From c801efdd033ac03749d97dade2bf01431d92b214 Mon Sep 17 00:00:00 2001
From: Kovid Goyal <kovid@kovidgoyal.net>
Date: Fri, 26 Jun 2026 11:45:55 +0530
Subject: [PATCH] Function to build slang code to IR

---
 kitty/constants.py     |  2 +-
 kitty/shaders/slang.py | 61 +++++++++++++++++++++++++++++++++++++-----
 2 files changed, 56 insertions(+), 7 deletions(-)

diff --git a/kitty/constants.py b/kitty/constants.py
index 2d14a7007..d38c4a8cb 100644
--- a/kitty/constants.py
+++ b/kitty/constants.py
@@ -35,7 +35,7 @@ kitty_run_data: dict[str, Any] = getattr(sys, 'kitty_run_data', {})
 launched_by_launch_services = kitty_run_data.get('launched_by_launch_services', False)
 is_quick_access_terminal_app = kitty_run_data.get('is_quick_access_terminal_app', False)
 unserialize_launch_flag = 'kitty-unserialize-data='
-slangc = [os.environ.get('SLANGC', 'slangc')]
+slangc = os.environ.get('SLANGC', 'slangc').split()
 
 
 if getattr(sys, 'frozen', False):
diff --git a/kitty/shaders/slang.py b/kitty/shaders/slang.py
index 049b29280..c00f17f0b 100644
--- a/kitty/shaders/slang.py
+++ b/kitty/shaders/slang.py
@@ -7,9 +7,12 @@
 import os
 import re
 import shutil
+import time
+from collections import OrderedDict
+from contextlib import suppress
 from enum import Enum
 from functools import lru_cache
-from typing import NamedTuple
+from typing import Iterator, NamedTuple
 
 
 class Stage(Enum):
@@ -29,6 +32,10 @@ class SlangFile(NamedTuple):
     entry_points: frozenset[EntryPoint]
     module: str
 
+    @property
+    def should_compile_to_ir(self) -> bool:
+        return bool(self.module or self.entry_points)
+
 
 def parse_slang_text(text: str, path: str = '') -> SlangFile:
     text = re.sub(r'/\*[\s\S]*?\*/', '', text)
@@ -102,10 +109,9 @@ def topological_sort(graph: dict[str, SlangFile]) -> list[str]:
     return order
 
 
-def get_ordered_sources_in_tree(dirpath: str) -> dict[str, SlangFile]:
-    ans = build_import_graph(dirpath)
-    topological_sort(ans)
-    return ans
+def get_ordered_sources_in_tree(dirpath: str) -> OrderedDict[str, SlangFile]:
+    g = build_import_graph(dirpath)
+    return OrderedDict({k: g[k] for k in topological_sort(g)})
 
 
 
@@ -118,4 +124,47 @@ def slangc() -> tuple[str, ...]:
         if not ans:
             raise SystemExit('Could not find the slangc shader compiler on PATH')
         slangc = [ans]
-    return tuple(slangc + ['-std', '2026'])
+    return tuple(slangc)
+
+
+def future() -> float:
+    return time.time() + 1000000
+
+
+def safe_mtime(path: str, defval: float = 0) -> float:
+    with suppress(OSError):
+        return os.path.getmtime(path)
+    return defval if defval >= 0 else future()
+
+
+def read_deps_file(path: str) -> Iterator[str]:
+    with open(path) as f:
+        for line in f:
+            line = line.partition(':')[2].strip()
+            yield from line.split()
+
+
+def get_newest_dep_time(path: str) -> float:
+    with suppress(OSError):
+        ans = 0.
+        for deppath in read_deps_file(path):
+            mtime = os.path.getmtime(deppath)
+            ans = max(mtime, ans)
+        return ans
+    return future()
+
+
+def commands_to_compile_dir_to_ir(dirpath: str, output_dirpath: str) -> Iterator[tuple[bool, list[str]]]:
+    cmdbase = list(slangc())
+    for name, sfile in get_ordered_sources_in_tree(dirpath).items():
+        if sfile.should_compile_to_ir:
+            parts = name.split('.')
+            base_dest = os.path.join(output_dirpath, *parts)
+            slang_module = f'{base_dest}.slang-module'
+            deps_file = f'{base_dest}.deps'
+            module_mtime = safe_mtime(slang_module)
+            needs_build = module_mtime < get_newest_dep_time(deps_file)
+            yield needs_build, cmdbase + [
+                sfile.path, '-I', output_dirpath, '-I', dirpath, '-depfile', deps_file,
+                '-target', 'none', '-o', slang_module
+            ]