From eb168a2da2e14a85834b98c3961eee909dc618f9 Mon Sep 17 00:00:00 2001
From: Nikita Karpey <paunia@protonmail.com>
Date: Thu, 12 Mar 2020 01:54:42 +0500
Subject: [PATCH] Fix shared build (#113)

* Fix PIC property in util library.
* Force PIC when building shared lib on unix.
* Enable CMP0077 for better option handling.
---
 CMakeLists.txt | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index daf21ae..2c52e77 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1,5 +1,11 @@
 cmake_minimum_required(VERSION 3.0)
 
+# option() honors normal variables.
+# see: https://cmake.org/cmake/help/git-stage/policy/CMP0077.html
+if(POLICY CMP0077)
+  cmake_policy(SET CMP0077 NEW)
+endif()
+
 project(CpuFeatures VERSION 0.1.0 LANGUAGES C)
 
 set(CMAKE_C_STANDARD 99)
@@ -23,6 +29,12 @@ option(BUILD_SHARED_LIBS "Build library as shared." OFF)
 # PIC
 option(BUILD_PIC "Build with Position Independant Code." OFF) # Default is off at least for GCC
 
+# Force PIC on unix when building shared libs
+# see: https://en.wikipedia.org/wiki/Position-independent_code
+if(BUILD_SHARED_LIBS AND UNIX)
+  set(BUILD_PIC ON)
+endif()
+
 include(CheckIncludeFile)
 include(CheckSymbolExists)
 include(GNUInstallDirs)
@@ -92,6 +104,7 @@ add_library(utils OBJECT
   ${PROJECT_SOURCE_DIR}/src/stack_line_reader.c
   ${PROJECT_SOURCE_DIR}/src/string_view.c
 )
+set_property(TARGET utils PROPERTY POSITION_INDEPENDENT_CODE ${BUILD_PIC})
 setup_include_and_definitions(utils)
 
 #