[lldb][Runtime] Move VerboseTrapFrameRecognizer into CPPLanguageRuntime (#166157)

#165996 is adding a Clang
dependency to Target because we're moving some of the functionality of
the VerboseTrapFrameRecognizer into libClang. To avoid adding this
dependency this patch moves VerboseTrapFrameRecognizer into the
CPPLanguageRuntime. Most of the frame recognizers already live in the
various runtime plugins.

An alternative discussed was to create a common `CLanguageRuntime` whose
currently sole responsibility was to register the
`VerboseTrapFrameRecognizer` and `AssertStackFrameRecognizer`. The main
issue I ran into here was frame recognizers aren't uniqued in the
target. Currently this only manifests when re-running a target, which
re-triggers all the recognizer registration (added a test with a FIXME
for this). If we had a common `CLanguageRuntime` that
`CPPLanguageRuntime` and `ObjCLanguageRuntime` inherited from, I didn't
find a great way to avoid registering the recognizer multiple times. We
can't just call_once on it because we do want the recognisers to be
re-registered for new targets in the same debugger session. If the
recognisers were stored in something like a UniqueVector in the Target,
then we wouldn't have that issue. But currently that's not the case, and
it would take a bit of refactoring to de-dupe the recognisers.

There may very well be solutions I haven't considered, but all the
things I've tried so far I wasn't very happy with. So in the end I just
moved this to the C++ runtime for now in order to unblock
#165996.

The C++ language runtime is always available (even for C targets) if the
C++ language plugin is available. Which it should also be unless someone
is using an LLDB with the C++ plugin compiled out. But at that point
numerous things wouldn't work when even debugging just C.

Author: Michael137

lldb/source/Plugins/LanguageRuntime/CPlusPlus/CMakeLists.txt

@@ -1,5 +1,6 @@
 add_lldb_library(lldbPluginCPPRuntime
   CPPLanguageRuntime.cpp
+  VerboseTrapFrameRecognizer.cpp
 
   LINK_LIBS
     lldbCore

lldb/source/Plugins/LanguageRuntime/CPlusPlus/CPPLanguageRuntime.cpp

@@ -12,6 +12,7 @@
 #include <memory>
 
 #include "CPPLanguageRuntime.h"
+#include "VerboseTrapFrameRecognizer.h"
 
 #include "llvm/ADT/StringRef.h"
 
@@ -107,12 +108,15 @@ class LibCXXFrameRecognizer : public StackFrameRecognizer {
 
 CPPLanguageRuntime::CPPLanguageRuntime(Process *process)
     : LanguageRuntime(process) {
-  if (process)
+  if (process) {
     process->GetTarget().GetFrameRecognizerManager().AddRecognizer(
         StackFrameRecognizerSP(new LibCXXFrameRecognizer()), {},
         std::make_shared<RegularExpression>("^std::__[^:]*::"),
         /*mangling_preference=*/Mangled::ePreferDemangledWithoutArguments,
         /*first_instruction_only=*/false);
+
+    RegisterVerboseTrapFrameRecognizer(*process);
+  }
 }
 
 bool CPPLanguageRuntime::IsAllowedRuntimeValue(ConstString name) {

lldb/source/Target/VerboseTrapFrameRecognizer.cpp renamed to lldb/source/Plugins/LanguageRuntime/CPlusPlus/VerboseTrapFrameRecognizer.cpp

@@ -1,4 +1,4 @@
-#include "lldb/Target/VerboseTrapFrameRecognizer.h"
+#include "VerboseTrapFrameRecognizer.h"
 
 #include "lldb/Core/Module.h"
 #include "lldb/Symbol/Function.h"

lldb/include/lldb/Target/VerboseTrapFrameRecognizer.h renamed to lldb/source/Plugins/LanguageRuntime/CPlusPlus/VerboseTrapFrameRecognizer.h

@@ -1,5 +1,13 @@
-#ifndef LLDB_TARGET_VERBOSETRAPFRAMERECOGNIZER_H
-#define LLDB_TARGET_VERBOSETRAPFRAMERECOGNIZER_H
+//===-- VerboseTrapFrameRecognizer.h --------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLDB_SOURCE_PLUGINS_LANGUAGERUNTIME_C_PLUS_PLUS_VERBOSETRAPFRAMERECOGNIZER_H
+#define LLDB_SOURCE_PLUGINS_LANGUAGERUNTIME_C_PLUS_PLUS_VERBOSETRAPFRAMERECOGNIZER_H
 
 #include "lldb/Target/StackFrameRecognizer.h"
 
@@ -36,4 +44,4 @@ class VerboseTrapFrameRecognizer : public StackFrameRecognizer {
 
 } // namespace lldb_private
 
-#endif // LLDB_TARGET_VERBOSETRAPFRAMERECOGNIZER_H
+#endif // LLDB_SOURCE_PLUGINS_LANGUAGERUNTIME_C_PLUS_PLUS_VERBOSETRAPFRAMERECOGNIZER_H

lldb/source/Target/CMakeLists.txt

@@ -80,7 +80,6 @@ add_lldb_library(lldbTarget
   UnixSignals.cpp
   UnwindAssembly.cpp
   UnwindLLDB.cpp
-  VerboseTrapFrameRecognizer.cpp
 
   ADDITIONAL_HEADER_DIRS
     ${LLDB_INCLUDE_DIR}/lldb/Target

lldb/source/Target/Process.cpp

@@ -65,7 +65,6 @@
 #include "lldb/Target/ThreadPlanCallFunction.h"
 #include "lldb/Target/ThreadPlanStack.h"
 #include "lldb/Target/UnixSignals.h"
-#include "lldb/Target/VerboseTrapFrameRecognizer.h"
 #include "lldb/Utility/AddressableBits.h"
 #include "lldb/Utility/Event.h"
 #include "lldb/Utility/LLDBLog.h"
@@ -513,7 +512,6 @@ Process::Process(lldb::TargetSP target_sp, ListenerSP listener_sp,
   // We should have a plugin do the registration instead, for example, a
   // common C LanguageRuntime plugin.
   RegisterAssertFrameRecognizer(this);
-  RegisterVerboseTrapFrameRecognizer(*this);
 }
 
 Process::~Process() {

lldb/test/Shell/Recognizer/Inputs/verbose_trap.m

@@ -0,0 +1,4 @@
+int main() {
+  __builtin_verbose_trap("Foo", "Bar");
+  return 0;
+}

lldb/test/Shell/Recognizer/registration-unique.test

@@ -0,0 +1,54 @@
+# Checks that the recognizers that should work across language runtimes
+# are only registered once with the target.
+
+# RUN: split-file %s %t
+
+# RUN: %clang_host %t/main.cpp -g -o %t/cpp.out
+# RUN: %lldb -b -s %t/commands.input %t/cpp.out | FileCheck %s
+
+# RUN: %clang_host -x objective-c++ %t/main.mm -g -o %t/objcxx.out
+# RUN: %lldb -b -s %t/commands.input %t/objcxx.out | FileCheck %s
+
+# RUN: %clang_host %t/main.c -g -o %t/c.out
+# RUN: %lldb -b -s %t/commands.input %t/c.out | FileCheck %s
+
+# RUN: %clang_host -x objective-c %t/main.m -g -o %t/objc.out
+# RUN: %lldb -b -s %t/commands.input %t/objc.out | FileCheck %s
+
+#--- main.m
+int main() {}
+
+#--- main.c
+int main() {}
+
+#--- main.mm
+int main() {}
+
+#--- main.cpp
+int main() {}
+
+#--- commands.input
+
+b main
+frame recognizer list
+run
+frame recognizer list
+continue
+run
+frame recognizer list
+
+# CHECK: frame recognizer list
+# CHECK-NEXT: no matching results found.
+
+# CHECK: frame recognizer list
+# CHECK: Verbose Trap StackFrame Recognizer
+# CHECK: Assert StackFrame Recognizer
+# CHECK-NOT: Verbose Trap StackFrame Recognizer
+# CHECK-NOT: Assert StackFrame Recognizer
+
+# FIXME: avoid duplicate frame recognizers in the target: https://github.com/llvm/llvm-project/issues/166341
+# CHECK: frame recognizer list
+# CHECK: Verbose Trap StackFrame Recognizer
+# CHECK: Assert StackFrame Recognizer
+# CHECK: Verbose Trap StackFrame Recognizer
+# CHECK: Assert StackFrame Recognizer

lldb/test/Shell/Recognizer/verbose_trap-objc.test

@@ -0,0 +1,12 @@
+# REQUIRES: system-darwin
+#
+# RUN: %clangxx_host -x objective-c -g %S/Inputs/verbose_trap.m -o %t.out
+# RUN: %lldb -b -s %s %t.out | FileCheck %s
+
+run
+# CHECK: thread #{{.*}}stop reason = Foo: Bar
+frame info
+# CHECK: frame #{{.*}}`main at verbose_trap.m
+frame recognizer info 0
+# CHECK: frame 0 is recognized by Verbose Trap StackFrame Recognizer
+q