[Build] Convert buildshaders to custom build rules

tools/build/compile_shader_dxbc.py

@@ -0,0 +1,121 @@
+#!/usr/bin/env python3
+
+"""Compiles a single shader to DXBC and generates a C header via FXC.
+
+Usage: compile_shader_dxbc.py <input_path> <output_path>
+
+FXC directly produces the .h file — no post-processing needed.
+"""
+
+import os
+import subprocess
+import sys
+from glob import glob
+
+
+DXBC_STAGES = ["vs", "hs", "ds", "gs", "ps", "cs"]
+
+
+def find_fxc():
+    """Find FXC via FXC_PATH env or Windows SDK search."""
+    fxc = os.environ.get("FXC_PATH")
+    if fxc:
+        return fxc
+
+    # Search Windows Kits.
+    program_files_x86 = os.environ.get("ProgramFiles(x86)", "")
+    candidates = glob(os.path.join(
+        program_files_x86, "Windows Kits", "10", "bin", "*", "x64", "fxc.exe"))
+    if candidates:
+        return candidates[-1]  # Highest version is last
+
+    return None
+
+
+def parse_stage(filename):
+    """Extract the 2-char shader stage from filename like 'foo.cs.xesl'."""
+    basename = os.path.splitext(filename)[0]  # 'foo.cs'
+    identifier = basename.replace(".", "_")    # 'foo_cs'
+    stage_key = identifier[-2:]
+    if stage_key not in DXBC_STAGES:
+        return None
+    return stage_key
+
+
+def main():
+    if len(sys.argv) != 3:
+        print(f"Usage: {sys.argv[0]} <input_path> <output_path>", file=sys.stderr)
+        return 1
+
+    input_path = sys.argv[1]
+    output_path = sys.argv[2]
+
+    src_name = os.path.basename(input_path)
+    src_dir = os.path.dirname(input_path)
+
+    stage = parse_stage(src_name)
+    if stage is None:
+        print(f"ERROR: cannot determine shader stage from: {src_name}", file=sys.stderr)
+        return 1
+
+    identifier = os.path.splitext(src_name)[0].replace(".", "_")
+
+    fxc = find_fxc()
+    if not fxc:
+        print("ERROR: could not find fxc! Set FXC_PATH environment variable "
+              "or install Windows SDK.", file=sys.stderr)
+        return 1
+
+    # Create output directory if needed.
+    os.makedirs(os.path.dirname(output_path), exist_ok=True)
+
+    is_dxc = "dxc" in os.path.basename(fxc).lower()
+
+    # Start with base command — use wine on non-Windows platforms.
+    if sys.platform != "win32":
+        compiler_args = ["wine", fxc]
+    else:
+        compiler_args = [fxc]
+
+    if is_dxc:
+        # DXC only supports SM 6.0+.
+        compiler_args.extend([
+            "-T", f"{stage}_6_0",
+            "-HV", "2017",
+            "-D", "SHADING_LANGUAGE_HLSL_XE=1",
+            "-I", src_dir,
+            "-Fh", output_path,
+            "-Vn", identifier,
+            "-nologo",
+            input_path,
+        ])
+    else:
+        # FXC uses traditional syntax.
+        compiler_args.extend([
+            "/D", "SHADING_LANGUAGE_HLSL_XE=1",
+            "/I", src_dir,
+            "/Fh", output_path,
+            "/T", f"{stage}_5_1",
+            "/Vn", identifier,
+            "/O3",
+            "/Qstrip_reflect",
+            "/Qstrip_debug",
+            "/Qstrip_priv",
+            "/Gfp",
+            "/nologo",
+            input_path,
+        ])
+
+    result = subprocess.run(compiler_args, stdout=subprocess.DEVNULL,
+                            stderr=subprocess.PIPE)
+    if result.returncode != 0:
+        print(f"ERROR: failed to compile DXBC shader: {src_name}", file=sys.stderr)
+        if result.stderr:
+            sys.stderr.buffer.write(result.stderr)
+        return 1
+
+    return 0
+
+
+if __name__ == "__main__":
+    sys.exit(main())