From 4dff5ad07ff82a848209a72880cb93768b42efca Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Pa=CC=84vels=20Nadtoc=CC=8Cajevs?=
 <7645683+bruvzg@users.noreply.github.com>
Date: Wed, 11 Dec 2024 17:28:29 +0200
Subject: [PATCH] [Windows] Fix loading debug symbol files over 2GB.

---
 .../windows/crash_handler_windows_signal.cpp  |  5 +-
 thirdparty/README.md                          |  4 ++
 .../libbacktrace/patches/patch_big_files.diff | 47 +++++++++++++++++++
 thirdparty/libbacktrace/read.c                | 22 +++++----
 4 files changed, 68 insertions(+), 10 deletions(-)
 create mode 100644 thirdparty/libbacktrace/patches/patch_big_files.diff

diff --git a/platform/windows/crash_handler_windows_signal.cpp b/platform/windows/crash_handler_windows_signal.cpp
index ddfb9b65de00..ebc89a8181fe 100644
--- a/platform/windows/crash_handler_windows_signal.cpp
+++ b/platform/windows/crash_handler_windows_signal.cpp
@@ -167,7 +167,10 @@ extern void CrashHandlerException(int signal) {
 	if (FileAccess::exists(_execpath + ".debugsymbols")) {
 		_execpath = _execpath + ".debugsymbols";
 	}
-	data.state = backtrace_create_state(_execpath.utf8().get_data(), 0, &error_callback, reinterpret_cast<void *>(&data));
+	_execpath = _execpath.replace("/", "\\");
+
+	CharString cs = _execpath.utf8(); // Note: should remain in scope during backtrace_simple call.
+	data.state = backtrace_create_state(cs.get_data(), 0, &error_callback, reinterpret_cast<void *>(&data));
 	if (data.state != nullptr) {
 		data.index = 1;
 		backtrace_simple(data.state, 1, &trace_callback, &error_callback, reinterpret_cast<void *>(&data));
diff --git a/thirdparty/README.md b/thirdparty/README.md
index 669e6829fa37..258a12b840eb 100644
--- a/thirdparty/README.md
+++ b/thirdparty/README.md
@@ -468,6 +468,10 @@ Files extracted from upstream source:
 - `*.{c,h}` files for Windows platform
 - `LICENSE`
 
+Important: Some files have Godot-made changes to load big debug symbol files.
+They are marked with `/* GODOT start */` and `/* GODOT end */`
+comments and a patch is provided in the `patches` folder.
+
 
 ## libktx
 
diff --git a/thirdparty/libbacktrace/patches/patch_big_files.diff b/thirdparty/libbacktrace/patches/patch_big_files.diff
new file mode 100644
index 000000000000..6c3185c8d160
--- /dev/null
+++ b/thirdparty/libbacktrace/patches/patch_big_files.diff
@@ -0,0 +1,47 @@
+diff --git a/thirdparty/libbacktrace/read.c b/thirdparty/libbacktrace/read.c
+index 1811c8d2e0..fda8e222d4 100644
+--- a/thirdparty/libbacktrace/read.c
++++ b/thirdparty/libbacktrace/read.c
+@@ -52,14 +52,9 @@ backtrace_get_view (struct backtrace_state *state, int descriptor,
+ {
+   uint64_t got;
+   ssize_t r;
+-
+-  if ((uint64_t) (size_t) size != size)
+-    {
+-      error_callback (data, "file size too large", 0);
+-      return 0;
+-    }
+-
+-  if (lseek (descriptor, offset, SEEK_SET) < 0)
++/* GODOT start */
++  if (_lseeki64 (descriptor, offset, SEEK_SET) < 0)
++/* GODOT end */
+     {
+       error_callback (data, "lseek", errno);
+       return 0;
+@@ -74,7 +69,13 @@ backtrace_get_view (struct backtrace_state *state, int descriptor,
+   got = 0;
+   while (got < size)
+     {
+-      r = read (descriptor, view->base, size - got);
++/* GODOT start */
++      uint64_t sz = size - got;
++      if (sz > INT_MAX) {
++        sz = INT_MAX;
++      }
++      r = _read (descriptor, view->base, sz);
++/* GODOT end */
+       if (r < 0)
+ 	{
+ 	  error_callback (data, "read", errno);
+@@ -84,6 +85,9 @@ backtrace_get_view (struct backtrace_state *state, int descriptor,
+       if (r == 0)
+ 	break;
+       got += (uint64_t) r;
++/* GODOT start */
++      view->base += r;
++/* GODOT end */
+     }
+ 
+   if (got < size)
diff --git a/thirdparty/libbacktrace/read.c b/thirdparty/libbacktrace/read.c
index 1811c8d2e086..f5e01f01b0bf 100644
--- a/thirdparty/libbacktrace/read.c
+++ b/thirdparty/libbacktrace/read.c
@@ -52,14 +52,9 @@ backtrace_get_view (struct backtrace_state *state, int descriptor,
 {
   uint64_t got;
   ssize_t r;
-
-  if ((uint64_t) (size_t) size != size)
-    {
-      error_callback (data, "file size too large", 0);
-      return 0;
-    }
-
-  if (lseek (descriptor, offset, SEEK_SET) < 0)
+/* GODOT start */
+  if (_lseeki64 (descriptor, offset, SEEK_SET) < 0)
+/* GODOT end */
     {
       error_callback (data, "lseek", errno);
       return 0;
@@ -74,7 +69,13 @@ backtrace_get_view (struct backtrace_state *state, int descriptor,
   got = 0;
   while (got < size)
     {
-      r = read (descriptor, view->base, size - got);
+/* GODOT start */
+      uint64_t sz = size - got;
+      if (sz > INT_MAX) {
+        sz = INT_MAX;
+      }
+      r = _read (descriptor, view->base, sz);
+/* GODOT end */
       if (r < 0)
 	{
 	  error_callback (data, "read", errno);
@@ -84,6 +85,9 @@ backtrace_get_view (struct backtrace_state *state, int descriptor,
       if (r == 0)
 	break;
       got += (uint64_t) r;
+/* GODOT start */
+      view->base += r;
+/* GODOT end */
     }
 
   if (got < size)