如何获取默认的clang搜索路径以引用已安装的命令行工具框架目录？

在安装MacOS / Xcode命令行工具后，我希望clang默认框架搜索路径会更新为SDK框架的位置。像这样：

#include <...> search starts here:
 /usr/local/include
 /library/Developer/CommandLineTools/usr/lib/clang/10.0.1/include
 /library/Developer/CommandLineTools/usr/include
 /library/Developer/CommandLineTools/SDKs/MacOSX10.14.sdk/usr/include
 /library/Developer/CommandLineTools/SDKs/MacOSX10.14.sdk/System/library/Frameworks (framework directory)

相反，我仍然具有默认值：

$ echo | clang -v -E -
Apple clang version 11.0.0 (clang-1100.0.33.12)
Target: x86_64-apple-darwin19.0.0
Thread model: posix
InstalledDir: /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin
 "/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/clang" -cc1 -triple x86_64-apple-macosx10.15.0 -Wdeprecated-objc-isa-usage -Werror=deprecated-objc-isa-usage -E -disable-free -disable-llvm-verifier -discard-value-names -main-file-name - -mrelocation-model pic -pic-level 2 -mthread-model posix -mdisable-fp-elim -fno-strict-return -masm-verbose -munwind-tables -target-cpu penryn -dwarf-column-info -debugger-tuning=lldb -ggnu-pubnames -target-linker-version 520 -v -resource-dir /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/lib/clang/11.0.0 -Wno-framework-include-private-from-public -Wno-atimport-in-framework-header -Wno-extra-semi-stmt -Wno-quoted-include-in-framework-header -fdebug-compilation-dir /Users/ebg -ferror-limit 19 -fmessage-length 261 -stack-protector 1 -fstack-check -mdarwin-stkchk-strong-link -fblocks -fencode-extended-block-signature -fregister-global-dtors-with-atexit -fobjc-runtime=macosx-10.15.0 -fmax-type-align=16 -fdiagnostics-show-option -fcolor-diagnostics -o - -x c -
clang -cc1 version 11.0.0 (clang-1100.0.33.12) default target x86_64-apple-darwin19.0.0
ignoring nonexistent directory "/usr/include"
#include "..." search starts here:
#include <...> search starts here:
 /usr/local/include
 /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/lib/clang/11.0.0/include
 /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/include
 /System/library/Frameworks (framework directory)
 /library/Frameworks (framework directory)
End of search list.

即使我从工具的/ usr / bin中明确指定了clang的位置，我也会得到：

#include <...> search starts here:
 /usr/local/include
 /library/Developer/CommandLineTools/usr/lib/clang/11.0.0/include
 /library/Developer/CommandLineTools/usr/include
 /System/library/Frameworks (framework directory)
 /library/Frameworks (framework directory)
End of search list

$ ls /library/Developer/CommandLineTools/SDKs/MacOSX
MacOSX.sdk/      MacOSX10.14.sdk/ MacOSX10.15.sdk/