[crashtracking] Allow runtimes to register runtime stack collection callbacks

bin_tests/src/modes/behavior.rs

@@ -129,6 +129,8 @@ pub fn get_behavior(mode_str: &str) -> Box<dyn Behavior> {
         "chained" => Box::new(test_007_chaining::Test),
         "fork" => Box::new(test_008_fork::Test),
         "prechain_abort" => Box::new(test_009_prechain_with_abort::Test),
+        "runtime_callback_frame" => Box::new(test_010_runtime_callback_frame::Test),
+        "runtime_callback_string" => Box::new(test_011_runtime_callback_string::Test),
         _ => panic!("Unknown mode: {mode_str}"),
     }
 }

bin_tests/src/modes/unix/mod.rs

@@ -10,3 +10,5 @@ pub mod test_006_sigchld_sigstack;
 pub mod test_007_chaining;
 pub mod test_008_fork;
 pub mod test_009_prechain_with_abort;
+pub mod test_010_runtime_callback_frame;
+pub mod test_011_runtime_callback_string;

bin_tests/src/modes/unix/test_010_runtime_callback_frame.rs

@@ -0,0 +1,131 @@
+// Copyright 2024-Present Datadog, Inc. https://www.datadoghq.com/
+// SPDX-License-Identifier: Apache-2.0
+//
+// This test validates the runtime stack collection callback mechanism using frame-by-frame mode.
+// It registers a test callback that provides mock runtime stack frames,
+// then crashes and verifies that the runtime frames appear in the crash report.
+//
+// This test uses CallbackType::Frame to emit structured runtime stack data.
+
+use crate::modes::behavior::{file_write_msg, Behavior};
+use datadog_crashtracker::{
+    register_runtime_stack_callback, CallbackType, CrashtrackerConfiguration, RuntimeStackFrame,
+};
+use std::ffi::c_char;
+use std::path::Path;
+use std::ptr;
+
+pub struct Test;
+
+impl Behavior for Test {
+    fn setup(
+        &self,
+        output_dir: &Path,
+        _config: &mut CrashtrackerConfiguration,
+    ) -> anyhow::Result<()> {
+        // Write a marker file to indicate we're testing runtime callback frame mode
+        let marker_file = output_dir.join("runtime_callback_test");
+        file_write_msg(&marker_file, "frame_mode")?;
+        Ok(())
+    }
+
+    fn pre(&self, _output_dir: &Path) -> anyhow::Result<()> {
+        // Register our test runtime callback before crashtracker initialization
+        register_runtime_stack_callback(test_runtime_callback_frame, CallbackType::Frame)
+            .map_err(|e| anyhow::anyhow!("Failed to register runtime callback: {:?}", e))?;
+        Ok(())
+    }
+
+    fn post(&self, _output_dir: &Path) -> anyhow::Result<()> {
+        // Nothing to do post-initialization for this test
+        Ok(())
+    }
+}
+
+// Signal-safe test callback that emits mock runtime stack frames
+unsafe extern "C" fn test_runtime_callback_frame(
+    emit_frame: unsafe extern "C" fn(*const RuntimeStackFrame),
+    _emit_stacktrace_string: unsafe extern "C" fn(*const c_char),
+) {
+    // Use static null-terminated strings to avoid allocation in signal context
+    // In a real runtime, these would come from the runtime's managed string pool
+    static FUNCTION_NAME_1: &[u8] = b"runtime_function_1\0";
+    static FUNCTION_NAME_2: &[u8] = b"runtime_function_2\0";
+    static FUNCTION_NAME_3: &[u8] = b"runtime_main\0";
+    static FILE_NAME_1: &[u8] = b"script.py\0";
+    static FILE_NAME_2: &[u8] = b"module.py\0";
+    static FILE_NAME_3: &[u8] = b"main.py\0";
+    static CLASS_NAME_1: &[u8] = b"TestClass\0";
+    static CLASS_NAME_2: &[u8] = b"MyModule\0";
+    static MODULE_NAME_1: &[u8] = b"test_module\0";
+    static MODULE_NAME_2: &[u8] = b"my_package.submodule\0";
+    static MODULE_NAME_3: &[u8] = b"__main__\0";
+
+    // Frame 1: runtime_function_1 in script.py
+    let frame1 = RuntimeStackFrame {
+        function_name: FUNCTION_NAME_1.as_ptr() as *const c_char,
+        file_name: FILE_NAME_1.as_ptr() as *const c_char,
+        line_number: 42,
+        column_number: 15,
+        class_name: CLASS_NAME_1.as_ptr() as *const c_char,
+        module_name: MODULE_NAME_1.as_ptr() as *const c_char,
+    };
+    emit_frame(&frame1);
+
+    // Frame 2: runtime_function_2 in module.py
+    let frame2 = RuntimeStackFrame {
+        function_name: FUNCTION_NAME_2.as_ptr() as *const c_char,
+        file_name: FILE_NAME_2.as_ptr() as *const c_char,
+        line_number: 100,
+        column_number: 8,
+        class_name: CLASS_NAME_2.as_ptr() as *const c_char,
+        module_name: MODULE_NAME_2.as_ptr() as *const c_char,
+    };
+    emit_frame(&frame2);
+
+    // Frame 3: runtime_main in main.py (no class)
+    let frame3 = RuntimeStackFrame {
+        function_name: FUNCTION_NAME_3.as_ptr() as *const c_char,
+        file_name: FILE_NAME_3.as_ptr() as *const c_char,
+        line_number: 10,
+        column_number: 1,
+        class_name: ptr::null(), // No class for main function
+        module_name: MODULE_NAME_3.as_ptr() as *const c_char,
+    };
+    emit_frame(&frame3);
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use datadog_crashtracker::{clear_runtime_callback, is_runtime_callback_registered};
+
+    #[test]
+    fn test_runtime_callback_frame_registration() {
+        // Ensure clean state
+        unsafe {
+            clear_runtime_callback();
+        }
+
+        // Test that no callback is initially registered
+        assert!(!is_runtime_callback_registered());
+
+        // Test frame mode registration
+        let result =
+            register_runtime_stack_callback(test_runtime_callback_frame, CallbackType::Frame);
+        assert!(result.is_ok(), "Frame callback registration should succeed");
+        assert!(
+            is_runtime_callback_registered(),
+            "Callback should be registered"
+        );
+
+        // Clean up
+        unsafe {
+            clear_runtime_callback();
+        }
+        assert!(
+            !is_runtime_callback_registered(),
+            "Callback should be cleared"
+        );
+    }
+}

bin_tests/src/modes/unix/test_011_runtime_callback_string.rs

@@ -0,0 +1,102 @@
+// Copyright 2024-Present Datadog, Inc. https://www.datadoghq.com/
+// SPDX-License-Identifier: Apache-2.0
+//
+// This test validates the runtime stack collection callback mechanism using stacktrace string mode.
+// It registers a test callback that provides a complete stacktrace string,
+// then crashes and verifies that the runtime stacktrace appears in the crash report.
+//
+// This test uses CallbackType::StacktraceString to emit complete stacktrace text.
+//
+// NOTE: This test currently has issues with the receiver's line-by-line parsing
+// of multiline stacktrace strings. It serves as a demonstration of the string mode
+// but may timeout due to receiver implementation details.
+
+use crate::modes::behavior::{file_write_msg, Behavior};
+use datadog_crashtracker::{
+    register_runtime_stack_callback, CallbackType, CrashtrackerConfiguration,
+};
+use std::ffi::{c_char, c_void};
+use std::path::Path;
+
+pub struct Test;
+
+impl Behavior for Test {
+    fn setup(
+        &self,
+        output_dir: &Path,
+        _config: &mut CrashtrackerConfiguration,
+    ) -> anyhow::Result<()> {
+        // Write a marker file to indicate we're testing runtime callback string mode
+        let marker_file = output_dir.join("runtime_callback_test");
+        file_write_msg(&marker_file, "string_mode")?;
+        Ok(())
+    }
+
+    fn pre(&self, _output_dir: &Path) -> anyhow::Result<()> {
+        // Register our test runtime callback before crashtracker initialization
+        register_runtime_stack_callback(
+            test_runtime_callback_string,
+            CallbackType::StacktraceString,
+        )
+        .map_err(|e| anyhow::anyhow!("Failed to register runtime callback: {:?}", e))?;
+        Ok(())
+    }
+
+    fn post(&self, _output_dir: &Path) -> anyhow::Result<()> {
+        // Nothing to do post-initialization for this test
+        Ok(())
+    }
+}
+
+// Signal-safe test callback that emits a complete stacktrace string
+unsafe extern "C" fn test_runtime_callback_string(
+    _emit_frame: unsafe extern "C" fn(*const datadog_crashtracker::RuntimeStackFrame),
+    emit_stacktrace_string: unsafe extern "C" fn(*const c_char),
+) {
+    // Use static null-terminated string to avoid allocation in signal context
+    // IMPORTANT: No embedded newlines - the receiver processes this line by line
+    static STACKTRACE: &[u8] = b"RuntimeError in script.py:42 runtime_function_1 -> module.py:100 runtime_function_2 -> main.py:10 runtime_main\0";
+
+    // Emit the complete stacktrace string
+    emit_stacktrace_string(STACKTRACE.as_ptr() as *const c_char);
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use datadog_crashtracker::{clear_runtime_callback, is_runtime_callback_registered};
+
+    #[test]
+    fn test_runtime_callback_string_registration() {
+        // Ensure clean state
+        unsafe {
+            clear_runtime_callback();
+        }
+
+        // Test that no callback is initially registered
+        assert!(!is_runtime_callback_registered());
+
+        // Test string mode registration
+        let result = register_runtime_stack_callback(
+            test_runtime_callback_string,
+            CallbackType::StacktraceString,
+        );
+        assert!(
+            result.is_ok(),
+            "String callback registration should succeed"
+        );
+        assert!(
+            is_runtime_callback_registered(),
+            "Callback should be registered"
+        );
+
+        // Clean up
+        unsafe {
+            clear_runtime_callback();
+        }
+        assert!(
+            !is_runtime_callback_registered(),
+            "Callback should be cleared"
+        );
+    }
+}