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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 # This flag are used to provide compiler protection against format
     57 # string vulnerabilities.
     58 TARGET_FORMAT_STRING_CFLAGS := -Wformat -Werror=format-security
     59 
     60 # This flag disables the above security checks
     61 TARGET_DISABLE_FORMAT_STRING_CFLAGS := -Wno-error=format-security
     62 
     63 # NOTE: Ensure that TARGET_LIBGCC is placed after all private objects
     64 #       and static libraries, but before any other library in the link
     65 #       command line when generating shared libraries and executables.
     66 #
     67 #       This ensures that all libgcc.a functions required by the target
     68 #       will be included into it, instead of relying on what's available
     69 #       on other libraries like libc.so, which may change between system
     70 #       releases due to toolchain or library changes.
     71 #
     72 define cmd-build-shared-library
     73 $(PRIVATE_CXX) \
     74     -Wl,-soname,$(notdir $(LOCAL_BUILT_MODULE)) \
     75     -shared \
     76     --sysroot=$(call host-path,$(PRIVATE_SYSROOT_LINK)) \
     77     $(PRIVATE_LINKER_OBJECTS_AND_LIBRARIES) \
     78     $(PRIVATE_LDFLAGS) \
     79     $(PRIVATE_LDLIBS) \
     80     -o $(call host-path,$(LOCAL_BUILT_MODULE))
     81 endef
     82 
     83 define cmd-build-executable
     84 $(PRIVATE_CXX) \
     85     -Wl,--gc-sections \
     86     -Wl,-z,nocopyreloc \
     87     --sysroot=$(call host-path,$(PRIVATE_SYSROOT_LINK)) \
     88     $(PRIVATE_LINKER_OBJECTS_AND_LIBRARIES) \
     89     $(PRIVATE_LDFLAGS) \
     90     $(PRIVATE_LDLIBS) \
     91     -o $(call host-path,$(LOCAL_BUILT_MODULE))
     92 endef
     93 
     94 define cmd-build-static-library
     95 $(PRIVATE_AR) $(call host-path,$(LOCAL_BUILT_MODULE)) $(PRIVATE_AR_OBJECTS)
     96 endef
     97 
     98 # The strip command is only used for shared libraries and executables.
     99 # It is thus safe to use --strip-unneeded, which is only dangerous
    100 # when applied to static libraries or object files.
    101 cmd-strip = $(PRIVATE_STRIP) --strip-unneeded $(call host-path,$1)
    102 
    103 TARGET_LIBGCC = -lgcc
    104 TARGET_LDLIBS := -lc -lm
    105 
    106 #
    107 # IMPORTANT: The following definitions must use lazy assignment because
    108 # the value of TOOLCHAIN_PREFIX or TARGET_CFLAGS can be changed later by
    109 # the toolchain's setup.mk script.
    110 #
    111 
    112 ifneq ($(findstring ccc-analyzer,$(CC)),)
    113 TARGET_CC       = $(CC)
    114 else
    115 TARGET_CC       = $(TOOLCHAIN_PREFIX)gcc
    116 endif
    117 TARGET_CFLAGS   =
    118 
    119 ifneq ($(findstring c++-analyzer,$(CXX)),)
    120 TARGET_CXX      = $(CXX)
    121 else
    122 TARGET_CXX      = $(TOOLCHAIN_PREFIX)g++
    123 endif
    124 TARGET_CXXFLAGS = $(TARGET_CFLAGS) -fno-exceptions -fno-rtti
    125 
    126 TARGET_LD       = $(TOOLCHAIN_PREFIX)ld
    127 TARGET_LDFLAGS :=
    128 
    129 TARGET_AR       = $(TOOLCHAIN_PREFIX)ar
    130 TARGET_ARFLAGS := crs
    131 
    132 TARGET_STRIP    = $(TOOLCHAIN_PREFIX)strip
    133 
    134 TARGET_OBJ_EXTENSION := .o
    135 TARGET_LIB_EXTENSION := .a
    136 TARGET_SONAME_EXTENSION := .so
    137