From 543952eb87f7b06a41dd001273a59a0dea728c39 Mon Sep 17 00:00:00 2001
From: Wander Lairson Costa <wander.lairson@gmail.com>
Date: Tue, 20 Mar 2018 11:46:31 +0000
Subject: [PATCH] Include libxml2 and zlib as required libraries

libxml2 is a required library, but we only find out that when the build
fails to link against it, if it is not present. The same for zlib.

We use find_library to find these two libraries and print nice fail
messages if they are not found.
---
 CMakeLists.txt | 18 +++++++++++++++++-
 1 file changed, 17 insertions(+), 1 deletion(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 9a4f57171..979d771cd 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -49,6 +49,22 @@ option(ZIG_FORCE_EXTERNAL_LLD "If your system has the LLD patches use it instead
 find_package(llvm)
 find_package(clang)
 
+if(NOT MSVC)
+    find_library(LIBXML2 NAMES xml2 libxml2)
+    if(${LIBXML2} STREQUAL "LIBXML2-NOTFOUND")
+        message(FATAL_ERROR "Could not find libxml2")
+    else()
+        message("${LIBXML2} found")
+    endif()
+
+    find_library(ZLIB NAMES z zlib libz)
+    if(${ZLIB} STREQUAL "ZLIB-NOTFOUND")
+        message(FATAL_ERROR "Could not find zlib")
+    else()
+        message("${ZLIB} found")
+    endif()
+endif()
+
 set(ZIG_CPP_LIB_DIR "${CMAKE_BINARY_DIR}/zig_cpp")
 
 if(ZIG_FORCE_EXTERNAL_LLD)
@@ -710,7 +726,7 @@ target_link_libraries(zig LINK_PUBLIC
     ${CMAKE_THREAD_LIBS_INIT}
 )
 if(NOT MSVC)
-    target_link_libraries(zig LINK_PUBLIC xml2)
+    target_link_libraries(zig LINK_PUBLIC ${LIBXML2})
 endif()
 if(ZIG_DIA_GUIDS_LIB)
     target_link_libraries(zig LINK_PUBLIC ${ZIG_DIA_GUIDS_LIB})