Swift: first skeleton extractor

This adds a first dummy extractor for swift.

Running `bazel run //swift:install` will create an `extractor_pack`
directory in `swift`. From that moment providing `--search-path=swift`
will pick up the extractor.

.bazelrc

@@ -0,0 +1,3 @@
+build --copt="-std=c++17"
+
+try-import %workspace%/local.bazelrc

WORKSPACE.bazel

@@ -1,2 +1,45 @@
 # Please notice that any bazel targets and definitions in this repository are currently experimental
 # and for internal use only.
+
+workspace(name = "ql")
+
+load("@bazel_tools//tools/build_defs/repo:http.bzl", "http_archive")
+
+http_archive(
+    name = "rules_pkg",
+    sha256 = "62eeb544ff1ef41d786e329e1536c1d541bb9bcad27ae984d57f18f314018e66",
+    urls = [
+        "https://mirror.bazel.build/github.com/bazelbuild/rules_pkg/releases/download/0.6.0/rules_pkg-0.6.0.tar.gz",
+        "https://github.com/bazelbuild/rules_pkg/releases/download/0.6.0/rules_pkg-0.6.0.tar.gz",
+    ],
+)
+
+load("@rules_pkg//:deps.bzl", "rules_pkg_dependencies")
+
+rules_pkg_dependencies()
+
+http_archive(
+    name = "platforms",
+    sha256 = "460caee0fa583b908c622913334ec3c1b842572b9c23cf0d3da0c2543a1a157d",
+    urls = [
+        "https://mirror.bazel.build/github.com/bazelbuild/platforms/releases/download/0.0.3/platforms-0.0.3.tar.gz",
+        "https://github.com/bazelbuild/platforms/releases/download/0.0.3/platforms-0.0.3.tar.gz",
+    ],
+)
+
+http_archive(
+    name = "bazel_skylib",
+    sha256 = "c6966ec828da198c5d9adbaa94c05e3a1c7f21bd012a0b29ba8ddbccb2c93b0d",
+    urls = [
+        "https://github.com/bazelbuild/bazel-skylib/releases/download/1.1.1/bazel-skylib-1.1.1.tar.gz",
+        "https://mirror.bazel.build/github.com/bazelbuild/bazel-skylib/releases/download/1.1.1/bazel-skylib-1.1.1.tar.gz",
+    ],
+)
+
+load("@bazel_skylib//:workspace.bzl", "bazel_skylib_workspace")
+
+bazel_skylib_workspace()
+
+load("@ql//:defs.bzl", "ql_utils")
+
+ql_utils(name = "utils")

cpp/BUILD.bazel

@@ -4,14 +4,14 @@ load("@rules_pkg//:mappings.bzl", "pkg_filegroup")
 
 alias(
     name = "dbscheme",
-    actual = "//cpp/ql/lib:dbscheme",
+    actual = "@ql//cpp/ql/lib:dbscheme",
 )
 
 pkg_filegroup(
     name = "db-files",
     srcs = [
         ":dbscheme",
-        "//cpp/downgrades",
-        "//cpp/ql/lib:dbscheme-stats",
+        "@ql//cpp/downgrades",
+        "@ql//cpp/ql/lib:dbscheme-stats",
     ],
 )

defs.bzl

@@ -0,0 +1,19 @@
+codeql_platform = select({
+    "@platforms//os:linux": "linux64",
+    "@platforms//os:macos": "osx64",
+    "@platforms//os:windows": "win64",
+})
+
+_paths_bzl = """
+def source_dir():
+    return '%s/' + native.package_name()
+"""
+
+def _ql_utils_impl(repository_ctx):
+    root = repository_ctx.path(Label("@ql//:WORKSPACE.bazel")).realpath.dirname
+    repository_ctx.file("BUILD.bazel")
+    repository_ctx.file("paths.bzl", content = _paths_bzl % root)
+
+ql_utils = repository_rule(
+    implementation = _ql_utils_impl,
+)

swift/.clang-format

@@ -0,0 +1,7 @@
+BasedOnStyle: Chromium
+ColumnLimit: 100
+IndentWidth: 2
+SortIncludes: false
+AllowShortIfStatementsOnASingleLine: WithoutElse
+AlwaysBreakBeforeMultilineStrings: false
+Standard: c++17

swift/.codeqlmanifest.json

@@ -0,0 +1,7 @@
+{
+  "provide": [
+    "ql/lib/qlpack.yml",
+    "ql/test/qlpack.yml",
+    "extractor_pack/codeql-extractor.yml"
+  ]
+}

swift/.gitignore

@@ -0,0 +1 @@
+extractor_pack

swift/BUILD.bazel

@@ -0,0 +1,66 @@
+load("@rules_pkg//:mappings.bzl", "pkg_attributes", "pkg_filegroup", "pkg_files")
+load("@rules_pkg//:install.bzl", "pkg_install")
+load("@ql//:defs.bzl", "codeql_platform")
+load("@bazel_skylib//rules:native_binary.bzl", "native_binary")
+load("@utils//:paths.bzl", "source_dir")
+
+pkg_files(
+    name = "dbscheme",
+    srcs = [
+        "ql/lib/swift.dbscheme",
+        "ql/lib/swift.dbscheme.stats",
+    ],
+)
+
+pkg_files(
+    name = "qltest",
+    srcs = ["tools/qltest.sh"],
+    attributes = pkg_attributes(mode = "0755"),
+    prefix = "tools",
+)
+
+pkg_files(
+    name = "manifest",
+    srcs = ["codeql-extractor.yml"],
+)
+
+pkg_filegroup(
+    name = "extractor-pack-generic",
+    srcs = [
+        ":dbscheme",
+        ":manifest",
+        ":qltest",
+    ],
+    visibility = ["//visibility:public"],
+)
+
+pkg_files(
+    name = "extractor",
+    srcs = ["//swift/extractor"],
+    attributes = pkg_attributes(mode = "0755"),
+    prefix = "tools/" + codeql_platform,
+)
+
+pkg_filegroup(
+    name = "extractor-pack-arch",
+    srcs = [":extractor"],
+    visibility = ["//visibility:public"],
+)
+
+pkg_filegroup(
+    name = "extractor-pack",
+    srcs = [
+        ":extractor-pack-arch",
+        ":extractor-pack-generic",
+    ],
+    visibility = ["//visibility:public"],
+)
+
+pkg_install(
+    name = "install",
+    srcs = [":extractor-pack"],
+    args = [
+        "--destdir",
+        source_dir() + "/extractor_pack",
+    ],
+)

swift/README.md

@@ -0,0 +1,8 @@
+## Warning
+
+The Swift codeql package is an experimental and unsupported work in progress.
+
+## Usage
+
+Run `bazel run //swift:install-extractor`, which will install `swift/extractor_pack`. Using `--search-path=swift` will
+then pick up the Swift extractor.

swift/codeql-extractor.yml

@@ -0,0 +1,10 @@
+name: "swift"
+display_name: "Swift"
+version: 0.0.1
+column_kind: "utf8"
+legacy_qltest_extraction: true
+file_types:
+  - name: swift
+    display_name: Swift files
+    extensions:
+       - .swift

swift/extractor/BUILD.bazel

@@ -0,0 +1,5 @@
+cc_binary(
+    name = "extractor",
+    srcs = ["main.cpp"],
+    visibility = ["//swift:__pkg__"],
+)

swift/extractor/main.cpp

@@ -0,0 +1,14 @@
+#include <fstream>
+#include <iomanip>
+#include <stdlib.h>
+
+int main() {
+  if (auto trapDir = getenv("CODEQL_EXTRACTOR_SWIFT_TRAP_DIR")) {
+    std::string file = trapDir;
+    file += "/my_first.trap";
+    if (std::ofstream out{file}) {
+      out << "answer_to_life_the_universe_and_everything(42)\n";
+    }
+  }
+  return 0;
+}

swift/ql/lib/qlpack.yml

@@ -0,0 +1,5 @@
+name: codeql/swift-all
+version: 0.0.0
+dbscheme: swift.dbscheme
+extractor: swift
+library: true

swift/ql/lib/swift.dbscheme

@@ -0,0 +1,7 @@
+sourceLocationPrefix(
+   string prefix: string ref
+);
+
+answer_to_life_the_universe_and_everything(
+   int answer: int ref
+)

swift/ql/lib/swift.dbscheme.stats

@@ -0,0 +1,4 @@
+<dbstats>
+     <typesizes />
+     <stats />
+</dbstats>

swift/ql/test/answer.expected

@@ -0,0 +1 @@
+| 42 |

swift/ql/test/answer.ql

@@ -0,0 +1,3 @@
+from int answer
+where answer_to_life_the_universe_and_everything(answer)
+select answer

swift/ql/test/qlpack.yml

@@ -0,0 +1,5 @@
+name: codeql-swift-tests
+version: 0.0.0
+libraryPathDependencies:
+  - codeql/swift-all
+extractor: swift

swift/tools/qltest.sh

@@ -0,0 +1,5 @@
+#!/bin/bash
+
+mkdir -p "$CODEQL_EXTRACTOR_SWIFT_TRAP_DIR"
+
+exec "$CODEQL_EXTRACTOR_SWIFT_ROOT/tools/$CODEQL_PLATFORM/extractor"