From 0e408d392e445726e48ae0699e6ad28401dd67ef Mon Sep 17 00:00:00 2001
From: Victor Bombi <sonoroster@gmail.com>
Date: Sat, 3 Oct 2020 16:34:58 +0200
Subject: [PATCH] cpp2ffi: gen_structs_and_enums declares nested struct before
 parent struct, if nested struct declares member of parent keep it (imnodes
 needs that)

---
 cimgui.h              | 20 ++++++++++----------
 generator/cpp2ffi.lua | 23 ++++++++++++++++++-----
 2 files changed, 28 insertions(+), 15 deletions(-)

diff --git a/cimgui.h b/cimgui.h
index 7df08d8..3b31fb6 100644
--- a/cimgui.h
+++ b/cimgui.h
@@ -888,32 +888,32 @@ struct ImGuiOnceUponAFrame
 {
      int RefFrame;
 };
+struct ImGuiTextRange
+{
+        const char* b;
+        const char* e;
+};
 struct ImGuiTextFilter
 {
     char InputBuf[256];
     ImVector_ImGuiTextRange Filters;
     int CountGrep;
 };
-struct ImGuiTextRange
-{
-        const char* b;
-        const char* e;
-};
 struct ImGuiTextBuffer
 {
     ImVector_char Buf;
 };
+struct ImGuiStoragePair
+{
+        ImGuiID key;
+        union { int val_i; float val_f; void* val_p; };
+};
 struct ImGuiStorage
 {
     ImVector_ImGuiStoragePair Data;
 };
 typedef struct ImVector_ImGuiTabBar {int Size;int Capacity;ImGuiTabBar* Data;} ImVector_ImGuiTabBar;
 typedef struct ImPool_ImGuiTabBar {ImVector_ImGuiTabBar Buf;ImGuiStorage Map;ImPoolIdx FreeIdx;} ImPool_ImGuiTabBar;
-struct ImGuiStoragePair
-{
-        ImGuiID key;
-        union { int val_i; float val_f; void* val_p; };
-};
 struct ImGuiListClipper
 {
     int DisplayStart, DisplayEnd;
diff --git a/generator/cpp2ffi.lua b/generator/cpp2ffi.lua
index 84d40a0..f40c121 100644
--- a/generator/cpp2ffi.lua
+++ b/generator/cpp2ffi.lua
@@ -1057,6 +1057,7 @@ function M.Parser()
 		local stru = itst.item
 		local outtab = {}
 		local commtab = {}
+		local predeclare = ""
 		--local iner = strip_end(stru:match("%b{}"):sub(2,-2))
 		local inistruct = clean_spaces(stru:match("(.-)%b{}"))
 		--local stname = stru:match("struct%s*(%S+)%s*%b{}")
@@ -1124,7 +1125,16 @@ function M.Parser()
 				table.insert(outtab,it2)
 				table.insert(commtab,it.comments )--or "")
 				end
-			elseif it.re_name == "struct_re"  or it.re_name == "enum_re" then
+			elseif it.re_name == "struct_re" then
+				--check if has declaration
+				local decl = it.item:match"%b{}%s*([^%s}{]+)%s*;"
+				if decl then
+					table.insert(outtab,"\n    "..it.name.." "..decl..";")
+					table.insert(commtab,it.comments )--or "")
+				end
+				local cleanst,structname,strtab,comstab,predec = self:clean_structR1(it)
+				predeclare = predeclare .. predec .. cleanst
+			elseif it.re_name == "enum_re" then
 				--nop
 			elseif it.re_name ~= "functionD_re" and it.re_name ~= "function_re" then
 				print(it.re_name,"not processed clean_struct",it.item:sub(1,12))
@@ -1133,7 +1143,7 @@ function M.Parser()
 		end
 		--final
 		table.insert(outtab,"\n};")
-		return table.concat(outtab,""),stname,outtab,commtab
+		return table.concat(outtab,""),stname,outtab,commtab, predeclare
 	end
 	local function get_parents_name(it)
 		local parnam = ""
@@ -1180,11 +1190,14 @@ function M.Parser()
 					table.insert(outtab,cl_item)
 				end
 			elseif it.re_name == "struct_re" or it.re_name == "typedef_st_re" then
-				local cleanst,structname = self:clean_structR1(it, it.locat)
+				local cleanst,structname,strtab,comstab,predec = self:clean_structR1(it)
 				if not structname then print("NO NAME",cleanst,it.item) end
 				--if not void stname or templated
 				if structname and not self.typenames[structname] then
-					table.insert(outtab,cleanst)
+					--dont insert child structs as they are inserted before parent struct
+					if not (it.parent and it.parent.re_name == "struct_re") then
+						table.insert(outtab,predec .. cleanst)
+					end
 					table.insert(typedefs_table,"typedef struct "..structname.." "..structname..";\n")
 					self.typedefs_dict[structname]="struct "..structname
 				end
@@ -1348,7 +1361,7 @@ function M.Parser()
 			elseif it.re_name == "enum_re" then
 				enums_for_table(it, outtab, enumsordered)
 			elseif it.re_name == "struct_re" or it.re_name == "typedef_st_re" then
-				local cleanst,structname,strtab,comstab = self:clean_structR1(it, it.locat)
+				local cleanst,structname,strtab,comstab = self:clean_structR1(it)
 				--if not void stname or templated
 				if not structname then print("NO NAME",cleanst,it.item) end
 				if structname and not self.typenames[structname] then