workspace: rework code completion using a custom build runner (zml#131)

steeve · web-flow · commit e0041974d229 · 2024-12-16T13:20:27.000+01:00
Following the new release of the VSCode Zig plugin, rework the code
completion logic to leverage a build runner. This is much lighter,
faster and more reliable.
diff --git a/.bazelrc-examples b/.bazelrc-examples
@@ -1,2 +1,2 @@
-common   --override_module=zml=../
+common   --override_module=zml=%workspace%/../../
 common   --registry=file://%workspace%/../third_party/
diff --git a/BUILD.bazel b/BUILD.bazel
@@ -2,6 +2,7 @@ load("@rules_zig//zig:defs.bzl", "zls_completion")
 
 zls_completion(
     name = "completion",
+    visibility = ["//visibility:public"],
     deps = [
         "//async",
         "//stdx",
diff --git a/MODULE.bazel.lock b/MODULE.bazel.lock
diff --git a/examples/.vscode/settings.json b/examples/.vscode/settings.json
@@ -19,11 +19,16 @@
         "."
     ],
     "bazel.buildifierExecutable": "@buildifier_prebuilt//:buildifier",
-    "zig.formattingProvider": "zls",
-    "zig.initialSetupDone": true,
-    "zig.path": "${workspaceFolder}/tools/zig.sh",
-    "zig.zls.globalCachePath": null,
-    "zig.zls.path": "${workspaceFolder}/tools/zls.sh",
     "C_Cpp.formatting": "clangFormat",
     "C_Cpp.clang_format_style": "Microsoft",
+    "zig.formattingProvider": "zls",
+    "zig.path": "x",
+    "zig.zls.path": "${workspaceFolder}/tools/zls.sh",
+    "[zig]": {
+        "editor.suggest.insertMode": "replace",
+        "editor.stickyScroll.defaultModel": "foldingProviderModel",
+        "editor.codeActionsOnSave": {
+            "source.fixAll": "explicit",
+        }
+    },
 }
diff --git a/examples/MODULE.bazel.lock b/examples/MODULE.bazel.lock
diff --git a/examples/tools/buildifier.sh b/examples/tools/buildifier.sh
@@ -1,3 +1,4 @@
 #!/bin/bash
 cd "$(dirname "${BASH_SOURCE[0]}")"
+cd "$(bazel info workspace)"
 exec bazel run -- @buildifier_prebuilt//:buildifier "$@"
diff --git a/examples/tools/zig.sh b/examples/tools/zig.sh
diff --git a/examples/tools/zls.sh b/examples/tools/zls.sh
@@ -1,3 +1,4 @@
 #!/bin/bash
 cd "$(dirname "${BASH_SOURCE[0]}")"
-exec bazel run --config=silent @zml//third_party/zls:zls -- "${@}"
+cd "$(bazel info workspace)"
+exec bazel run -- @zml//third_party/zls:zls "${@}"
diff --git a/examples/zls.build.json b/examples/zls.build.json
@@ -1,8 +1,2 @@
 {
-  "build_options": [
-    {
-      "name": "cmd",
-      "value": "bazel run @zml//:completion"
-    }
-  ]
 }
diff --git a/third_party/zls/BUILD.bazel b/third_party/zls/BUILD.bazel
@@ -1,14 +1,10 @@
-load(":zls.bzl", "targets", "zig_runner", "zls_runner")
+load(":zls.bzl", "targets", "zls_runner")
 
 toolchain_type(name = "toolchain_type")
 
 targets()
 
-zig_runner(
-    name = "zig",
-)
-
 zls_runner(
     name = "zls",
-    zig = ":zig",
+    target = "//:completion",
 )
diff --git a/third_party/zls/zls.bzl b/third_party/zls/zls.bzl
@@ -88,98 +88,69 @@ def targets():
             toolchain_type = "@zml//third_party/zls:toolchain_type",
         )
 
-_ZIG_RUNNER_TPL = """\
-#!/bin/bash
+def build_runner_tpl(target):
+    return """\
+const std = @import("std");
+
+pub fn main() !void {{
+    var gpa: std.heap.GeneralPurposeAllocator(.{{}}) = .{{}};
+    defer _ = gpa.deinit();
+    var arena_ = std.heap.ArenaAllocator.init(gpa.allocator());
+    defer arena_.deinit();
+    const arena = arena_.allocator();
+
+    const build_workspace_directory = try std.process.getEnvVarOwned(arena, "BUILD_WORKSPACE_DIRECTORY");
+    var child = std.process.Child.init(&.{{
+        "bazel",
+        "run",
+        {target},
+    }}, arena);
+    child.stdin_behavior = .Ignore;
+    child.stdout_behavior = .Inherit;
+    child.stderr_behavior = .Inherit;
+    child.cwd = build_workspace_directory;
+    _ = try child.spawnAndWait();
+}}
+""".format(target = repr(target))
 
-if [[ "${{1}}" == "build" ]]; then
-    for arg in "${{@:2}}"; do
-        if [[ "${{arg}}" == "-Dcmd="* ]]; then
-            cd ${{BUILD_WORKSPACE_DIRECTORY}}
-            exec ${{arg/-Dcmd=/}}
-        fi
-    done
-fi
-
-export ZIG_GLOBAL_CACHE_DIR="$(realpath {zig_cache})"
-export ZIG_LOCAL_CACHE_DIR="$(realpath {zig_cache})"
-export ZIG_LIB_DIR="$(realpath {zig_lib_path})"
-exec {zig_exe_path} "${{@}}"
-"""
-
-_RUNNER_TPL = """\
+def runner_tpl(zls, zig_exe_path, zig_lib_path, zig_cache, build_runner):
+    return """\
 #!/bin/bash
 set -eo pipefail
 
-zig() {{
-    if [[ "${{1}}" == "build" ]]; then
-        for arg in "${{@:2}}"; do
-            if [[ "${{arg}}" == "-Dcmd="* ]]; then
-                cd ${{BUILD_WORKSPACE_DIRECTORY}}
-                exec ${{arg/-Dcmd=/}}
-            fi
-        done
-    fi
-
-    export ZIG_GLOBAL_CACHE_DIR="$(realpath {zig_cache})"
-    export ZIG_LOCAL_CACHE_DIR="$(realpath {zig_cache})"
-    export ZIG_LIB_DIR="$(realpath {zig_lib_path})"
-    exec {zig_exe_path} "${{@}}"
-}}
-
-zls() {{
-    json_config="$(mktemp)"
-    ZLS_ARGS=("--config-path" "${{json_config}}")
-
-    cat <<EOF > ${{json_config}}
+json_config="$(mktemp)"
+cat <<EOF > ${{json_config}}
 {{
-    "zig_lib_path": "$(realpath {zig_lib_path})",
+    "build_runner_path": "$(realpath {build_runner})",
+    "global_cache_path": "$(realpath {zig_cache})",
     "zig_exe_path": "$(realpath {zig_exe_path})",
-    "global_cache_path": "$(realpath {zig_cache})"
+    "zig_lib_path": "$(realpath {zig_lib_path})"
 }}
 EOF
 
-    while ((${{#}})); do
-        case "${{1}}" in
-        --config-path)
-            cat "${{2}}" >> "${{json_config}}"
-            {jq} -s add "${{json_config}}" > "${{json_config}}.tmp"
-            mv "${{json_config}}.tmp" "${{json_config}}"
-            shift 2
-            ;;
-        *)
-            ZLS_ARGS+=("${{1}}")
-            shift
-            ;;
-        esac
-    done
-
-    exec {zls} "${{ZLS_ARGS[@]}}"
-}}
-
-case $1 in
-    zig)
-        shift
-        zig "${{@}}"
-        ;;
-    zls)
-        shift
-        zls "${{@}}"
-        ;;
-esac
-"""
+exec {zls} --config-path "${{json_config}}" "${{@}}"
+""".format(
+        zig_lib_path = zig_lib_path,
+        zig_exe_path = zig_exe_path,
+        zig_cache = zig_cache,
+        zls = zls,
+        build_runner = build_runner,
+    )
 
 def _zls_runner_impl(ctx):
-    jqinfo = ctx.toolchains["@aspect_bazel_lib//lib:jq_toolchain_type"].jqinfo
     zigtoolchaininfo = ctx.toolchains["@rules_zig//zig:toolchain_type"].zigtoolchaininfo
     zlsinfo = ctx.toolchains["@zml//third_party/zls:toolchain_type"].zlsinfo
 
+    build_runner = ctx.actions.declare_file(ctx.label.name + ".build_runner.zig")
+    ctx.actions.write(build_runner, build_runner_tpl(str(ctx.attr.target.label)))
+
     zls_runner = ctx.actions.declare_file(ctx.label.name + ".zls_runner.sh")
-    ctx.actions.write(zls_runner, _RUNNER_TPL.format(
-        jq = jqinfo.bin.short_path,
+    ctx.actions.write(zls_runner, runner_tpl(
         zig_cache = zigtoolchaininfo.zig_cache,
         zig_exe_path = zigtoolchaininfo.zig_exe.short_path,
         zig_lib_path = zigtoolchaininfo.zig_lib.short_path,
         zls = zlsinfo.bin.short_path,
+        build_runner = build_runner.short_path,
     ))
 
     return [
@@ -188,8 +159,7 @@ def _zls_runner_impl(ctx):
             executable = zls_runner,
             runfiles = ctx.runfiles(
                 files = [
-                    ctx.executable.zig,
-                    jqinfo.bin,
+                    build_runner,
                     zlsinfo.bin,
                 ],
                 transitive_files = zigtoolchaininfo.zig_files,
@@ -200,39 +170,11 @@ def _zls_runner_impl(ctx):
 zls_runner = rule(
     implementation = _zls_runner_impl,
     attrs = {
-        "zig": attr.label(mandatory = True, executable = True, cfg = "exec"),
+        "target": attr.label(mandatory = True, executable = True, cfg = "exec"),
     },
     executable = True,
     toolchains = [
         "@rules_zig//zig:toolchain_type",
-        "@aspect_bazel_lib//lib:jq_toolchain_type",
         "@zml//third_party/zls:toolchain_type",
     ],
 )
-
-def _zig_runner_impl(ctx):
-    zigtoolchaininfo = ctx.toolchains["@rules_zig//zig:toolchain_type"].zigtoolchaininfo
-
-    zig_runner = ctx.actions.declare_file(ctx.label.name + ".zig_runner.sh")
-    ctx.actions.write(zig_runner, _ZIG_RUNNER_TPL.format(
-        zig_cache = zigtoolchaininfo.zig_cache,
-        zig_exe_path = zigtoolchaininfo.zig_exe.short_path,
-        zig_lib_path = zigtoolchaininfo.zig_lib.short_path,
-    ))
-
-    return [
-        DefaultInfo(
-            files = depset([zig_runner]),
-            executable = zig_runner,
-            runfiles = ctx.runfiles(
-                files = [zig_runner],
-                transitive_files = zigtoolchaininfo.zig_files,
-            ),
-        ),
-    ]
-
-zig_runner = rule(
-    implementation = _zig_runner_impl,
-    executable = True,
-    toolchains = ["@rules_zig//zig:toolchain_type"],
-)
diff --git a/tools/buildifier.sh b/tools/buildifier.sh
@@ -1,3 +1,4 @@
 #!/bin/bash
 cd "$(dirname "${BASH_SOURCE[0]}")"
+cd "$(bazel info workspace)"
 exec bazel run -- @buildifier_prebuilt//:buildifier "$@"
diff --git a/tools/zig.sh b/tools/zig.sh
diff --git a/tools/zls.sh b/tools/zls.sh
@@ -1,3 +1,4 @@
 #!/bin/bash
 cd "$(dirname "${BASH_SOURCE[0]}")"
-exec bazel run --config=silent @zml//third_party/zls:zls -- zls "${@}"
+cd "$(bazel info workspace)"
+exec bazel run -- @zml//third_party/zls:zls "${@}"
diff --git a/zls.build.json b/zls.build.json

Original file line number	Diff line number	Diff line change
`@@ -1,2 +1,2 @@`
`1`		`-common --override_module=zml=../`
	`1`	`+common --override_module=zml=%workspace%/../../`
`2`	`2`	`common --registry=file://%workspace%/../third_party/`
Original file line number	Diff line number	Diff line change
`@@ -1,8 +1,2 @@`
`1`	`1`	`{`
`2`		`- "build_options": [`
`3`		`- {`
`4`		`- "name": "cmd",`
`5`		`- "value": "bazel run @zml//:completion"`
`6`		`- }`
`7`		`- ]`
`8`	`2`	`}`