From b8ca51fd01a68b9b6040f8c3c631eedefd7d7735 Mon Sep 17 00:00:00 2001
From: Ahmad Fatoum <ahmad@a3f.at>
Date: Thu, 10 May 2018 21:03:43 +0200
Subject: [PATCH] CMake: Don't create symlinks on unsupporting file systems
 (#539)

Panders to the idiosyncrasies of my work flow:
I have my raylib build directory mounted as a VirtualBox vboxfs for use
with my Linux VM, but vboxfs doesn't support symlinks, while raylib shared
library versioning on Unix expects symlinks to work.
If this happens, library versioning is now disabled on Unix with
an error message instead of just failing the build.
---
 .gitignore         |  3 ++-
 CMakeLists.txt     | 12 ++++++++++++
 src/CMakeLists.txt | 10 ++++++++--
 3 files changed, 22 insertions(+), 3 deletions(-)
 mode change 100755 => 100644 CMakeLists.txt

diff --git a/.gitignore b/.gitignore
index d22e46efb..1b4d5e411 100644
--- a/.gitignore
+++ b/.gitignore
@@ -98,7 +98,7 @@ project/vs2015.UWP/*.db
 !project/vs2015.UWP/*.sln
 !project/vs2015.UWP/raylib.App.UWP/*.vcxproj
 
-# Web examples 
+# Web examples
 docs/examples/web/*.html
 docs/examples/web/*/*.html
 !docs/examples/web/loader.html
@@ -116,6 +116,7 @@ CMakeCache.txt
 CMakeFiles
 CMakeScripts
 Testing
+TestingIfSymlinkWorks
 cmake_install.cmake
 install_manifest.txt
 compile_commands.json
diff --git a/CMakeLists.txt b/CMakeLists.txt
old mode 100755
new mode 100644
index 6d5994f4f..a2f14088c
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -33,6 +33,18 @@ add_if_flag_works(-Werror=implicit-function-declaration CMAKE_C_FLAGS)
 # src/external/jar_xm.h does shady stuff
 add_if_flag_works(-fno-strict-aliasing CMAKE_C_FLAGS)
 
+message(STATUS "Check for symlink support in file system")
+execute_process(
+  COMMAND ${CMAKE_COMMAND} -E create_symlink CMakeLists.txt "${CMAKE_CURRENT_BINARY_DIR}/TestingIfSymlinkWorks"
+    WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}
+    RESULT_VARIABLE FILESYSTEM_LACKS_SYMLINKS
+)
+If (FILESYSTEM_LACKS_SYMLINKS)
+  message(STATUS "Testing if file system supports symlinks -- unsupported")
+else()
+  message(STATUS "Testing if file system supports symlinks -- supported")
+endif()
+
 if (ENABLE_ASAN)
     add_if_flag_works(-fno-omit-frame-pointer CMAKE_C_FLAGS CMAKE_LINKER_FLAGS)
     add_if_flag_works(-fsanitize=address CMAKE_C_FLAGS CMAKE_LINKER_FLAGS)
diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index 64d7f1fdf..f04e88f34 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -101,9 +101,15 @@ if(${PLATFORM} MATCHES "PLATFORM_DESKTOP")
     set(CMAKE_MACOSX_RPATH ON)
 
     target_link_libraries(${RAYLIB}_shared ${LIBS_PRIVATE})
+    if (UNIX AND ${FILESYSTEM_LACKS_SYMLINKS})
+      MESSAGE(WARNING "Can't version UNIX shared library on file system without symlink support")
+    else()
+        set_target_properties(${RAYLIB}_shared PROPERTIES
+            VERSION   ${PROJECT_VERSION}
+            SOVERSION ${API_VERSION}
+        )
+    endif()
     set_target_properties(${RAYLIB}_shared PROPERTIES
-        VERSION   ${PROJECT_VERSION}
-        SOVERSION ${API_VERSION}
         PUBLIC_HEADER "raylib.h"
     )
     if(WIN32)