Use swift-lmdb instead of copying LMDB source

CMakeLists.txt

@@ -13,6 +13,7 @@ set(CMAKE_POSITION_INDEPENDENT_CODE YES)
 
 find_package(dispatch CONFIG)
 find_package(Foundation CONFIG)
+find_package(LMDB CONFIG)
 
 include(SwiftSupport)
 

Package.swift

@@ -1,7 +1,28 @@
 // swift-tools-version:5.5
 
+import Foundation
 import PackageDescription
 
+func hasEnvironmentVariable(_ name: String) -> Bool {
+  return ProcessInfo.processInfo.environment[name] != nil
+}
+
+/// Assume that all the package dependencies are checked out next to indexstore-db and use that instead of fetching a
+/// remote dependency.
+var useLocalDependencies: Bool { hasEnvironmentVariable("SWIFTCI_USE_LOCAL_DEPS") }
+
+var dependencies: [Package.Dependency] {
+  if useLocalDependencies {
+    return [
+      .package(path: "../swift-lmdb"),
+    ]
+  } else {
+    return [
+      .package(url: "https://github.com/swiftlang/swift-lmdb.git", branch: "main"),
+    ]
+  }
+}
+
 let package = Package(
   name: "IndexStoreDB",
   products: [
@@ -18,7 +39,7 @@ let package = Package(
       name: "tibs",
       targets: ["tibs"])
   ],
-  dependencies: [],
+  dependencies: dependencies,
   targets: [
 
     // MARK: Swift interface
@@ -81,18 +102,13 @@ let package = Package(
     // The lmdb database layer.
     .target(
       name: "IndexStoreDB_Database",
-      dependencies: ["IndexStoreDB_Core"],
+      dependencies: [
+        "IndexStoreDB_Core",
+        .product(name: "CLMDB", package: "swift-lmdb"),
+      ],
       path: "lib/Database",
       exclude: [
         "CMakeLists.txt",
-        "lmdb/LICENSE",
-        "lmdb/COPYRIGHT",
-      ],
-      cSettings: [
-        .define("MDB_USE_POSIX_MUTEX", to: "1",
-                // Windows does not use POSIX mutex
-                .when(platforms: [.linux, .macOS])),
-        .define("MDB_USE_ROBUST", to: "0"),
       ]),
 
     // Core index types.

lib/Database/CMakeLists.txt

@@ -2,9 +2,7 @@ add_library(Database STATIC
   Database.cpp
   DatabaseError.cpp
   ImportTransaction.cpp
-  ReadTransaction.cpp
-  lmdb/mdb.c
-  lmdb/midl.c)
+  ReadTransaction.cpp)
 target_compile_definitions(Database PRIVATE
   _CRT_NONSTDC_NO_WARNINGS
   _CRT_SECURE_NO_WARNINGS)
@@ -13,6 +11,7 @@ target_compile_options(Database PRIVATE
 target_include_directories(Database PRIVATE
   include)
 target_link_libraries(Database PRIVATE
+  LMDB::CLMDB
   Core
   LLVMSupport)
 if(NOT CMAKE_SYSTEM_NAME STREQUAL Darwin)