GCC命令-详细请参考GCC手册

GNU ToolKit User's Guide

D:\Tornado2.2\docs\gnu2.96+ppc\gcc.html

-Dmacro

Define macro macro with the string `1' as its definition.

-Dmacro=defn

Define macro macro as defn. All instances of `-D' on the command line are processed before any `-U' options.

-fsigned-char

Let the type char be signed, like signed char.

-ansi

Support all ANSI standard C programs.

This turns off certain features of GNU C that are incompatible with ANSI C, such as the asm, inline and typeof keywords, and predefined macros such as unix and vax that identify the type of system you are using. It also enables the undesirable and rarely used
ANSI trigraph feature, and it disables recognition of C++ style `//' comments.

-Idir

Add the directory dir to the head of the list of directories to be searched for header files. This can be used to override a system header file, substituting your own version, since these directories are searched before the system header file directories. If
you use more than one `-I' option, the directories are scanned in left-to-right order; the standard system directories come after.

The following is an example command to compile an application module for a VxWorks PowerPC 604 system:

c:\> ccppc -mcpu=604 -mstrict-align -I %WIND_BASE%\target\h \

-DCPU=PPC603 -DTOOL_FAMILY=gnu -DTOOL=gnu -c applic.c

This compiles the module applic.c into an object file applic.o.

Below we give summary descriptions of the target-independent flags used in the example. Flags that are specific to a particular target architecture are described in the relevant architecture supplement. For more information on any of these flags, see the
GNU ToolKit User's Guide.

-g

Generate debugging information.

-c

Compile only to produce a relocatable object file. The result is an object module with the suffix .o, in this case, applic.o.

-DCPU=CPU

Required; defines the CPU type.

-DTOOL_FAMILY=gnu

Optional; defines the compilation toolkit used to compile VxWorks. If not entered, it is derived from -DTOOL=.

-DTOOL=gnu

Required; specifies the compilation toolkit and the tool environment. For more information, see the GNU ToolKit User's Guide.

-I$(WIND_BASE)/target/h

Include VxWorks header files. (See 5.2.1 Using VxWorks Header Files.)

-fno-builtin

Use library calls even for common library subroutines such as memcpy. Used by VxWorks for historical reasons. There is no need for application code to use this flag.

-Wall

Turn on all warnings. This flag is optional.

-ansi

Reject non-ANSI-compliant code. This flag is optional.

-O

Perform basic optimizations.

-O2

Perform most supported optimizations (except those involving a space-speed trade-off)