Pass SymlinksCheckFunc to GitRepo as not_null

+ invoke it only if there are symlinks to check
+ remove the corresponding runtime check since it is replaced by a compile-time check

3 files changed, 16 insertions, 16 deletions

diff --git a/src/buildtool/file_system/TARGETS b/src/buildtool/file_system/TARGETS
index 724d6b8d..6eb9cc70 100644
--- a/src/buildtool/file_system/TARGETS
+++ b/src/buildtool/file_system/TARGETS
@@ -123,6 +123,7 @@
     , ["src/buildtool/common", "bazel_types"]
     , ["src/utils/cpp", "expected"]
     , ["src/buildtool/storage", "config"]
+    , ["@", "gsl", "", "gsl"]
     ]
   , "stage": ["src", "buildtool", "file_system"]
   , "private-deps":
diff --git a/src/buildtool/file_system/git_repo.cpp b/src/buildtool/file_system/git_repo.cpp
index f87f8e6b..346c1c13 100644
--- a/src/buildtool/file_system/git_repo.cpp
+++ b/src/buildtool/file_system/git_repo.cpp
@@ -1791,7 +1791,7 @@ auto GitRepo::IsRepoFake() const noexcept -> bool {
 }
 
 auto GitRepo::ReadTree(std::string const& id,
-                       SymlinksCheckFunc const& check_symlinks,
+                       gsl::not_null<SymlinksCheckFunc> const& check_symlinks,
                        bool is_hex_id,
                        bool ignore_special) const noexcept
     -> std::optional<tree_entries_t> {
@@ -1851,11 +1851,8 @@ auto GitRepo::ReadTree(std::string const& id,
                 }
             }
             // we check symlinks in bulk, optimized for network-backed repos
-            if (not check_symlinks) {
-                Logger::Log(LogLevel::Debug, "check_symlink callable is empty");
-                return std::nullopt;
-            }
-            if (not check_symlinks(symlinks)) {
+            if (not symlinks.empty() and
+                not std::invoke(check_symlinks.get(), symlinks)) {
                 Logger::Log(LogLevel::Error,
                             "found upwards symlinks in Git tree {}",
                             is_hex_id ? std::string{id} : ToHexString(id));
@@ -1928,11 +1925,11 @@ auto GitRepo::CreateTree(tree_entries_t const& entries) const noexcept
 #endif
 }
 
-auto GitRepo::ReadTreeData(std::string const& data,
-                           std::string const& id,
-                           SymlinksCheckFunc const& check_symlinks,
-                           bool is_hex_id) noexcept
-    -> std::optional<tree_entries_t> {
+auto GitRepo::ReadTreeData(
+    std::string const& data,
+    std::string const& id,
+    gsl::not_null<SymlinksCheckFunc> const& check_symlinks,
+    bool is_hex_id) noexcept -> std::optional<tree_entries_t> {
 #ifndef BOOTSTRAP_BUILD_TOOL
     try {
         InMemoryODBBackend b{.parent = kInMemoryODBParent};
diff --git a/src/buildtool/file_system/git_repo.hpp b/src/buildtool/file_system/git_repo.hpp
index 95fa14a6..1e5ec839 100644
--- a/src/buildtool/file_system/git_repo.hpp
+++ b/src/buildtool/file_system/git_repo.hpp
@@ -23,6 +23,7 @@
 #include <utility>  // std::move
 #include <vector>
 
+#include "gsl/gsl"
 #include "src/buildtool/common/bazel_types.hpp"
 #include "src/buildtool/file_system/git_cas.hpp"
 #include "src/buildtool/file_system/git_types.hpp"
@@ -107,10 +108,11 @@ class GitRepo {
     /// \param check_symlinks   Function to check non-upwardness condition.
     /// \param is_hex_id  Specify whether `id` is hex string or raw.
     /// \param ignore_special   If set, treat symlinks as absent.
-    [[nodiscard]] auto ReadTree(std::string const& id,
-                                SymlinksCheckFunc const& check_symlinks,
-                                bool is_hex_id = false,
-                                bool ignore_special = false) const noexcept
+    [[nodiscard]] auto ReadTree(
+        std::string const& id,
+        gsl::not_null<SymlinksCheckFunc> const& check_symlinks,
+        bool is_hex_id = false,
+        bool ignore_special = false) const noexcept
         -> std::optional<tree_entries_t>;
 
     /// \brief Create a flat tree from entries and store tree in CAS.
@@ -132,7 +134,7 @@ class GitRepo {
     [[nodiscard]] static auto ReadTreeData(
         std::string const& data,
         std::string const& id,
-        SymlinksCheckFunc const& check_symlinks,
+        gsl::not_null<SymlinksCheckFunc> const& check_symlinks,
         bool is_hex_id = false) noexcept -> std::optional<tree_entries_t>;
 
     /// \brief Create a flat shallow (without objects in db) tree and return it.