function patchHFile()

in patcher/patcher.js [553:645]
91 lines of code
24 McCabe index (conditional complexity)

function patchHFile(file, patch) {
    configkeysH()
    let resFile = ""
    let inZone = false
    let flags = {}
    let lineNo = 0
    let nums = []
    for (let line0 of file.split(/\n/)) {
        lineNo++
        let append = line0 + "\n"
        let line = line0.trim().replace(/\/\/.*/, "")
        if (inZone) {
            if (line.indexOf("/* CF2 END */") >= 0) {
                inZone = false
                if (patch) {
                    let portSize = lookupCfg(patch, configKeys.PINS_PORT_SIZE)
                    let s = ""
                    let size = flags["size"] || 100
                    let numentries = patch.length >> 1
                    size = Math.max(size, numentries + 4)
                    s += `    ${CFG_MAGIC0}, ${CFG_MAGIC1}, // magic\n`
                    s += `    ${numentries}, ${size},  // used entries, total entries\n`
                    for (let i = 0; i < numentries; ++i) {
                        let k = patch[i * 2]
                        let v = patch[i * 2 + 1]
                        s += `    ${k}, 0x${v.toString(16)}, // ${showKV(k, v, portSize, patch)}\n`
                    }
                    s += "   "
                    for (let i = 0; i < size - numentries; ++i) {
                        if (i && i % 16 == 0)
                            s += "\n   "
                        s += " 0, 0,"
                    }
                    s += "\n"
                    append = s + line0 + "\n"
                }
            } else {
                append = ""
                let toks = line.split(/,\s*/).map(s => s.trim()).filter(s => !!s)
                for (let tok of toks) {
                    let n = parseInt(tok)
                    if (isNaN(n)) {
                        n = all_defines[tok]
                        if (n === undefined) {
                            let portSize = lookupCfg(nums, configKeys.PINS_PORT_SIZE)
                            if (portSize) portSize &= 0xfff;
                            let pp = parsePinName(tok.replace(/^PIN_/, ""), portSize)
                            if (pp !== undefined) {
                                n = pp
                            } else {
                                err(`unknown value ${tok} at line ${lineNo}`)
                            }
                        }
                    }
                    nums.push(n)
                }
            }
        } else {
            let m = /\/\* CF2 START (.*)/.exec(line)
            if (m) {
                inZone = true
                for (let k of m[1].split(/\s+/)) {
                    let mm = /^(\w+)=(\d+)$/.exec(k)
                    if (mm)
                        flags[mm[1]] = parseInt(mm[2])
                    else
                        flags[k] = true
                }
            }
        }
        resFile += append
    }

    if (nums.length) {
        if (nums[0] != CFG_MAGIC0 || nums[1] != CFG_MAGIC1)
            err("no magic in H file")
        nums = nums.slice(4)
        for (let i = 0; i < nums.length; i += 2) {
            if (nums[i] == 0) {
                if (nums.slice(i).some(x => x != 0))
                    err("config keys follow zero terminator")
                else
                    nums = nums.slice(0, i)
                break
            }
        }
    }

    return {
        patched: resFile,
        data: nums
    }
}