BoringSSL: always build with symbol visibility flags.

When building for shared libraries, setting BORINGSSL_SHARED_LIBRARY,
BORINGSSL_IMPLEMENTATION and setting the default symbol visibility to
“hidden” causes the correct symbol visibility to be set.

This change causes symbol visibility always to be set, even for the
static builds. The reason is the the static builds are often then
included in shared libraries, so they're not really static after all.
Setting the symbol visibility in this case can avoid a lot of references
via the PLT and GOT for internal symbols.

Most importantly, some of the x86 asm code has IP-relative references to
data and, unless the visibility of the target symbol is “hidden”, the
linker believes that it needs a textrel, which breaks linking that code
into shared libraries.

Change-Id: I00e8d045bcece7b872d88bdf965c5baf65c2d639

1 files changed, 6 insertions, 6 deletions

diff --git a/Android.mk b/Android.mk
index e904263..5ae544c 100644
--- a/Android.mk
+++ b/Android.mk
@@ -13,7 +13,7 @@ LOCAL_MODULE := libcrypto_static
 LOCAL_EXPORT_C_INCLUDE_DIRS := $(LOCAL_PATH)/src/include
 LOCAL_ADDITIONAL_DEPENDENCIES := $(LOCAL_PATH)/Android.mk $(LOCAL_PATH)/crypto-sources.mk
 LOCAL_SDK_VERSION := 9
-LOCAL_CFLAGS = -Wno-unused-parameter
+LOCAL_CFLAGS += -fvisibility=hidden -DBORINGSSL_SHARED_LIBRARY -DBORINGSSL_IMPLEMENTATION -Wno-unused-parameter
 # sha256-armv4.S does not compile with clang.
 LOCAL_CLANG_ASFLAGS_arm += -no-integrated-as
 LOCAL_CLANG_ASFLAGS_arm64 += -march=armv8-a+crypto
@@ -41,7 +41,7 @@ LOCAL_CPP_EXTENSION := cc
 LOCAL_MODULE := bssl
 LOCAL_MODULE_TAGS := optional
 LOCAL_ADDITIONAL_DEPENDENCIES := $(LOCAL_PATH)/Android.mk $(LOCAL_PATH)/sources.mk
-LOCAL_CFLAGS = -Wno-unused-parameter
+LOCAL_CFLAGS += -fvisibility=hidden -DBORINGSSL_SHARED_LIBRARY -DBORINGSSL_IMPLEMENTATION -Wno-unused-parameter
 LOCAL_SHARED_LIBRARIES=libcrypto libssl
 include $(LOCAL_PATH)/sources.mk
 LOCAL_SRC_FILES = $(tool_sources)
@@ -54,7 +54,7 @@ LOCAL_MODULE := libcrypto_static
 LOCAL_MODULE_HOST_OS := darwin linux windows
 LOCAL_EXPORT_C_INCLUDE_DIRS := $(LOCAL_PATH)/src/include
 LOCAL_ADDITIONAL_DEPENDENCIES := $(LOCAL_PATH)/Android.mk $(LOCAL_PATH)/crypto-sources.mk
-LOCAL_CFLAGS = -Wno-unused-parameter
+LOCAL_CFLAGS += -fvisibility=hidden -DBORINGSSL_SHARED_LIBRARY -DBORINGSSL_IMPLEMENTATION -Wno-unused-parameter
 # Windows and Macs both have problems with assembly files
 LOCAL_CFLAGS_darwin += -DOPENSSL_NO_ASM
 LOCAL_CFLAGS_windows += -DOPENSSL_NO_ASM
@@ -85,7 +85,7 @@ LOCAL_MODULE := libssl_static
 LOCAL_EXPORT_C_INCLUDE_DIRS := $(LOCAL_PATH)/src/include
 LOCAL_ADDITIONAL_DEPENDENCIES := $(LOCAL_PATH)/Android.mk $(LOCAL_PATH)/ssl-sources.mk
 LOCAL_SDK_VERSION := 9
-LOCAL_CFLAGS = -Wno-unused-parameter
+LOCAL_CFLAGS += -fvisibility=hidden -DBORINGSSL_SHARED_LIBRARY -DBORINGSSL_IMPLEMENTATION -Wno-unused-parameter
 include $(LOCAL_PATH)/ssl-sources.mk
 include $(BUILD_STATIC_LIBRARY)
 
@@ -107,7 +107,7 @@ LOCAL_MODULE_TAGS := optional
 LOCAL_MODULE := libssl_static-host
 LOCAL_EXPORT_C_INCLUDE_DIRS := $(LOCAL_PATH)/src/include
 LOCAL_ADDITIONAL_DEPENDENCIES := $(LOCAL_PATH)/Android.mk $(LOCAL_PATH)/ssl-sources.mk
-LOCAL_CFLAGS = -Wno-unused-parameter
+LOCAL_CFLAGS += -fvisibility=hidden -DBORINGSSL_SHARED_LIBRARY -DBORINGSSL_IMPLEMENTATION -Wno-unused-parameter
 include $(LOCAL_PATH)/ssl-sources.mk
 include $(BUILD_HOST_STATIC_LIBRARY)
 
@@ -119,7 +119,7 @@ LOCAL_CPP_EXTENSION := cc
 LOCAL_MODULE := bssl
 LOCAL_MODULE_TAGS := optional
 LOCAL_ADDITIONAL_DEPENDENCIES := $(LOCAL_PATH)/Android.mk $(LOCAL_PATH)/sources.mk
-LOCAL_CFLAGS = -Wno-unused-parameter
+LOCAL_CFLAGS += -fvisibility=hidden -DBORINGSSL_SHARED_LIBRARY -DBORINGSSL_IMPLEMENTATION -Wno-unused-parameter
 LOCAL_SHARED_LIBRARIES=libcrypto-host libssl-host
 # Needed for clock_gettime.
 LOCAL_LDFLAGS := -lrt