摘自GCC 备忘
-pipe
Use pipes rather than temporary files for communication between the various
stages of compilation. This fails to work on some systems where the assembler
is unable to read from a pipe; but the GNU assembler has no trouble.
-fno-builtin
-fno-builtin-function
Don’t recognize built-in functions that do not begin with ‘__builtin_’ as prefix.
GCC normally generates special code to handle certain built-in functions more
efficiently; for instance, calls to alloca may become single instructions that
adjust the stack directly, and calls to memcpy may become inline copy loops.
The resulting code is often both smaller and faster, but since the function
calls no longer appear as such, you cannot set a breakpoint on those calls,
nor can you change the behavior of the functions by linking with a different
library. In addition, when a function is recognized as a built-in function, GCC
may use information about that function to warn about problems with calls to
that function, or to generate more efficient code, even if the resulting code still
contains calls to that function. For example, warnings are given with ‘-Wformat’
for bad calls to printf, when printf is built in, and strlen is known not to
modify global memory.
With the ‘-fno-builtin-function’ option only the built-in function function
is disabled. function must not begin with ‘__builtin_’. If a function is named
that is not built-in in this version of GCC, this option is ignored. There is
no corresponding ‘-fbuiltin-function’ option; if you wish to enable built-in
functions selectively when using ‘-fno-builtin’ or ‘-ffreestanding’, you may
define ma
-nostdinc
Do not search the standard system directories for header files. Only the directories
you have specified with ‘-I’ options (and the directory of the current file,
if appropriate) are searched.cros such as:
-nostartfiles
Do not use the standard system startup files when linking. The standard system
libraries are used normally, unless ‘-nostdlib’ or ‘-nodefaultlibs’ is used.
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