of
an LLDB-powered jetliner and deleted one implementation.

On a more serious note: This function got duplicated a long time ago when the
idea of CompilerType with a backing TypeSystemClang subclass happened
(56939cb310). One implementation was supposed to
be called from CompilerType::CreateTypedef and the other has just always been
around to create typedefs. By accident one of the implementations is only used
by the PDB parser while the CompilerType::CreateTypedef backend is used by the
rest of LLDB.

We also had some patches over the year that only fixed one of the two functions
(D18099 for example only fixed up the CompilerType::CreateTypedef
implementation). D51162 and D86140 both fixed the same missing `addDecl` call
for one of the two implementations.

This patch:
* deletes the `CreateTypedefType` function as its only used by the PDB parser
  and the `CreateTypedef` implementation is anyway needed as it's the backend
  implementation of CompilerType.
* replaces the calls in the PDB parser by just calling the CompilerType wrapper.
* moves the documentation to the remaining function.
* moves the check for empty typedef names that was only in the deleted
  implementation to the other (I don't think this fixes anything as I believe
  all callers are already doing the same check).

I'll fix up the usual stuff (not using StringRef, not doing early exit) in a NFC
follow-up.

This patch is not NFC as the PDB parser now calls the function that has the fix
from D18099.

Reviewed By: labath, JDevlieghere

Differential Revision: https://reviews.llvm.org/D93382
2020-12-17 10:49:26 +01:00