From 7f8495c44b48b2995e45419bdd4149896eec536d Mon Sep 17 00:00:00 2001
From: Campbell Barton <campbell@blender.org>
Date: Sun, 7 May 2023 13:32:46 +1000
Subject: [PATCH] CMake: add WITH_STRSIZE_DEBUG option, RNA support

Support string size debug so it can be used for regular development.

It works be writing values into strings, ensuring the buffer size
given is actually available. Developers can use this with memory
checking tools such as ASAN/valgrind to force an error when
the value used for the size of a buffer is larger than the buffer.

Resolve remaining issue with RNA using BLI_strncpy* in generated
callback functions where the size argument didn't represent the
size of the destination buffer.

This is automatically enabled along with ASAN for the
blender_developer.cmake configuration.

Ref PR !107602.
---
 CMakeLists.txt                                |  6 +++++
 .../cmake/config/blender_developer.cmake      |  1 +
 source/blender/makesrna/intern/makesrna.c     | 27 +++++++------------
 source/creator/CMakeLists.txt                 |  4 +++
 4 files changed, 20 insertions(+), 18 deletions(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 93fddfb1d15..d32692f1fbd 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -651,6 +651,12 @@ if(WIN32)
   set(CPACK_INSTALL_PREFIX ${CMAKE_GENERIC_PROGRAM_FILES}/${})
 endif()
 
+option(WITH_STRSIZE_DEBUG "\
+Ensure string operations on fixed size buffers \
+(works well with with \"WITH_COMPILER_ASAN\" & valgrind to detect incorrect buffer size arguments)"
+  OFF)
+mark_as_advanced(WITH_STRSIZE_DEBUG)
+
 # Compiler tool-chain.
 if(UNIX)
   if(CMAKE_COMPILER_IS_GNUCC)
diff --git a/build_files/cmake/config/blender_developer.cmake b/build_files/cmake/config/blender_developer.cmake
index ebc5727a79c..8c954feefbe 100644
--- a/build_files/cmake/config/blender_developer.cmake
+++ b/build_files/cmake/config/blender_developer.cmake
@@ -12,6 +12,7 @@ set(WITH_BUILDINFO                    OFF CACHE BOOL "" FORCE)
 # developer profile for now.
 if(NOT WIN32)
   set(WITH_COMPILER_ASAN              ON  CACHE BOOL "" FORCE)
+  set(WITH_STRSIZE_DEBUG              ON  CACHE BOOL "" FORCE)
 endif()
 set(WITH_CYCLES_NATIVE_ONLY           ON  CACHE BOOL "" FORCE)
 set(WITH_DOC_MANPAGE                  OFF CACHE BOOL "" FORCE)
diff --git a/source/blender/makesrna/intern/makesrna.c b/source/blender/makesrna/intern/makesrna.c
index 33777bbc33d..47cfb6f8fbf 100644
--- a/source/blender/makesrna/intern/makesrna.c
+++ b/source/blender/makesrna/intern/makesrna.c
@@ -726,18 +726,13 @@ static char *rna_def_property_get_func(
   switch (prop->type) {
     case PROP_STRING: {
       StringPropertyRNA *sprop = (StringPropertyRNA *)prop;
+      UNUSED_VARS_NDEBUG(sprop);
       fprintf(f, "void %s(PointerRNA *ptr, char *value)\n", func);
       fprintf(f, "{\n");
       if (manualfunc) {
         fprintf(f, "    %s(ptr, value);\n", manualfunc);
       }
       else {
-        const PropertySubType subtype = prop->subtype;
-        const char *string_copy_func =
-            ELEM(subtype, PROP_FILEPATH, PROP_DIRPATH, PROP_FILENAME, PROP_BYTESTRING) ?
-                "BLI_strncpy" :
-                "BLI_strncpy_utf8";
-
         rna_print_data_get(f, dp);
 
         if (dp->dnapointerlevel == 1) {
@@ -746,28 +741,24 @@ static char *rna_def_property_get_func(
           fprintf(f, "        *value = '\\0';\n");
           fprintf(f, "        return;\n");
           fprintf(f, "    }\n");
-          fprintf(f,
-                  "    %s(value, data->%s, strlen(data->%s) + 1);\n",
-                  string_copy_func,
-                  dp->dnaname,
-                  dp->dnaname);
+          fprintf(f, "    strcpy(value, data->%s);\n", dp->dnaname);
         }
         else {
           /* Handle char array properties. */
+
+#ifndef NDEBUG /* Assert lengths never exceed their maximum expected value. */
           if (sprop->maxlength) {
-            fprintf(f,
-                    "    %s(value, data->%s, %d);\n",
-                    string_copy_func,
-                    dp->dnaname,
-                    sprop->maxlength);
+            fprintf(f, "    BLI_assert(strlen(data->%s) < %d);\n", dp->dnaname, sprop->maxlength);
           }
           else {
             fprintf(f,
-                    "    %s(value, data->%s, sizeof(data->%s));\n",
-                    string_copy_func,
+                    "    BLI_assert(strlen(data->%s) < sizeof(data->%s));\n",
                     dp->dnaname,
                     dp->dnaname);
           }
+#endif
+
+          fprintf(f, "    strcpy(value, data->%s);\n", dp->dnaname);
         }
       }
       fprintf(f, "}\n\n");
diff --git a/source/creator/CMakeLists.txt b/source/creator/CMakeLists.txt
index 14bb46d60c3..e1aa7d72a66 100644
--- a/source/creator/CMakeLists.txt
+++ b/source/creator/CMakeLists.txt
@@ -26,6 +26,10 @@ if(HAVE_FEENABLEEXCEPT)
   add_definitions(-DHAVE_FEENABLEEXCEPT)
 endif()
 
+if(WITH_STRSIZE_DEBUG)
+  add_definitions(-DDEBUG_STRSIZE)
+endif()
+
 if(WITH_TBB)
   # Force TBB libraries to be in front of MKL (part of `OpenImageDenoise`), so
   # that it is initialized before MKL and static library initialization order issues are avoided.