0x00 前言
《深入理解JVM》这本书都看了大半了，但是里面的实验还没真正动手操作过，于是趁这段时间一一操作一遍。
首当其冲的当然是编译JVM了，似乎所有的坑都被我都趟了一遍，就写篇文来记录一下，顺便告诫大家，不要试图在新版本的macOS中编译OpenJDK7！
0x01 编译环境
macOS Catalina 10.15.2
Xcode 11.6
Command Line Tools MacOSX10.15.sdk
0x02 准备工作
1. 下载源码
在macOS中，先用brew安装mercurial代码版本管理工具
brew install mercurial
获取源码：
hg clone http://hg.openjdk.java.net/jdk7u/jdk7u-dev
cd jdk7u-dev
chmod 755 get_source.sh
./get_source.sh
而国内的网络到了./get_source.sh这一步，下载过程中总是会网络异常中断，所以我是在国外的vps上面下载好之后，再压缩拉回来的。
2. 安装XCode和Command Line Tools for XCode
由于我之前已经安装了，所以这一步跳过，具体的版本可以看0x01编译环境中的描述
3. 准备一个Bootstrap SDK
书中说到，“如果编译OpenJDK 7，Bootstrap JDK必须使用JDK6 Update 14或之后的版本”，而我用的是JDK1.7.80版本。
4. 安装Apache Ant
Apache Ant 对版本有要求，1.7.1以上即可。
同时，Apache Ant 官网上有一句话必须要看一下：
“The 1.9.x releases require Java5 at runtime and 1.10.x requires Java8 at runtime. ”
大意就是1.9.x版本的ant 要求Java5以上版本的jre，而1.10.x版本的ant则要求Java8以上版本的jre。
0x03 编译
书中作者给出的编译脚本如下：
#语言选项，这个必须设置，否则编译好后会出现一个HashTable的NPE错
export LANG=C
#Bootstrap JDK的安装路径。必须设置
export ALT_BOOTDIR=/Library/Java/JavaVirtualMachines/jdk1.7.0_04.jdk/Contents/Home
#允许自动下载依赖
export ALLOW_DOWNLOADS=true
#并行编译的线程数，设置为和CPU内核数量一致即可
export HOTSPOT_BUILD_JOBS=6
export ALT_PARALLEL_COMPILE_JOBS=6
#比较本次build出来的映像与先前版本的差异。这对我们来说没有意义，
#必须设置为false，否则sanity检查会报缺少先前版本JDK的映像的错误提示。
#如果已经设置dev或者DEV_ONLY=true，这个不显式设置也行
export SKIP_COMPARE_IMAGES=true
#使用预编译头文件，不加这个编译会更慢一些
export USE_PRECOMPILED_HEADER=true
#要编译的内容
export BUILD_LANGTOOLS=true
#export BUILD_JAXP=false
#export BUILD_JAXWS=false
#export BUILD_CORBA=false
export BUILD_HOTSPOT=true
export BUILD_JDK=true
#要编译的版本
#export SKIP_DEBUG_BUILD=false
#export SKIP_FASTDEBUG_BUILD=true
#export DEBUG_NAME=debug
#把它设置为false可以避开javaws和浏览器Java插件之类的部分的build
BUILD_DEPLOY=false
#把它设置为false就不会build出安装包。因为安装包里有些奇怪的依赖，
#但即便不build出它也已经能得到完整的JDK映像，所以还是别build它好了
BUILD_INSTALL=false
#编译结果所存放的路径
export ALT_OUTPUTDIR=/Users/IcyFenix/Develop/JVM/jdkBuild/openjdk_7u4/build
#这两个环境变量必须去掉，不然会有很诡异的事情发生（我没有具体查过这些"诡异的
#事情"，Makefile脚本检查到有这2个变量就会提示警告）
unset JAVA_HOME
unset CLASSPATH
make 2>&1|tee $ALT_OUTPUTDIR/build.log
0x04 坑
1.llvm-gcc 缺失导致的freetype_versioncheck的编译错误
首先最底下出现的是：
ERROR: The Compiler version is undefined.
ERROR: FreeType version 2.3.0 or higher is required.
/bin/mkdir -p /Users/jackietsoi/Documents/develop/jdk7u-dev/JVM/jdkBuild/openjdk_7u4/build/btbins
rm -f /Users/jackietsoi/Documents/develop/jdk7u-dev/JVM/jdkBuild/openjdk_7u4/build/btbins/freetype_versioncheck
Failed to build freetypecheck.
Exiting because of the above error(s).
上网搜了一下，还以为是缺失FreeType，于是根据网友说的安装XQuartz(http://xquartz.macosforge.org/landing/)，因为XQuartz里面自带了freetype2，但是安装之后并没有解决问题，于是继续往上看输出:
make[2]: /Applications/Xcode.app/Contents/Developer/usr/bin/llvm-gcc: No such file or directory
make[2]: *** [/Users/jackietsoi/Documents/develop/jdk7u-dev/JVM/jdkBuild/openjdk_7u4/build/btbins/freetype_versioncheck] Error 1
解决方法：
sudo ln -s /usr/bin/llvm-g++ /Library/Developer/CommandLineTools/usr/bin/llvm-g++
sudo ln -s /usr/bin/llvm-gcc /Library/Developer/CommandLineTools/usr/bin/llvm-gcc
2.cups 头文件缺失问题
ERROR: You do not have access to valid Cups header files.
Please check your access to
/usr/include/cups/cups.h
and/or check your value of ALT_CUPS_HEADERS_PATH,
CUPS is frequently pre-installed on many systems,
or may be downloaded from http://www.cups.org
解决方法：
到 http://www.cups.org 去下载cups2.3.3 然后解压整个文件夹，放到编译项目根目录
然后在编译脚本文件中加入一句：export ALT_CUPS_HEADERS_PATH=/Users/jackietsoi/Documents/develop/jdk7u-dev/cups-2.3.3
3.freetype 版本问题
ERROR: FreeType version 2.3.0 or higher is required.
/Users/jackietsoi/Documents/develop/jdk7u-dev/JVM/jdkBuild/openjdk_7u4/build/btbins/freetype_versioncheck
Required version of freetype: 2.3.0
Detected freetype headers: 2.10.4
Failed: headers are too old.
Detected freetype library: 2.10.4
Failed: too old library.
Exiting because of the above error(s).
make: *** [post-sanity] Error 1
去官网(https://www.freetype.org/download.html)下载 freetype-2.3.0 版本压缩包
解压，进入根目录执行以下命令进行编译，并安装：
./configure
make
make install
在编译脚本文件中加入两句：
export ALT_FREETYPE_HEADERS_PATH=/usr/local/include
export ALT_FREETYPE_LIB_PATH=/usr/local/lib
4.ant 1.10.x 要求最低jdk8问题
Exception in thread "main" java.lang.UnsupportedClassVersionError: org/apache/tools/ant/launch/Launcher : Unsupported major.minor version 52.0
at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClass(ClassLoader.java:791)
at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142)
at java.net.URLClassLoader.defineClass(URLClassLoader.java:449)
at java.net.URLClassLoader.access$100(URLClassLoader.java:71)
at java.net.URLClassLoader$1.run(URLClassLoader.java:361)
at java.net.URLClassLoader$1.run(URLClassLoader.java:355)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:354)
at java.lang.ClassLoader.loadClass(ClassLoader.java:423)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:308)
at java.lang.ClassLoader.loadClass(ClassLoader.java:356)
at sun.launcher.LauncherHelper.checkAndLoadMain(LauncherHelper.java:480)
Exception in thread "main" java.lang.UnsupportedClassVersionError: org/apache/tools/ant/launch/Launcher : Unsupported major.minor version 52.0
at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClass(ClassLoader.java:791)
at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142)
at java.net.URLClassLoader.defineClass(URLClassLoader.java:449)
at java.net.URLClassLoader.access$100(URLClassLoader.java:71)
at java.net.URLClassLoader$1.run(URLClassLoader.java:361)
at java.net.URLClassLoader$1.run(URLClassLoader.java:355)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:354)
at java.lang.ClassLoader.loadClass(ClassLoader.java:423)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:308)
at java.lang.ClassLoader.loadClass(ClassLoader.java:356)
at sun.launcher.LauncherHelper.checkAndLoadMain(LauncherHelper.java:480)
make[2]: *** [/Users/jackietsoi/Documents/develop/jdk7u-dev/JVM/jdkBuild/openjdk_7u4/build/langtools/build/ant-diagnostics.log] Error 1
make[1]: *** [langtools-build] Error 2
make: *** [build_product_image] Error 2
解决方法：
到Apache Ant官网(http://ant.apache.org/bindownload.cgi)下载 1.9.x版本的ant，将压缩包解压到一个目录下，如/usr/local
配置环境变量：
编辑 ~/.zshrc，在末尾加入两行：
export ANT_HOME=/usr/local/apache-ant-1.9.15
export PATH=$ANT_HOME/bin:$PATH
然后 source ~/.zshrc 使其生效
5.jdk版本问题
[javac] Compiling 298 source files to /Users/jackietsoi/Documents/develop/jdk7u-dev/JVM/jdkBuild/openjdk_7u4/build/langtools/build/bootstrap/classes
[javac] /Users/jackietsoi/Documents/develop/jdk7u-dev/langtools/src/share/classes/com/sun/tools/javac/comp/Resolve.java:2182: ??: [overrides] ?Resolve.InapplicableSymbolsError.Candidate??? equals, ???????????? hashCode ??
[javac] private class Candidate {
[javac] ^
[javac] ??: ????, ???? -Werror
[javac] 1 ???
[javac] 1 ???
BUILD FAILED
/Users/jackietsoi/Documents/develop/jdk7u-dev/langtools/make/build.xml:452: The following error occurred while executing this line:
/Users/jackietsoi/Documents/develop/jdk7u-dev/langtools/make/build.xml:795: Compile failed; see the compiler error output for details.
Total time: 4 seconds
make[2]: *** [build] Error 1
make[1]: *** [langtools-build] Error 2
make: *** [build_product_image] Error 2
解决方法：
将Bootstrap JDK 从1.8换到1.7即可，下载jdk7(https://www.oracle.com/java/technologies/javase/javase7-archive-downloads.html)
这里我下载的是jdk7u80，然后在编译脚本更改Bootstrap JDK的路径：
export ALT_BOOTDIR=/Library/Java/JavaVirtualMachines/jdk1.7.0_80.jdk/Contents/Home
6. warning 转义错误
/Users/jackietsoi/Documents/develop/jdk7u-dev/hotspot/src/share/vm/adlc/filebuff.cpp:109:8: error: 'this' pointer cannot be null in well-defined C++ code; pointer may be assumed to always convert to true [-Werror,-Wundefined-bool-conversion]
if( !this ) return NULL; // The empty buffer region
~^~~~
/Users/jackietsoi/Documents/develop/jdk7u-dev/hotspot/src/share/vm/adlc/filebuff.cpp:122:8: error: 'this' pointer cannot be null in well-defined C++ code; pointer may be assumed to always convert to true [-Werror,-Wundefined-bool-conversion]
if( !this ) return br; // Merging into nothing
~^~~~
/Users/jackietsoi/Documents/develop/jdk7u-dev/hotspot/src/share/vm/adlc/filebuff.cpp:228:8: error: reference cannot be bound to dereferenced null pointer in well-defined C++ code; comparison may be assumed to always evaluate to false [-Werror,-Wtautological-undefined-compare]
if( &br == NULL ) return os; // The empty buffer region
^~ ~~~~
/Users/jackietsoi/Documents/develop/jdk7u-dev/hotspot/src/share/vm/adlc/filebuff.cpp:244:8: error: 'this' pointer cannot be null in well-defined C++ code; pointer may be assumed to always convert to true [-Werror,-Wundefined-bool-conversion]
if( !this ) return; // Nothing to print
~^~~~
/Users/jackietsoi/Documents/develop/jdk7u-dev/hotspot/src/share/vm/adlc/archDesc.cpp:335:35: error: '&&' within '||' [-Werror,-Wlogical-op-parentheses]
if ( instr->is_ideal_branch() && instr->label_position() == -1 ||
~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ~~
/Users/jackietsoi/Documents/develop/jdk7u-dev/hotspot/src/share/vm/adlc/archDesc.cpp:335:35: note: place parentheses around the '&&' expression to silence this warning
if ( instr->is_ideal_branch() && instr->label_position() == -1 ||
^
( )
/Users/jackietsoi/Documents/develop/jdk7u-dev/hotspot/src/share/vm/adlc/archDesc.cpp:336:35: error: '&&' within '||' [-Werror,-Wlogical-op-parentheses]
!instr->is_ideal_branch() && instr->label_position() != -1) {
~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/Users/jackietsoi/Documents/develop/jdk7u-dev/hotspot/src/share/vm/adlc/archDesc.cpp:336:35: note: place parentheses around the '&&' expression to silence this warning
!instr->is_ideal_branch() && instr->label_position() != -1) {
^
( )
4 errors generated.
2 errors generated.
make[8]: *** [../generated/adfiles/filebuff.o] Error 1
make[8]: *** Waiting for unfinished jobs....
make[8]: *** [../generated/adfiles/archDesc.o] Error 1
Compiling /Users/jackietsoi/Documents/develop/jdk7u-dev/hotspot/src/share/vm/adlc/forms.cpp
rm -f ../generated/adfiles/forms.o
llvm-g++ -D_ALLBSD_SOURCE -D_GNU_SOURCE -DAMD64 -I/Users/jackietsoi/Documents/develop/jdk7u-dev/hotspot/src/share/vm/prims -I/Users/jackietsoi/Documents/develop/jdk7u-dev/hotspot/src/share/vm -I/Users/jackietsoi/Documents/develop/jdk7u-dev/hotspot/src/share/vm/precompiled -I/Users/jackietsoi/Documents/develop/jdk7u-dev/hotspot/src/cpu/x86/vm -I/Users/jackietsoi/Documents/develop/jdk7u-dev/hotspot/src/os_cpu/bsd_x86/vm -I/Users/jackietsoi/Documents/develop/jdk7u-dev/hotspot/src/os/bsd/vm -I/Users/jackietsoi/Documents/develop/jdk7u-dev/hotspot/src/os/posix/vm -I/Users/jackietsoi/Documents/develop/jdk7u-dev/hotspot/src/share/vm/adlc -I../generated -DASSERT -DTARGET_OS_FAMILY_bsd -DTARGET_ARCH_x86 -DTARGET_ARCH_MODEL_x86_64 -DTARGET_OS_ARCH_bsd_x86 -DTARGET_OS_ARCH_MODEL_bsd_x86_64 -DTARGET_COMPILER_gcc -DCOMPILER2 -DCOMPILER1 -fno-rtti -fno-exceptions -pthread -fcheck-new -fvisibility=hidden -m64 -pipe -Werror -g -c -o ../generated/adfiles/forms.o /Users/jackietsoi/Documents/develop/jdk7u-dev/hotspot/src/share/vm/adlc/forms.cpp
/Users/jackietsoi/Documents/develop/jdk7u-dev/hotspot/src/share/vm/adlc/adlparse.cpp:3217:71: error: equality comparison with extraneous parentheses [-Werror,-Wparentheses-equality]
if ( ((primary = get_ident_or_literal_constant("primary opcode")) == NULL) ) {
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~
/Users/jackietsoi/Documents/develop/jdk7u-dev/hotspot/src/share/vm/adlc/adlparse.cpp:3217:71: note: remove extraneous parentheses around the comparison to silence this warning
if ( ((primary = get_ident_or_literal_constant("primary opcode")) == NULL) ) {
~ ^ ~
/Users/jackietsoi/Documents/develop/jdk7u-dev/hotspot/src/share/vm/adlc/adlparse.cpp:3217:71: note: use '=' to turn this equality comparison into an assignment
if ( ((primary = get_ident_or_literal_constant("primary opcode")) == NULL) ) {
^~
=
/Users/jackietsoi/Documents/develop/jdk7u-dev/hotspot/src/share/vm/adlc/adlparse.cpp:3226:77: error: equality comparison with extraneous parentheses [-Werror,-Wparentheses-equality]
if ( ((secondary = get_ident_or_literal_constant("secondary opcode")) == NULL) ) {
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~
/Users/jackietsoi/Documents/develop/jdk7u-dev/hotspot/src/share/vm/adlc/adlparse.cpp:3226:77: note: remove extraneous parentheses around the comparison to silence this warning
if ( ((secondary = get_ident_or_literal_constant("secondary opcode")) == NULL) ) {
~ ^ ~
/Users/jackietsoi/Documents/develop/jdk7u-dev/hotspot/src/share/vm/adlc/adlparse.cpp:3226:77: note: use '=' to turn this equality comparison into an assignment
if ( ((secondary = get_ident_or_literal_constant("secondary opcode")) == NULL) ) {
^~
=
/Users/jackietsoi/Documents/develop/jdk7u-dev/hotspot/src/share/vm/adlc/adlparse.cpp:3235:77: error: equality comparison with extraneous parentheses [-Werror,-Wparentheses-equality]
if ( ((tertiary = get_ident_or_literal_constant("tertiary opcode")) == NULL) ) {
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~
/Users/jackietsoi/Documents/develop/jdk7u-dev/hotspot/src/share/vm/adlc/adlparse.cpp:3235:77: note: remove extraneous parentheses around the comparison to silence this warning
if ( ((tertiary = get_ident_or_literal_constant("tertiary opcode")) == NULL) ) {
~ ^ ~
/Users/jackietsoi/Documents/develop/jdk7u-dev/hotspot/src/share/vm/adlc/adlparse.cpp:3235:77: note: use '=' to turn this equality comparison into an assignment
if ( ((tertiary = get_ident_or_literal_constant("tertiary opcode")) == NULL) ) {
^~
=
/Users/jackietsoi/Documents/develop/jdk7u-dev/hotspot/src/share/vm/adlc/adlparse.cpp:4476:21: error: '&&' within '||' [-Werror,-Wlogical-op-parentheses]
while ((c >= '0') && (c <= '9')
~~~~~~~~~~~^~~~~~~~~~~~~
/Users/jackietsoi/Documents/develop/jdk7u-dev/hotspot/src/share/vm/adlc/adlparse.cpp:4476:21: note: place parentheses around the '&&' expression to silence this warning
while ((c >= '0') && (c <= '9')
^
( )
/Users/jackietsoi/Documents/develop/jdk7u-dev/hotspot/src/share/vm/adlc/adlparse.cpp:4515:17: error: equality comparison with extraneous parentheses [-Werror,-Wparentheses-equality]
if( (second == '=') ) {
~~~~~~~^~~~~~
/Users/jackietsoi/Documents/develop/jdk7u-dev/hotspot/src/share/vm/adlc/adlparse.cpp:4515:17: note: remove extraneous parentheses around the comparison to silence this warning
if( (second == '=') ) {
~ ^ ~
/Users/jackietsoi/Documents/develop/jdk7u-dev/hotspot/src/share/vm/adlc/adlparse.cpp:4515:17: note: use '=' to turn this equality comparison into an assignment
if( (second == '=') ) {
^~
=
5 errors generated.
make[8]: *** [../generated/adfiles/adlparse.o] Error 1
make[7]: *** [ad_stuff] Error 2
make[6]: *** [product] Error 2
make[5]: *** [generic_build2] Error 2
make[4]: *** [product] Error 2
make[3]: *** [all_product_universal] Error 2
make[2]: *** [universal_product] Error 2
make[1]: *** [hotspot-build] Error 2
make: *** [build_product_image] Error 2
解决方法：
关掉warning警告，打开编译脚本加入一行export COMPILER_WARNINGS_FATAL=false，继续执行即可
7. clang: error: unknown argument: ‘-fpch-deps’错误
clang: error: unknown argument: '-fpch-deps'
make[8]: *** [precompiled.hpp.gch] Error 1
make[7]: *** [the_vm] Error 2
make[6]: *** [product] Error 2
make[5]: *** [generic_build2] Error 2
make[4]: *** [product] Error 2
make[3]: *** [all_product_universal] Error 2
make[2]: *** [universal_product] Error 2
make[1]: *** [hotspot-build] Error 2
make: *** [build_product_image] Error 2
解决方法：
vi ./hotspot/make/bsd/makefiles/gcc.make将以下两段代码注释掉
#ifneq ($(COMPILER_WARNINGS_FATAL),false)
# WARNINGS_ARE_ERRORS = -Werror
#endif
#ifneq ("${CC_VER_MAJOR}", "2")
#DEPFLAGS = -fpch-deps -MMD -MP -MF $(DEP_DIR)/$(@:%=%.d)
#endif
8.error: friend declaration specifying a default argument must be a definition 错误
/Users/jackietsoi/Documents/develop/jdk7u-dev/hotspot/src/share/vm/code/relocInfo.hpp:374:27: error: friend declaration specifying a default argument must be a definition
inline friend relocInfo prefix_relocInfo(int datalen = 0);
^
/Users/jackietsoi/Documents/develop/jdk7u-dev/hotspot/src/share/vm/code/relocInfo.hpp:469:18: error: friend declaration specifying a default argument must be the only declaration
inline relocInfo prefix_relocInfo(int datalen) {
解决方法：
vi hotspot/src/share/vm/code/relocInfo.hpp
将inline friend relocInfo prefix_relocInfo(int datalen = 0);改成
inline friend relocInfo prefix_relocInfo(int datalen);
将inline relocInfo prefix_relocInfo(int datalen) {改成inline relocInfo prefix_relocInfo(int datalen = 0) {
9.指针与0比较问题
/Users/jackietsoi/Documents/develop/jdk7u-dev/hotspot/src/share/vm/runtime/virtualspace.cpp:527:14: error: ordered comparison between pointer and zero ('char *' and 'int')
if (base() > 0) {
~~~~~~ ^ ~
/Users/jackietsoi/Documents/develop/jdk7u-dev/hotspot/src/share/vm/runtime/virtualspace.cpp:546:14: error: ordered comparison between pointer and zero ('char *' and 'int')
if (base() > 0) {
~~~~~~ ^ ~
解决方法：
vi ./hotspot/src/share/vm/runtime/virtualspace.cpp
用/if (base() > 0)查找所有该语句，并将其改成if (base() != NULL)
10.找不到JavaNativeFoundation.h头文件问题
/Users/jackietsoi/Documents/develop/jdk7u-dev/hotspot/agent/src/os/bsd/MacosxDebuggerLocal.m:27:9: fatal error: 'JavaNativeFoundation/JavaNativeFoundation.h' file not found
#import <JavaNativeFoundation/JavaNativeFoundation.h>
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/Users/jackietsoi/Documents/develop/jdk7u-dev/hotspot/agent/src/os/bsd/MacosxDebuggerLocal.m:27:9: note: did not find header 'JavaNativeFoundation.h' in framework 'JavaNativeFoundation' (loaded from '/System/Library/Frameworks/JavaVM.framework/Frameworks')
1 error generated.
解决方法：
终端执行find / -name "*JavaNativeFoundation.h*"命令，出现结果：
/Library/Developer/CommandLineTools/SDKs/MacOSX10.14.sdk/System/Library/Frameworks/JavaVM.framework/Versions/A/Frameworks/JavaNativeFoundation.framework/Versions/A/Headers/JavaNativeFoundation.h
/Library/Developer/CommandLineTools/SDKs/MacOSX10.15.sdk/System/Library/Frameworks/JavaVM.framework/Versions/A/Frameworks/JavaNativeFoundation.framework/Versions/A/Headers/JavaNativeFoundation.h
编辑hotspot/make/bsd/makefiles/saproc.make进行如下修改：
原：
SALIBS = -g -framework Foundation -F/System/Library/Frameworks/JavaVM.framework/Frameworks -framework JavaNativeFoundation -framework Security -framework CoreFoundation
修改后：
SALIBS = -g -framework Foundation -F/Library/Developer/CommandLineTools/SDKs/MacOSX10.15.sdk/System/Library/Frameworks -framework JavaNativeFoundation -framework Security -framework CoreFoundation
原：
-I/System/Library/Frameworks/JavaVM.framework/Headers
修改后：
-I/Library/Developer/CommandLineTools/SDKs/MacOSX10.15.sdk/System/Library/Frameworks/JavaVM.framework/Versions/A/Frameworks/JavaNativeFoundation.framework/Versions/A/Headers
11.Undefined symbols for architecture x86_64
llvm-gcc -m64 -m64 -L`pwd` -framework CoreFoundation -o gamma launcher/java_md.o launcher/java.o launcher/jli_util.o launcher/wildcard.o -ljvm -lm -pthread
Undefined symbols for architecture x86_64:
"_JNI_CreateJavaVM", referenced from:
_LoadJavaVM in java_md.o
"_JNI_GetDefaultJavaVMInitArgs", referenced from:
_LoadJavaVM in java_md.o
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)
make[8]: *** [gamma] Error 1
make[7]: *** [the_vm] Error 2
make[6]: *** [product] Error 2
make[5]: *** [generic_build2] Error 2
make[4]: *** [product] Error 2
make[3]: *** [all_product_universal] Error 2
make[2]: *** [universal_product] Error 2
make[1]: *** [hotspot-build] Error 2
make: *** [build_product_image] Error 2
解决方法：
这个错误困扰了我很久，一开始看上面的
Linking vm...
ld: warning: cannot export hidden symbol _AsyncGetCallTrace from forte.o
还以为是export symbol过程中出现问题，修改过jdk/src/macosx/native/sun/osxapp/ThreadUtilities.中的attachCurrentThread函数，改为static，还是无法解决问题
后面上stackflow上面搜了以下，发现应该是llvm-gcc编译的时候，找不到库文件导致的，仔细看了以下编译命令
llvm-gcc -m64 -m64 -L`pwd`...
其中-L是指定库文件目录，它指向了当前pwd即目录，然后我find ./ -name "java_md.o",发现它在.//JVM/jdkBuild/openjdk_7u4/build/hotspot/outputdir/bsd_amd64_compiler2/product/launcher/java_md.o，那么此时pwd就应该在.//JVM/jdkBuild/openjdk_7u4/build/hotspot/outputdir/bsd_amd64_compiler2/product，而当前编译所需要的库文件是/Library/Java/JavaVirtualMachines/jdk1.7.0_80.jdk/Contents/Home/jre/lib/server/libjvm.dylib
使用cp命令将其复制到pwd就好了：
sudo cp /Library/Java/JavaVirtualMachines/jdk1.7.0_80.jdk/Contents/Home/jre/lib/server/libjvm.dylib ./JVM/jdkBuild/openjdk_7u4/build/hotspot/outputdir/bsd_amd64_compiler2/product
12.找不到CGBase.h头文件问题
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/System/Library/Frameworks/Foundation.framework/Headers/NSGeometry.h:9:9: fatal error:
'CoreGraphics/CGBase.h' file not found
#import <CoreGraphics/CGBase.h>
^~~~~~~~~~~~~~~~~~~~~~~
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/System/Library/Frameworks/Foundation.framework/Headers/NSGeometry.h:9:9: note:
did not find header 'CGBase.h' in framework 'CoreGraphics' (loaded from
'/System/Library/Frameworks/ApplicationServices.framework/Frameworks')
1 error generated.
make[5]: *** [/Users/jackietsoi/Documents/develop/jdk7u-dev/JVM/jdkBuild/openjdk_7u4/build/tmp/java/java.lang/java/obj64/java_props_macosx.o] Error 1
make[4]: *** [library_parallel_compile] Error 2
make[3]: *** [all] Error 1
make[2]: *** [all] Error 1
make[1]: *** [jdk-build] Error 2
make: *** [build_product_image] Error 2
解决方法：
vi ./jdk/make/common/Defs-macosx.gmk进行如下更改：
#OTHER_CFLAGS = \
# -F/System/Library/Frameworks/JavaVM.framework/Frameworks \
# -F/System/Library/Frameworks/CoreGraphics.framework \
# -F/System/Library/Frameworks/ApplicationServices.framework/Frameworks
OTHER_CFLAGS = \
-F/Library/Developer/CommandLineTools/SDKs/MacOSX10.14.sdk/System/Library/Frameworks/JavaVM.framework/Frameworks \
-F/Library/Developer/CommandLineTools/SDKs/MacOSX10.14.sdk/System/Library/Frameworks/CoreGraphics.framework/Frameworks \
-F/Library/Developer/CommandLineTools/SDKs/MacOSX10.14.sdk/System/Library/Frameworks/ApplicationServices.framework/Frameworks
同样使用find ./ -name "CGBase.h"找到路径，将/System/Library/Frameworks/JavaVM.framework/Frameworks等路径替换掉即可。
15 从macOS14 sdk开始不再支持32位程序编译
awt库的编译需要有i386架构的库的支持，但是Apple从macOS14 sdk开始就不再包含32位程序编译支持了，最后一个支持32位程序编译的版本是macOS13 sdk。
ld: warning: The i386 architecture is deprecated for macOS (remove from the Xcode build setting: ARCHS)
ld: warning: ignoring file /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/lib/libSystem.tbd, missing required architecture i386 in file /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/lib/libSystem.tbd
Undefined symbols for architecture i386:
"___stack_chk_fail", referenced from:
_main in sizer-32b644.o
"___stack_chk_guard", referenced from:
_main in sizer-32b644.o
"_printf", referenced from:
_main in sizer-32b644.o
ld: symbol(s) not found for architecture i386
clang: error: linker command failed with exit code 1 (use -v to see invocation)
make[4]: *** [/Users/jackietsoi/Documents/develop/jdk7u-dev/JVM/jdkBuild/openjdk_7u4/build/gensrc/sun/awt/X11/generator/sizer.32] Error 1
make[3]: *** [all] Error 1
make[2]: *** [all] Error 1
make[1]: *** [jdk-build] Error 2
make: *** [build_product_image] Error 2
解决方法：
我也尝试去下载了Command_Line_Tools_macOS_10.13_for_Xcode_10.1.dmg进行安装，但是却提示“该软件包与此版本的macOS不兼容”，有兴趣的朋友可以自己再试一下，我就不再折腾了。最后给出最后给出Command Line Tools的下载地址https://developer.apple.com/download/more/。
0x05 总结
在macOS中编译openjdk7也折腾了两天，最终还是以失败告终，接下来我将使用Ubuntu16.04进行再一次编译尝试，敬请期待。