Add support for libbacktrace to detect new elfs have been dynamically loaded after backtrace_initialize() has been called, and consider them for symbol resolution

CMakeLists.txt

@@ -86,6 +86,7 @@ set_option(TRACY_NO_CRASH_HANDLER "Disable crash handling" OFF)
 set_option(TRACY_TIMER_FALLBACK "Use lower resolution timers" OFF)
 set_option(TRACE_CLIENT_LIBUNWIND_BACKTRACE "Use libunwind backtracing where supported" OFF)
 set_option(TRACY_SYMBOL_OFFLINE_RESOLVE "Instead of full runtime symbol resolution, only resolve the image path and offset to enable offline symbol resolution" OFF)
+set_option(TRACY_LIBBACKTRACE_ELF_DYNLOAD_SUPPORT "Enable libbacktrace to support dynamically loaded elfs in symbol resolution resolution after the first symbol resolve operation" OFF)
 
 if(NOT TRACY_STATIC)
     target_compile_definitions(TracyClient PRIVATE TRACY_EXPORTS)

public/libbacktrace/dwarf.cpp

@@ -4251,6 +4251,19 @@ dwarf_lookup_pc (struct backtrace_state *state, struct dwarf_data *ddata,
   }
 }
 
+bool dwarf_fileline_dwarf_lookup_pc_in_all_entries(struct backtrace_state *state, uintptr_t pc,
+      backtrace_full_callback callback, backtrace_error_callback error_callback, void *data,
+      int& found, int ret)
+{
+    for (struct dwarf_data* ddata = (struct dwarf_data *)state->fileline_data;
+         ddata != NULL;
+         ddata = ddata->next)
+    {
+      ret = dwarf_lookup_pc(state, ddata, pc, callback, error_callback, data, &found);
+      if (ret != 0 || found) return true;
+    }
+    return false;
+}
 
 /* Return the file/line information for a PC using the DWARF mapping
    we built earlier.  */
@@ -4265,17 +4278,27 @@ dwarf_fileline (struct backtrace_state *state, uintptr_t pc,
   int ret;
 
   if (!state->threaded)
+  {
+    if (dwarf_fileline_dwarf_lookup_pc_in_all_entries(state, pc, callback, error_callback, data, found, ret))
     {
-      for (ddata = (struct dwarf_data *) state->fileline_data;
+       return ret;
-	   ddata != NULL;
-	   ddata = ddata->next)
-	{
-	  ret = dwarf_lookup_pc (state, ddata, pc, callback, error_callback,
-				 data, &found);
-	  if (ret != 0 || found)
-	    return ret;
-	}
     }
+
+    // if we failed to obtain an entry in range, it can mean that the address map has been cahnges and new entries
+    //  have been loaded in the meantime. Request a refresh and try again
+    if (state->request_known_address_ranges_refresh_fn)
+    {
+        int new_range_count = state->request_known_address_ranges_refresh_fn(state, pc);
+        if (new_range_count > 0)
+        {
+          if (dwarf_fileline_dwarf_lookup_pc_in_all_entries(state, pc, callback, error_callback, data, found, ret))
+          {
+            return ret;
+          }
+        }
+    }
+
+  }
   else
     {
       struct dwarf_data **pp;

public/libbacktrace/internal.hpp

@@ -133,6 +133,11 @@ typedef void (*syminfo) (struct backtrace_state *state, uintptr_t pc,
 			 backtrace_syminfo_callback callback,
 			 backtrace_error_callback error_callback, void *data);
 
+/* The type of the function that will trigger an known address range refresh
+ (if pc passed in is for an address whichs lies ourtisde of known ranges) */
+typedef int (*request_known_address_ranges_refresh)(struct backtrace_state *state,
+             uintptr_t pc);
+
 /* What the backtrace state pointer points to.  */
 
 struct backtrace_state
@@ -159,6 +164,8 @@ struct backtrace_state
   int lock_alloc;
   /* The freelist when using mmap.  */
   struct backtrace_freelist_struct *freelist;
+  /* Trigger an known address range refresh */
+  request_known_address_ranges_refresh request_known_address_ranges_refresh_fn;
 };
 
 /* Open a file for reading.  Returns -1 on error.  If DOES_NOT_EXIST