Add env and env_inherit to native_binary and native_test (using @bazel_features)

MODULE.bazel

@@ -10,7 +10,7 @@ register_toolchains(
     "//toolchains/unittest:bash_toolchain",
 )
 
-bazel_dep(name = "platforms", version = "0.0.4")
+bazel_dep(name = "platforms", version = "0.0.9")
 bazel_dep(name = "rules_license", version = "0.0.7")
 
 ### INTERNAL ONLY - lines after this are not included in the release packaging.

docs/native_binary_doc.md

@@ -12,7 +12,7 @@ don't depend on Bash and work with --shell_executable="".
 ## native_binary
 
 <pre>
-native_binary(<a href="#native_binary-name">name</a>, <a href="#native_binary-src">src</a>, <a href="#native_binary-data">data</a>, <a href="#native_binary-out">out</a>)
+native_binary(<a href="#native_binary-name">name</a>, <a href="#native_binary-src">src</a>, <a href="#native_binary-data">data</a>, <a href="#native_binary-out">out</a>, <a href="#native_binary-env">env</a>)
 </pre>
 
 Wraps a pre-built binary or script with a binary rule.
@@ -29,14 +29,15 @@ in genrule.tools for example. You can also augment the binary with runfiles.
 | <a id="native_binary-src"></a>src |  path of the pre-built executable   | <a href="https://bazel.build/concepts/labels">Label</a> | required |  |
 | <a id="native_binary-data"></a>data |  data dependencies. See https://bazel.build/reference/be/common-definitions#typical.data   | <a href="https://bazel.build/concepts/labels">List of labels</a> | optional |  `[]`  |
 | <a id="native_binary-out"></a>out |  An output name for the copy of the binary. Defaults to name.exe. (We add .exe to the name by default because it's required on Windows and tolerated on other platforms.)   | String | optional |  `""`  |
+| <a id="native_binary-env"></a>env |  additional environment variables to set when the target is executed by `bazel`. Values are subject to location expansion for labels in `src` and `data`.   | <a href="https://bazel.build/rules/lib/dict">Dictionary: String -> String</a> | optional |  `{}`  |
 
 
 <a id="native_test"></a>
 
 ## native_test
 
 <pre>
-native_test(<a href="#native_test-name">name</a>, <a href="#native_test-src">src</a>, <a href="#native_test-data">data</a>, <a href="#native_test-out">out</a>)
+native_test(<a href="#native_test-name">name</a>, <a href="#native_test-src">src</a>, <a href="#native_test-data">data</a>, <a href="#native_test-out">out</a>, <a href="#native_test-env">env</a>, <a href="#native_test-env_inherit">env_inherit</a>)
 </pre>
 
 Wraps a pre-built binary or script with a test rule.
@@ -53,5 +54,7 @@ the binary with runfiles.
 | <a id="native_test-src"></a>src |  path of the pre-built executable   | <a href="https://bazel.build/concepts/labels">Label</a> | required |  |
 | <a id="native_test-data"></a>data |  data dependencies. See https://bazel.build/reference/be/common-definitions#typical.data   | <a href="https://bazel.build/concepts/labels">List of labels</a> | optional |  `[]`  |
 | <a id="native_test-out"></a>out |  An output name for the copy of the binary. Defaults to name.exe. (We add .exe to the name by default because it's required on Windows and tolerated on other platforms.)   | String | optional |  `""`  |
+| <a id="native_test-env"></a>env |  additional environment variables to set when the target is executed by `bazel`. Values are subject to location expansion for labels in `src` and `data`.   | <a href="https://bazel.build/rules/lib/dict">Dictionary: String -> String</a> | optional |  `{}`  |
+| <a id="native_test-env_inherit"></a>env_inherit |  additional environment variables to inherit from the external environment when the test is executed by `bazel test`.   | List of strings | optional |  `[]`  |
 
 

rules/native_binary.bzl

@@ -29,23 +29,25 @@ def _impl_rule(ctx):
     )
     runfiles = ctx.runfiles(files = ctx.files.data)
 
-    # Bazel 4.x LTS does not support `merge_all`.
-    # TODO: remove `merge` branch once we drop support for Bazel 4.x.
-    if hasattr(runfiles, "merge_all"):
-        runfiles = runfiles.merge_all([
-            d[DefaultInfo].default_runfiles
-            for d in ctx.attr.data + [ctx.attr.src]
-        ])
-    else:
-        for d in ctx.attr.data:
-            runfiles = runfiles.merge(d[DefaultInfo].default_runfiles)
-        runfiles = runfiles.merge(ctx.attr.src[DefaultInfo].default_runfiles)
+    runfiles = runfiles.merge_all([
+        d[DefaultInfo].default_runfiles
+        for d in ctx.attr.data + [ctx.attr.src]
+    ])
 
-    return DefaultInfo(
-        executable = out,
-        files = depset([out]),
-        runfiles = runfiles,
-    )
+    targets = [ctx.attr.src] + ctx.attr.data
+    env = {k: ctx.expand_location(v, targets) for k, v in ctx.attr.env.items()}
+
+    return [
+        DefaultInfo(
+            executable = out,
+            files = depset([out]),
+            runfiles = runfiles,
+        ),
+        RunEnvironmentInfo(
+            environment = env,
+            inherited_environment = getattr(ctx.attr, "env_inherit", []),
+        ),
+    ]
 
 _ATTRS = {
     "src": attr.label(
@@ -70,6 +72,12 @@ _ATTRS = {
               "name.exe. (We add .exe to the name by default because it's " +
               "required on Windows and tolerated on other platforms.)",
     ),
+    "env": attr.string_dict(
+        doc = "additional environment variables to set when the target is executed by " +
+              "`bazel`. Values are subject to location expansion for labels in `src` and " +
+              "`data`.",
+        default = {},
+    ),
 }
 
 native_binary = rule(
@@ -86,7 +94,14 @@ in genrule.tools for example. You can also augment the binary with runfiles.
 
 native_test = rule(
     implementation = _impl_rule,
-    attrs = _ATTRS,
+    attrs = dict(
+        _ATTRS,
+        env_inherit = attr.string_list(
+            doc = "additional environment variables to inherit from the external " +
+                  "environment when the test is executed by `bazel test`. ",
+            default = [],
+        ),
+    ),
     test = True,
     doc = """
 Wraps a pre-built binary or script with a test rule.

tests/native_binary/BUILD

@@ -30,6 +30,11 @@ cc_binary(
     deps = ["@bazel_tools//tools/cpp/runfiles"],
 )
 
+cc_binary(
+    name = "assertenv",
+    srcs = ["assertenv.cc"],
+)
+
 # A rule that copies "assertarg"'s output as an opaque executable, simulating a
 # binary that's not built from source and needs to be wrapped in native_binary.
 copy_file(
@@ -54,6 +59,16 @@ copy_file(
     is_executable = True,
 )
 
+copy_file(
+    name = "copy_assertenv_exe",
+    src = ":assertenv",
+    # On Windows we need the ".exe" extension.
+    # On other platforms the extension doesn't matter.
+    # Therefore we can use ".exe" on every platform.
+    out = "assertenv_copy.exe",
+    is_executable = True,
+)
+
 _ARGS = [
     "'a b'",
     "c\\ d",
@@ -121,3 +136,17 @@ native_test(
     # Therefore we can use ".exe" on every platform.
     out = "data_from_binary_test.exe",
 )
+
+native_test(
+    name = "env_test",
+    src = ":copy_assertenv_exe",
+    data = ["BUILD"],
+    env = {
+        "TEST_ENV_VAR": "test_env_var_value",
+        "TEST_ENV_VAR_WITH_EXPANSION": "|$(rootpath BUILD)|",
+    },
+    env_inherit = [
+        "HOME",  # for POSIX
+        "APPDATA",  # for Windows
+    ],
+)

tests/native_binary/assertenv.cc

@@ -0,0 +1,31 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+bool check(const char *var, const char *expected = nullptr);
+
+int main() {
+  bool ok = true;
+  ok = ok && check("TEST_ENV_VAR", "test_env_var_value");
+#ifdef _WIN32
+  ok = ok && check("APPDATA");
+#else
+  ok = ok && check("HOME");
+#endif
+  ok =
+      ok && check("TEST_ENV_VAR_WITH_EXPANSION", "|tests/native_binary/BUILD|");
+  return ok ? 0 : 1;
+}
+
+bool check(const char *var, const char *expected) {
+  const char *actual = getenv(var);
+  if (actual == nullptr) {
+    fprintf(stderr, "expected %s\n", var);
+    return false;
+  }
+  if (expected && strcmp(actual, expected) != 0) {
+    fprintf(stderr, "expected %s=%s, got %s\n", var, expected, actual);
+    return false;
+  }
+  return true;
+}