1 files changed, 122 insertions, 100 deletions

diff --git a/src/buildtool/file_system/git_cas.cpp b/src/buildtool/file_system/git_cas.cpp
index b49a75dd..85635c4e 100644
--- a/src/buildtool/file_system/git_cas.cpp
+++ b/src/buildtool/file_system/git_cas.cpp
@@ -58,51 +58,51 @@ auto GitCAS::Open(std::filesystem::path const& repo_path,
 #ifdef BOOTSTRAP_BUILD_TOOL
     return nullptr;
 #else
-    auto result = std::make_shared<GitCAS>();
-
-    // lock as git_repository API has no thread-safety guarantees
-    static std::mutex repo_mutex{};
-    std::unique_lock lock{repo_mutex};
-    git_repository* repo_ptr = nullptr;
-    if (git_repository_open_ext(&repo_ptr,
-                                repo_path.c_str(),
-                                GIT_REPOSITORY_OPEN_NO_SEARCH,
-                                nullptr) != 0 or
-        repo_ptr == nullptr) {
-        Logger::Log(log_failure,
-                    "Opening git repository {} failed with:\n{}",
-                    repo_path.string(),
-                    GitLastError());
-        return nullptr;
-    }
-    result->repo_.reset(repo_ptr);
+    try {
+        auto result = std::make_shared<GitCAS>();
+
+        // lock as git_repository API has no thread-safety guarantees
+        static std::mutex repo_mutex{};
+        std::unique_lock lock{repo_mutex};
+        git_repository* repo_ptr = nullptr;
+        if (git_repository_open_ext(&repo_ptr,
+                                    repo_path.c_str(),
+                                    GIT_REPOSITORY_OPEN_NO_SEARCH,
+                                    nullptr) != 0 or
+            repo_ptr == nullptr) {
+            Logger::Log(log_failure,
+                        "Opening git repository {} failed with:\n{}",
+                        repo_path.string(),
+                        GitLastError());
+            return nullptr;
+        }
+        result->repo_.reset(repo_ptr);
 
-    git_odb* odb_ptr = nullptr;
-    if (git_repository_odb(&odb_ptr, result->repo_.get()) != 0 or
-        odb_ptr == nullptr) {
-        Logger::Log(log_failure,
-                    "Obtaining git object database {} failed with:\n{}",
-                    repo_path.string(),
-                    GitLastError());
-        return nullptr;
-    }
-    result->odb_.reset(odb_ptr);
+        git_odb* odb_ptr = nullptr;
+        if (git_repository_odb(&odb_ptr, result->repo_.get()) != 0 or
+            odb_ptr == nullptr) {
+            Logger::Log(log_failure,
+                        "Obtaining git object database {} failed with:\n{}",
+                        repo_path.string(),
+                        GitLastError());
+            return nullptr;
+        }
+        result->odb_.reset(odb_ptr);
 
-    auto const git_path =
-        git_repository_is_bare(result->repo_.get()) != 0
-            ? ToNormalPath(git_repository_path(result->repo_.get()))
-            : ToNormalPath(git_repository_workdir(result->repo_.get()));
+        auto const git_path =
+            git_repository_is_bare(result->repo_.get()) != 0
+                ? ToNormalPath(git_repository_path(result->repo_.get()))
+                : ToNormalPath(git_repository_workdir(result->repo_.get()));
 
-    try {
         result->git_path_ = std::filesystem::absolute(git_path);
+        return std::const_pointer_cast<GitCAS const>(result);
     } catch (std::exception const& e) {
         Logger::Log(log_failure,
-                    "Failed to obtain absolute path for {}: {}",
-                    git_path.string(),
+                    "Unexpected failure opening git object database {}:\n{}",
+                    repo_path.string(),
                     e.what());
         return nullptr;
     }
-    return std::const_pointer_cast<GitCAS const>(result);
 #endif
 }
 
@@ -110,27 +110,34 @@ auto GitCAS::CreateEmpty() noexcept -> GitCASPtr {
 #ifdef BOOTSTRAP_BUILD_TOOL
     return nullptr;
 #else
-    auto result = std::make_shared<GitCAS>();
+    try {
+        auto result = std::make_shared<GitCAS>();
 
-    git_odb* odb_ptr{nullptr};
-    if (git_odb_new(&odb_ptr) != 0 or odb_ptr == nullptr) {
-        Logger::Log(LogLevel::Error,
-                    "creating an empty database failed with:\n{}",
-                    GitLastError());
-        return nullptr;
-    }
-    result->odb_.reset(odb_ptr);  // retain odb pointer
+        git_odb* odb_ptr{nullptr};
+        if (git_odb_new(&odb_ptr) != 0 or odb_ptr == nullptr) {
+            Logger::Log(LogLevel::Error,
+                        "Creating an empty database failed with:\n{}",
+                        GitLastError());
+            return nullptr;
+        }
+        result->odb_.reset(odb_ptr);  // retain odb pointer
 
-    git_repository* repo_ptr = nullptr;
-    if (git_repository_wrap_odb(&repo_ptr, result->odb_.get()) != 0 or
-        repo_ptr == nullptr) {
+        git_repository* repo_ptr = nullptr;
+        if (git_repository_wrap_odb(&repo_ptr, result->odb_.get()) != 0 or
+            repo_ptr == nullptr) {
+            Logger::Log(LogLevel::Error,
+                        "Creating an empty repository failed with:\n{}",
+                        GitLastError());
+            return nullptr;
+        }
+        result->repo_.reset(repo_ptr);  // retain repo pointer
+        return std::const_pointer_cast<GitCAS const>(result);
+    } catch (std::exception const& e) {
         Logger::Log(LogLevel::Error,
-                    "creating an empty repository failed with:\n{}",
-                    GitLastError());
+                    "Unexpected failure creating empty repository:\n{}",
+                    e.what());
         return nullptr;
     }
-    result->repo_.reset(repo_ptr);  // retain repo pointer
-    return std::const_pointer_cast<GitCAS const>(result);
 #endif
 }
 
@@ -142,70 +149,85 @@ auto GitCAS::ReadObject(std::string const& id,
 #ifdef BOOTSTRAP_BUILD_TOOL
     return std::nullopt;
 #else
-    if (not odb_) {
-        return std::nullopt;
-    }
-
-    auto oid = GitObjectID(id, is_hex_id);
-    if (not oid) {
-        return std::nullopt;
-    }
-
-    git_odb_object* obj = nullptr;
-    if (git_odb_read(&obj, odb_.get(), &oid.value()) != 0) {
-        Logger::Log(log_failure,
-                    "reading git object {} from database failed with:\n{}",
-                    is_hex_id ? id : ToHexString(id),
-                    GitLastError());
-        return std::nullopt;
-    }
-
-    std::string data(static_cast<char const*>(git_odb_object_data(obj)),
-                     git_odb_object_size(obj));
-    auto obj_type = GitTypeToObjectType(git_odb_object_type(obj));
-    git_odb_object_free(obj);
+    try {
+        if (not odb_) {
+            return std::nullopt;
+        }
 
-    if (as_valid_symlink) {
-        if (not obj_type) {
+        auto oid = GitObjectID(id, is_hex_id);
+        if (not oid) {
             return std::nullopt;
         }
-        if (not IsTreeObject(*obj_type) and not PathIsNonUpwards(data)) {
+
+        git_odb_object* obj = nullptr;
+        if (git_odb_read(&obj, odb_.get(), &oid.value()) != 0) {
             Logger::Log(log_failure,
-                        "invalid git object {}: upwards symlink",
-                        is_hex_id ? id : ToHexString(id));
+                        "Reading git object {} from database failed with:\n{}",
+                        is_hex_id ? id : ToHexString(id),
+                        GitLastError());
             return std::nullopt;
         }
-    }
 
-    return data;
+        std::string data(static_cast<char const*>(git_odb_object_data(obj)),
+                         git_odb_object_size(obj));
+        auto obj_type = GitTypeToObjectType(git_odb_object_type(obj));
+        git_odb_object_free(obj);
+
+        if (as_valid_symlink) {
+            if (not obj_type) {
+                return std::nullopt;
+            }
+            if (not IsTreeObject(*obj_type) and not PathIsNonUpwards(data)) {
+                Logger::Log(log_failure,
+                            "Invalid git object {}: upwards symlink",
+                            is_hex_id ? id : ToHexString(id));
+                return std::nullopt;
+            }
+        }
+
+        return data;
+    } catch (std::exception const& e) {
+        Logger::Log(log_failure,
+                    "Unexpected failure reading git object {}:\n{}",
+                    is_hex_id ? id : ToHexString(id),
+                    e.what());
+        return std::nullopt;
+    }
 #endif
 }
 
 auto GitCAS::ReadHeader(std::string const& id, bool is_hex_id) const noexcept
     -> std::optional<std::pair<std::size_t, ObjectType>> {
 #ifndef BOOTSTRAP_BUILD_TOOL
-    if (not odb_) {
-        return std::nullopt;
-    }
+    try {
+        if (not odb_) {
+            return std::nullopt;
+        }
 
-    auto oid = GitObjectID(id, is_hex_id);
-    if (not oid) {
-        return std::nullopt;
-    }
+        auto oid = GitObjectID(id, is_hex_id);
+        if (not oid) {
+            return std::nullopt;
+        }
 
-    std::size_t size{};
-    git_object_t type{};
-    if (git_odb_read_header(&size, &type, odb_.get(), &oid.value()) != 0) {
-        Logger::Log(LogLevel::Error,
-                    "reading git object header {} from database failed "
-                    "with:\n{}",
-                    is_hex_id ? id : ToHexString(id),
-                    GitLastError());
-        return std::nullopt;
-    }
+        std::size_t size{};
+        git_object_t type{};
+        if (git_odb_read_header(&size, &type, odb_.get(), &oid.value()) != 0) {
+            Logger::Log(LogLevel::Debug,
+                        "Reading git object header {} from database failed "
+                        "with:\n{}",
+                        is_hex_id ? id : ToHexString(id),
+                        GitLastError());
+            return std::nullopt;
+        }
 
-    if (auto obj_type = GitTypeToObjectType(type)) {
-        return std::make_pair(size, *obj_type);
+        if (auto obj_type = GitTypeToObjectType(type)) {
+            return std::make_pair(size, *obj_type);
+        }
+    } catch (std::exception const& e) {
+        Logger::Log(LogLevel::Debug,
+                    "Unexpected failure reading git object header {}:\n{}",
+                    is_hex_id ? id : ToHexString(id),
+                    e.what());
     }
 #endif
     return std::nullopt;