From 32427d6903b2a32508eb7cc76c8e83ccea126be6 Mon Sep 17 00:00:00 2001
From: Chih-Hung Hsieh <chh@google.com>
Date: Thu, 12 Apr 2018 10:55:54 -0700
Subject: [PATCH] Add USE_CLANG_LLD and LOCAL_USE_CLANG_LLD

* Current default is not using lld.
* When USE_CLANG_LLD or LOCAL_USE_CLANG_LLD is true or 1,
  * Use *GLOBAL_LLDFLAGS instead of *GLOBAL_LDFLAGS.
    GLOBAL_LLDFLAGS should call lld and with correct lld flags.
  * set my_pack_module_relocations to false.

Bug: 73768157
Test: make checkbuild
Change-Id: I3e63cf8ae0865d01d2bc1f36e9304f4a5d092cb8
---
 core/binary.mk            |  7 ++++++-
 core/clear_vars.mk        |  1 +
 core/dynamic_binary.mk    |  5 +++++
 core/prebuilt_internal.mk |  8 ++++++++
 core/soong_config.mk      |  1 +
 core/use_lld_setup.mk     | 14 ++++++++++++++
 6 files changed, 35 insertions(+), 1 deletion(-)
 create mode 100644 core/use_lld_setup.mk

diff --git a/core/binary.mk b/core/binary.mk
index 954df1f44..a5f46daee 100644
--- a/core/binary.mk
+++ b/core/binary.mk
@@ -7,6 +7,7 @@
 
 #######################################
 include $(BUILD_SYSTEM)/base_rules.mk
+include $(BUILD_SYSTEM)/use_lld_setup.mk
 #######################################
 
 ##################################################
@@ -516,7 +517,11 @@ ifeq ($(my_clang),true)
 my_target_global_cflags := $($(LOCAL_2ND_ARCH_VAR_PREFIX)CLANG_$(my_prefix)GLOBAL_CFLAGS)
 my_target_global_conlyflags := $($(LOCAL_2ND_ARCH_VAR_PREFIX)CLANG_$(my_prefix)GLOBAL_CONLYFLAGS) $(my_c_std_conlyflags)
 my_target_global_cppflags := $($(LOCAL_2ND_ARCH_VAR_PREFIX)CLANG_$(my_prefix)GLOBAL_CPPFLAGS) $(my_cpp_std_cppflags)
-my_target_global_ldflags := $($(LOCAL_2ND_ARCH_VAR_PREFIX)CLANG_$(my_prefix)GLOBAL_LDFLAGS)
+ifeq ($(my_use_clang_lld),true)
+  my_target_global_ldflags := $($(LOCAL_2ND_ARCH_VAR_PREFIX)CLANG_$(my_prefix)GLOBAL_LLDFLAGS)
+else
+  my_target_global_ldflags := $($(LOCAL_2ND_ARCH_VAR_PREFIX)CLANG_$(my_prefix)GLOBAL_LDFLAGS)
+endif # my_use_clang_lld
 else
 my_target_global_cflags := $($(LOCAL_2ND_ARCH_VAR_PREFIX)$(my_prefix)GLOBAL_CFLAGS)
 my_target_global_conlyflags := $($(LOCAL_2ND_ARCH_VAR_PREFIX)$(my_prefix)GLOBAL_CONLYFLAGS) $(my_c_std_conlyflags)
diff --git a/core/clear_vars.mk b/core/clear_vars.mk
index eccaad54d..62549d97e 100644
--- a/core/clear_vars.mk
+++ b/core/clear_vars.mk
@@ -264,6 +264,7 @@ LOCAL_TIDY_FLAGS:=
 LOCAL_UNINSTALLABLE_MODULE:=
 LOCAL_UNSTRIPPED_PATH:=
 LOCAL_USE_AAPT2:=$(USE_AAPT2)
+LOCAL_USE_CLANG_LLD:=
 LOCAL_USE_R8:=
 LOCAL_USE_VNDK:=
 LOCAL_VENDOR_MODULE:=
diff --git a/core/dynamic_binary.mk b/core/dynamic_binary.mk
index ebbe71c2d..74e0fa2de 100644
--- a/core/dynamic_binary.mk
+++ b/core/dynamic_binary.mk
@@ -67,6 +67,11 @@ ifneq ($(HOST_OS),linux)
   my_pack_module_relocations := false
 endif
 
+# Relocation packer does not work with LLD yet.
+ifeq ($(my_use_clang_lld),true)
+  my_pack_module_relocations := false
+endif
+
 ifeq (true,$(my_pack_module_relocations))
 # Pack relocations
 $(relocation_packer_output): $(relocation_packer_input)
diff --git a/core/prebuilt_internal.mk b/core/prebuilt_internal.mk
index 96e26137a..a9eb29e01 100644
--- a/core/prebuilt_internal.mk
+++ b/core/prebuilt_internal.mk
@@ -6,6 +6,8 @@
 ##
 ###########################################################
 
+include $(BUILD_SYSTEM)/use_lld_setup.mk
+
 ifneq ($(LOCAL_PREBUILT_LIBS),)
 $(error dont use LOCAL_PREBUILT_LIBS anymore LOCAL_PATH=$(LOCAL_PATH))
 endif
@@ -70,6 +72,12 @@ ifeq (SHARED_LIBRARIES,$(LOCAL_MODULE_CLASS))
   ifeq ($(DISABLE_RELOCATION_PACKER),true)
     my_pack_module_relocations := false
   endif
+
+  # Relocation packer does not work with LLD yet.
+  # my_use_clang_lld might be used befor set up in binary.mk
+  ifeq ($(my_use_clang_lld),true)
+    my_pack_module_relocations := false
+  endif
 endif
 
 ifneq ($(filter STATIC_LIBRARIES SHARED_LIBRARIES,$(LOCAL_MODULE_CLASS)),)
diff --git a/core/soong_config.mk b/core/soong_config.mk
index ab493d916..296d54988 100644
--- a/core/soong_config.mk
+++ b/core/soong_config.mk
@@ -99,6 +99,7 @@ $(call add_json_list, CFIExcludePaths,                   $(CFI_EXCLUDE_PATHS) $(
 $(call add_json_list, CFIIncludePaths,                   $(CFI_INCLUDE_PATHS) $(PRODUCT_CFI_INCLUDE_PATHS))
 $(call add_json_list, IntegerOverflowExcludePaths,       $(INTEGER_OVERFLOW_EXCLUDE_PATHS) $(PRODUCT_INTEGER_OVERFLOW_EXCLUDE_PATHS))
 
+$(call add_json_bool, UseClangLld,                       $(filter 1 true,$(USE_CLANG_LLD)))
 $(call add_json_bool, ClangTidy,                         $(filter 1 true,$(WITH_TIDY)))
 $(call add_json_str,  TidyChecks,                        $(WITH_TIDY_CHECKS))
 
diff --git a/core/use_lld_setup.mk b/core/use_lld_setup.mk
new file mode 100644
index 000000000..69ceddc53
--- /dev/null
+++ b/core/use_lld_setup.mk
@@ -0,0 +1,14 @@
+#############################################################
+## Set up flags based on USE_CLANG_LLD and LOCAL_USE_CLANG_LLD.
+## Input variables: USE_CLANG_LLD,LOCAL_USE_CLANG_LLD.
+## Output variables: my_use_clang_lld
+#############################################################
+
+# Use LLD only if it's not disabled by LOCAL_USE_CLANG_LLD,
+# and enabled by LOCAL_USE_CLANG_LLD or USE_CLANG_LLD.
+my_use_clang_lld := false
+ifeq (,$(filter 0 false,$(LOCAL_USE_CLANG_LLD)))
+  ifneq (,$(filter 1 true,$(LOCAL_USE_CLANG_LLD) $(USE_CLANG_LLD)))
+    my_use_clang_lld := true
+  endif
+endif