From e861c5b4bedb752adbdca9bfb863e9cc131c2a5c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Motiejus=20Jak=C5=A1tys?= <motiejus@uber.com>
Date: Mon, 29 Aug 2022 12:46:33 +0300
Subject: [PATCH] cache_prefix: clean up OS logic

'Windows' and 'Other' and guessing of cache prefix was convoluted
---
 toolchain/defs.bzl | 101 ++++++++++++++++++++++-----------------------
 1 file changed, 50 insertions(+), 51 deletions(-)

diff --git a/toolchain/defs.bzl b/toolchain/defs.bzl
index 53fd161..57e4fde 100644
--- a/toolchain/defs.bzl
+++ b/toolchain/defs.bzl
@@ -76,14 +76,41 @@ def toolchains(
         },
     )
 
-ZIG_TOOL_WRAPPER_CACHE_KNOWN = """#!/usr/bin/env sh
+_ZIG_TOOLS = [
+    "c++",
+    "cc",
+    "ar",
+    "ld.lld",  # ELF
+    "ld64.lld",  # Mach-O
+    "lld-link",  # COFF
+    "wasm-ld",  # WebAssembly
+]
+
+_ZIG_TOOL_WRAPPER_WINDOWS_CACHE_KNOWN = """@echo off
+set ZIG_LOCAL_CACHE_DIR={cache_prefix}\\bazel-zig-cc
+set ZIG_GLOBAL_CACHE_DIR=%ZIG_LOCAL_CACHE_DIR%
+"{zig}" "{zig_tool}" %*
+"""
+
+_ZIG_TOOL_WRAPPER_WINDOWS_CACHE_GUESS = """@echo off
+if exist "%TMP%\\*" goto :usertmp
+set ZIG_LOCAL_CACHE_DIR=C:\\Temp\\bazel-zig-cc
+goto zig
+:usertmp
+set ZIG_LOCAL_CACHE_DIR=%TMP%\\bazel-zig-cc
+:zig
+set ZIG_GLOBAL_CACHE_DIR=%ZIG_LOCAL_CACHE_DIR%
+"{zig}" "{zig_tool}" %*
+"""
+
+_ZIG_TOOL_WRAPPER_CACHE_KNOWN = """#!/usr/bin/env sh
 _cache_prefix="{cache_prefix}"
 export ZIG_LOCAL_CACHE_DIR="$_cache_prefix/bazel-zig-cc"
 export ZIG_GLOBAL_CACHE_DIR=$ZIG_LOCAL_CACHE_DIR
 exec "{zig}" "{zig_tool}" "$@"
 """
 
-ZIG_TOOL_WRAPPER_CACHE_GUESS = """#!/usr/bin/env sh
+_ZIG_TOOL_WRAPPER_CACHE_GUESS = """#!/usr/bin/env sh
 set -e
 if [ -n "$TMPDIR" ]; then
     _cache_prefix=$TMPDIR
@@ -101,32 +128,22 @@ export ZIG_GLOBAL_CACHE_DIR=$ZIG_LOCAL_CACHE_DIR
 exec "{zig}" "{zig_tool}" "$@"
 """
 
-ZIG_TOOL_WRAPPER_WINDOWS_CACHE_KNOWN = """@echo off
-set ZIG_LOCAL_CACHE_DIR={cache_prefix}\\bazel-zig-cc
-set ZIG_GLOBAL_CACHE_DIR=%ZIG_LOCAL_CACHE_DIR%
-"{zig}" "{zig_tool}" %*
-"""
+def _zig_tool_wrapper(zig_tool, zig, is_windows, cache_prefix):
+    kwargs = dict(
+        zig = str(zig).replace("/", "\\") + ".exe" if is_windows else zig,
+        zig_tool = zig_tool,
+        cache_prefix = cache_prefix,
+    )
 
-ZIG_TOOL_WRAPPER_WINDOWS_CACHE_GUESS = """@echo off
-if exist "%TMP%\\*" goto :usertmp
-set ZIG_LOCAL_CACHE_DIR=C:\\Temp\\bazel-zig-cc
-goto zig
-:usertmp
-set ZIG_LOCAL_CACHE_DIR=%TMP%\\bazel-zig-cc
-:zig
-set ZIG_GLOBAL_CACHE_DIR=%ZIG_LOCAL_CACHE_DIR%
-"{zig}" "{zig_tool}" %*
-"""
-
-_ZIG_TOOLS = [
-    "c++",
-    "cc",
-    "ar",
-    "ld.lld",  # ELF
-    "ld64.lld",  # Mach-O
-    "lld-link",  # COFF
-    "wasm-ld",  # WebAssembly
-]
+    if is_windows:
+        if cache_prefix:
+            return _ZIG_TOOL_WRAPPER_WINDOWS_CACHE_KNOWN.format(**kwargs)
+        else:
+            return _ZIG_TOOL_WRAPPER_WINDOWS_CACHE_GUESS.format(**kwargs)
+    elif cache_prefix:
+        return _ZIG_TOOL_WRAPPER_CACHE_KNOWN.format(**kwargs)
+    else:
+        return _ZIG_TOOL_WRAPPER_CACHE_GUESS.format(**kwargs)
 
 def _quote(s):
     return "'" + s.replace("'", "'\\''") + "'"
@@ -163,30 +180,12 @@ def _zig_repository_impl(repository_ctx):
     )
 
     for zig_tool in _ZIG_TOOLS:
-        cache_prefix = repository_ctx.os.environ.get("BAZEL_ZIG_CC_CACHE_PREFIX", "")
-        if os == "windows":
-            if cache_prefix:
-                zig_tool_wrapper = ZIG_TOOL_WRAPPER_WINDOWS_CACHE_KNOWN.format(
-                    zig = str(repository_ctx.path("zig")).replace("/", "\\") + ".exe",
-                    zig_tool = zig_tool,
-                    cache_prefix = cache_prefix,
-                )
-            else:
-                zig_tool_wrapper = ZIG_TOOL_WRAPPER_WINDOWS_CACHE_GUESS.format(
-                    zig = str(repository_ctx.path("zig")).replace("/", "\\") + ".exe",
-                    zig_tool = zig_tool,
-                )
-        elif cache_prefix:
-            zig_tool_wrapper = ZIG_TOOL_WRAPPER_CACHE_KNOWN.format(
-                zig = str(repository_ctx.path("zig")),
-                zig_tool = zig_tool,
-                cache_prefix = cache_prefix,
-            )
-        else:
-            zig_tool_wrapper = ZIG_TOOL_WRAPPER_CACHE_GUESS.format(
-                zig = str(repository_ctx.path("zig")),
-                zig_tool = zig_tool,
-            )
+        zig_tool_wrapper = _zig_tool_wrapper(
+            zig_tool,
+            str(repository_ctx.path("zig")),
+            os == "windows",
+            repository_ctx.os.environ.get("BAZEL_ZIG_CC_CACHE_PREFIX", ""),
+        )
 
         repository_ctx.file(
             zig_tool_path(os).format(zig_tool = zig_tool),