chore: add e2e examples: custom toolchain glibc version + foreign_cc cmake

.bazelrc

@@ -18,8 +18,8 @@ build --workspace_status_command=$(pwd)/workspace_status.sh
 # To update these lines, execute
 # `bazel run @rules_bazel_integration_test//tools:update_deleted_packages`
 # docs: https://bazel.build/reference/command-line-reference#flag--deleted_packages
-build --deleted_packages=e2e/workspace,e2e/workspace/bazel_builtin,e2e/workspace/c-sources,e2e/workspace/canonical-name-module,e2e/workspace/canonical-name-module/other,e2e/workspace/cc-dependencies,e2e/workspace/cc-dependencies/shared-library,e2e/workspace/cc-dependencies/static-library,e2e/workspace/cc-dependencies/static-library-cdeps,e2e/workspace/configure-mode,e2e/workspace/configure-target,e2e/workspace/configure-threaded,e2e/workspace/configure-use_cc_common_link,e2e/workspace/configure-use_cc_common_link/shared-library,e2e/workspace/configure-use_cc_common_link/static-library,e2e/workspace/configure-version,e2e/workspace/data-dependencies,e2e/workspace/embed-file,e2e/workspace/env-attr,e2e/workspace/import-name-attr,e2e/workspace/include-dependencies,e2e/workspace/include-dependencies/zig-include,e2e/workspace/include-dependencies/zig-include-define,e2e/workspace/include-dependencies/zig-include-isystem,e2e/workspace/include-dependencies/zig-std-include,e2e/workspace/link-dependencies,e2e/workspace/link-dependencies/shared-library,e2e/workspace/link-dependencies/static-library,e2e/workspace/linker-script,e2e/workspace/linkopts-attr,e2e/workspace/location-expansion,e2e/workspace/multiple-sources-and-packages-test,e2e/workspace/multiple-sources-binary,e2e/workspace/root-module-from-single-dependency,e2e/workspace/runfiles-library,e2e/workspace/runfiles-library/dependency,e2e/workspace/runfiles-library/dependency/transitive-dependency,e2e/workspace/simple-binary,e2e/workspace/simple-library,e2e/workspace/simple-shared-library,e2e/workspace/simple-test,e2e/workspace/test-runner-attr,e2e/workspace/transitive-zig-modules-binary,e2e/workspace/transitive-zig-modules-binary/hello-world,e2e/workspace/transitive-zig-modules-binary/hello-world/data,e2e/workspace/transitive-zig-modules-binary/hello-world/data/hello,e2e/workspace/transitive-zig-modules-binary/hello-world/data/world,e2e/workspace/transitive-zig-modules-binary/hello-world/io,e2e/workspace/translate-c/transitive-cc-library-zig-binary,e2e/workspace/zig-docs,e2e/workspace/zig-header,e2e/workspace/zig-module-binary,e2e/workspace/zig-module-binary/data,e2e/workspace/zig-module-binary/io,zig/tests/integration_tests/minimal,zig/tests/integration_tests/mirrors,zig/tests/integration_tests/workspace,zig/tests/integration_tests/workspace/custom_interpreter,zig/tests/integration_tests/workspace/env-attr,zig/tests/integration_tests/workspace/runfiles
-query --deleted_packages=e2e/workspace,e2e/workspace/bazel_builtin,e2e/workspace/c-sources,e2e/workspace/canonical-name-module,e2e/workspace/canonical-name-module/other,e2e/workspace/cc-dependencies,e2e/workspace/cc-dependencies/shared-library,e2e/workspace/cc-dependencies/static-library,e2e/workspace/cc-dependencies/static-library-cdeps,e2e/workspace/configure-mode,e2e/workspace/configure-target,e2e/workspace/configure-threaded,e2e/workspace/configure-use_cc_common_link,e2e/workspace/configure-use_cc_common_link/shared-library,e2e/workspace/configure-use_cc_common_link/static-library,e2e/workspace/configure-version,e2e/workspace/data-dependencies,e2e/workspace/embed-file,e2e/workspace/env-attr,e2e/workspace/import-name-attr,e2e/workspace/include-dependencies,e2e/workspace/include-dependencies/zig-include,e2e/workspace/include-dependencies/zig-include-define,e2e/workspace/include-dependencies/zig-include-isystem,e2e/workspace/include-dependencies/zig-std-include,e2e/workspace/link-dependencies,e2e/workspace/link-dependencies/shared-library,e2e/workspace/link-dependencies/static-library,e2e/workspace/linker-script,e2e/workspace/linkopts-attr,e2e/workspace/location-expansion,e2e/workspace/multiple-sources-and-packages-test,e2e/workspace/multiple-sources-binary,e2e/workspace/root-module-from-single-dependency,e2e/workspace/runfiles-library,e2e/workspace/runfiles-library/dependency,e2e/workspace/runfiles-library/dependency/transitive-dependency,e2e/workspace/simple-binary,e2e/workspace/simple-library,e2e/workspace/simple-shared-library,e2e/workspace/simple-test,e2e/workspace/test-runner-attr,e2e/workspace/transitive-zig-modules-binary,e2e/workspace/transitive-zig-modules-binary/hello-world,e2e/workspace/transitive-zig-modules-binary/hello-world/data,e2e/workspace/transitive-zig-modules-binary/hello-world/data/hello,e2e/workspace/transitive-zig-modules-binary/hello-world/data/world,e2e/workspace/transitive-zig-modules-binary/hello-world/io,e2e/workspace/translate-c/transitive-cc-library-zig-binary,e2e/workspace/zig-docs,e2e/workspace/zig-header,e2e/workspace/zig-module-binary,e2e/workspace/zig-module-binary/data,e2e/workspace/zig-module-binary/io,zig/tests/integration_tests/minimal,zig/tests/integration_tests/mirrors,zig/tests/integration_tests/workspace,zig/tests/integration_tests/workspace/custom_interpreter,zig/tests/integration_tests/workspace/env-attr,zig/tests/integration_tests/workspace/runfiles
+build --deleted_packages=e2e/workspace,e2e/workspace/bazel_builtin,e2e/workspace/c-sources,e2e/workspace/canonical-name-module,e2e/workspace/canonical-name-module/other,e2e/workspace/cc-dependencies,e2e/workspace/cc-dependencies/shared-library,e2e/workspace/cc-dependencies/static-library,e2e/workspace/cc-dependencies/static-library-cdeps,e2e/workspace/configure-mode,e2e/workspace/configure-target,e2e/workspace/configure-threaded,e2e/workspace/configure-use_cc_common_link,e2e/workspace/configure-use_cc_common_link/shared-library,e2e/workspace/configure-use_cc_common_link/static-library,e2e/workspace/configure-version,e2e/workspace/data-dependencies,e2e/workspace/embed-file,e2e/workspace/env-attr,e2e/workspace/import-name-attr,e2e/workspace/include-dependencies,e2e/workspace/include-dependencies/zig-include,e2e/workspace/include-dependencies/zig-include-define,e2e/workspace/include-dependencies/zig-include-isystem,e2e/workspace/include-dependencies/zig-std-include,e2e/workspace/link-dependencies,e2e/workspace/link-dependencies/shared-library,e2e/workspace/link-dependencies/static-library,e2e/workspace/linker-script,e2e/workspace/linkopts-attr,e2e/workspace/location-expansion,e2e/workspace/multiple-sources-and-packages-test,e2e/workspace/multiple-sources-binary,e2e/workspace/root-module-from-single-dependency,e2e/workspace/runfiles-library,e2e/workspace/runfiles-library/dependency,e2e/workspace/runfiles-library/dependency/transitive-dependency,e2e/workspace/simple-binary,e2e/workspace/simple-cmake-library,e2e/workspace/simple-library,e2e/workspace/simple-shared-library,e2e/workspace/simple-test,e2e/workspace/test-runner-attr,e2e/workspace/toolchain-glibc-version,e2e/workspace/transitive-zig-modules-binary,e2e/workspace/transitive-zig-modules-binary/hello-world,e2e/workspace/transitive-zig-modules-binary/hello-world/data,e2e/workspace/transitive-zig-modules-binary/hello-world/data/hello,e2e/workspace/transitive-zig-modules-binary/hello-world/data/world,e2e/workspace/transitive-zig-modules-binary/hello-world/io,e2e/workspace/translate-c/transitive-cc-library-zig-binary,e2e/workspace/zig-docs,e2e/workspace/zig-header,e2e/workspace/zig-module-binary,e2e/workspace/zig-module-binary/data,e2e/workspace/zig-module-binary/io,zig/tests/integration_tests/minimal,zig/tests/integration_tests/mirrors,zig/tests/integration_tests/workspace,zig/tests/integration_tests/workspace/custom_interpreter,zig/tests/integration_tests/workspace/env-attr,zig/tests/integration_tests/workspace/runfiles
+query --deleted_packages=e2e/workspace,e2e/workspace/bazel_builtin,e2e/workspace/c-sources,e2e/workspace/canonical-name-module,e2e/workspace/canonical-name-module/other,e2e/workspace/cc-dependencies,e2e/workspace/cc-dependencies/shared-library,e2e/workspace/cc-dependencies/static-library,e2e/workspace/cc-dependencies/static-library-cdeps,e2e/workspace/configure-mode,e2e/workspace/configure-target,e2e/workspace/configure-threaded,e2e/workspace/configure-use_cc_common_link,e2e/workspace/configure-use_cc_common_link/shared-library,e2e/workspace/configure-use_cc_common_link/static-library,e2e/workspace/configure-version,e2e/workspace/data-dependencies,e2e/workspace/embed-file,e2e/workspace/env-attr,e2e/workspace/import-name-attr,e2e/workspace/include-dependencies,e2e/workspace/include-dependencies/zig-include,e2e/workspace/include-dependencies/zig-include-define,e2e/workspace/include-dependencies/zig-include-isystem,e2e/workspace/include-dependencies/zig-std-include,e2e/workspace/link-dependencies,e2e/workspace/link-dependencies/shared-library,e2e/workspace/link-dependencies/static-library,e2e/workspace/linker-script,e2e/workspace/linkopts-attr,e2e/workspace/location-expansion,e2e/workspace/multiple-sources-and-packages-test,e2e/workspace/multiple-sources-binary,e2e/workspace/root-module-from-single-dependency,e2e/workspace/runfiles-library,e2e/workspace/runfiles-library/dependency,e2e/workspace/runfiles-library/dependency/transitive-dependency,e2e/workspace/simple-binary,e2e/workspace/simple-cmake-library,e2e/workspace/simple-library,e2e/workspace/simple-shared-library,e2e/workspace/simple-test,e2e/workspace/test-runner-attr,e2e/workspace/toolchain-glibc-version,e2e/workspace/transitive-zig-modules-binary,e2e/workspace/transitive-zig-modules-binary/hello-world,e2e/workspace/transitive-zig-modules-binary/hello-world/data,e2e/workspace/transitive-zig-modules-binary/hello-world/data/hello,e2e/workspace/transitive-zig-modules-binary/hello-world/data/world,e2e/workspace/transitive-zig-modules-binary/hello-world/io,e2e/workspace/translate-c/transitive-cc-library-zig-binary,e2e/workspace/zig-docs,e2e/workspace/zig-header,e2e/workspace/zig-module-binary,e2e/workspace/zig-module-binary/data,e2e/workspace/zig-module-binary/io,zig/tests/integration_tests/minimal,zig/tests/integration_tests/mirrors,zig/tests/integration_tests/workspace,zig/tests/integration_tests/workspace/custom_interpreter,zig/tests/integration_tests/workspace/env-attr,zig/tests/integration_tests/workspace/runfiles
 
 # Load any settings specific to the current user.
 # Place settings that should affect the integration tests into `.bazelrc.ic.user`.

e2e/workspace/MODULE.bazel

@@ -38,3 +38,9 @@ local_path_override(
     module_name = "runfiles_library_transitive_dependency",
     path = "runfiles-library/dependency/transitive-dependency",
 )
+
+bazel_dep(
+    name = "rules_foreign_cc",
+    version = "0.15.0",
+    dev_dependency = True,
+)

e2e/workspace/simple-cmake-library/BUILD.bazel

@@ -0,0 +1,37 @@
+load("@rules_foreign_cc//foreign_cc:defs.bzl", "cmake")
+load("@rules_zig//zig:defs.bzl", "zig_binary")
+
+# --------------------
+# external library using foreign_cc
+filegroup(
+    name = "c-hello-srcs",
+    srcs = glob(["external_library/**"]),
+)
+
+cmake(
+    name = "c-hello",
+    lib_source = ":c-hello-srcs",
+    out_include_dir = "hello",
+    out_shared_libs = select({
+        "@platforms//os:macos": ["libhello.dylib"],
+        "//conditions:default": ["libhello.so"],
+    }),
+)
+# --------------------
+# equivalent implementation with cc_rules
+# cc_library(
+#     name = "c-hello",
+#     srcs = ["external_library/hello.c"],
+#     hdrs = ["external_library/hello.h"],
+#     includes = ["external_library"],
+# )
+# --------------------
+
+zig_binary(
+    name = "main",
+    main = "main.zig",
+    deps = [
+        ":c-hello",
+        "@rules_zig//zig/lib:libc",
+    ],
+)

e2e/workspace/simple-cmake-library/external_library/CMakeLists.txt

@@ -0,0 +1,15 @@
+cmake_minimum_required(VERSION 3.20)
+project(hello)
+
+add_library(hello SHARED hello.c)
+target_include_directories(hello PRIVATE ".")
+
+
+install(TARGETS hello EXPORT helloTargets
+  ARCHIVE DESTINATION "${CMAKE_INSTALL_LIBDIR}"
+)
+
+install(FILES hello.h
+  DESTINATION "hello/"
+)
+

e2e/workspace/simple-cmake-library/external_library/hello.c

@@ -0,0 +1,7 @@
+#include "hello.h"
+#include "stdio.h"
+
+void hello()
+{
+  printf("Hello World from hello.c!\n");
+}

e2e/workspace/simple-cmake-library/external_library/hello.h

@@ -0,0 +1,3 @@
+#pragma once
+
+void hello();

e2e/workspace/simple-cmake-library/main.zig

@@ -0,0 +1,7 @@
+const c = @cImport({
+    @cInclude("hello.h");
+});
+
+pub fn main() !void {
+    c.hello();
+}

e2e/workspace/toolchain-glibc-version/BUILD.bazel

@@ -0,0 +1,78 @@
+load("@bazel_skylib//rules:diff_test.bzl", "diff_test")
+load("@rules_zig//zig:defs.bzl", "zig_binary", "zig_configure_binary", "zig_test")
+load("@rules_zig//zig:toolchain.bzl", "zig_target_toolchain")
+
+platform(
+    name = "x86_64-linux-gnu-2.25",
+    constraint_values = [
+        "@platforms//os:linux",
+        "@platforms//cpu:x86_64",
+        ":gnu-2.25",
+    ],
+)
+
+constraint_value(
+    name = "gnu-2.25",
+    constraint_setting = "@rules_zig//zig/platforms/abi:abi",
+    visibility = ["//visibility:public"],
+)
+
+zig_target_toolchain(
+    name = "glibc-2.25",
+    target = "x86_64-linux-gnu.2.25",
+)
+
+toolchain(
+    name = "glibc_2.25_toolchain",
+    target_compatible_with = [
+        "@platforms//os:linux",
+        "@platforms//cpu:x86_64",
+        ":gnu-2.25",
+    ],
+    toolchain = ":glibc-2.25",
+    toolchain_type = "@rules_zig//zig/target:toolchain_type",
+)
+
+zig_binary(
+    name = "main-unconfigured",
+    main = "main.zig",
+    target_compatible_with = ["@platforms//os:linux"],
+    deps = [
+        "@rules_zig//zig/lib:libc",
+    ],
+)
+
+zig_configure_binary(
+    name = "main-2.25",
+    actual = ":main-unconfigured",
+    extra_toolchains = [":glibc_2.25_toolchain"],
+    target = ":x86_64-linux-gnu-2.25",
+    target_compatible_with = ["@platforms//os:linux"],
+)
+
+zig_test(
+    name = "fallback_glibc.2.17",
+    size = "small",
+    main = "main.zig",
+    target_compatible_with = ["@platforms//os:linux"],
+    visibility = ["//zig/tests:__pkg__"],
+    deps = [
+        "@rules_zig//zig/lib:libc",
+    ],
+)
+
+genrule(
+    name = "main-2.25-glibc-version",
+    outs = ["main-2.25-glibc-version.actual"],
+    cmd = "$(execpath :main-2.25) |& grep compile-time > $(OUTS)",
+    target_compatible_with = ["@platforms//os:linux"],
+    tools = [":main-2.25"],
+)
+
+diff_test(
+    name = "main-2.25-glibc-version-test",
+    size = "small",
+    file1 = ":main-2.25-glibc-version.expected",
+    file2 = ":main-2.25-glibc-version.actual",
+    target_compatible_with = ["@platforms//os:linux"],
+)

e2e/workspace/toolchain-glibc-version/README.md

@@ -0,0 +1,22 @@
+By default, `rules_zig` targets a "lowest common denominator" glibc version to ensure broad compatibility. You can find the discussion behind this choice in [this PR](https://github.com/aherrmann/rules_zig/pull/299) and see the implementation [here](https://github.com/aherrmann/rules_zig/blob/main/zig/target/BUILD.bazel#L56).
+
+This example project demonstrates how to manually configure and use a specific glibc version with `rules_zig`.
+
+
+```bash
+# navigate to the workspace directory:
+cd e2e/workspace
+
+# run with the default glibc version
+# "main-unconfigured" uses the default glibc version
+# note that the runtime glibc version depends on the execution environment
+bazel run toolchain-glibc-version:main-unconfigured
+
+# run with a custom glibc version
+# "main-2.25" uses a custom toolchain using glibc 2.25
+bazel run toolchain-glibc-version:main-2.25
+
+# verify the fallback behaviour
+# this shows the "unconfigured" zig_test still uses the fallback version
+bazel test toolchain-glibc-version:fallback_glibc.2.17
+```

e2e/workspace/toolchain-glibc-version/main-2.25-glibc-version.expected

@@ -0,0 +1 @@
+glibc compile-time version: 2.25

e2e/workspace/toolchain-glibc-version/main.zig

@@ -0,0 +1,16 @@
+const std = @import("std");
+const c = @cImport({
+    @cInclude("features.h");
+});
+
+extern "c" fn gnu_get_libc_version() [*c]const u8;
+
+pub fn main() !void {
+    std.debug.print("glibc compile-time version: {d}.{d}\n", .{ c.__GLIBC__, c.__GLIBC_MINOR__ });
+    std.debug.print("glibc runtime version:      {s}\n", .{gnu_get_libc_version()});
+}
+
+test "test_fallback_glibc.2.17" {
+    try std.testing.expectEqual(2, c.__GLIBC__);
+    try std.testing.expectEqual(17, c.__GLIBC_MINOR__);
+}