原本想在 Windows 下编译调试，但过程中遇到了诸多错误（老是报路径错误。。。），最后只好放弃。
此次记录调试的方法为 CentOS7 上编译，Windows 上使用 Clion 远程调试（也可直接在 CentOS7 桌面环境直接调试，速度快）。
一、下载源码（OpenJDK8）
yum 源使用的是阿里的 https://opsx.alibaba.com/mirror?lang=zh-CN
这里使用 mercurial（类似 Git 的版本控制系统） 下载源码，方便更新。
下面网址可以下载 mercurial 较新的版本。
https://mercurial.selenic.com/wiki/ChineseDownload
https://www.mercurial-scm.org/wiki/Download
# 或者 yum install hg -y yum install mercurial -y # 下载源码，目标目录需要为空 hg clone http://hg.openjdk.java.net/jdk8u/jdk8u /opt/jdk8u # 更新代码，操作和 Git 类似 hg pull # 获取完整源码（需要在源码目录下执行，下载时间较长，一次可能下载不成功，多试几次） cd /opt/jdk8u/ sh get_source.sh # 完全下载成功的打印信息。若输出中出现回滚字样，即代表下载过程中出错了，需重新执行下载脚本 No repositories to process. # Repositories: . corba jaxp jaxws langtools jdk hotspot nashorn .: cd . && hg pull -u corba: cd corba && hg pull -u jaxp: cd jaxp && hg pull -u jaxws: cd jaxws && hg pull -u langtools: cd langtools && hg pull -u jdk: cd jdk && hg pull -u hotspot: cd hotspot && hg pull -u nashorn: cd nashorn && hg pull -u .: 正在拉自 http://hg.openjdk.java.net/jdk8u/jdk8u/ corba: 正在拉自 http://hg.openjdk.java.net/jdk8u/jdk8u/corba jaxp: 正在拉自 http://hg.openjdk.java.net/jdk8u/jdk8u/jaxp jaxws: 正在拉自 http://hg.openjdk.java.net/jdk8u/jdk8u/jaxws jdk: 正在拉自 http://hg.openjdk.java.net/jdk8u/jdk8u/jdk langtools: 正在拉自 http://hg.openjdk.java.net/jdk8u/jdk8u/langtools hotspot: 正在拉自 http://hg.openjdk.java.net/jdk8u/jdk8u/hotspot nashorn: 正在拉自 http://hg.openjdk.java.net/jdk8u/jdk8u/nashorn corba: 正在搜索修改 corba: 没有发现修改 jdk: 正在搜索修改 jdk: 没有发现修改 jaxws: 正在搜索修改 jaxws: 没有发现修改 .: 正在搜索修改 .: 没有发现修改 langtools: 正在搜索修改 langtools: 没有发现修改 hotspot: 正在搜索修改 hotspot: 没有发现修改 jaxp: 正在搜索修改 jaxp: 没有发现修改 nashorn: 正在搜索修改 nashorn: 没有发现修改
这里手动执行多次比较麻烦，自己写了个小脚本，循环执行。
#!/bin/bash for i in {1..28} do cd /opt/jdk8u/; sh ./get_source.sh; done
二、编译源码
Linux 下编译比 Windows 下简单太多。
https://hg.openjdk.java.net/jdk/jdk/file/tip/doc/building.md
https://hg.openjdk.java.net/jdk8u/jdk8u/raw-file/tip/README-builds.html
构建 JDK 8 需要使用 Update 7 或更高版本的 JDK 7 版本。JDK 8 开发人员不应使用 JDK 8 作为引导 JDK，以确保 JDK 8 依赖关系不会引入使用 JDK 7 构建的系统部分。
# 查询 yum list installed | grep jdk rpm -qa | grep jdk # 卸载 yum remove -y xxxxxxx # 验证 java -version # -bash: java: 未找到命令 # 安装 JDK7 # https://www.oracle.com/technetwork/java/javase/downloads/java-archive-downloads-javase7-521261.html tar -zxf jdk-7u80-linux-x64.tar.gz -C /opt/
配置
cd /opt/jdk8u/ chmod +x configure # 直接执行配置，看看缺少什么工具或参数，按照错误提示安装和添加参数即可 ./configure # 安装编译所需工具包 yum install -y unzip zip libXtst-devel libXt-devel libXrender-devel cups-devel freetype-devel alsa-lib-devel fontconfig-devel yum groupinstall -y "Development Tools" # 配置编译环境 ./configure --with-boot-jdk=/opt/jdk1.7.0_80/ --with-debug-level=slowdebug --with-native-debug-symbols=internal # --with-debug-level=slowdebug 输出更多调试信息 # --with-native-debug-symbols=internal 内链方式生成调试链接符号（可执行文件与源代码的对应关系） # 生成调试链接符号还有以下方式，相当于 --enable-debug-symbols --disable-zip-debug-info # ZIP_DEBUGINFO_FILES=0 生成调试信息文件 libjvm.debuginfo，否则会被压缩成 libjvm.diz，debug 时只能看到汇编代码，不能跟进源码 # ENABLE_FULL_DEBUG_SYMBOLS=1 生成调试符号，可不加，不影响调试 ##################################### 配置生产成功打印信息 ################################# A new configuration has been successfully created in /opt/jdk8u/build/linux-x86_64-normal-server-release using configure arguments '--with-boot-jdk=/opt/jdk1.7.0_80/ --with-debug-level=slowdebug --with-native-debug-symbols=internal'. Configuration summary: * Debug level: release * JDK variant: normal * JVM variants: server * OpenJDK target: OS: linux, CPU architecture: x86, address length: 64 Tools summary: * Boot JDK: java version "1.7.0_80" Java(TM) SE Runtime Environment (build 1.7.0_80-b15) Java HotSpot(TM) 64-Bit Server VM (build 2 4.80-b11, mixed mode) (at /opt/jdk1.7.0_80) * Toolchain: gcc (GNU Compiler Collection) * C Compiler: Version 4.8.5 (at /usr/bin/gcc) * C++ Compiler: Version 4.8.5 (at /usr/bin/g++) Build performance summary: * Cores to use: 7 * Memory limit: 15884 MB WARNING: The result of this configuration has overridden an older configuration. You *should* run 'make clean' to make sure you get a proper build. Failure to do so might result in strange build problems.
configure 帮助文档
Running generated-configure.sh
`configure' configures OpenJDK jdk8 to adapt to many kinds of systems.
Usage: /opt/jdk8u/configure [OPTION]... [VAR=VALUE]...
To assign environment variables (e.g., CC, CFLAGS...), specify them as
VAR=VALUE. See below for descriptions of some of the useful variables.
Defaults for the options are specified in brackets.
Configuration:
-h, --help display this help and exit
--help=short display options specific to this package
--help=recursive display the short help of all the included packages
-V, --version display version information and exit
-q, --quiet, --silent do not print `checking ...' messages
--cache-file=FILE cache test results in FILE [disabled]
-C, --config-cache alias for `--cache-file=config.cache'
-n, --no-create do not create output files
--srcdir=DIR find the sources in DIR [configure dir or `..']
Installation directories:
--prefix=PREFIX install architecture-independent files in PREFIX [/usr/local]
--exec-prefix=EPREFIX install architecture-dependent files in EPREFIX [PREFIX]
By default, `make install' will install all the files in `/usr/local/bin', `/usr/local/lib' etc. You can specify an installation prefix other than `/usr/local' using `--prefix', for instance `--prefix=$HOME'.
For better control, use the options below.
Fine tuning of the installation directories:
--bindir=DIR user executables [EPREFIX/bin]
--sbindir=DIR system admin executables [EPREFIX/sbin]
--libexecdir=DIR program executables [EPREFIX/libexec]
--sysconfdir=DIR read-only single-machine data [PREFIX/etc]
--sharedstatedir=DIR modifiable architecture-independent data [PREFIX/com]
--localstatedir=DIR modifiable single-machine data [PREFIX/var]
--libdir=DIR object code libraries [EPREFIX/lib]
--includedir=DIR C header files [PREFIX/include]
--oldincludedir=DIR C header files for non-gcc [/usr/include]
--datarootdir=DIR read-only arch.-independent data root [PREFIX/share]
--datadir=DIR read-only architecture-independent data [DATAROOTDIR]
--infodir=DIR info documentation [DATAROOTDIR/info]
--localedir=DIR locale-dependent data [DATAROOTDIR/locale]
--mandir=DIR man documentation [DATAROOTDIR/man]
--docdir=DIR documentation root [DATAROOTDIR/doc/openjdk]
--htmldir=DIR html documentation [DOCDIR]
--dvidir=DIR dvi documentation [DOCDIR]
--pdfdir=DIR pdf documentation [DOCDIR]
--psdir=DIR ps documentation [DOCDIR]
X features:
--x-includes=DIR X include files are in DIR
--x-libraries=DIR X library files are in DIR
System types:
--build=BUILD configure for building on BUILD [guessed]
--host=HOST cross-compile to build programs to run on HOST [BUILD]
--target=TARGET configure for building compilers for TARGET [HOST]
Optional Features:
--disable-option-checking ignore unrecognized --enable/--with options
--disable-FEATURE do not include FEATURE (same as --enable-FEATURE=no)
--enable-FEATURE[=ARG] include FEATURE [ARG=yes]
--enable-openjdk-only suppress building custom source even if present [disabled]
--enable-debug set the debug level to fastdebug (shorthand for --with-debug-level=fastdebug) [disabled]
--disable-headful disable building headful support (graphical UI support) [enabled]
--enable-hotspot-test-in-build
run the Queens test after Hotspot build [disabled]
--enable-unlimited-crypto
Enable unlimited crypto policy [disabled]
--disable-debug-symbols disable generation of debug symbols [enabled]
--disable-zip-debug-info
disable zipping of debug-info files [enabled]
--enable-macosx-runtime-support
Deprecated. Option is kept for backwards compatibility and is ignored
--disable-freetype-bundling
disable bundling of the freetype library with the build result [enabled on Windows or when using --with-freetype, disabled otherwise]
--enable-sjavac use sjavac to do fast incremental compiles [disabled]
--disable-precompiled-headers
disable using precompiled headers when compiling C++ [enabled]
--enable-ccache enable using ccache to speed up recompilations [disabled]
Optional Packages:
--with-PACKAGE[=ARG] use PACKAGE [ARG=yes]
--without-PACKAGE do not use PACKAGE (same as --with-PACKAGE=no)
--with-custom-make-dir use this directory for custom build/make files
--with-target-bits build 32-bit or 64-bit binaries (for platforms that support it), e.g. --with-target-bits=32 [guessed]
--with-jdk-variant JDK variant to build (normal) [normal]
--with-jvm-interpreter JVM interpreter to build (template, cpp) [template]
--with-jvm-variants JVM variants (separated by commas) to build (server, client, minimal1, kernel, zero, zeroshark, core) [server]
--with-debug-level set the debug level (release, fastdebug, slowdebug) [release]
--with-devkit use this devkit for compilers, tools and resources
--with-sys-root alias for --with-sysroot for backwards compatability
--with-sysroot use this directory as sysroot)
--with-tools-dir alias for --with-toolchain-path for backwards compatibility
--with-toolchain-path prepend these directories when searching for toolchain binaries (compilers etc)
--with-extra-path prepend these directories to the default path
--with-xcode-path explicit path to Xcode 4 (generally for building on 10.9 and later)
--with-conf-name use this as the name of the configuration [generated from important configuration options]
--with-builddeps-conf use this configuration file for the builddeps
--with-builddeps-server download and use build dependencies from this server url
--with-builddeps-dir store downloaded build dependencies here [/localhome/builddeps]
--with-builddeps-group chgrp the downloaded build dependencies to this group
--with-cacerts-file specify alternative cacerts file
--with-milestone Set milestone value for build [internal]
--with-update-version Set update version value for build [b00]
--with-user-release-suffix
Add a custom string to the version string if build number isn't set.[username_builddateb00]
--with-build-number Set build number value for build [b00]
--with-vendor-name Set vendor name. Among others, used to set the 'java.vendor' and 'java.vm.vendor' system properties. [not specified]
--with-vendor-url Set the 'java.vendor.url' system property [not specified]
--with-vendor-bug-url Set the 'java.vendor.url.bug' system property [not specified]
--with-vendor-vm-bug-url
Sets the bug URL which will be displayed when the VM crashes [not specified]
--with-copyright-year Set copyright year value for build [current year]
--with-boot-jdk path to Boot JDK (used to bootstrap build) [probed]
--with-boot-jdk-jvmargs specify JVM arguments to be passed to all invocations of the Boot JDK, overriding the default values, e.g --with-boot-jdk-jvmargs="-Xmx8G -enableassertions"
--with-add-source-root for each and every source directory, look in this additional source root for the same directory; if it exists and have files in it, include it in the build
--with-override-source-root
for each and every source directory, look in this override source root for the same directory; if it exists, use that directory instead and ignore the directory in the original source root
--with-adds-and-overrides
use the subdirs 'adds' and 'overrides' in the specified directory as add-source-root and override-source-root
--with-override-langtools
use this langtools dir for the build
--with-override-corba use this corba dir for the build
--with-override-jaxp use this jaxp dir for the build
--with-override-jaxws use this jaxws dir for the build
--with-override-hotspot use this hotspot dir for the build
--with-override-nashorn use this nashorn dir for the build
--with-override-jdk use this jdk dir for the build
--with-import-hotspot import hotspot binaries from this jdk image or hotspot build dist dir instead of building from source
--with-toolchain-type the toolchain type (or family) to use, use '--help' to show possible values [platform dependent]
--with-toolchain-version
the version of the toolchain to look for, use '--help' to show possible values [platform dependent]
--with-jtreg Regression Test Harness [probed]
--with-extra-cflags extra flags to be used when compiling jdk c-files
--with-extra-cxxflags extra flags to be used when compiling jdk c++-files
--with-extra-ldflags extra flags to be used when linking jdk
--with-native-debug-symbols
set the native debug symbol configuration (none, internal, external, zipped) [varying]
--with-x use the X Window System
--with-cups specify prefix directory for the cups package (expecting the headers under PATH/include)
--with-cups-include specify directory for the cups include files
--with-freetype specify prefix directory for the freetype package (expecting the libraries under PATH/lib and the headers under PATH/include)
--with-freetype-include specify directory for the freetype include files
--with-freetype-lib specify directory for the freetype library
--with-freetype-src specify directory with freetype sources to automatically build the library (experimental, Windows-only)
--with-alsa specify prefix directory for the alsa package (expecting the libraries under PATH/lib and the headers under PATH/include)
--with-alsa-include specify directory for the alsa include files
--with-alsa-lib specify directory for the alsa library
--with-fontconfig specify prefix directory for the fontconfig package (expecting the headers under PATH/include)
--with-fontconfig-include
specify directory for the fontconfig include files
--with-giflib use giflib from build system or OpenJDK source (system, bundled) [bundled]
--with-zlib use zlib from build system or OpenJDK source (system, bundled) [bundled]
--with-stdc++lib=<static>,<dynamic>,<default>
force linking of the C++ runtime on Linux to either static or dynamic, default is static with dynamic as fallback
--with-msvcr-dll path to microsoft C runtime dll (msvcr*.dll) (Windows only) [probed]
--with-msvcp-dll path to microsoft C++ runtime dll (msvcp*.dll) (Windows only) [probed]
--with-ucrt-dll-dir path to Microsoft Windows Kit UCRT DLL dir (Windows only) [probed]
--with-dxsdk Deprecated. Option is kept for backwards compatibility and is ignored
--with-dxsdk-lib Deprecated. Option is kept for backwards compatibility and is ignored
--with-dxsdk-include Deprecated. Option is kept for backwards compatibility and is ignored
--with-num-cores number of cores in the build system, e.g. --with-num-cores=8 [probed]
--with-memory-size memory (in MB) available in the build system, e.g. --with-memory-size=1024 [probed]
--with-jobs number of parallel jobs to let make run [calculated based on cores and memory]
--with-sjavac-server-java
use this java binary for running the sjavac background server [Boot JDK java]
--with-ccache-dir where to store ccache files [~/.ccache]
Some influential environment variables:
BASENAME Override default value for BASENAME
BASH Override default value for BASH
CAT Override default value for CAT
CHMOD Override default value for CHMOD
CMP Override default value for CMP
COMM Override default value for COMM
CP Override default value for CP
CUT Override default value for CUT
DATE Override default value for DATE
DIFF Override default value for DIFF
DIRNAME Override default value for DIRNAME
ECHO Override default value for ECHO
EXPR Override default value for EXPR
FILE Override default value for FILE
FIND Override default value for FIND
HEAD Override default value for HEAD
LN Override default value for LN
LS Override default value for LS
MKDIR Override default value for MKDIR
MKTEMP Override default value for MKTEMP
MV Override default value for MV
NAWK Override default value for NAWK
PRINTF Override default value for PRINTF
RM Override default value for RM
SH Override default value for SH
SORT Override default value for SORT
TAIL Override default value for TAIL
TAR Override default value for TAR
TEE Override default value for TEE
TOUCH Override default value for TOUCH
TR Override default value for TR
UNAME Override default value for UNAME
UNIQ Override default value for UNIQ
WC Override default value for WC
WHICH Override default value for WHICH
XARGS Override default value for XARGS
AWK Override default value for AWK
GREP Override default value for GREP
EGREP Override default value for EGREP
FGREP Override default value for FGREP
SED Override default value for SED
CYGPATH Override default value for CYGPATH
READLINK Override default value for READLINK
DF Override default value for DF
SETFILE Override default value for SETFILE
CPIO Override default value for CPIO
UNZIP Override default value for UNZIP
ZIP Override default value for ZIP
LDD Override default value for LDD
READELF Override default value for READELF
HG Override default value for HG
STAT Override default value for STAT
TIME Override default value for TIME
DSYMUTIL Override default value for DSYMUTIL
XATTR Override default value for XATTR
CODESIGN Override default value for CODESIGN
PKG_CONFIG path to pkg-config utility
CC C compiler command
CFLAGS C compiler flags
LDFLAGS linker flags, e.g. -L<lib dir> if you have libraries in a
nonstandard directory <lib dir>
LIBS libraries to pass to the linker, e.g. -l<library>
CPPFLAGS (Objective) C/C++ preprocessor flags, e.g. -I<include dir> if
you have headers in a nonstandard directory <include dir>
CXX C++ compiler command
CXXFLAGS C++ compiler flags
CPP C preprocessor
CXXCPP C++ preprocessor
AS Override default value for AS
AR Override default value for AR
OBJC Objective C compiler command
OBJCFLAGS Objective C compiler flags
LIPO Override default value for LIPO
STRIP Override default value for STRIP
NM Override default value for NM
GNM Override default value for GNM
MCS Override default value for MCS
OBJCOPY Override default value for OBJCOPY
OBJDUMP Override default value for OBJDUMP
BUILD_CC Override default value for BUILD_CC
BUILD_CXX Override default value for BUILD_CXX
BUILD_LD Override default value for BUILD_LD
JTREGEXE Override default value for JTREGEXE
XMKMF Path to xmkmf, Makefile generator for X Window System
FREETYPE_CFLAGS
C compiler flags for FREETYPE, overriding pkg-config
FREETYPE_LIBS
linker flags for FREETYPE, overriding pkg-config
ALSA_CFLAGS C compiler flags for ALSA, overriding pkg-config
ALSA_LIBS linker flags for ALSA, overriding pkg-config
LIBFFI_CFLAGS
C compiler flags for LIBFFI, overriding pkg-config
LIBFFI_LIBS linker flags for LIBFFI, overriding pkg-config
CCACHE Override default value for CCACHE
Use these variables to override the choices made by `configure' or to help
it to find libraries and programs with nonstandard names/locations.
Report bugs to <build-dev@openjdk.java.net>.
OpenJDK home page: <http://openjdk.java.net>.
Additional (non-autoconf) OpenJDK Options:
--openjdk-target=TARGET cross-compile with TARGET as target platform (i.e. the one you will run the resulting binary on).
Equivalent to --host=TARGET --target=TARGET --build=<current platform>
--debug-configure Run the configure script with additional debug logging enabled.
The following toolchains are available as arguments to --with-toolchain-type.
Which are valid to use depends on the build platform.
gcc GNU Compiler Collection
clang clang/LLVM
solstudio Oracle Solaris Studio
xlc IBM XL C/C++
microsoft Microsoft Visual Studio
Please be aware that, when cross-compiling, the OpenJDK configure script will
generally use 'target' where autoconf traditionally uses 'host'.
Also note that variables must be passed on the command line. Variables in the
environment will generally be ignored, unlike traditional autoconf scripts.
编译
make images JOBS=8 # 编译成功打印信息 ----- Build times ------- Start 2019-06-27 01:22:28 End 2019-06-27 01:31:44 00:00:20 corba 00:00:09 demos 00:01:53 docs 00:03:01 hotspot 00:00:17 images 00:00:18 jaxp 00:00:23 jaxws 00:02:06 jdk 00:00:34 langtools 00:00:15 nashorn 00:09:16 TOTAL ------------------------- Finished building OpenJDK for target 'all' # 测试 ./build/linux-x86_64-normal-server-release/jdk/bin/java -version # openjdk version "1.8.0-internal" # OpenJDK Runtime Environment (build 1.8.0-internal-root_2019_06_27_00_56-b00) # OpenJDK 64-Bit Server VM (build 25.71-b00, mixed mode) # 查看 libjvm.debuginfo ls ./build/linux-x86_64-normal-server-release/jdk/lib/amd64/server/ # 若编译时没有设置生成，可进入该目录（libjvm.so 所在目录）手动解压 unzip libjvm.diz
make 帮助文档
OpenJDK Makefile help ===================== Common make targets . make [default] # Compile all product in langtools, hotspot, jaxp, jaxws, corba and jdk . make all # Compile everything, all repos and images . make images # Create complete j2sdk and j2re images . make docs # Create javadocs . make overlay-images # Create limited images for sparc 64 bit platforms . make profiles # Create complete j2re compact profile images . make bootcycle-images # Build images twice, second time with newly build JDK . make install # Install the generated images locally . make clean # Remove all files generated by make, but not those generated by configure . make dist-clean # Remove all files, including configuration . make help # Give some help on using make . make test # Run tests, default is all tests (see TEST below) Targets for specific components (Component is any of langtools, corba, jaxp, jaxws, hotspot, jdk, nashorn, images, overlay-images, docs or test) . make <component> # Build <component> and everything it depends on. . make <component>-only # Build <component> only, without dependencies. This is faster but can result in incorrect build results! . make clean-<component> # Remove files generated by make for <component> Useful make variables . make CONF= # Build all configurations (note, assignment is empty) . make CONF=<substring> # Build the configuration(s) with a name matching <substring> . make LOG=<loglevel> # Change the log level from warn to <loglevel> Available log levels are: 'warn' (default), 'info', 'debug' and 'trace' To see executed command lines, use LOG=debug . make JOBS=<n> # Run <n> parallel make jobs Note that -jN does not work as expected! . make test TEST=<test> # Only run the given test or tests, e.g. make test TEST="jdk_lang jdk_net"
三、Windows 远程调试
CentOS7 端
yum remove -y cmake gdb yum install -y gcc gcc-c++ make wget # 安装 cmake，yum 源安装的版本较低 cd /opt/ wget https://cmake.org/files/v3.14/cmake-3.14.5.tar.gz tar -zxf cmake-3.14.5.tar.gz cd cmake-3.14.5 # 默认安装在 /usr/local/share/，可执行文件在 /usr/local/bin/ ./bootstrap && make && make install ln -s /usr/local/bin/cmake /usr/bin/cmake cmake -version # 安装 gdb # 这里可以找到 gdb 镜像站点 https://www.gnu.org/software/gdb/download/ # 这里下载 texinfo 新版本 http://ftp.gnu.org/gnu/texinfo/ yum install -y texinfo cd /opt/ wget https://mirrors.ustc.edu.cn/gnu/gdb/gdb-8.2.1.tar.gz tar -zxf gdb-8.2.1.tar.gz cd gdb-8.2.1 # 之前若出现过编译错误需要删掉（有缓存），重新解压编译 # 默认安装在 /usr/local/share/，可执行文件在 /usr/local/bin/ ./configure && make && make install ln -s /usr/local/bin/gdb /usr/bin/gdb gdb -ver
Windows 端
首先用 Clion 新建一个空项目
远程调试
同步代码（windows 上的代码需要和 CentOS 上的代码一样）
连接信息
对应目录，本地目录为新建的 Hello World 项目路径
同步时要排除的本地目录
下载远程代码
关闭项目，用载入的方式重新打开项目
设置远程调试，地址为 CentOS 地址，端口随意
在 CentOS 上启动 GDB，端口与上面对应
yum install gdb-gdbserver -y gdbserver :1234 /opt/jdk8u/build/linux-x86_64-normal-server-release/jdk/bin/java -version
打上断点，启动的 DeBug（比较慢，载入 libjvm.debuginfo 的时候）
四、CentOS 桌面本地调试
只调试 JVM 可以直接导入 hotspot 项目，速度快点
配置调试
忽略调试时的 SIGSEGV 信号，在用户目录新建 .gdbinit 文件
handle SIGSEGV pass noprint nostop
https://blog.csdn.net/tjiyu/article/details/53725247
https://my.oschina.net/u/3982963/blog/3045233
https://www.jianshu.com/p/ee7e9176632c
https://yddmax.github.io/2017/06/11/openjdk7%E4%B9%8B%E7%BC%96%E8%AF%91%E5%92%8Cdebug/