Remove indirect dependency on system ZLIB (#26888)

* Remove indirect dependency on system ZLIB

- build LLVM without ZLIB support
- use the bundled ZLIB for libgit

* backport bundled zlib patch

deps/libgit2.mk

@@ -18,7 +18,7 @@ $(BUILDDIR)/$(LIBGIT2_SRC_DIR)/build-configured: | $(build_prefix)/manifest/curl
 endif
 endif
 
-LIBGIT2_OPTS := $(CMAKE_COMMON) -DCMAKE_BUILD_TYPE=Release -DTHREADSAFE=ON
+LIBGIT2_OPTS := $(CMAKE_COMMON) -DCMAKE_BUILD_TYPE=Release -DTHREADSAFE=ON -DUSE_BUNDLED_ZLIB=ON
 ifeq ($(OS),WINNT)
 LIBGIT2_OPTS += -DWIN32=ON -DMINGW=ON
 ifneq ($(ARCH),x86_64)
@@ -71,6 +71,10 @@ $(LIBGIT2_SRC_PATH)/libgit2-ssh-loop.patch-applied: $(LIBGIT2_SRC_PATH)/source-e
  cd $(LIBGIT2_SRC_PATH) && \
  patch -p1 -f < $(SRCDIR)/patches/libgit2-ssh-loop.patch
  echo 1 > $@
+$(LIBGIT2_SRC_PATH)/libgit2-bundled_zlib.patch-applied: $(LIBGIT2_SRC_PATH)/source-extracted | $(LIBGIT2_SRC_PATH)/libgit2-ssh-loop.patch-applied
+ cd $(LIBGIT2_SRC_PATH) && \
+ patch -p1 -f < $(SRCDIR)/patches/libgit2-bundled_zlib.patch
+ echo 1 > $@
 
 $(build_datarootdir)/julia/cert.pem:
  $(JLDOWNLOAD) $(shell pwd)/cacert-2018-01-17.pem https://curl.haxx.se/ca/cacert-2018-01-17.pem
@@ -85,6 +89,7 @@ $(BUILDDIR)/$(LIBGIT2_SRC_DIR)/build-configured: \
  $(LIBGIT2_SRC_PATH)/libgit2-mbedtls-verify.patch-applied \
  $(LIBGIT2_SRC_PATH)/libgit2-mbedtls-fixup.patch-applied \
  $(LIBGIT2_SRC_PATH)/libgit2-ssh-loop.patch-applied \
+ $(LIBGIT2_SRC_PATH)/libgit2-bundled_zlib.patch-applied \
 
 $(BUILDDIR)/$(LIBGIT2_SRC_DIR)/build-configured: $(LIBGIT2_SRC_PATH)/source-extracted $(build_datarootdir)/julia/cert.pem
  mkdir -p $(dir $@)

deps/llvm.mk

@@ -64,6 +64,7 @@ LLVM_CXXFLAGS += $(CXXFLAGS)
 LLVM_CPPFLAGS += $(CPPFLAGS)
 LLVM_LDFLAGS += $(LDFLAGS)
 LLVM_CMAKE += -DLLVM_TARGETS_TO_BUILD:STRING="$(LLVM_TARGETS)" -DCMAKE_BUILD_TYPE="$(LLVM_CMAKE_BUILDTYPE)"
+LLVM_CMAKE += -DLLVM_ENABLE_ZLIB=OFF
 ifeq ($(USE_POLLY_ACC),1)
 LLVM_CMAKE += -DPOLLY_ENABLE_GPGPU_CODEGEN=ON
 endif

deps/patches/libgit2-bundled_zlib.patch

@@ -0,0 +1,55 @@
+From 637f75b2a341df6e308f8a20827dea938a39bd35 Mon Sep 17 00:00:00 2001
+From: Valentin Churavy <[email protected]>
+Date: Mon, 23 Apr 2018 13:27:50 -0400
+Subject: [PATCH] backport bundled zlib patch
+
+---
+ CMakeLists.txt | 23 ++++++++++++++---------
+ 1 file changed, 14 insertions(+), 9 deletions(-)
+
+diff --git a/CMakeLists.txt b/CMakeLists.txt
+index 4783e3ef9..aff84e75c 100644
+--- a/CMakeLists.txt
++++ b/CMakeLists.txt
+@@ -44,6 +44,7 @@ OPTION( USE_GSSAPI "Link with libgssapi for SPNEGO auth" OFF )
+ OPTION( VALGRIND "Configure build for valgrind" OFF )
+ OPTION( CURL "Use curl for HTTP if available" ON)
+ OPTION( DEBUG_POOL "Enable debug pool allocator" OFF )
++OPTION( USE_BUNDLED_ZLIB "Use the bundled version of zlib" OFF )
+
+ IF(DEBUG_POOL)
+ ADD_DEFINITIONS(-DGIT_DEBUG_POOL)
+@@ -340,17 +341,21 @@ ELSE()
+ ENDIF()
+
+ # Optional external dependency: zlib
+-FIND_PACKAGE(ZLIB)
+-IF (ZLIB_FOUND)
+- INCLUDE_DIRECTORIES(${ZLIB_INCLUDE_DIRS})
+- LINK_LIBRARIES(${ZLIB_LIBRARIES})
+- IF(APPLE OR CMAKE_SYSTEM_NAME MATCHES "FreeBSD")
+- LIST(APPEND LIBGIT2_PC_LIBS "-lz")
++IF(NOT USE_BUNDLED_ZLIB)
++ FIND_PACKAGE(ZLIB)
++ IF (ZLIB_FOUND)
++ INCLUDE_DIRECTORIES(${ZLIB_INCLUDE_DIRS})
++ LINK_LIBRARIES(${ZLIB_LIBRARIES})
++ IF(APPLE OR CMAKE_SYSTEM_NAME MATCHES "FreeBSD")
++ LIST(APPEND LIBGIT2_PC_LIBS "-lz")
++ ELSE()
++ SET(LIBGIT2_PC_REQUIRES "${LIBGIT2_PC_REQUIRES} zlib")
++ ENDIF()
+ ELSE()
+- SET(LIBGIT2_PC_REQUIRES "${LIBGIT2_PC_REQUIRES} zlib")
++ MESSAGE(STATUS "zlib was not found; using bundled 3rd-party sources." )
+ ENDIF()
+-ELSE()
+- MESSAGE(STATUS "zlib was not found; using bundled 3rd-party sources." )
++ENDIF()
++IF(USE_BUNDLED_ZLIB OR NOT ZLIB_FOUND)
+ INCLUDE_DIRECTORIES(deps/zlib)
+ ADD_DEFINITIONS(-DNO_VIZ -DSTDC -DNO_GZIP)
+ FILE(GLOB SRC_ZLIB deps/zlib/*.c deps/zlib/*.h)
+-- 
+2.17.0
+