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      1 # The following definitions are the defaults used by all toolchains.
      2 # This is included in setup-toolchain.mk just before the inclusion
      3 # of the toolchain's specific setup.mk file which can then override
      4 # these definitions.
      5 #
      6 
      7 # These flags are used to ensure that a binary doesn't reference undefined
      8 # flags.
      9 TARGET_NO_UNDEFINED_LDFLAGS := -Wl,--no-undefined
     10 
     11 
     12 # Return the list of object, static libraries and shared libraries as they
     13 # must appear on the final static linker command (order is important).
     14 #
     15 # This can be over-ridden by a specific toolchain. Note that by default
     16 # we always put libgcc _after_ all static libraries and _before_ shared
     17 # libraries. This ensures that any libgcc function used by the final
     18 # executable will be copied into it. Otherwise, it could contain
     19 # symbol references to the same symbols as exported by shared libraries
     20 # and this causes binary compatibility problems when they come from
     21 # system libraries (e.g. libc.so and others).
     22 #
     23 # IMPORTANT: The result must use the host path convention.
     24 #
     25 # $1: object files
     26 # $2: static libraries
     27 # $3: whole static libraries
     28 # $4: shared libraries
     29 #
     30 TARGET-get-linker-objects-and-libraries = \
     31     $(call host-path, $1) \
     32     $(call link-whole-archives,$3) \
     33     $(call host-path, $2 $(PRIVATE_LIBGCC) $4) \
     34 
     35 
     36 # These flags are used to enforce the NX (no execute) security feature in the
     37 # generated machine code. This adds a special section to the generated shared
     38 # libraries that instruct the Linux kernel to disable code execution from
     39 # the stack and the heap.
     40 TARGET_NO_EXECUTE_CFLAGS  := -Wa,--noexecstack
     41 TARGET_NO_EXECUTE_LDFLAGS := -Wl,-z,noexecstack
     42 
     43 # These flags disable the above security feature
     44 TARGET_DISABLE_NO_EXECUTE_CFLAGS  := -Wa,--execstack
     45 TARGET_DISABLE_NO_EXECUTE_LDFLAGS := -Wl,-z,execstack
     46 
     47 # These flags are used to mark certain regions of the resulting
     48 # executable or shared library as being read-only after the dynamic
     49 # linker has run. This makes GOT overwrite security attacks harder to
     50 # exploit.
     51 TARGET_RELRO_LDFLAGS := -Wl,-z,relro -Wl,-z,now
     52 
     53 # These flags disable the above security feature
     54 TARGET_DISABLE_RELRO_LDFLAGS := -Wl,-z,norelro -Wl,-z,lazy
     55 
     56 # NOTE: Ensure that TARGET_LIBGCC is placed after all private objects
     57 #       and static libraries, but before any other library in the link
     58 #       command line when generating shared libraries and executables.
     59 #
     60 #       This ensures that all libgcc.a functions required by the target
     61 #       will be included into it, instead of relying on what's available
     62 #       on other libraries like libc.so, which may change between system
     63 #       releases due to toolchain or library changes.
     64 #
     65 define cmd-build-shared-library
     66 $(PRIVATE_CXX) \
     67     -Wl,-soname,$(notdir $(LOCAL_BUILT_MODULE)) \
     68     -shared \
     69     --sysroot=$(call host-path,$(PRIVATE_SYSROOT_LINK)) \
     70     $(PRIVATE_LINKER_OBJECTS_AND_LIBRARIES) \
     71     $(PRIVATE_LDFLAGS) \
     72     $(PRIVATE_LDLIBS) \
     73     -o $(call host-path,$(LOCAL_BUILT_MODULE))
     74 endef
     75 
     76 define cmd-build-executable
     77 $(PRIVATE_CXX) \
     78     -Wl,--gc-sections \
     79     -Wl,-z,nocopyreloc \
     80     --sysroot=$(call host-path,$(PRIVATE_SYSROOT_LINK)) \
     81     $(PRIVATE_LINKER_OBJECTS_AND_LIBRARIES) \
     82     $(PRIVATE_LDFLAGS) \
     83     $(PRIVATE_LDLIBS) \
     84     -o $(call host-path,$(LOCAL_BUILT_MODULE))
     85 endef
     86 
     87 define cmd-build-static-library
     88 $(PRIVATE_AR) $(call host-path,$(LOCAL_BUILT_MODULE)) $(PRIVATE_AR_OBJECTS)
     89 endef
     90 
     91 # The strip command is only used for shared libraries and executables.
     92 # It is thus safe to use --strip-unneeded, which is only dangerous
     93 # when applied to static libraries or object files.
     94 cmd-strip = $(PRIVATE_STRIP) --strip-unneeded $(call host-path,$1)
     95 
     96 TARGET_LIBGCC = -lgcc
     97 TARGET_LDLIBS := -lc -lm
     98 
     99 #
    100 # IMPORTANT: The following definitions must use lazy assignment because
    101 # the value of TOOLCHAIN_PREFIX or TARGET_CFLAGS can be changed later by
    102 # the toolchain's setup.mk script.
    103 #
    104 
    105 ifneq ($(findstring ccc-analyzer,$(CC)),)
    106 TARGET_CC       = $(CC)
    107 else
    108 TARGET_CC       = $(TOOLCHAIN_PREFIX)gcc
    109 endif
    110 TARGET_CFLAGS   =
    111 
    112 ifneq ($(findstring c++-analyzer,$(CXX)),)
    113 TARGET_CXX      = $(CXX)
    114 else
    115 TARGET_CXX      = $(TOOLCHAIN_PREFIX)g++
    116 endif
    117 TARGET_CXXFLAGS = $(TARGET_CFLAGS) -fno-exceptions -fno-rtti
    118 
    119 TARGET_LD       = $(TOOLCHAIN_PREFIX)ld
    120 TARGET_LDFLAGS :=
    121 
    122 TARGET_AR       = $(TOOLCHAIN_PREFIX)ar
    123 TARGET_ARFLAGS := crs
    124 
    125 TARGET_STRIP    = $(TOOLCHAIN_PREFIX)strip
    126 
    127 TARGET_OBJ_EXTENSION := .o
    128 TARGET_LIB_EXTENSION := .a
    129 TARGET_SONAME_EXTENSION := .so
    130