Swift: replace all usages of std::to_string with absl::StrCat or absl::StrAppend

swift/extractor/infra/SwiftDispatcher.h

@@ -5,6 +5,7 @@
 #include <swift/AST/SourceFile.h>
 #include <swift/Basic/SourceManager.h>
 #include <swift/Parse/Token.h>
+#include "absl/strings/str_cat.h"
 
 #include "swift/extractor/trap/TrapDomain.h"
 #include "swift/extractor/infra/SwiftTagTraits.h"
@@ -83,7 +84,7 @@ class SwiftDispatcher {
           valid = false;
         }
         LOG_ERROR("{} has undefined field {}{}, {}", entry.NAME, field,
-                  index >= 0 ? ('[' + std::to_string(index) + ']') : "", action);
+                  index >= 0 ? absl::StrCat("[", index, "]") : "", action);
       }
     });
     if (valid) {

swift/extractor/infra/SwiftMangledName.cpp

@@ -1,4 +1,5 @@
 #include "swift/extractor/infra/SwiftMangledName.h"
+#include "absl/strings/str_cat.h"
 
 namespace codeql {
 
@@ -8,13 +9,11 @@ void appendPart(std::string& out, const std::string& prefix) {
 }
 
 void appendPart(std::string& out, UntypedTrapLabel label) {
-  out += '{';
-  out += label.str();
-  out += '}';
+  absl::StrAppend(&out, "{", label.str(), "}");
 }
 
 void appendPart(std::string& out, unsigned index) {
-  out += std::to_string(index);
+  absl::StrAppend(&out, index);
 }
 
 }  // namespace

swift/extractor/main.cpp

@@ -10,6 +10,7 @@
 #include <swift/Basic/InitializeSwiftModules.h>
 
 #include "absl/strings/str_join.h"
+#include "absl/strings/str_cat.h"
 
 #include "swift/extractor/SwiftExtractor.h"
 #include "swift/extractor/infra/TargetDomains.h"
@@ -166,7 +167,7 @@ static void checkWhetherToRunUnderTool(int argc, char* const* argv) {
 // compilations, diagnostics, etc.
 codeql::TrapDomain invocationTrapDomain(codeql::SwiftExtractorState& state) {
   auto timestamp = std::chrono::system_clock::now().time_since_epoch().count();
-  auto filename = std::to_string(timestamp) + '-' + std::to_string(getpid());
+  auto filename = absl::StrCat(timestamp, "-", getpid());
   auto target = std::filesystem::path("invocations") / std::filesystem::path(filename);
   auto maybeDomain = codeql::createTargetTrapDomain(state, target, codeql::TrapType::invocation);
   CODEQL_ASSERT(maybeDomain, "Cannot create invocation trap file for {}", target);

swift/extractor/trap/TrapDomain.h

@@ -2,6 +2,7 @@
 
 #include <memory>
 #include <sstream>
+#include "absl/strings/str_cat.h"
 
 #include "swift/extractor/trap/TrapLabel.h"
 #include "swift/extractor/infra/file/TargetFile.h"
@@ -27,7 +28,7 @@ class TrapDomain {
       e.forEachLabel([&e, this](const char* field, int index, auto& label) {
         if (!label.valid()) {
           LOG_ERROR("{} has undefined field {}{}", e.NAME, field,
-                    index >= 0 ? ('[' + std::to_string(index) + ']') : "");
+                    index >= 0 ? absl::StrCat("[", index, "]") : "");
         }
       });
     }

swift/logging/SwiftLogging.cpp

@@ -4,6 +4,7 @@
 #include <stdlib.h>
 #include <optional>
 #include <unistd.h>
+#include "absl/strings/str_cat.h"
 
 #define LEVEL_REGEX_PATTERN "trace|debug|info|warning|error|critical|no_logs"
 
@@ -98,9 +99,8 @@ std::vector<std::string> Log::collectLevelRulesAndReturnProblems(const char* env
 void Log::configure() {
   // as we are configuring logging right now, we collect problems and log them at the end
   auto problems = collectLevelRulesAndReturnProblems("CODEQL_EXTRACTOR_SWIFT_LOG_LEVELS");
-  auto logBaseName = std::to_string(std::chrono::system_clock::now().time_since_epoch().count());
-  logBaseName += '-';
-  logBaseName += std::to_string(getpid());
+  auto timestamp = std::chrono::system_clock::now().time_since_epoch().count();
+  auto logBaseName = absl::StrCat(timestamp, "-", getpid());
   if (text || binary) {
     std::filesystem::path logFile = getEnvOr("CODEQL_EXTRACTOR_SWIFT_LOG_DIR", "extractor-out/log");
     logFile /= "swift";