Fixed some issues with #defines in the header (#114, #115)

Author: ShironekoBen

dear_bindings.py

@@ -632,20 +632,36 @@ def convert_header(
     # Remove these #defines as they don't make sense in C
     mod_remove_defines.apply(dom_root, ["IM_PLACEMENT_NEW(_PTR)", "IM_NEW(_TYPE)"])
     # Rewrite these defines to reference the new function names
-    # This could be done more generically but there are only three at present and there's a limit to how generic
+    # This could be done more generically but there are only four at present and there's a limit to how generic
     # we can get (as there's all sorts of #define trickery that could break the general case), so for now we'll
     # just do it the easy way
     mod_rewrite_defines.apply(dom_root, [
         "IM_ALLOC(_SIZE)",
         "IM_FREE(_PTR)",
-        "IMGUI_CHECKVERSION()"
+        "IMGUI_CHECKVERSION()",
+        "IMGUI_DEBUG_LOG(...)"
     ], {"ImGui::": "ImGui_"})
+    # Also rewrite IMGUI_DEBUG_LOG_FONT to use ImGui_GetCurrentContext() instead of GImGui as the latter isn't
+    # accessible from C
+    mod_rewrite_defines.apply(dom_root, [
+        "IMGUI_DEBUG_LOG_FONT(...)"
+    ], {"GImGui": "ImGui_GetCurrentContext()"})
     # Rename these to stop them generating compile warnings as they clash with those in imgui.h
     mod_rename_defines.apply(dom_root, {
         'IM_ALLOC(_SIZE)': 'CIM_ALLOC(_SIZE)',
         'IM_FREE(_PTR)': 'CIM_FREE(_PTR)',
         'IMGUI_CHECKVERSION()': 'CIMGUI_CHECKVERSION()'
     })
+    # Put these behind a guard to avoid spurious warnings
+    mod_add_define_guards.apply(dom_root, [
+        "IMGUI_DEBUG_LOG(...)",
+        "IMGUI_DEBUG_LOG_FONT(...)",
+        # We guard these specifically because although they are in theory the same, if the user has a slightly
+        # mismatched version of the headers (i.e. C++ headers from one version but generated headers from another),
+        # they will generate a warning.
+        "IMGUI_VERSION_NUM",
+        "IMGUI_VERSION"
+    ], "DEAR_BINDINGS_INTERNAL_GLUE_CODE")
 
     mod_forward_declare_structs.apply(dom_root)
     mod_wrap_with_extern_c.apply(main_src_root)  # main_src_root here to avoid wrapping the config headers

docs/Changelog.txt

@@ -1,8 +1,10 @@
---- v0.18 WIP
+--- v0.18
 
 * Added support for SDLGPU3 backend + SDL3+SDLGPU3 example.
 * Added support for NULL backend. (#110)
 * Added all generated backends to GitHub release packages. (#109)
+* Fixed IMGUI_DEBUG_LOG() macros using only-accessible-from-C++ symbols. (#115)
+* Added define guards to prevent redefinition warnings in some situations. (#114)
 
 --- v0.17
 

src/modifiers/__init__.py

@@ -65,3 +65,4 @@
 from . import mod_mark_structs_as_single_line_definition
 from . import mod_add_field_comment
 from . import mod_add_defines
+from . import mod_add_define_guards

src/modifiers/mod_add_define_guards.py

@@ -0,0 +1,21 @@
+from src import code_dom
+from src import utils
+
+
+# This modifier adds the specified guard to a list of #defines.
+# This is primarily intended as a way to avoid duplicate definitions when both the C and C++ headers are included
+# in the same file.
+def apply(dom_root, define_names, guard_name):
+    for define in dom_root.list_all_children_of_type(code_dom.DOMDefine):
+        if define.name in define_names:
+            # Add #ifndef check
+            ifguard = code_dom.DOMPreprocessorIf()
+            ifguard.is_ifdef = True
+            ifguard.is_negated = True
+            ifguard.expression_tokens = [utils.create_token(guard_name)]
+
+            # Insert at the same point as the original define
+            define.parent.insert_after_child(define, [ifguard])
+
+            # Move the define into the guard
+            ifguard.add_child(define)

src/templates/imgui-header-template.cpp

@@ -4,10 +4,15 @@
 #include <stdio.h>
 
 // Wrap this in a namespace to keep it separate from the C++ API
+
+// This define prevents #defines in the header getting defined again (as they are already in the normal header above),
+// and thus generating redefinition warnings
+#define DEAR_BINDINGS_INTERNAL_GLUE_CODE
 namespace cimgui
 {
 #include "%OUTPUT_HEADER_NAME%"
 }
+#undef DEAR_BINDINGS_INTERNAL_GLUE_CODE
 
 // Manual helpers
 // These implement functionality that isn't in the original C++ API, but is useful to callers from other languages

src/templates/imgui_impl_allegro5-header-template.cpp

@@ -4,8 +4,11 @@
 #include <stdio.h>
 
 // Wrap this in a namespace to keep it separate from the C++ API
+// This define prevents #defines in the header getting defined again (as they are already in the normal header above),
+// and thus generating redefinition warnings
+#define DEAR_BINDINGS_INTERNAL_GLUE_CODE
 namespace cimgui
 {
 #include "%OUTPUT_HEADER_NAME%"
 }
-
+#undef DEAR_BINDINGS_INTERNAL_GLUE_CODE

src/templates/imgui_impl_android-header-template.cpp

@@ -4,8 +4,11 @@
 #include <stdio.h>
 
 // Wrap this in a namespace to keep it separate from the C++ API
+// This define prevents #defines in the header getting defined again (as they are already in the normal header above),
+// and thus generating redefinition warnings
+#define DEAR_BINDINGS_INTERNAL_GLUE_CODE
 namespace cimgui
 {
 #include "%OUTPUT_HEADER_NAME%"
 }
-
+#undef DEAR_BINDINGS_INTERNAL_GLUE_CODE

src/templates/imgui_impl_dx10-header-template.cpp

@@ -4,8 +4,12 @@
 #include <stdio.h>
 
 // Wrap this in a namespace to keep it separate from the C++ API
+// This define prevents #defines in the header getting defined again (as they are already in the normal header above),
+// and thus generating redefinition warnings
+#define DEAR_BINDINGS_INTERNAL_GLUE_CODE
 namespace cimgui
 {
 #include "%OUTPUT_HEADER_NAME%"
 }
+#undef DEAR_BINDINGS_INTERNAL_GLUE_CODE
 

src/templates/imgui_impl_dx11-header-template.cpp

@@ -4,8 +4,12 @@
 #include <stdio.h>
 
 // Wrap this in a namespace to keep it separate from the C++ API
+// This define prevents #defines in the header getting defined again (as they are already in the normal header above),
+// and thus generating redefinition warnings
+#define DEAR_BINDINGS_INTERNAL_GLUE_CODE
 namespace cimgui
 {
 #include "%OUTPUT_HEADER_NAME%"
 }
+#undef DEAR_BINDINGS_INTERNAL_GLUE_CODE
 

src/templates/imgui_impl_dx12-header-template.cpp

@@ -5,8 +5,12 @@
 #include <d3d12.h>
 
 // Wrap this in a namespace to keep it separate from the C++ API
+// This define prevents #defines in the header getting defined again (as they are already in the normal header above),
+// and thus generating redefinition warnings
+#define DEAR_BINDINGS_INTERNAL_GLUE_CODE
 namespace cimgui
 {
 #include "%OUTPUT_HEADER_NAME%"
 }
+#undef DEAR_BINDINGS_INTERNAL_GLUE_CODE