From d2ff15715976bcb0179518565de134508236b5c2 Mon Sep 17 00:00:00 2001
From: Colin Cross <ccross@android.com>
Date: Mon, 3 Oct 2016 16:49:02 -0700
Subject: [PATCH] Enable toc optimization for host builds

The toc optimization had been disabled for host builds to ensure that
the timestamp of the final binary changed whenever its implementation
changed, in order to support rerunning host tools that were modified
during incremental builds.  However, only the final install rule must be
re-run to update the timestamp, and not the link rule.

Update the shared library install dependencies to use normal
dependencies instead of order-only dependencies for host modules, and
then enable the the toc optimization for host modules.  If the
implementation of a library changes it will be reinstalled, and
libraries or binaries that depend on it will also be reinstalled.

Bug: 26015464
Test: m -j; touch art/disassembler/disassembler_x86.cc; m -j, verify
      out/host/linux-x86/bin/oatdump is updated
Change-Id: I0a14decc1994eb55ad269d841943aef66e320c63
---
 core/base_rules.mk |  4 ----
 core/binary.mk     |  6 ------
 core/main.mk       | 12 +++++++++++-
 3 files changed, 11 insertions(+), 11 deletions(-)

diff --git a/core/base_rules.mk b/core/base_rules.mk
index 56df2a918c..13d20e073f 100644
--- a/core/base_rules.mk
+++ b/core/base_rules.mk
@@ -269,9 +269,6 @@ LOCAL_INTERMEDIATE_TARGETS += $(LOCAL_BUILT_MODULE)
 # dependent binaries of a .toc file will be rebuilt only when the content of
 # the .toc file is changed.
 ###########################################################
-ifndef LOCAL_IS_HOST_MODULE
-# Disable .toc optimization for host modules: we may run the host binaries during the build process
-# and the libraries' implementation matters.
 ifeq ($(LOCAL_MODULE_CLASS),SHARED_LIBRARIES)
 LOCAL_INTERMEDIATE_TARGETS += $(LOCAL_BUILT_MODULE).toc
 $(LOCAL_BUILT_MODULE).toc: $(LOCAL_BUILT_MODULE)
@@ -283,7 +280,6 @@ $(LOCAL_BUILT_MODULE).toc: $(LOCAL_BUILT_MODULE)
 # Build .toc file when using mm, mma, or make $(my_register_name)
 $(my_all_targets): $(LOCAL_BUILT_MODULE).toc
 endif
-endif
 
 ###########################################################
 ## logtags: Add .logtags files to global list
diff --git a/core/binary.mk b/core/binary.mk
index 6413153ebd..4dcb152b74 100644
--- a/core/binary.mk
+++ b/core/binary.mk
@@ -1507,13 +1507,7 @@ built_shared_libraries := \
     $(addprefix $($(LOCAL_2ND_ARCH_VAR_PREFIX)$(my_prefix)OUT_INTERMEDIATE_LIBRARIES)/, \
       $(addsuffix $(so_suffix), \
         $(installed_shared_library_module_names)))
-ifdef LOCAL_IS_HOST_MODULE
-# Disable .toc optimization for host modules: we may run the host binaries during the build process
-# and the libraries' implementation matters.
-built_shared_library_deps := $(built_shared_libraries)
-else
 built_shared_library_deps := $(addsuffix .toc, $(built_shared_libraries))
-endif
 my_system_shared_libraries_fullpath :=
 endif
 
diff --git a/core/main.mk b/core/main.mk
index fee299569b..de77927a06 100644
--- a/core/main.mk
+++ b/core/main.mk
@@ -660,6 +660,14 @@ define add-required-deps
 $(1): | $(2)
 endef
 
+# Use a normal dependency instead of an order-only dependency when installing
+# host dynamic binaries so that the timestamp of the final binary always
+# changes, even if the toc optimization has skipped relinking the binary
+# and its dependant shared libraries.
+define add-required-host-so-deps
+$(1): $(2)
+endef
+
 $(foreach m,$(ALL_MODULES), \
   $(eval r := $(ALL_MODULES.$(m).REQUIRED)) \
   $(if $(r), \
@@ -702,7 +710,9 @@ $(foreach m,$($(if $(2),$($(1)2ND_ARCH_VAR_PREFIX))$(1)DEPENDENCIES_ON_SHARED_LI
   $(if $(3),$(eval deps := $(addprefix host_cross_,$(deps))))\
   $(eval r := $(filter $($(root))/%,$(call module-installed-files,\
     $(deps))))\
-  $(eval $(call add-required-deps,$(word 2,$(p)),$(r)))\
+  $(if $(filter $(1),HOST_),\
+    $(eval $(call add-required-host-so-deps,$(word 2,$(p)),$(r))),\
+    $(eval $(call add-required-deps,$(word 2,$(p)),$(r))))\
   $(eval ALL_MODULES.$(mod).REQUIRED += $(deps)))
 endef