Prefer system-provided robin-map (#248)

* Prefer system-provided robin-map

* Use find_package

* Use submodule

* PR feedback

* Include FetchContent

.github/workflows/main.yml

@@ -44,8 +44,6 @@ jobs:
     name: ${{ matrix.os }} ${{ matrix.build-type }} LLVM-${{ matrix.llvm-version }} ${{ matrix.cxxlib }}
     steps:
       - uses: actions/checkout@v3
-        with:
-          submodules: true
       - name: Install dependencies 
         run: |
           sudo apt install ninja-build
@@ -92,8 +90,6 @@ jobs:
     name: Cross-build for ${{ matrix.arch.triple }} LLVM-${{ matrix.llvm-version}} ${{ matrix.build-type }}
     steps:
       - uses: actions/checkout@v3
-        with:
-          submodules: true
       - name: Install cross-compile toolchain and QEMU
         run: |
           sudo apt update

ANNOUNCE

@@ -37,16 +37,6 @@ Alternatively, a tarball is available from:
 https://github.com/gnustep/libobjc2/archive/v2.2.zip
 https://github.com/gnustep/libobjc2/archive/v2.2.tar.gz
 
-The submodule is available from:
-
-https://github.com/Tessil/robin-map/archive/d37a410.zip
-https://github.com/Tessil/robin-map/archive/d37a410.tar.gz
-
-This will extract as robin-map-d37a41003bfbc7e12e34601f93c18ca2ff6d7c07.
-You must move the contents of that directory into third_party/robin_map in the
-libobjc2 tree.
-
-
 The runtime library is responsible for implementing the core features of the
 object model, as well as exposing introspection features to the user.  The
 GNUstep runtime implements a superset of Apple's Objective-C Runtime APIs.

CMakeLists.txt

@@ -21,6 +21,7 @@ endif()
 enable_language(OBJC OBJCXX)
 
 INCLUDE (CheckCXXSourceCompiles)
+INCLUDE (FetchContent)
 
 set(libobjc_VERSION 4.6)
 
@@ -120,14 +121,16 @@ else ()
 	list(APPEND libobjc_C_SRCS eh_personality.c)
 endif (WIN32)
 
-if (NOT EXISTS "${CMAKE_SOURCE_DIR}/third_party/robin-map/include/tsl/robin_map.h")
-	message(FATAL_ERROR "Git submodules not present, please run:\n\n"
-						" $ git submodule init && git submodule update\n\n"
-						"If you did not checkout via git, you will need to"
-						"fetch the submodule's contents from"
-						"https://github.com/Tessil/robin-map/")
-endif ()
+find_package(tsl-robin-map)
+
+if (NOT tls-robin-map_FOUND)
+	FetchContent_Declare(
+		robinmap
+		GIT_REPOSITORY https://github.com/Tessil/robin-map/
+		GIT_TAG        v1.2.1)
 
+	FetchContent_MakeAvailable(robinmap)
+endif()
 
 if (WIN32)
 	set(OLD_ABI_COMPAT_DEFAULT false)
@@ -235,6 +238,7 @@ if (WIN32)
 	target_link_libraries(objc ntdll.dll)
 endif()
 
+target_link_libraries(objc tsl::robin_map)
 
 set_target_properties(objc PROPERTIES
 	LINKER_LANGUAGE C

INSTALL

@@ -14,15 +14,6 @@ things that can be used by other programs that actually perform the building.
 I recommend that you use Ninja for building if you are compiling regularly, but
 these instructions will use Make to avoid the need for an extra dependency.
 
-When checking out the code make sure you check out git submodules as well
-either by using
-
-	$ git checkout --recursive <URL>
-
-or by getting submodules after checkout using
-
-	$ git submodule update --init
-
 After checking out the code, build as follows:
 
 	$ mkdir Build

arc.mm

@@ -7,7 +7,7 @@
 #include <stdlib.h>
 #include <assert.h>
 #include <vector>
-#include "third_party/robin-map/include/tsl/robin_map.h"
+#include <tsl/robin_map.h>
 #import "lock.h"
 #import "objc/runtime.h"
 #import "objc/blocks_runtime.h"

selector_table.cc

@@ -11,7 +11,7 @@
 #include <vector>
 #include <mutex>
 #include <forward_list>
-#include "third_party/robin-map/include/tsl/robin_set.h"
+#include <tsl/robin_set.h>
 #include "class.h"
 #include "lock.h"
 #include "method.h"