From 4f144a2147817fc435229fc76f955141185f5f3c Mon Sep 17 00:00:00 2001
From: Kovid Goyal <kovid@kovidgoyal.net>
Date: Wed, 1 Jul 2026 10:23:27 +0530
Subject: [PATCH] Automatically validate GLSL shaders after build

---
 kitty/shaders/slang.py            |  6 ++-
 kitty/shaders/validate_shaders.py | 66 +++++++++++++++++++++++++++++++
 2 files changed, 71 insertions(+), 1 deletion(-)
 create mode 100755 kitty/shaders/validate_shaders.py

diff --git a/kitty/shaders/slang.py b/kitty/shaders/slang.py
index 6463612b0..d326feff7 100644
--- a/kitty/shaders/slang.py
+++ b/kitty/shaders/slang.py
@@ -291,7 +291,8 @@ def commands_to_compile_to_glsl(sources: dict[str, SlangFile], build_dir: str, d
         extra_cmd = ['-line-directive-mode', 'none', '-target', 'glsl', '-profile', 'glsl_330']
         for ep in sfile.entry_points:
             for sp in sfile.specializations:
-                dest = f'{base_dest}.{ep.stage.name}.glsl'
+                v = {Stage.vertex: 'vert', Stage.fragment: 'frag'}[ep.stage]
+                dest = f'{base_dest}.{v}.glsl'
                 c = list(cmd)
                 if sp.name:
                     dest = f'{base_dest}{sp.filename_insert}.{ep.stage.name}.glsl'
@@ -461,6 +462,9 @@ def main() -> None:
                 needed.append(Command(desc, cmd, lambda: True))
         parallel_run(needed)
     compile_builtin_shaders(sys.argv[-2], sys.argv[-1], prun)
+    if shutil.which('glslangValidator'):
+        from kitty.shaders.validate_shaders import validate_glsl
+        validate_glsl('shaders')
 
 
 def test_slang_build() -> None:
diff --git a/kitty/shaders/validate_shaders.py b/kitty/shaders/validate_shaders.py
new file mode 100755
index 000000000..a2c510543
--- /dev/null
+++ b/kitty/shaders/validate_shaders.py
@@ -0,0 +1,66 @@
+#!/usr/bin/env python3
+import subprocess
+import sys
+from pathlib import Path
+
+
+def validate_glsl(directory_path: str = '.', verbose: bool = False) -> None:
+    '''
+    Validates all GLSL shaders in the specified directory with names matching
+    name.vert.glsl or name.frag.glsl using glslangValidator.
+    '''
+    target_dir = Path(directory_path)
+
+    if not target_dir.is_dir():
+        raise SystemExit(f"Error: Directory '{directory_path}' does not exist.")
+
+    # Map the custom extensions to the required glslangValidator stage strings
+    stage_mapping = {
+        '.vert.glsl': 'vert',
+        '.frag.glsl': 'frag'
+    }
+
+    # Find all files matching the patterns
+    shader_files: list[Path] = []
+    for ext in stage_mapping.keys():
+        shader_files.extend(target_dir.glob(f'*{ext}'))
+
+    if not shader_files:
+        if verbose:
+            print(f"No matching shaders (*.vert.glsl or *.frag.glsl) found in '{target_dir}'.")
+        return
+
+    error_count = 0
+    print(f"Scanning directory: {target_dir.resolve()}\n" + "-" * 50)
+
+    # Process each shader file
+    for file_path in sorted(shader_files):
+        # Identify extension matching suffix
+        matched_ext = next(ext for ext in stage_mapping if file_path.name.endswith(ext))
+        stage = stage_mapping[matched_ext]
+        if verbose:
+            print(f'Validating: {file_path.name}')
+        result = subprocess.run(['glslangValidator', '-S', stage, str(file_path)],)
+
+        # Check exit code
+        if result.returncode != 0:
+            error_count += 1
+            print(f'❌ Failed: {file_path.name}', file=sys.stderr)
+        else:
+            if verbose:
+                print(f'✅ Passed: {file_path.name}')
+
+        if verbose:
+            print('-' * 50)
+
+    # Print execution summary
+    if error_count == 0:
+        if verbose:
+            print("Success: All shaders validated successfully!")
+    else:
+        raise SystemExit(f"Failure: {error_count} shader(s) failed validation.")
+
+
+if __name__ == "__main__":
+    dir_to_scan = sys.argv[1] if len(sys.argv) > 1 else 'shaders'
+    validate_glsl(dir_to_scan, verbose=True)