llvmbot wrote:
<!--LLVM PR SUMMARY COMMENT-->
@llvm/pr-subscribers-lldb
Author: Michael Buch (Michael137)
<details>
<summary>Changes</summary>
This attempts to improve user-experience when LLDB stops on a verbose_trap.
Currently if a `__builtin_verbose_trap` triggers, we display the first frame
above the call to the verbose_trap. So in the newly added test case, we
would've previously stopped here:
```
(lldb) run
Process 28095 launched: '/Users/michaelbuch/a.out' (arm64)
Process 28095 stopped
* thread #<!-- -->1, queue = 'com.apple.main-thread', stop reason = Bounds
error: out-of-bounds access
frame #<!-- -->1: 0x0000000100003f5c
a.out`std::__1::vector<int>::operator[](this=0x000000016fdfebef size=0,
(null)=10) at verbose_trap.cpp:6:9
3 template <typename T>
4 struct vector {
5 void operator[](unsigned) {
-> 6 __builtin_verbose_trap("Bounds error", "out-of-bounds
access");
7 }
8 };
```
After this patch, we would stop in the first non-`std` frame:
```
(lldb) run
Process 27843 launched: '/Users/michaelbuch/a.out' (arm64)
Process 27843 stopped
* thread #<!-- -->1, queue = 'com.apple.main-thread', stop reason = Bounds
error: out-of-bounds access
frame #<!-- -->2: 0x0000000100003f44 a.out`g() at verbose_trap.cpp:14:5
11
12 void g() {
13 std::vector<int> v;
-> 14 v[10];
15 }
16
```
---
Full diff: https://github.com/llvm/llvm-project/pull/108825.diff
7 Files Affected:
- (modified) lldb/source/Target/VerboseTrapFrameRecognizer.cpp (+26-1)
- (added) lldb/test/Shell/Recognizer/Inputs/verbose_trap-in-stl-callback.cpp
(+22)
- (added) lldb/test/Shell/Recognizer/Inputs/verbose_trap-in-stl-nested.cpp
(+21)
- (added) lldb/test/Shell/Recognizer/Inputs/verbose_trap-in-stl.cpp (+17)
- (added) lldb/test/Shell/Recognizer/verbose_trap-in-stl-callback.test (+13)
- (added) lldb/test/Shell/Recognizer/verbose_trap-in-stl-nested.test (+13)
- (added) lldb/test/Shell/Recognizer/verbose_trap-in-stl.test (+13)
``````````diff
diff --git a/lldb/source/Target/VerboseTrapFrameRecognizer.cpp
b/lldb/source/Target/VerboseTrapFrameRecognizer.cpp
index de710fcda54064..530a8941c8d504 100644
--- a/lldb/source/Target/VerboseTrapFrameRecognizer.cpp
+++ b/lldb/source/Target/VerboseTrapFrameRecognizer.cpp
@@ -16,6 +16,31 @@ using namespace llvm;
using namespace lldb;
using namespace lldb_private;
+/// The 0th frame is the artificial inline frame generated to store
+/// the verbose_trap message. So, starting with the current parent frame,
+/// find the first frame that's not inside of the STL.
+static StackFrameSP FindMostRelevantFrame(Thread &selected_thread) {
+ StackFrameSP most_relevant_frame_sp =
selected_thread.GetStackFrameAtIndex(1);
+ while (most_relevant_frame_sp) {
+ auto const &sc =
+ most_relevant_frame_sp->GetSymbolContext(eSymbolContextEverything);
+ ConstString frame_name = sc.GetFunctionName();
+ if (!frame_name)
+ return nullptr;
+
+ // Found a frame outside of the `std` namespace. That's the
+ // first frame in user-code that ended up triggering the
+ // verbose_trap. Hence that's the one we want to display.
+ if (!frame_name.GetStringRef().starts_with("std::"))
+ return most_relevant_frame_sp;
+
+ most_relevant_frame_sp = selected_thread.GetStackFrameAtIndex(
+ most_relevant_frame_sp->GetFrameIndex() + 1);
+ }
+
+ return nullptr;
+}
+
VerboseTrapRecognizedStackFrame::VerboseTrapRecognizedStackFrame(
StackFrameSP most_relevant_frame_sp, std::string stop_desc)
: m_most_relevant_frame(most_relevant_frame_sp) {
@@ -30,7 +55,7 @@ VerboseTrapFrameRecognizer::RecognizeFrame(lldb::StackFrameSP
frame_sp) {
ThreadSP thread_sp = frame_sp->GetThread();
ProcessSP process_sp = thread_sp->GetProcess();
- StackFrameSP most_relevant_frame_sp = thread_sp->GetStackFrameAtIndex(1);
+ StackFrameSP most_relevant_frame_sp = FindMostRelevantFrame(*thread_sp);
if (!most_relevant_frame_sp) {
Log *log = GetLog(LLDBLog::Unwind);
diff --git a/lldb/test/Shell/Recognizer/Inputs/verbose_trap-in-stl-callback.cpp
b/lldb/test/Shell/Recognizer/Inputs/verbose_trap-in-stl-callback.cpp
new file mode 100644
index 00000000000000..23beed4c62c3b3
--- /dev/null
+++ b/lldb/test/Shell/Recognizer/Inputs/verbose_trap-in-stl-callback.cpp
@@ -0,0 +1,22 @@
+namespace std {
+void definitely_aborts() { __builtin_verbose_trap("Failed", "Invariant
violated"); }
+
+void aborts_soon() { definitely_aborts(); }
+} // namespace std
+
+void g() { std::aborts_soon(); }
+
+namespace std {
+namespace detail {
+void eventually_aborts() { g(); }
+} // namespace detail
+
+inline namespace __1 {
+void eventually_aborts() { detail::eventually_aborts(); }
+} // namespace __1
+} // namespace std
+
+int main() {
+ std::eventually_aborts();
+ return 0;
+}
diff --git a/lldb/test/Shell/Recognizer/Inputs/verbose_trap-in-stl-nested.cpp
b/lldb/test/Shell/Recognizer/Inputs/verbose_trap-in-stl-nested.cpp
new file mode 100644
index 00000000000000..67fa65c9ceae22
--- /dev/null
+++ b/lldb/test/Shell/Recognizer/Inputs/verbose_trap-in-stl-nested.cpp
@@ -0,0 +1,21 @@
+namespace std {
+namespace detail {
+void function_that_aborts() { __builtin_verbose_trap("Bounds error",
"out-of-bounds access"); }
+} // namespace detail
+
+inline namespace __1 {
+template <typename T> struct vector {
+ void operator[](unsigned) { detail::function_that_aborts(); }
+};
+} // namespace __1
+} // namespace std
+
+void g() {
+ std::vector<int> v;
+ v[10];
+}
+
+int main() {
+ g();
+ return 0;
+}
diff --git a/lldb/test/Shell/Recognizer/Inputs/verbose_trap-in-stl.cpp
b/lldb/test/Shell/Recognizer/Inputs/verbose_trap-in-stl.cpp
new file mode 100644
index 00000000000000..4f01827944e166
--- /dev/null
+++ b/lldb/test/Shell/Recognizer/Inputs/verbose_trap-in-stl.cpp
@@ -0,0 +1,17 @@
+namespace std {
+inline namespace __1 {
+template <typename T> struct vector {
+ void operator[](unsigned) { __builtin_verbose_trap("Bounds error",
"out-of-bounds access"); }
+};
+} // namespace __1
+} // namespace std
+
+void g() {
+ std::vector<int> v;
+ v[10];
+}
+
+int main() {
+ g();
+ return 0;
+}
diff --git a/lldb/test/Shell/Recognizer/verbose_trap-in-stl-callback.test
b/lldb/test/Shell/Recognizer/verbose_trap-in-stl-callback.test
new file mode 100644
index 00000000000000..6ea397d3ee700b
--- /dev/null
+++ b/lldb/test/Shell/Recognizer/verbose_trap-in-stl-callback.test
@@ -0,0 +1,13 @@
+# Tests that we show the first non-STL frame when
+# a verbose_trap triggers from within the STL.
+
+# UNSUPPORTED: system-windows
+#
+# RUN: %clang_host -g -O0 %S/Inputs/verbose_trap-in-stl-callback.cpp -o %t.out
+# RUN: %lldb -b -s %s %t.out | FileCheck %s --check-prefixes=CHECK
+
+run
+# CHECK: thread #{{.*}}stop reason = Failed: Invariant violated
+frame info
+# CHECK: frame #{{.*}}`g() at verbose_trap-in-stl-callback.cpp
+q
diff --git a/lldb/test/Shell/Recognizer/verbose_trap-in-stl-nested.test
b/lldb/test/Shell/Recognizer/verbose_trap-in-stl-nested.test
new file mode 100644
index 00000000000000..81a492d1ed5791
--- /dev/null
+++ b/lldb/test/Shell/Recognizer/verbose_trap-in-stl-nested.test
@@ -0,0 +1,13 @@
+# Tests that we show the first non-STL frame when
+# a verbose_trap triggers from within the STL.
+
+# UNSUPPORTED: system-windows
+#
+# RUN: %clang_host -g -O0 %S/Inputs/verbose_trap-in-stl-nested.cpp -o %t.out
+# RUN: %lldb -b -s %s %t.out | FileCheck %s --check-prefixes=CHECK
+
+run
+# CHECK: thread #{{.*}}stop reason = Bounds error: out-of-bounds access
+frame info
+# CHECK: frame #{{.*}}`g() at verbose_trap-in-stl-nested.cpp
+q
diff --git a/lldb/test/Shell/Recognizer/verbose_trap-in-stl.test
b/lldb/test/Shell/Recognizer/verbose_trap-in-stl.test
new file mode 100644
index 00000000000000..dd08290174e3af
--- /dev/null
+++ b/lldb/test/Shell/Recognizer/verbose_trap-in-stl.test
@@ -0,0 +1,13 @@
+# Tests that we show the first non-STL frame when
+# a verbose_trap triggers from within the STL.
+
+# UNSUPPORTED: system-windows
+#
+# RUN: %clang_host -g -O0 %S/Inputs/verbose_trap-in-stl.cpp -o %t.out
+# RUN: %lldb -b -s %s %t.out | FileCheck %s --check-prefixes=CHECK
+
+run
+# CHECK: thread #{{.*}}stop reason = Bounds error: out-of-bounds access
+frame info
+# CHECK: frame #{{.*}}`g() at verbose_trap-in-stl.cpp
+q
``````````
</details>
https://github.com/llvm/llvm-project/pull/108825
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