+
−.. -*- coding: utf-8; -*-
+
−
+
−=====
+
− GCC
+
−=====
+
−.. contents::
+
−   :local:
+
−
+
−Remove dead code
+
−================
+
−::
+
−
+
−  STRIP_DEAD_CODE = -Wl,-static -fvtable-gc -fdata-sections -ffunction-sections -Wl,--gc-sections -Wl,-s
+
−
+
−``-Wl,-static``
+
−  Link against static libraries. Required for dead-code
+
−  elimination.
+
−
+
−``-fvtable-gc``
+
−  C++ virtual method table instrumented with garbage collection
+
−  information for the linker.
+
−
+
−``-fdata-sections``
+
−  Keeps data in separate data sections, so they can be discarded
+
−  if unused.
+
−
+
−``-ffunction-sections``
+
−  Keeps funcitons in separate data sections, so they can be
+
−  discarded if unused.
+
−
+
−``-Wl,--gc-sections``
+
−  Tell the linker to garbage collect and discard unused
+
−  sections.
+
−
+
−``-s``
+
−  Strip the debug information, so as to make the code as small
+
−  as possible. (I presume that you'd want to do this in a
+
−  dead-code removal build.)
+
−
+
−Map file
+
−========
+
−::
+
−
+
−  $ ld -Map=file.map <opts> <files>
+
−
+
−or::
+
−
+
−  $ gcc -Wl,-Map=file.map <opts> <files>
+
−
+
−Predefined macros
+
−=================
+
−::
+
−
+
−  $ gcc -arch ppc -dM -E - < /dev/null | sort
+
−
+
−Default search path
+
−===================
+
−::
+
−
+
−  $ echo | gcc -v -x c -E -
+
−
+
−  $ gcc -print-search-dirs
+
−  install: ...
+
−  programs: ...
+
−  libraries: ...
+
−
+
−Use ``-###`` in actual invoking::
+
−
+
−  $ gcc -### -o foo foo.c
+
−
+
−  $ ld --verbose | grep SEARCH_DIR
+
−
+
−``LIBRARY_PATH`` and ``LD_LIBRARY_PATH``::
+
−
+
−  $ cpp -Wp,-v
+
−  $ cpp -Wp,-lang-c++,-v
+
−  $ cpp -x c++ -Wp,-v
+
−