openjdk给出debug配置选项，common/autoconf/jdk-options.m4
AC_DEFUN_ONCE([JDKOPT_SETUP_DEBUG_LEVEL],
[################################################################################# Set the debug level# release: no debug information, all optimizations, no asserts.# fastdebug: debug information (-g), all optimizations, all asserts# slowdebug: debug information (-g), no optimizations, all asserts#DEBUG_LEVEL="release"AC_MSG_CHECKING([which debug level to use])AC_ARG_ENABLE([debug], [AS_HELP_STRING([--enable-debug],[set the debug level to fastdebug (shorthand for --with-debug-level=fastdebug) @<:@disabled@:>@])],[ENABLE_DEBUG="${enableval}"DEBUG_LEVEL="fastdebug"], [ENABLE_DEBUG="no"])AC_ARG_WITH([debug-level], [AS_HELP_STRING([--with-debug-level],[set the debug level (release, fastdebug, slowdebug) @<:@release@:>@])],[DEBUG_LEVEL="${withval}"if test "x$ENABLE_DEBUG" = xyes; thenAC_MSG_ERROR([You cannot use both --enable-debug and --with-debug-level at the same time.])fi])AC_MSG_RESULT([$DEBUG_LEVEL])if test "x$DEBUG_LEVEL" != xrelease && \test "x$DEBUG_LEVEL" != xfastdebug && \test "x$DEBUG_LEVEL" != xslowdebug; thenAC_MSG_ERROR([Allowed debug levels are: release, fastdebug and slowdebug])fi开启调试信息
./configure --with-target-bits=64 --with-debug-level=slowdebug --enable-debug-symbols ZIP_DEBUGINFO_FILES=0--with-boot-jdk：指定引导JDK所在目录；--with-target-bits：指定编译64位系统的JDK；为可以进行源码调试，再指定下面三个参数：--with-debug-level=slowdebug：指定可以生成最多的调试信息；--enable-debug-symbols ZIP_DEBUGINFO_FILES=0：生成调试的符号信息，并且不压缩执行编译命令
make all ZIP_DEBUGINFO_FILES=0java调试用例源码
https://github.com/fenixsoft/jvm_book.git
执行java的C++代码
关键执行class字节码步骤
1、加载MainClass
2、获取appClass
3、获取MainID和入参
4、执行java的main函数
执行的所有线程栈
堆空间OOM
疑问
libjvm.so 明明有编译信息，却没有符号
而且也断点不到oom需要打印的函数，估计不是搜到的退出函数了。
