bundle.py: build-time Luau optimizations (draw-data identical; IMGUI_BUNDLE_NOOPT=1 disables): hot library globals as bundle locals, enum/constant folding (values dumped by the luau CLI; IMGUI_BUNDLE_STRICT=1 in CI), --@hoist pure helpers to inlinable bundle-level local functions, statement IM_ASSERT -> assert; builtin type instead of ImGui._GetTypeFunc() alias (GETGLOBAL 15903 -> 540)

.github/workflows/release.yml

@@ -30,6 +30,8 @@ jobs:
           unzip -q luau.zip -d luau && chmod +x luau/* && echo "$PWD/luau" >> "$GITHUB_PATH"
 
       - name: Build
+        env:
+          IMGUI_BUNDLE_STRICT: "1" # fail if enum folding (needs the luau CLI above) can't run
         run: |
           mkdir -p dist
           python3 tools/bundle.py dist/roblox                       # ImGui.luau (library + demo)

build/ImGui.linemap.json

@@ -1 +1 @@
-[[12, "imgui.lua"], [21355, "imgui_demo.lua"], [29773, "imgui_draw.lua"], [35711, "imgui_h.lua"], [38377, "imgui_impl_roblox.lua"], [40024, "imgui_impl_roblox_fonts.lua"], [46427, "imgui_internal.lua"], [49888, "imgui_tables.lua"], [54947, "imgui_widgets.lua"], [65587, "imstb_rectpack.lua"], [66251, "imstb_textedit.lua"], [67793, "imstb_truetype.lua"], [70581, "imstd_minstdio.lua"]]
+[[46, "imgui.lua"], [21389, "imgui_demo.lua"], [29807, "imgui_draw.lua"], [35745, "imgui_h.lua"], [38412, "imgui_impl_roblox.lua"], [40059, "imgui_impl_roblox_fonts.lua"], [46462, "imgui_internal.lua"], [49931, "imgui_tables.lua"], [54990, "imgui_widgets.lua"], [65630, "imstb_rectpack.lua"], [66294, "imstb_textedit.lua"], [67836, "imstb_truetype.lua"], [70624, "imstd_minstdio.lua"]]

build/imgui_love.linemap.json

@@ -1 +1 @@
-[[149, "imgui.lua"], [21492, "imgui_demo.lua"], [29910, "imgui_draw.lua"], [35848, "imgui_h.lua"], [38514, "imgui_impl_love.lua"], [39054, "imgui_internal.lua"], [42515, "imgui_tables.lua"], [47574, "imgui_widgets.lua"], [58214, "imstb_rectpack.lua"], [58878, "imstb_textedit.lua"], [60420, "imstb_truetype.lua"], [63208, "imstd_minstdio.lua"]]
+[[183, "imgui.lua"], [21526, "imgui_demo.lua"], [29944, "imgui_draw.lua"], [35882, "imgui_h.lua"], [38549, "imgui_impl_love.lua"], [39089, "imgui_internal.lua"], [42558, "imgui_tables.lua"], [47617, "imgui_widgets.lua"], [58257, "imstb_rectpack.lua"], [58921, "imstb_textedit.lua"], [60463, "imstb_truetype.lua"], [63251, "imstd_minstdio.lua"]]

imgui_h.lua

@@ -30,7 +30,7 @@
 
 --- @meta
 
-local type   = ImGui._GetTypeFunc()
+local type   = type -- [Luau] builtin (FASTCALL); ImGui._GetTypeFunc() kept for compatibility
 local rawget = rawget; local rawset = rawset
 
 -- [LuaBitOp](https://bitop.luajit.org/semantics.html)
@@ -2130,7 +2130,8 @@ IM_COL32_A_MASK  = 0xFF000000
 --- @param G ImU32
 --- @param B ImU32
 --- @param A ImU32
-IM_COL32             = function(R, G, B, A) return (bitOr(bitLShift(A, IM_COL32_A_SHIFT), bitLShift(B, IM_COL32_B_SHIFT), bitLShift(G, IM_COL32_G_SHIFT), bitLShift(R, IM_COL32_R_SHIFT))) end
+--@hoist
+function IM_COL32(R, G, B, A) return (bitOr(bitLShift(A, IM_COL32_A_SHIFT), bitLShift(B, IM_COL32_B_SHIFT), bitLShift(G, IM_COL32_G_SHIFT), bitLShift(R, IM_COL32_R_SHIFT))) end
 IM_COL32_WHITE       = IM_COL32(255, 255, 255, 255)
 IM_COL32_BLACK       = IM_COL32(0, 0, 0, 255)
 IM_COL32_BLACK_TRANS = IM_COL32(0, 0, 0, 0)

imgui_internal.lua

@@ -30,7 +30,7 @@
 
 --- @meta
 
-local type   = ImGui._GetTypeFunc()
+local type   = type -- [Luau] builtin (FASTCALL); ImGui._GetTypeFunc() kept for compatibility
 local rawget = rawget
 
 local mathMin   = math.min; local mathMax    = math.max
@@ -189,6 +189,7 @@ end
 -- - ImMin/ImMax/ImClamp/ImLerp/ImSwap are used by widgets which support variety of types: signed/unsigned int/long long float/double
 --- @overload fun(lhs: number, rhs: number): number
 --- @overload fun(lhs: ImVec2, rhs: ImVec2): ImVec2
+--@hoist
 @native
 function ImMin(lhs, rhs)
     if type(lhs) == "number" then return mathMin(lhs, rhs) end
@@ -197,6 +198,7 @@ end
 
 --- @overload fun(lhs: number, rhs: number): number
 --- @overload fun(lhs: ImVec2, rhs: ImVec2): ImVec2
+--@hoist
 @native
 function ImMax(lhs, rhs)
     if type(lhs) == "number" then return mathMax(lhs, rhs) end
@@ -211,6 +213,7 @@ ImStd.ImQsort = function(base, count, cmp_func) if count > 0 then t_sort(base, c
 
 --- @overload fun(v: number, mn: number, mx: number): number
 --- @overload fun(v: ImVec2, mn: ImVec2, mx: ImVec2): ImVec2
+--@hoist
 @native
 function ImClamp(v, mn, mx)
     if     type(v) == "number" and type(mn) == "number" and type(mx) == "number" then return mathMin(mathMax(v, mn), mx)
@@ -221,6 +224,7 @@ end
 --- @overload fun(a: number, b: number, t: number): number
 --- @overload fun(a: ImVec2, b: ImVec2, t: number): ImVec2
 --- @overload fun(a: ImVec2, b: ImVec2, t: ImVec2): ImVec2
+--@hoist
 @native
 function ImLerp(a, b, t)
     if     type(a) == "number" and type(b) == "number" and type(t) == "number" then return ((a) + ((b) - (a)) * (t))
@@ -229,10 +233,12 @@ function ImLerp(a, b, t)
     end
 end
 
+--@hoist
 local function _Trunc(val) if val >= 0 then return mathFloor(val) else return mathCeil(val) end end
 
 --- @overload fun(v: float): float
 --- @overload fun(v: ImVec2): ImVec2
+--@hoist
 function ImTrunc(v)
     if     type(v) == "number" then return _Trunc(v)
     elseif type(v) == "table"  then return ImVec2(_Trunc(v.x), _Trunc(v.y))
@@ -256,6 +262,7 @@ function ImRsqrt(x)            return (1 / ImSqrt(x))       end
 function IM_TRUNC(VAL) return math.floor(VAL) end -- Positive values only!
 function IM_ROUND(VAL) return math.floor(VAL + 0.5) end -- Positive values only!
 
+--@hoist
 function ImFloor(f) if f >= 0 or math.floor(f) == f then return math.floor(f) else return math.floor(f) - 1 end end -- Decent replacement for floorf()
 
 -- Helpers: Bit manipulation
@@ -376,6 +383,7 @@ function ImStd.strncmp(str1, str2, max_count)
     return 0
 end
 
+--@hoist
 function ImSaturate(f) return ((f < 0.0 and 0.0) or (f > 1.0 and 1.0) or f) end
 
 IM_F32_TO_INT8_UNBOUND = function(val) return math.floor(val * 255.0 + (val >= 0 and 0.5 or -0.5)) end -- Unsaturated, for display purpose

tools/bundle.py

@@ -7,15 +7,34 @@
 # Each source file becomes a function in __FILES; IM_INCLUDE(name) runs it once and caches the result.
 # The module returns a table with every global the library defines (ImGui, ImVec2, ImGuiConfigFlags, ImGui_ImplRoblox, ...).
 # Roblox target also writes ImGuiTyped.luau (types + require(script.Impl), see tools/gen_types.py).
-import os, re
+#
+# Build-time optimizations (token rewrites with minify.py's lexer: strings/comments are never touched, every source line
+# stays on its line so linemap.json still maps errors). IMGUI_BUNDLE_NOOPT=1 turns all off, IMGUI_BUNDLE_NO_<X>=1 one:
+#   A  hot library globals (most referenced names assigned at a file's top level) become bundle-level locals declared
+#      before __FILES: every file's assignment/reference then hits an upvalue instead of GETGLOBAL. Fewer names for
+#      LuaJIT (60 upvalues per function). Library globals can't be patched from outside (use the returned table).
+#   B  enum folding: the bundle is loaded once headless (Luau CLI) to dump enum-like tables (all values numbers, never
+#      written inside a function) and numeric constants assigned once at top level; reads `ImGuiCol.Text` / `FLT_MAX`
+#      inside function bodies become `0 --[[ImGuiCol.Text]]`. Load-time (top-level) code is left alone.
+#   C  `--@hoist` functions in the sources (pure numeric helpers: ImMin, ImMax, ImClamp, ...) are moved to the bundle top
+#      as `local function`s (their source lines become blank) so Luau -O2 can inline them everywhere.
+#   E  statement-form `IM_ASSERT(...)` becomes `assert(...)` (fast builtin); expression uses are left alone.
+import os, re, sys, json, shutil, subprocess, tempfile
+
+HERE = os.path.dirname(os.path.abspath(__file__))
+ROOT = os.path.dirname(HERE)
+sys.path.insert(0, HERE)
+from minify import TOKEN
 
-ROOT = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
-import sys
 NO_DEMO = "--no-demo" in sys.argv
 LOVE = False
 if "--target" in sys.argv:
     i = sys.argv.index("--target"); LOVE = sys.argv[i + 1] == "love"; del sys.argv[i:i + 2]
 sys.argv = [a for a in sys.argv if a != "--no-demo"]
+OPT = {x: os.environ.get("IMGUI_BUNDLE_NOOPT") != "1" and os.environ.get("IMGUI_BUNDLE_NO_" + x) != "1" for x in "ABCE"}
+# A limits: Luau 200 locals in the main chunk (+ helpers, __FILES, ...), 200 upvalues per function; LuaJIT 60 upvalues
+# per function (margin left for nested functions that also capture file locals)
+MAX_LOCALS, MAX_UPVALUES = 160, (45 if LOVE else 150)
 BACKEND = "imgui_impl_love.lua" if LOVE else "imgui_impl_roblox.lua"
 SKIP = {"imgui_impl_roblox.lua", "imgui_impl_roblox_fonts.lua"} if LOVE else {"imgui_impl_love.lua"}
 FILES = {}
@@ -26,6 +45,7 @@ for d in (ROOT, os.path.join(ROOT, "backends"), os.path.join(ROOT, "fonts")):
             if LOVE: src = re.sub(r"^@native$", "", src, flags=re.M)  # keep line numbers
             FILES[f] = src
 
+ORIG = dict(FILES)  # for gen_types
 ENTRY = ["imgui.lua", BACKEND] + ([] if NO_DEMO else ["imgui_demo.lua"])  # run order
 
 names = set()
@@ -33,16 +53,207 @@ for src in FILES.values():
     names.update(re.findall(r"^function ([A-Za-z_]\w*)\s*\(", src, re.M))
     names.update(re.findall(r"^([A-Za-z_]\w*)\s*=[^=]", src, re.M))
 
-out = ["--!optimize 2", "-- GENERATED by tools/bundle.py from *.lua, backends/, fonts/ - do not edit", ""]
+# ---- lexer helpers ----
-if LOVE:
+KW = set("and break do else elseif end false for function goto if in local nil not or repeat return then true until while".split())
-    out = ["-- GENERATED by tools/bundle.py --target love - do not edit", re.search(r"--@compat-begin\n(.*?)--@compat-end", open(os.path.join(ROOT, "backends", "imgui_impl_love.lua")).read(), re.S).group(1), ""]
+
-out += [
+def lex(src):
-       "local __FILES, __LOADED = {}, {}",
+    """[(kind, text, start)] without whitespace/comments; kinds: name num str op."""
+    toks, pos = [], 0
+    while pos < len(src):
+        m = TOKEN.match(src, pos)
+        k = m.lastgroup
+        if k in ("ceq", "seq"): k = "lcom" if m.group(0).startswith("--") else "lstr"
+        if k not in ("ws", "lcom", "com"): toks.append(("str" if k == "lstr" else k, m.group(0), pos))
+        pos = m.end()
+    return toks
+
+def fdepths(toks):
+    """function nesting depth of every token (0 = runs at load time)"""
+    st, fd, out = [], 0, []
+    for k, t, _ in toks:
+        out.append(fd)
+        if k == "name":
+            if t == "function": st.append(1); fd += 1
+            elif t in ("if", "do", "repeat"): st.append(0)
+            elif t in ("end", "until"): fd -= st.pop()
+    assert not st, "unbalanced blocks"
+    return out
+
+def declared(toks):
+    """names declared as locals / parameters / loop variables anywhere"""
+    out, n = set(), len(toks)
+    for i, (k, t, _) in enumerate(toks):
+        j = None
+        if t == "local": j = i + 2 if toks[i + 1][1] == "function" else i + 1
+        elif t == "for": j = i + 1
+        elif t == "function":
+            j = i + 1
+            while toks[j][1] != "(": j += 1
+            j += 1
+        while j is not None and j < n and toks[j][0] == "name" and toks[j][1] not in KW:
+            out.add(toks[j][1])
+            j += 1
+            if j < n and toks[j][1] == ",": j += 1
+            else: break
+    return out
+
+def apply(src, edits):
+    for s, e, r in sorted(edits, reverse=True): src = src[:s] + r + src[e:]
+    return src
+
+def isref(toks, i):
+    """toks[i] is a variable read/write (not a field name)"""
+    return toks[i][0] == "name" and (i == 0 or toks[i - 1][1] not in (".", ":"))
+
+def nexttext(toks, i): return toks[i + 1][1] if i + 1 < len(toks) else ""
+
+# ---- C: --@hoist helpers ----
+hoisted, hoisted_names = [], []
+if OPT["C"]:
+    for f, src in FILES.items():
+        while "--@hoist\n" in src:
+            s = src.index("--@hoist\n") + len("--@hoist\n")
+            toks = lex(src[s:])
+            depth, i = 0, 0
+            while True:  # first `function` ... matching end
+                t = toks[i][1]
+                if t == "function" or t in ("if", "do", "repeat"): depth += 1
+                elif t in ("end", "until"):
+                    depth -= 1
+                    if depth == 0: break
+                i += 1
+            e = s + toks[i][2] + 3
+            text = src[s:e]
+            m = re.search(r"^(local )?function ([A-Za-z_]\w*)", text, re.M)
+            hoisted_names.append(m.group(2))
+            hoisted.append(text[:m.start()] + "local function " + text[m.start() + len(m.group(0)) - len(m.group(2)):])
+            src = src[:s - len("--@hoist\n")] + "\n" + re.sub(r"[^\n]", "", text) + src[e:]
+        FILES[f] = src
+HOIST_DEPS = "local type, mathMin, mathMax, mathFloor, mathCeil, bitOr, bitLShift = type, math.min, math.max, math.floor, math.ceil, bit32.bor, bit32.lshift"
+
+# ---- E: statement IM_ASSERT -> assert ----
+STMT_PREV_KW = {"end", "true", "false", "nil", "break", "then", "do", "else", "repeat"}
+def rewrite_assert(src):
+    toks, edits = lex(src), []
+    for i, (k, t, p) in enumerate(toks):
+        if t == "IM_ASSERT" and isref(toks, i) and nexttext(toks, i) == "(":
+            pk, pt = (toks[i - 1][0], toks[i - 1][1]) if i else ("op", ";")
+            if (pk == "name" and (pt not in KW or pt in STMT_PREV_KW)) or pk in ("num", "str") or pt in (")", "]", "}", ";", "..."):
+                edits.append((p, p + len(t), "assert"))
+    return apply(src, edits)
+
+if OPT["E"]:
+    FILES = {f: rewrite_assert(s) for f, s in FILES.items()}
+    hoisted = [rewrite_assert(s) for s in hoisted]
+
+# ---- B: enum / constant folding ----
+LUAU = shutil.which("luau") or "/nix/store/2m2ja613nndihc8qm10f2rhq6znp1nh4-luau-0.734/bin/luau"
+
+def header():
+    return ["local __FILES, __LOADED = {}, {}",
             "function IM_INCLUDE(name)",
             "    local r = __LOADED[name]",
             "    if r == nil then r = __FILES[name](); if r == nil then r = true end; __LOADED[name] = r end",
             "    return r",
             "end", ""]
+
+def numtext(s):
+    v = float(s)
+    if v != v or v in (float("inf"), float("-inf")) or (v == 0 and s.startswith("-")): return None
+    r = str(int(v)) if v.is_integer() and abs(v) < 2 ** 53 else repr(v)
+    return "(%s)" % r if v < 0 else r
+
+def dump_values():
+    """{name: number} and {name: {key: number}} of the loaded library (imgui.lua and what it includes)"""
+    src = ["--!optimize 1"] + ([HOIST_DEPS] + hoisted if hoisted else []) + header()
+    for name, s in sorted(FILES.items()): src += ["__FILES[%r] = function()" % name, s, "end"]
+    src += ['IM_INCLUDE("imgui.lua")',
+            'local function D(n, v) if type(v) == "number" then print("C", n, string.format("%.17g", v)) elseif type(v) == "table" then',
+            '  for k, x in pairs(v) do print("T", n, type(k) == "string" and k or "?", type(x) == "number" and string.format("%.17g", x) or "?") end end end']
+    src += ["D(%r, %s)" % (n, n) for n in sorted(names)]
+    with tempfile.NamedTemporaryFile("w", suffix=".luau", delete=False) as fp: fp.write("\n".join(src))
+    try:
+        p = subprocess.run([LUAU, fp.name], capture_output=True, text=True, timeout=60)
+    finally:
+        os.unlink(fp.name)
+    if p.returncode: raise RuntimeError("enum dump failed:\n" + p.stdout[-2000:] + p.stderr[-2000:])
+    consts, tables = {}, {}
+    for line in p.stdout.splitlines():
+        a = line.split("\t")
+        if a[0] == "C": consts[a[1]] = a[2]
+        elif a[0] == "T": tables.setdefault(a[1], {})[a[2]] = a[3]
+    tables = {n: t for n, t in tables.items() if "?" not in t and "?" not in t.values()}
+    return consts, tables
+
+def fold(files):
+    consts, tables = dump_values()
+    lexed = {f: lex(s) for f, s in files.items()}
+    depth = {f: fdepths(t) for f, t in lexed.items()}
+    # tables written inside a function, constants assigned more than once or not at top level: not foldable
+    assigns = {}
+    for f, toks in lexed.items():
+        for i, (k, t, _) in enumerate(toks):
+            if not isref(toks, i): continue
+            if t in tables and depth[f][i] > 0:
+                j = i + 1
+                if nexttext(toks, i) == ".": j = i + 3
+                elif nexttext(toks, i) == "[":
+                    b = 0
+                    while True:
+                        b += {"[": 1, "]": -1}.get(toks[j][1], 0); j += 1
+                        if b == 0: break
+                if j < len(toks) and toks[j][1] == "=": tables.pop(t, None)
+            if t in consts and nexttext(toks, i) == "=":
+                assigns[t] = assigns.get(t, 0) + (1 if depth[f][i] == 0 else 2)
+    consts = {n: v for n, v in consts.items() if assigns.get(n) == 1 and numtext(v)}
+    out = {}
+    for f, toks in lexed.items():
+        shadow = declared(toks)
+        edits = []
+        for i, (k, t, p) in enumerate(toks):
+            if depth[f][i] == 0 or not isref(toks, i) or t in shadow: continue
+            if t in tables and nexttext(toks, i) == "." and i + 2 < len(toks):
+                key = toks[i + 2][1]
+                if key in tables[t] and numtext(tables[t][key]) and nexttext(toks, i + 2) not in ("=", ".", ":", "[", "(", "{") and toks[i + 3][0] != "str":
+                    edits.append((p, toks[i + 2][2] + len(key), "%s --[[%s.%s]]" % (numtext(tables[t][key]), t, key)))
+            elif t in consts and nexttext(toks, i) not in ("=", ".", ":", "[", "(", "{") and toks[i + 1][0] != "str":
+                edits.append((p, p + len(t), "%s --[[%s]]" % (numtext(consts[t]), t)))
+        out[f] = apply(files[f], edits)
+    return out
+
+if OPT["B"]:
+    try:
+        allf = dict(FILES); allf.update({"@hoist%d" % i: "local function __h()\n" + s + "\nend" for i, s in enumerate(hoisted)})
+        allf = fold(allf)
+        hoisted = [allf.pop("@hoist%d" % i)[len("local function __h()\n"):-len("\nend")] for i in range(len(hoisted))]
+        FILES = allf
+    except (OSError, RuntimeError) as e:
+        if os.environ.get("IMGUI_BUNDLE_STRICT"): raise  # CI: a release must not silently lose the folding
+        print("bundle.py: enum folding skipped (%s)" % str(e).strip()[:300], file=sys.stderr)
+
+# ---- A: hot globals -> bundle locals ----
+hot = []
+if OPT["A"]:
+    count, used = {}, []
+    for src in FILES.values():
+        toks = lex(src)
+        used.append({t for i, (k, t, _) in enumerate(toks) if isref(toks, i)})
+        for i, (k, t, _) in enumerate(toks):
+            if t in names and isref(toks, i): count[t] = count.get(t, 0) + 1
+    # greedy by reference count; each file function's upvalues (hoisted names it uses) stay <= MAX_UPVALUES
+    taken = [len(u & set(hoisted_names + re.findall(r"\w+", HOIST_DEPS.split("=")[0]))) for u in used]
+    for n in sorted((n for n in count if n not in hoisted_names), key=lambda n: (-count[n], n)):
+        if len(hot) == MAX_LOCALS: break
+        if all(taken[i] < MAX_UPVALUES for i, u in enumerate(used) if n in u):
+            hot.append(n)
+            taken = [c + (n in u) for c, u in zip(taken, used)]
+
+out = ["--!optimize 2", "-- GENERATED by tools/bundle.py from *.lua, backends/, fonts/ - do not edit", ""]
+if LOVE:
+    out = ["-- GENERATED by tools/bundle.py --target love - do not edit", re.search(r"--@compat-begin\n(.*?)--@compat-end", open(os.path.join(ROOT, "backends", "imgui_impl_love.lua")).read(), re.S).group(1), ""]
+if hot: out.append("local " + ", ".join(hot))
+if hoisted: out += [HOIST_DEPS] + hoisted
+out += header()
 linemap = []  # (first bundle line, file) for error -> source mapping (tools/test/run.py)
 for name, src in sorted(FILES.items()):
     out.append("__FILES[%r] = function()" % name)
@@ -58,15 +269,12 @@ for n in sorted(names):
     out.append("    %s = %s," % (n, n))
 out.append("}")
 
-import sys
 OUT = sys.argv[1] if len(sys.argv) > 1 else os.path.join(ROOT, "build")
 os.makedirs(OUT, exist_ok=True)
 NAME = "imgui_love.lua" if LOVE else "ImGui.luau"
 open(os.path.join(OUT, NAME), "w").write("\n".join(out) + "\n")
-import json
 json.dump(linemap, open(os.path.join(OUT, NAME.rsplit(".", 1)[0] + ".linemap.json"), "w"))
 if not LOVE:
-    sys.path.insert(0, os.path.dirname(os.path.abspath(__file__)))
     from gen_types import wrapper
-    open(os.path.join(OUT, "ImGuiTyped.luau"), "w").write(wrapper(FILES))
+    open(os.path.join(OUT, "ImGuiTyped.luau"), "w").write(wrapper(ORIG))
 print("wrote build/%s (%d files, %d exports)" % (NAME, len(FILES), len(names)))