cimgui/cimgui/gen_imgui_structs.lua

--script for imgui_structs.h generation

function strip(cad)
    return cad:gsub("^%s*(.-)%s*$","%1")
end


cdefs = {}

location_re = '^# %d+ "([^"]*)"'
cimpath_re = '^(.*[\\/])(imgui)%.h$' 
define_re = "^#define%s+([^%s]+)%s+([^%s]+)$"
function_re = "%b()"
function_closed_re = "[;}]$"
function_closing_re = "}"

number_re = "^-?[0-9]+$"
hex_re = "0x[0-9a-fA-F]+$"

local in_imgui = false
local in_function = false
for line in io.lines() do
repeat -- simulate continue with break

    --print(line)
    --line = strip(line)
    if #line == 0 then break end
    -- Is this a preprocessor statement?
    if line:sub(1,1) == "#" then
        -- Is this a location pragma?
        local location_match = line:match(location_re)
        if location_match then
            --print("location_match",line)
            -- If we are transitioning to a header we need to parse, set the flag
            local cimpath_match,aaa = location_match:match(cimpath_re)
            in_imgui = (cimpath_match ~= nil)
            --if in_gl then print(aaa) end
            break
        end
        
    
    elseif in_imgui then
        --if in_function discard
        if in_function then 
            if line:match(function_closing_re) then
                in_function = false
            end
            break
        end
        
        if line:match(function_re) and not line:match("typedef.*%b().*%b().*") then
            -- function and functypedef
            if not line:match(function_closed_re) then
                in_function = true
            end
        elseif line:match("template") then
            --nothing
        elseif line:match("public") then
            --nothing
        else
            --line = line:gsub("class","struct")
            --line = line:gsub("mutable","")
            line = line:gsub("%S+",{class="struct",mutable=""})
            line = line:gsub("(%b<>)","/%*%1%*/") --comment template parameters
            table.insert(cdefs,line)
        end
    end

until true
end

local namespace_re = "namespace"
local in_namespace = false
local struct_re = "^%s*struct%s+([^%s;]+)$"
local struct_closed_re = "^%s*struct%s+([^%s]+);$"
local struct_closing_re = "};"
local struct_op_close_re = "%b{}"
local structnames = {}
local innerstructs = {}
-- Output the file
    print("/////////////// BEGIN AUTOGENERATED SEGMENT")
    print("#ifndef IMGUI_STRUCTS_INCLUDED")
    print("#define IMGUI_STRUCTS_INCLUDED")
    
    for i,line in ipairs(cdefs) do
    repeat -- simulating continue with break
        
        if line:match(namespace_re) then
            in_namespace = true
        end
        local structbegin = line:match(struct_re)
        if structbegin then
            structnames[#structnames + 1] = structbegin
            if #structnames < 2 and structbegin~= "ImVector" then --not inner and not ImVector
                io.write(line,"\n")
                break
            end
        end
        
        if structnames[#structnames] == "ImVector" then
            if line:match(struct_closing_re) then
                io.write[[struct ImVector
{
    int Size;
    int Capacity;
    void* Data;
};
typedef struct ImVector ImVector;]]
                structnames[#structnames] = nil
            end
            break -- dont write
        end
        
        if in_namespace then
            if line:match(function_closing_re) then
                in_namespace = false
            end
            break -- dont write anything inside
        end
        
        if #structnames < 2 then -- not inner
            if (#structnames > 0) then
                if line:match("typedef") then --dont allow inner typedefs
                    break
                elseif not line:match("^{$") and not line:match(struct_closing_re) then --avoid tab { and };
                    --line = "    "..line
                end
            end
            io.write( line,"\n")
            local struct_closed_name = line:match(struct_closed_re)
            if struct_closed_name then
                io.write("typedef struct ",struct_closed_name," ",struct_closed_name,";\n")
            end
        end

        if #structnames > 0 then
            if #structnames > 1 then --inner structs
                innerstructs[structnames[#structnames]] = innerstructs[structnames[#structnames]] or {}
                local st = innerstructs[structnames[#structnames]]
                if not line:match("struct") and not line:match("^{$") and not line:match(struct_closing_re) then --avoid tab in struct { and };
                    --line = "    "..line
                end
                st[#st + 1] = line
                if line:match(struct_closing_re) and not line:match(struct_op_close_re) then
                    local structname = structnames[#structnames]
                    st[#st + 1] = string.format("typedef struct %s %s;\n",structname,structname)
                    structnames[#structnames] = nil
                end
            elseif line:match(struct_closing_re) and not line:match(struct_op_close_re) then
                local structname = structnames[#structnames]
                io.write("typedef struct ",structname," ",structname,";\n")
                structnames[#structnames] = nil
            end
        end
        

    until true
    end
    for k,v in pairs(innerstructs) do 
        for i,line in ipairs(v) do
            print(line) 
        end
    end
    print("#endif //IMGUI_STRUCTS_INCLUDED")
    print("//////////////// END AUTOGENERATED SEGMENT ")