build: support LTO in depends

No Qt for now.

depends/hosts/android.mk

@@ -5,6 +5,12 @@ else
 android_CXX=$(ANDROID_TOOLCHAIN_BIN)/$(HOST)$(ANDROID_API_LEVEL)-clang++
 android_CC=$(ANDROID_TOOLCHAIN_BIN)/$(HOST)$(ANDROID_API_LEVEL)-clang
 endif
+
+ifneq ($(LTO),)
+android_CFLAGS += -flto
+android_LDFLAGS += -flto
+endif
+
 android_AR=$(ANDROID_TOOLCHAIN_BIN)/llvm-ar
 android_RANLIB=$(ANDROID_TOOLCHAIN_BIN)/llvm-ranlib
 

depends/hosts/darwin.mk

@@ -110,6 +110,12 @@ darwin_CXX=env -u C_INCLUDE_PATH -u CPLUS_INCLUDE_PATH \
                -Xclang -internal-externc-isystem$(OSX_SDK)/usr/include
 
 darwin_CFLAGS=-pipe
+
+ifneq ($(LTO),)
+darwin_CFLAGS += -flto
+darwin_LDFLAGS += -flto
+endif
+
 darwin_CXXFLAGS=$(darwin_CFLAGS)
 
 darwin_release_CFLAGS=-O2

depends/hosts/freebsd.mk

@@ -1,4 +1,10 @@
 freebsd_CFLAGS=-pipe
+
+ifneq ($(LTO),)
+freebsd_CFLAGS += -flto
+freebsd_LDFLAGS += -flto
+endif
+
 freebsd_CXXFLAGS=$(freebsd_CFLAGS)
 
 freebsd_release_CFLAGS=-O2

depends/hosts/linux.mk

@@ -1,4 +1,10 @@
 linux_CFLAGS=-pipe
+
+ifneq ($(LTO),)
+linux_CFLAGS += -flto
+linux_LDFLAGS += -flto
+endif
+
 linux_CXXFLAGS=$(linux_CFLAGS)
 
 linux_release_CFLAGS=-O2

depends/hosts/mingw32.mk

@@ -3,6 +3,12 @@ mingw32_CXX := $(host)-g++-posix
 endif
 
 mingw32_CFLAGS=-pipe
+
+ifneq ($(LTO),)
+mingw32_CFLAGS += -flto
+mingw32_LDFLAGS += -flto
+endif
+
 mingw32_CXXFLAGS=$(mingw32_CFLAGS)
 
 mingw32_release_CFLAGS=-O2

depends/hosts/netbsd.mk

@@ -1,4 +1,10 @@
 netbsd_CFLAGS=-pipe
+
+ifneq ($(LTO),)
+netbsd_CFLAGS += -flto
+netbsd_LDFLAGS += -flto
+endif
+
 netbsd_CXXFLAGS=$(netbsd_CFLAGS)
 
 netbsd_release_CFLAGS=-O2

depends/hosts/openbsd.mk

@@ -1,6 +1,11 @@
 openbsd_CFLAGS=-pipe
 openbsd_CXXFLAGS=$(openbsd_CFLAGS)
 
+ifneq ($(LTO),)
+openbsd_CFLAGS += -flto
+openbsd_LDFLAGS += -flto
+endif
+
 openbsd_release_CFLAGS=-O2
 openbsd_release_CXXFLAGS=$(openbsd_release_CFLAGS)