Generates Geany function tags from LÖVE sources.

geany-love-tag-gen.lua

--[[
   geany tag generator.lua

   Generates Geany function tags from LÖVE sources.

   You require lua file system to run this:

    luarocks install luafilesystem

   Copyright 2018 wesley werner <wesley.werner@gmail.com>

   This program is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation, either version 3 of the License, or
   any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program. If not, see http://www.gnu.org/licenses/.

]]--

local TAG_FILENAME = "love.lua.tags"

function trim1(s)
  return (s:gsub("^%s*(.-)%s*$", "%1"))
end

function string.starts(String,Start)
   return string.sub(String,1,string.len(Start))==Start
end

function string.ends(String,End)
   return End=='' or string.sub(String,-string.len(End))==End
end


--- Cleans a line from unwanted tokens and keywords
function clean(line)

    -- removes "TOKEN::" identifiers like "love::" and "image::" in:
    -- love::image::ImageData *newScreenshot(love::image::Image *image, bool copyAlpha = true)
    line = line:gsub("(%w+)::", "")

    -- remove a list of parameter keywords
    line = line:gsub("const ", "")
    line = line:gsub("vector", "")
    line = line:gsub("StrongRef", "")

    -- trim and return
    return trim1(line)

end

--- Returns if the given line is a function definition
function isDefinition(line)

    local hasterminator = string.ends(line, ";")
    local hasbrackets = line:match("%(")
    return hasbrackets and hasterminator

end

--- Returns if the line indicates public functions start
function publicSectionStart(line)

    return line == "public:"

end

--- Returns if the line indicates public functions end
function publicSectionEnd(line)

    return line == "private:"

end

--- Returns if the line begins a comment
function commentStart(line)

    return string.starts(line, "/*")

end

--- Returns if the line end a comment
function commentEnd(line)

    return string.ends(line, "*/")

end

--- parse a line into it's components
function parseline(line)

    local parts = { type="", name="", parameters={} }
    local parametertype = nil

    local id = 1
    for value in line:gmatch("[_%a][_%w]*") do

        --print(id..": "..value)

        if id == 1 then
            -- return value
            parts["type"] = value
        elseif id == 2 then
            -- name
            parts["name"] = value
        else
            -- odd numbers are types, even the name
            if id % 2 == 0 then

                -- only add the parameter if there is a stored type
                if parametertype then

                    table.insert(parts.parameters, { name=value, type=parametertype } )

                    -- reset parameter type
                    parametertype = nil

                end

            else
                -- store the parameter type
                parametertype = value
            end

        end

        id = id + 1

    end

    -- ignore definitions with no name
    if parts.name == "" then
        return nil
    else
        return parts
    end

end

--- translates function parts into a pipe string.
function topipe(parts)

    -- geany tags format
    -- basename|string|(string path [, string suffix])|
    --
    -- The first field is the symbol name (usually a function name).
    -- The second field is the type of the return value.
    -- The third field is the argument list for this symbol.
    -- The fourth field is the description for this symbol
    -- but currently unused and should be left empty.
    -- Except for the first field (symbol name), all other field
    -- can be left empty but the pipe separator must appear for them.

    local p = { }
    for _, n in ipairs(parts.parameters) do
        table.insert(p, string.format("%s %s", n.type, n.name))
    end

    return string.format("%s|%s|(%s)|", parts.name, parts.type, table.concat(p, ", "))

end

function parsefile(filename)

    local taglines = { }
    local insidePublicSection = false
    local insideComment = false
    local f = io.lines(filename)

    for line in f do

        line = clean(line)

        -- flag when inside comments
        if not insideComment then
            if commentStart(line) then
                insideComment = true
            end
        end

        -- flag when inside and outside public functions sections
        if not insidePublicSection then
            if publicSectionStart(line) then
                insidePublicSection = true
            end
        else
            if publicSectionEnd(line) then
                insidePublicSection = false
            end
        end

        if not insideComment and insidePublicSection and isDefinition(line) then

            local parts = parseline(line)

            if parts then

                --print(string.format("found %s (%s) with %d parameters", parts.name, parts.type, #parts.parameters))

                table.insert(taglines, topipe(parts))

                --print("\n"..line)
                --print(string.format("%s %s", parts.type, parts.name))
                --for n, v in ipairs(parts.parameters) do
                    --print(string.format("param %d) %s %s", n, v.type, v.name))
                --end

            end

        end

        if insideComment then
            if commentEnd(line) then
                insideComment = false
            end
        end

    end

    return taglines

end

--- Creates a new tags file
function createTags()

    file = io.open(TAG_FILENAME, "w")

    file:write("# format=pipe\n")

    file:close()

end

--- Appends tags to file
function writeTags(lines)

    file = io.open(TAG_FILENAME, "a+")

    for _, line in ipairs(lines) do
        file:write(line.."\n")
    end

    file:flush()
    file:close()

end

--- Process source files recursively
function processSource(path)

    local lfs = require("lfs")

    for file in lfs.dir(path) do

        if file ~= "." and file ~= ".." then

            local fullpath = path..'/'..file
            local attr = lfs.attributes(fullpath)
            assert(type(attr) == "table")

            if attr.mode == "directory" then
                -- recurse subdirectories
                processSource(fullpath)
            else

                if string.ends(file, ".h") then

                    print(string.format("Processing: %s", fullpath))
                    local filetags = parsefile(fullpath)
                    print(string.format("\tFound %d definitions", #filetags))
                    writeTags(filetags)

                end

            end

        end

    end

end

if not arg[1] then
    print(string.format("Usage: lua %s [LOVE SOURCE PATH]", arg[0]))
else
    createTags()
    processSource(arg[1])
    print(string.format("\nWritten %s", TAG_FILENAME))
end