ludic/selfhost/frontend/natives.ludic

# natives.ludic - a package can carry a native library (phase 15).
#
# A package's package.ludic says `native "<target>" "<path>"` for each library it links, per
# target. When an import is found in a package, its manifest is read once and the libraries for
# this build's target are kept, as absolute paths. ir_flush writes them into the IR as
# `; ludic-native: <path>` lines, so every link - ludicc's own, `ludic build`, `ludic test` and
# `ludic bundle` - reads one list, and a program that imports no such package links nothing new.
var g_native_libs: []pointer = new []pointer
var g_native_pkgs: []pointer = new []pointer

# the target a `native` line names: windows-x64, macos-arm64 or linux-x64.
# $LUDIC_NATIVE_TARGET names another (an Intel Mac says macos-x64).
function native_target() -> pointer {
  let env = getenv("LUDIC_NATIVE_TARGET")
  if (env != null) { return env }
  if g_target_win { return "windows-x64" }
  if Fs.is_dir("/System/Library") { return "macos-arm64" }
  return "linux-x64"
}

# the words of one manifest line, a quoted word as one word without its quotes
function native_words(line: pointer) -> []pointer {
  let out = new []pointer
  let n = len(line)
  var i = 0
  while i < n {
    while (i < n) and ((line[i] == ' ') or (line[i] == 9)) { i += 1 }
    if (i >= n) or (line[i] == '#') { return out }
    if line[i] == '"' {
      let s = i + 1
      i = s
      while (i < n) and (line[i] != '"') { i += 1 }
      push(out, line[s..i])
      i += 1
    } else {
      let s = i
      while (i < n) and (line[i] != ' ') and (line[i] != 9) { i += 1 }
      push(out, line[s..i])
    }
  }
  return out
}

function native_have(xs: []pointer, s: pointer) -> bool {
  var i = 0
  while i < len(xs) { if xs[i] == s { return true };  i += 1 }
  return false
}

# `full` was found as `rel` under a package root (ludic_modules or $LUDIC_HOME/packages):
# read that package's manifest once and keep its libraries for this target
function native_note_pkg(full: pointer, rel: pointer) -> void {
  var n = 0
  while (n < len(rel)) and (rel[n] != '/') { n += 1 }
  let root = full[0..len(full) - len(rel) + n] + "/"
  if native_have(g_native_pkgs, root) { return }
  push(g_native_pkgs, root)
  let txt = read_file(root + "package.ludic")
  if (txt == null) { return }
  let want = native_target()
  var i = 0
  let tn = len(txt)
  while i < tn {
    var e = i
    while (e < tn) and (txt[e] != '\n') { e += 1 }
    var le = e
    if (le > i) and (txt[le - 1] == 13) { le -= 1 }
    let ws = native_words(txt[i..le])
    if (len(ws) == 3) and (ws[0] == "native") and (ws[1] == want) {
      let lib = root + ws[2]
      if not native_have(g_native_libs, lib) { push(g_native_libs, lib) }
    }
    i = e + 1
  }
}

# the `; ludic-native:` lines ir_flush puts at the head of the IR
function native_ir_lines() -> pointer {
  var s = ""
  var i = 0
  while i < len(g_native_libs) { s = s + `; ludic-native: {g_native_libs[i]}\n`;  i += 1 }
  return s
}

# what ludicc's own link adds: on macOS the library and an rpath to its directory (and to where
# a bundle keeps it); on Windows the import library beside the .dll, the .dll copied beside the exe
function native_link_args(out: pointer) -> pointer {
  var s = ""
  var i = 0
  while i < len(g_native_libs) {
    let lib = g_native_libs[i]
    let dir = dir_of(lib)
    if g_target_win {
      let n = len(lib)
      s = s + ` "{lib[0..n - 4]}.lib"`
      var od = dir_of(out)
      if len(od) == 0 { od = "." }
      run(`copy /y "{win_path(lib)}" "{win_path(od)}" >nul 2>nul`)
    } else {
      s = s + ` "{lib}" -Wl,-rpath,{dir} -Wl,-rpath,@executable_path/../Frameworks`
    }
    i += 1
  }
  return s
}