From f2fdc183b7bb771acd44bc9433557f36479fff79 Mon Sep 17 00:00:00 2001
From: Pavel Labath <labath@google.com>
Date: Mon, 4 Dec 2017 16:46:20 +0000
Subject: [PATCH] Revert "[cmake] Enable zlib support on windows"

This reverts commit r319533 as it broke llvm-config --system-libs output
and everything that depends on it (which is mostly out of tree or
downstream folks, but includes a couple of llvm buildbots as well).

I think I have a fix for this in D40779, but I want someone to look
review it first. In the mean time, I am reverting this change, as it
seems to break a lot of people.

llvm-svn: 319663
---
 llvm/cmake/config-ix.cmake      | 74 ++++++++++++++++-----------------
 llvm/lib/Support/CMakeLists.txt |  6 +--
 2 files changed, 38 insertions(+), 42 deletions(-)

diff --git a/llvm/cmake/config-ix.cmake b/llvm/cmake/config-ix.cmake
index 836c4941f5d5..caa538082fc7 100644
--- a/llvm/cmake/config-ix.cmake
+++ b/llvm/cmake/config-ix.cmake
@@ -127,49 +127,45 @@ if(HAVE_LIBPTHREAD)
   set(LLVM_PTHREAD_LIB ${CMAKE_THREAD_LIBS_INIT})
 endif()
 
-# Don't look for these libraries if we're using MSan, since uninstrumented third
-# party code may call MSan interceptors like strlen, leading to false positives.
-if(NOT LLVM_USE_SANITIZER MATCHES "Memory.*")
-  find_library(ZLIB_LIBRARY_PATH NAMES z zlib)
-  if (LLVM_ENABLE_ZLIB AND ZLIB_LIBRARY_PATH)
-    check_library_exists(${ZLIB_LIBRARY_PATH} compress2 "" HAVE_LIBZ)
+# Don't look for these libraries on Windows. Also don't look for them if we're
+# using MSan, since uninstrumented third party code may call MSan interceptors
+# like strlen, leading to false positives.
+if( NOT PURE_WINDOWS AND NOT LLVM_USE_SANITIZER MATCHES "Memory.*")
+  if (LLVM_ENABLE_ZLIB)
+    check_library_exists(z compress2 "" HAVE_LIBZ)
   else()
     set(HAVE_LIBZ 0)
   endif()
-
-  # Don't look for these libraries on Windows.
-  if (NOT PURE_WINDOWS)
-    # Skip libedit if using ASan as it contains memory leaks.
-    if (LLVM_ENABLE_LIBEDIT AND HAVE_HISTEDIT_H AND NOT LLVM_USE_SANITIZER MATCHES ".*Address.*")
-      check_library_exists(edit el_init "" HAVE_LIBEDIT)
-    else()
-      set(HAVE_LIBEDIT 0)
-    endif()
-    if(LLVM_ENABLE_TERMINFO)
-      set(HAVE_TERMINFO 0)
-      foreach(library tinfo terminfo curses ncurses ncursesw)
-        string(TOUPPER ${library} library_suffix)
-        check_library_exists(${library} setupterm "" HAVE_TERMINFO_${library_suffix})
-        if(HAVE_TERMINFO_${library_suffix})
-          set(HAVE_TERMINFO 1)
-          set(TERMINFO_LIBS "${library}")
-          break()
-        endif()
-      endforeach()
-    else()
-      set(HAVE_TERMINFO 0)
-    endif()
-
-    find_library(ICONV_LIBRARY_PATH NAMES iconv libiconv libiconv-2 c)
-    set(LLVM_LIBXML2_ENABLED 0)
-    set(LIBXML2_FOUND 0)
-    if((LLVM_ENABLE_LIBXML2) AND ((CMAKE_SYSTEM_NAME MATCHES "Linux") AND (ICONV_LIBRARY_PATH) OR APPLE))
-      find_package(LibXml2)
-      if (LIBXML2_FOUND)
-        set(LLVM_LIBXML2_ENABLED 1)
-        include_directories(${LIBXML2_INCLUDE_DIR})
-        set(LIBXML2_LIBS "xml2")
+  # Skip libedit if using ASan as it contains memory leaks.
+  if (LLVM_ENABLE_LIBEDIT AND HAVE_HISTEDIT_H AND NOT LLVM_USE_SANITIZER MATCHES ".*Address.*")
+    check_library_exists(edit el_init "" HAVE_LIBEDIT)
+  else()
+    set(HAVE_LIBEDIT 0)
+  endif()
+  if(LLVM_ENABLE_TERMINFO)
+    set(HAVE_TERMINFO 0)
+    foreach(library tinfo terminfo curses ncurses ncursesw)
+      string(TOUPPER ${library} library_suffix)
+      check_library_exists(${library} setupterm "" HAVE_TERMINFO_${library_suffix})
+      if(HAVE_TERMINFO_${library_suffix})
+        set(HAVE_TERMINFO 1)
+        set(TERMINFO_LIBS "${library}")
+        break()
       endif()
+    endforeach()
+  else()
+    set(HAVE_TERMINFO 0)
+  endif()
+
+  find_library(ICONV_LIBRARY_PATH NAMES iconv libiconv libiconv-2 c)
+  set(LLVM_LIBXML2_ENABLED 0)
+  set(LIBXML2_FOUND 0)
+  if((LLVM_ENABLE_LIBXML2) AND ((CMAKE_SYSTEM_NAME MATCHES "Linux") AND (ICONV_LIBRARY_PATH) OR APPLE))
+    find_package(LibXml2)
+    if (LIBXML2_FOUND)
+      set(LLVM_LIBXML2_ENABLED 1)
+      include_directories(${LIBXML2_INCLUDE_DIR})
+      set(LIBXML2_LIBS "xml2")
     endif()
   endif()
 endif()
diff --git a/llvm/lib/Support/CMakeLists.txt b/llvm/lib/Support/CMakeLists.txt
index f2a59ec27436..5d95a9a9a56d 100644
--- a/llvm/lib/Support/CMakeLists.txt
+++ b/llvm/lib/Support/CMakeLists.txt
@@ -1,7 +1,4 @@
 set(system_libs)
-if ( LLVM_ENABLE_ZLIB AND HAVE_LIBZ )
-  set(system_libs ${system_libs} ${ZLIB_LIBRARY_PATH})
-endif()
 if( MSVC OR MINGW )
   # libuuid required for FOLDERID_Profile usage in lib/Support/Windows/Path.inc.
   set(system_libs ${system_libs} psapi shell32 ole32 uuid)
@@ -24,6 +21,9 @@ elseif( CMAKE_HOST_UNIX )
     set(system_libs ${system_libs} atomic)
   endif()
   set(system_libs ${system_libs} ${LLVM_PTHREAD_LIB})
+  if ( LLVM_ENABLE_ZLIB AND HAVE_LIBZ )
+    set(system_libs ${system_libs} z)
+  endif()
   if( UNIX AND NOT (BEOS OR HAIKU) )
     set(system_libs ${system_libs} m)
   endif()