refactor(3p/nix/libutil): Replace string2Int & trim functions r/843

Replaces these functions with corresponding functions from Abseil,
namely absl::StripAsciiWhitespace and absl::SimpleAtoi.

In the course of doing this some minor things I encountered along the
way were also refactored.

This also changes the signatures of the various custom readFile
functions to use absl::string_view types.

1 files changed, 2 insertions, 1 deletions

diff --git a/third_party/nix/src/libstore/globals.cc b/third_party/nix/src/libstore/globals.cc
index 61293dffed50..7307f035275f 100644
--- a/third_party/nix/src/libstore/globals.cc
+++ b/third_party/nix/src/libstore/globals.cc
@@ -4,6 +4,7 @@
 #include <map>
 #include <thread>
 
+#include <absl/strings/numbers.h>
 #include <dlfcn.h>
 
 #include "archive.hh"
@@ -163,7 +164,7 @@ void BaseSetting<SandboxMode>::convertToArg(Args& args,
 void MaxBuildJobsSetting::set(const std::string& str) {
   if (str == "auto") {
     value = std::max(1U, std::thread::hardware_concurrency());
-  } else if (!string2Int(str, value)) {
+  } else if (!absl::SimpleAtoi(str, &value)) {
     throw UsageError(
         "configuration setting '%s' should be 'auto' or an integer", name);
   }