Merge pull request github#12918 from github/sashabu/absl

Swift: Fix some TODOs with Abseil.

Author: sashabu

misc/bazel/workspace.bzl

@@ -43,3 +43,13 @@ def codeql_workspace(repository_name = "codeql"):
             "https://github.com/bazelbuild/bazel-skylib/releases/download/1.4.1/bazel-skylib-1.4.1.tar.gz",
         ],
     )
+
+    maybe(
+        repo_rule = http_archive,
+        name = "absl",
+        sha256 = "cec2e5bf780532bd0ac672eb8d43c0f8bbe84ca5df8718320184034b7f59a398",
+        urls = [
+            "https://github.com/abseil/abseil-cpp/archive/d2c5297a3c3948de765100cb7e5cccca1210d23c.tar.gz",
+        ],
+        strip_prefix = "abseil-cpp-d2c5297a3c3948de765100cb7e5cccca1210d23c",
+    )

swift/extractor/BUILD.bazel

@@ -16,6 +16,7 @@ swift_cc_binary(
         "//swift/extractor/remapping",
         "//swift/extractor/translators",
         "//swift/third_party/swift-llvm-support",
+        "@absl//absl/strings",
     ],
 )
 

swift/extractor/main.cpp

@@ -9,6 +9,8 @@
 #include <swift/FrontendTool/FrontendTool.h>
 #include <swift/Basic/InitializeSwiftModules.h>
 
+#include "absl/strings/str_join.h"
+
 #include "swift/extractor/SwiftExtractor.h"
 #include "swift/extractor/infra/TargetDomains.h"
 #include "swift/extractor/remapping/SwiftFileInterception.h"
@@ -184,18 +186,13 @@ codeql::SwiftExtractorConfiguration configure(int argc, char** argv) {
   return configuration;
 }
 
-// TODO: use `absl::StrJoin` or `boost::algorithm::join`
 static auto argDump(int argc, char** argv) {
-  std::string ret;
-  for (auto arg = argv + 1; arg < argv + argc; ++arg) {
-    ret += *arg;
-    ret += ' ';
+  if (argc < 2) {
+    return ""s;
   }
-  ret.pop_back();
-  return ret;
+  return absl::StrJoin(argv + 1, argv + argc, " ");
 }
 
-// TODO: use `absl::StrJoin` or `boost::algorithm::join`
 static auto envDump(char** envp) {
   std::string ret;
   for (auto env = envp; *env; ++env) {

swift/extractor/trap/BUILD.bazel

@@ -50,5 +50,6 @@ swift_cc_library(
     deps = [
         "//swift/extractor/infra/file",
         "//swift/extractor/infra/log",
+        "@absl//absl/numeric:bits",
     ],
 )

swift/extractor/trap/TrapLabel.h

@@ -5,6 +5,7 @@
 #include <iostream>
 #include <string>
 #include <vector>
+#include "absl/numeric/bits.h"
 #include <binlog/binlog.hpp>
 #include <cmath>
 #include <charconv>
@@ -53,10 +54,9 @@ class UntypedTrapLabel {
 
  private:
   size_t strSize() const {
-    if (id_ == undefined) return 17;  // #ffffffffffffffff
-    if (id_ == 0) return 2;           // #0
-    // TODO: use absl::bit_width or C+20 std::bit_width instead of this ugly formula
-    return /* # */ 1 + /* hex digits */ static_cast<size_t>(ceil(log2(id_ + 1) / 4));
+    if (id_ == 0) return 2;  // #0
+    // Number of hex digits is ceil(bit_width(id) / 4), but C++ integer division can only do floor.
+    return /* # */ 1 + /* hex digits */ 1 + (absl::bit_width(id_) - 1) / 4;
   }
 };