CHANGELOG.md

+# [1.0.0-alpha.8](https://git.gitlab.arm.com/bazel/rules_toolchain/compare/v1.0.0-alpha.7...v1.0.0-alpha.8) (2023-12-11)
+
+### Bug Fixes
+
+- make sure symlinks have `.exe` extension on Windows ([85f15d1](https://git.gitlab.arm.com/bazel/rules_toolchain/commit/85f15d1b590237374c59c8037eca3ea56777c8ee))
+
 # [1.0.0-alpha.7](https://git.gitlab.arm.com/bazel/rules_toolchain/compare/v1.0.0-alpha.6...v1.0.0-alpha.7) (2023-12-08)
 
 ### Bug Fixes

MODULE.bazel

 module(
     name = "rules_toolchain",
-    version = "1.0.0-alpha.7",
+    version = "1.0.0-alpha.8",
     bazel_compatibility = [
         ">=6.4.0",
     ],

README.md

@@ -87,4 +87,33 @@ toolchain(
 )
 ```
 
+## Usage
+
+### Toolchain
+
+Declare the usage of the toolchain in a rule definition:
+
+```py
+def implementation(ctx):
+    toolchain = ctx.toolchains["//toolchain/echo:type"]
+    print(toolchain.executable)
+    print(toolchain.default.files)
+    print(toolchain.default.runfiles)
+
+example = rule(
+    implementation = implementation,
+    toolchains = ["//toolchain/echo:type"],
+)
+```
+
+### Variable
+
+Pass the resolved toolchain to a rule that supports variables:
+
+```py
+genrule(
+    toolchains = ["//toolchain/echo:resolved"]
+)
+```
+
 [resolved]: https://github.com/bazelbuild/bazel/issues/14009

e2e/MODULE.bazel.lock

@@ -848,7 +848,7 @@
   "moduleExtensions": {
     "//:MODULE.bazel%_repo_rules": {
       "general": {
-        "bzlTransitiveDigest": "H6a/EFhNB57YKE/R9dWOnzyt7/yZUN4dwbh4eVfSEko=",
+        "bzlTransitiveDigest": "gyM/unRUgkxmFCQHcLcZtVkdb+4qFdRusznNLzQ7Ukc=",
         "accumulatedFileDigests": {},
         "envVariables": {},
         "generatedRepoSpecs": {

toolchain/resolved.bzl

@@ -21,16 +21,23 @@ ATTRS = {
         doc = "The toolchain type to resolve and forward on providers.",
         mandatory = True,
     ),
+    "_windows": attr.label(
+        providers = [platform_common.ConstraintValueInfo],
+        default = "//toolchain/constraint/os:windows",
+    ),
 }
 
 def implementation(ctx):
     basename = ctx.attr.basename or ctx.label.name
     toolchain = ctx.toolchains[ctx.attr.toolchain_type.label]
+    windows = ctx.attr._windows[platform_common.ConstraintValueInfo]
 
     target = toolchain.executable
     extension = target.extension
     if extension in ("bat", "cmd"):
         basename = "{}.{}".format(basename, extension)
+    elif not extension and "." not in basename and ctx.target_platform_has_constraint(windows):
+        basename = "{}.exe".format(basename)
 
     executable = ctx.actions.declare_file(basename)
     ctx.actions.symlink(

toolchain/symlink/path/rule.bzl

@@ -15,11 +15,26 @@ ATTRS = {
         doc = "Extra files that are needed at runtime.",
         allow_files = True,
     ),
+    "_windows": attr.label(
+        providers = [platform_common.ConstraintValueInfo],
+        default = "//toolchain/constraint/os:windows",
+    ),
 }
 
 def implementation(ctx):
     basename = ctx.attr.basename or ctx.label.name
     variable = ctx.attr.variable or basename.upper()
+    windows = ctx.attr._windows[platform_common.ConstraintValueInfo]
+
+    if "." not in ctx.attr.path:
+        extension = None
+    else:
+        _, extension = ctx.attr.path.rsplit(".", 1)
+
+    if extension in ("bat", "cmd"):
+        basename = "{}.{}".format(basename, extension)
+    elif not extension and "." not in basename and ctx.target_platform_has_constraint(windows):
+        basename = "{}.exe".format(basename)
 
     executable = ctx.actions.declare_symlink(basename)
     ctx.actions.symlink(

toolchain/symlink/target/rule.bzl

@@ -54,16 +54,23 @@ ATTRS = {
         doc = "Extra files that are needed at runtime.",
         allow_files = True,
     ),
+    "_windows": attr.label(
+        providers = [platform_common.ConstraintValueInfo],
+        default = "//toolchain/constraint/os:windows",
+    ),
 }
 
 def implementation(ctx):
     basename = ctx.attr.basename or ctx.label.name
     variable = ctx.attr.variable or basename.upper()
+    windows = ctx.attr._windows[platform_common.ConstraintValueInfo]
 
     target = ctx.executable.target
     extension = target.extension
     if extension in ("bat", "cmd"):
         basename = "{}.{}".format(basename, extension)
+    elif not extension and "." not in basename and ctx.target_platform_has_constraint(windows):
+        basename = "{}.exe".format(basename)
 
     executable = ctx.actions.declare_file(basename)
     ctx.actions.symlink(