1、前提是build GCC的时候要修改makefile，在configure之后生成的makefile忠，将CFLAGS和CFLAGS_FOR_BUILD改成-g3 -O0..
2、在root用户下，切换到源码所在目录，输入：
jRate-gcj --main=Test1 Test1.java -o Test1 -dr -O0 -v
-dr表示导出RTL代码，-v会显示GCC编译各个过程的命令行信息，在后面使用GDB的时候会用到。
这里我显示的如下所示：
Reading specs from /usr/local/lib/gcc-lib/i686-pc-linux-gnu/3.3.3/specs
Reading specs from /usr/local/lib/gcc-lib/i686-pc-linux-gnu/3.3.3/../../../libgcj.spec
rename spec lib to liborig
Configured with: /home/yanxin/jrate/gcc/configure --host=i686-pc-linux-gnu --build=i686-pc-linux-gnu --target=i686-pc-linux-gnu --disable-jvmpi --enable-java-gc=jRate --enable-threads=posix --enable-languages=c,c++,java --prefix=/usr/local --program-prefix=jRate- --disable-interpreter --disable-hash-synchronization --disable-pthread-self-cache --enable-shared --enable-static
Thread model: posix
gcc version 3.3.3
/usr/local/lib/gcc-lib/i686-pc-linux-gnu/3.3.3/jc1 Test1.java -fno-use-divide-subroutine -fnon-call-exceptions -fkeep-inline-functions -quiet -dumpbase Test1.java -dr -auxbase Test1 -O0 -version -o /tmp/ccUyN2au.s
GNU Java version 3.3.3 (i686-pc-linux-gnu)
compiled by GNU C version 3.3.3.
GGC heuristics: --param ggc-min-expand=100 --param ggc-min-heapsize=131072
Class path starts here:
./
/usr/local/share/java/libgcj-3.3.3.jar/ (system) (zip)
as --traditional-format -V -Qy -o /tmp/ccLz5gJN.o /tmp/ccUyN2au.s
GNU assembler version 2.22 (i686-linux-gnu) using BFD version (GNU Binutils for Ubuntu) 2.22
/usr/local/lib/gcc-lib/i686-pc-linux-gnu/3.3.3/jvgenmain Test1main /tmp/cc4SRZv7.i
/usr/local/lib/gcc-lib/i686-pc-linux-gnu/3.3.3/cc1 /tmp/cc4SRZv7.i -quiet -dumpbase Test1main.c -dr -O0 -version -fdollars-in-identifiers -o /tmp/ccUyN2au.s
GNU C version 3.3.3 (i686-pc-linux-gnu)
compiled by GNU C version 3.3.3.
GGC heuristics: --param ggc-min-expand=100 --param ggc-min-heapsize=131072
as --traditional-format -V -Qy -o /tmp/ccPD6vYr.o /tmp/ccUyN2au.s
GNU assembler version 2.22 (i686-linux-gnu) using BFD version (GNU Binutils for Ubuntu) 2.22
/usr/local/lib/gcc-lib/i686-pc-linux-gnu/3.3.3/collect2 --eh-frame-hdr -m elf_i386 -dynamic-linker /lib/ld-linux.so.2 -o Test1 /usr/lib/i386-linux-gnu/crt1.o /usr/lib/i386-linux-gnu/crti.o /usr/local/lib/gcc-lib/i686-pc-linux-gnu/3.3.3/crtbegin.o -L/usr/lib/i386-linux-gnu -L/usr/local/lib/gcc-lib/i686-pc-linux-gnu/3.3.3 -L/usr/local/lib/gcc-lib/i686-pc-linux-gnu/3.3.3/../../.. /tmp/ccPD6vYr.o /tmp/ccLz5gJN.o -lgcc_s -lgcc -lgcj -lm -lpthread -lgcc_s -lgcc -lc -lgcc_s -lgcc /usr/local/lib/gcc-lib/i686-pc-linux-gnu/3.3.3/crtend.o /usr/lib/i386-linux-gnu/crtn.o
我们主要用到这个：
/usr/local/lib/gcc-lib/i686-pc-linux-gnu/3.3.3/jc1 Test1.java -fno-use-divide-subroutine -fnon-call-exceptions -fkeep-inline-functions -quiet -dumpbase Test1.java -dr -auxbase Test1 -O0 -version -o /tmp/ccUyN2au.s
3、在终端里输入：
gdb /usr/local/lib/gcc-lib/i686-pc-linux-gnu/3.3.3/jc1
break main
run Test1.java -fno-use-divide-subroutine -fnon-call-exceptions -fkeep-inline-functions -quiet -dumpbase Test1.java -dr -auxbase Test1 -O0 -version -o /tmp/ccUyN2au.s
break rest_of_compilation continue backtrace
下面给出了显示出的从main到rest_of_compilation的函数调用情况：
#0 rest_of_compilation (decl=0xb7a9d488) at /home/yanxin/jrate/gcc/gcc/toplev.c:2368 #1 0x08059af0 in source_end_java_method () at /home/yanxin/jrate/gcc/gcc/java/parse.y:7568 #2 0x0805a835 in java_expand_method_bodies (class=0x5) at /home/yanxin/jrate/gcc/gcc/java/parse.y:8249 #3 0x0805becd in java_expand_classes () at /home/yanxin/jrate/gcc/gcc/java/parse.y:9230 #4 0x08083336 in java_parse_file (set_yydebug=0) at /home/yanxin/jrate/gcc/gcc/java/jcf-parse.c:1144 #5 0x08221d5a in compile_file () at /home/yanxin/jrate/gcc/gcc/toplev.c:2130 #6 0x08227055 in do_compile () at /home/yanxin/jrate/gcc/gcc/toplev.c:5407 #7 0x082270fd in toplev_main (argc=5, argv=0xbffff1f4) at /home/yanxin/jrate/gcc/gcc/toplev.c:5437 #8 0x080927cb in main (argc=5, argv=0x5) at /home/yanxin/jrate/gcc/gcc/main.c:35