build: reduce CMake handling for zlib

Rather than handling zlib handling manually, use `find_package` from CMake
to find zlib properly. Use this to normalize the `LLVM_ENABLE_ZLIB`,
`HAVE_ZLIB`, `HAVE_ZLIB_H`. Furthermore, require zlib if `LLVM_ENABLE_ZLIB` is
set to `YES`, which requires the distributor to explicitly select whether
zlib is enabled or not. This simplifies the CMake handling and usage in
the rest of the tooling.

clang/test/CMakeLists.txt

@@ -9,22 +9,13 @@ endif ()
 
 string(REPLACE ${CMAKE_CFG_INTDIR} ${LLVM_BUILD_MODE} CLANG_TOOLS_DIR ${LLVM_RUNTIME_OUTPUT_INTDIR})
 
-if(CLANG_BUILT_STANDALONE)
-  # Set HAVE_LIBZ according to recorded LLVM_ENABLE_ZLIB value. This
-  # value is forced to 0 if zlib was not found, so it is fine to use it
-  # instead of HAVE_LIBZ (not recorded).
-  if(LLVM_ENABLE_ZLIB)
-    set(HAVE_LIBZ 1)
-  endif()
-endif()
-
 llvm_canonicalize_cmake_booleans(
   CLANG_BUILD_EXAMPLES
   CLANG_ENABLE_ARCMT
   CLANG_ENABLE_STATIC_ANALYZER
   ENABLE_BACKTRACES
   ENABLE_EXPERIMENTAL_NEW_PASS_MANAGER
-  HAVE_LIBZ
+  LLVM_ENABLE_ZLIB
   LLVM_ENABLE_PER_TARGET_RUNTIME_DIR
   LLVM_ENABLE_PLUGINS
   LLVM_ENABLE_THREADS)

clang/test/lit.site.cfg.py.in

@@ -16,7 +16,7 @@ config.host_triple = "@LLVM_HOST_TRIPLE@"
 config.target_triple = "@TARGET_TRIPLE@"
 config.host_cxx = "@CMAKE_CXX_COMPILER@"
 config.llvm_use_sanitizer = "@LLVM_USE_SANITIZER@"
-config.have_zlib = @HAVE_LIBZ@
+config.have_zlib = @LLVM_ENABLE_ZLIB@
 config.clang_arcmt = @CLANG_ENABLE_ARCMT@
 config.clang_default_cxx_stdlib = "@CLANG_DEFAULT_CXX_STDLIB@"
 config.clang_staticanalyzer = @CLANG_ENABLE_STATIC_ANALYZER@

compiler-rt/test/lit.common.configured.in

@@ -50,7 +50,7 @@ if config.enable_per_target_runtime_dir:
 else:
   set_default("target_suffix", "-%s" % config.target_arch)
 
-set_default("have_zlib", "@HAVE_LIBZ@")
+set_default("have_zlib", "@LLVM_ENABLE_ZLIB@")
 set_default("libcxx_used", "@LLVM_LIBCXX_USED@")
 
 # LLVM tools dir can be passed in lit parameters, so try to

lld/test/CMakeLists.txt

@@ -4,17 +4,8 @@ set(LLVM_BUILD_MODE "%(build_mode)s")
 set(LLVM_TOOLS_DIR "${LLVM_TOOLS_BINARY_DIR}/%(build_config)s")
 set(LLVM_LIBS_DIR "${LLVM_BINARY_DIR}/lib${LLVM_LIBDIR_SUFFIX}/%(build_config)s")
 
-if(LLD_BUILT_STANDALONE)
-  # Set HAVE_LIBZ according to recorded LLVM_ENABLE_ZLIB value. This
-  # value is forced to 0 if zlib was not found, so it is fine to use it
-  # instead of HAVE_LIBZ (not recorded).
-  if(LLVM_ENABLE_ZLIB)
-    set(HAVE_LIBZ 1)
-  endif()
-endif()
-
 llvm_canonicalize_cmake_booleans(
-  HAVE_LIBZ
+  LLVM_ENABLE_ZLIB
   LLVM_LIBXML2_ENABLED
   )
 

lld/test/lit.site.cfg.py.in

@@ -14,7 +14,7 @@ config.lld_libs_dir = "@LLVM_LIBRARY_OUTPUT_INTDIR@"
 config.lld_tools_dir = "@LLVM_RUNTIME_OUTPUT_INTDIR@"
 config.target_triple = "@TARGET_TRIPLE@"
 config.python_executable = "@PYTHON_EXECUTABLE@"
-config.have_zlib = @HAVE_LIBZ@
+config.have_zlib = @LLVM_ENABLE_ZLIB@
 config.sizeof_void_p = @CMAKE_SIZEOF_VOID_P@
 
 # Support substitution of the tools and libs dirs with user parameters. This is

lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunication.cpp

@@ -50,7 +50,7 @@
 #include <compression.h>
 #endif
 
-#if defined(HAVE_LIBZ)
+#if LLVM_ENABLE_ZLIB
 #include <zlib.h>
 #endif
 
@@ -582,7 +582,7 @@ bool GDBRemoteCommunication::DecompressPacket() {
   }
 #endif
 
-#if defined(HAVE_LIBZ)
+#if LLVM_ENABLE_ZLIB
   if (decompressed_bytes == 0 && decompressed_bufsize != ULONG_MAX &&
       decompressed_buffer != nullptr &&
       m_compression_type == CompressionType::ZlibDeflate) {

lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationClient.cpp

@@ -1045,7 +1045,7 @@ void GDBRemoteCommunicationClient::MaybeEnableCompression(
   }
 #endif
 
-#if defined(HAVE_LIBZ)
+#if LLVM_ENABLE_ZLIB
   if (avail_type == CompressionType::None) {
     for (auto compression : supported_compressions) {
       if (compression == "zlib-deflate") {

llvm/cmake/config-ix.cmake

@@ -56,7 +56,6 @@ check_include_file(sys/types.h HAVE_SYS_TYPES_H)
 check_include_file(termios.h HAVE_TERMIOS_H)
 check_include_file(unistd.h HAVE_UNISTD_H)
 check_include_file(valgrind/valgrind.h HAVE_VALGRIND_VALGRIND_H)
-check_include_file(zlib.h HAVE_ZLIB_H)
 check_include_file(fenv.h HAVE_FENV_H)
 check_symbol_exists(FE_ALL_EXCEPT "fenv.h" HAVE_DECL_FE_ALL_EXCEPT)
 check_symbol_exists(FE_INEXACT "fenv.h" HAVE_DECL_FE_INEXACT)
@@ -118,17 +117,8 @@ 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.*")
-  set(HAVE_LIBZ 0)
   if(LLVM_ENABLE_ZLIB)
-    foreach(library z zlib_static zlib)
-      string(TOUPPER ${library} library_suffix)
-      check_library_exists(${library} compress2 "" HAVE_LIBZ_${library_suffix})
-      if(HAVE_LIBZ_${library_suffix})
-        set(HAVE_LIBZ 1)
-        set(ZLIB_LIBRARIES "${library}")
-        break()
-      endif()
-    endforeach()
+    find_package(ZLIB REQUIRED)
   endif()
 
   # Don't look for these libraries on Windows.
@@ -515,11 +505,8 @@ else( LLVM_ENABLE_THREADS )
   message(STATUS "Threads disabled.")
 endif()
 
-if (LLVM_ENABLE_ZLIB )
-  # Check if zlib is available in the system.
-  if ( NOT HAVE_ZLIB_H OR NOT HAVE_LIBZ )
-    set(LLVM_ENABLE_ZLIB 0)
-  endif()
+if(LLVM_ENABLE_ZLIB)
+  find_package(ZLIB REQUIRED)
 endif()
 
 if (LLVM_ENABLE_DOXYGEN)

llvm/include/llvm/Config/config.h.cmake

@@ -109,9 +109,6 @@
 /* Define to 1 if you have the `pthread_setname_np' function. */
 #cmakedefine HAVE_PTHREAD_SETNAME_NP ${HAVE_PTHREAD_SETNAME_NP}
 
-/* Define to 1 if you have the `z' library (-lz). */
-#cmakedefine HAVE_LIBZ ${HAVE_LIBZ}
-
 /* Define to 1 if you have the <link.h> header file. */
 #cmakedefine HAVE_LINK_H ${HAVE_LINK_H}
 
@@ -226,9 +223,6 @@
 /* Define to 1 if you have the <valgrind/valgrind.h> header file. */
 #cmakedefine HAVE_VALGRIND_VALGRIND_H ${HAVE_VALGRIND_VALGRIND_H}
 
-/* Define to 1 if you have the <zlib.h> header file. */
-#cmakedefine HAVE_ZLIB_H ${HAVE_ZLIB_H}
-
 /* Have host's _alloca */
 #cmakedefine HAVE__ALLOCA ${HAVE__ALLOCA}
 

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_LIBRARIES})
-endif()
+set(system_libs ${ZLIB_LIBRARY})
 if( MSVC OR MINGW )
   # libuuid required for FOLDERID_Profile usage in lib/Support/Windows/Path.inc.
   # advapi32 required for CryptAcquireContextW in lib/Support/Windows/Path.inc.

llvm/lib/Support/CRC.cpp

@@ -25,7 +25,7 @@
 
 using namespace llvm;
 
-#if LLVM_ENABLE_ZLIB == 0 || !HAVE_ZLIB_H
+#if !LLVM_ENABLE_ZLIB
 
 static const uint32_t CRCTable[256] = {
     0x00000000, 0x77073096, 0xee0e612c, 0x990951ba, 0x076dc419, 0x706af48f,

llvm/lib/Support/Compression.cpp

@@ -17,13 +17,13 @@
 #include "llvm/Support/Compiler.h"
 #include "llvm/Support/Error.h"
 #include "llvm/Support/ErrorHandling.h"
-#if LLVM_ENABLE_ZLIB == 1 && HAVE_ZLIB_H
+#if LLVM_ENABLE_ZLIB
 #include <zlib.h>
 #endif
 
 using namespace llvm;
 
-#if LLVM_ENABLE_ZLIB == 1 && HAVE_LIBZ
+#if LLVM_ENABLE_ZLIB
 static Error createError(StringRef Err) {
   return make_error<StringError>(Err, inconvertibleErrorCode());
 }

llvm/test/CMakeLists.txt

@@ -1,12 +1,12 @@
 llvm_canonicalize_cmake_booleans(
   BUILD_SHARED_LIBS
   HAVE_LIBXAR
-  HAVE_LIBZ
   HAVE_OCAMLOPT
   HAVE_OCAML_OUNIT
   LLVM_ENABLE_DIA_SDK
   LLVM_ENABLE_FFI
   LLVM_ENABLE_THREADS
+  LLVM_ENABLE_ZLIB
   LLVM_INCLUDE_GO_TESTS
   LLVM_LIBXML2_ENABLED
   LLVM_LINK_LLVM_DYLIB

llvm/test/lit.site.cfg.py.in

@@ -33,7 +33,7 @@ config.host_cxx = "@HOST_CXX@"
 config.host_ldflags = '@HOST_LDFLAGS@'
 config.llvm_use_intel_jitevents = @LLVM_USE_INTEL_JITEVENTS@
 config.llvm_use_sanitizer = "@LLVM_USE_SANITIZER@"
-config.have_zlib = @HAVE_LIBZ@
+config.have_zlib = @LLVM_ENABLE_ZLIB@
 config.have_libxar = @HAVE_LIBXAR@
 config.have_dia_sdk = @LLVM_ENABLE_DIA_SDK@
 config.enable_ffi = @LLVM_ENABLE_FFI@

llvm/unittests/Support/CompressionTest.cpp

@@ -21,7 +21,7 @@ using namespace llvm;
 
 namespace {
 
-#if LLVM_ENABLE_ZLIB == 1 && HAVE_LIBZ
+#if LLVM_ENABLE_ZLIB
 
 void TestZlibCompression(StringRef Input, int Level) {
   SmallString<32> Compressed;