From 54ed2cfcc583e57b366078b5952793f9e6db0c8f Mon Sep 17 00:00:00 2001
From: Gregory LEOCADIE <gregory.leocadie@datadoghq.com>
Date: Sat, 7 Sep 2024 01:46:01 +0200
Subject: [PATCH] Fix example

---
 examples/ffi/crashinfo.cpp   | 30 ++++++++++++++++++++----------
 examples/ffi/crashtracking.c |  1 -
 2 files changed, 20 insertions(+), 11 deletions(-)

diff --git a/examples/ffi/crashinfo.cpp b/examples/ffi/crashinfo.cpp
index 0e1a316ed..d5f34aefd 100644
--- a/examples/ffi/crashinfo.cpp
+++ b/examples/ffi/crashinfo.cpp
@@ -15,7 +15,8 @@ extern "C" {
 #include <vector>
 
 static ddog_CharSlice to_slice_c_char(const char *s) { return {.ptr = s, .len = strlen(s)}; }
-static ddog_CharSlice to_slice_string(std::string &s) {
+static ddog_CharSlice to_slice_c_char(const char *s, std::size_t size) { return {.ptr = s, .len = size}; }
+static ddog_CharSlice to_slice_string(std::string const &s) {
   return {.ptr = s.data(), .len = s.length()};
 }
 
@@ -39,19 +40,28 @@ void check_result(ddog_crasht_Result result, const char *msg) {
 void add_stacktrace(std::unique_ptr<ddog_crasht_CrashInfo, Deleter> &crashinfo) {
 
   // Collect things into vectors so they stay alive till the function exits
-  std::vector<std::string> filenames;
-  std::vector<std::string> function_names;
-  for (uintptr_t i = 0; i < 20; ++i) {
-    filenames.push_back("/path/to/code/file_" + std::to_string(i));
-    function_names.push_back("func_" + std::to_string(i));
+  constexpr std::size_t nb_elements = 20;
+  std::vector<std::pair<std::string, std::string>> functions_and_filenames{nb_elements};
+  for (uintptr_t i = 0; i < nb_elements; ++i) {
+    functions_and_filenames.push_back({"func_" + std::to_string(i), "/path/to/code/file_" + std::to_string(i)});
   }
 
-  std::vector<ddog_crasht_StackFrameNames> names;
-  for (uintptr_t i = 0; i < 20; ++i) {
+  std::vector<ddog_crasht_StackFrameNames> names{nb_elements};
+  for (auto i = 0; i < nb_elements; i++) {
+    auto const& [function_name, filename] = functions_and_filenames[i];
+
+    auto function_name_slice = to_slice_string(function_name);
+    auto res = ddog_crasht_demangle(function_name_slice, DDOG_CRASHT_DEMANGLE_OPTIONS_COMPLETE);
+    if (res.tag == DDOG_CRASHT_STRING_WRAPPER_RESULT_OK)
+    {
+      auto string_result = res.ok.message;
+      function_name_slice = to_slice_c_char((const char*)string_result.ptr, string_result.len);
+    }
+
     names.push_back({.colno = ddog_Option_U32_some(i),
-                     .filename = to_slice_string(filenames[i]),
+                     .filename = to_slice_string(filename),
                      .lineno = ddog_Option_U32_some(2 * i + 3),
-                     .name = to_slice_string(function_names[i])});
+                     .name = function_name_slice});
   }
 
   std::vector<ddog_crasht_StackFrame> trace;
diff --git a/examples/ffi/crashtracking.c b/examples/ffi/crashtracking.c
index fcb5ad1b8..6b7dd90b4 100644
--- a/examples/ffi/crashtracking.c
+++ b/examples/ffi/crashtracking.c
@@ -75,7 +75,6 @@ int main(int argc, char **argv) {
   handle_uintptr_t_result(ddog_crasht_insert_span_id(0, 42));
   handle_uintptr_t_result(ddog_crasht_insert_trace_id(1, 1));
 
-  ddog_crasht_demangle(DDOG_CHARSLICE_C("nopp"), DDOG_CRASHT_DEMANGLE_OPTIONS_COMPLETE);
 #ifdef EXPLICIT_RAISE_SEGV
   // Test raising SEGV explicitly, to ensure chaining works
   // properly in this case