Configuration flags do not show up when --verbose

[etiennemlb]

You can give the driver a set of .cfg files that are going to be used to inject flags before and after the user specified ones. See: https://releases.llvm.org/6.0.0/tools/clang/docs/UsersManual.html#configuration-files

Unfortunately, I do not see how to ask the driver to dump all the flags, user given and configuration ones.

[llvmbot]

@llvm/issue-subscribers-clang-driver

Author: None (etiennemlb)

You can give the driver a set of .cfg files that are going to be used to inject flags before and after the user specified ones. See: https://releases.llvm.org/6.0.0/tools/clang/docs/UsersManual.html#configuration-files

Unfortunately, I do not see how to ask the driver to dump all the flags, user given and configuration ones.

[AaronBallman]

Does -### work for you?

F:\source\llvm-project>llvm\out\build\x64-Debug\bin\clang.exe --config "C:\Users\aballman\OneDrive - Intel Corporation\Desktop\conf1.cfg" -std=c++23 --config "C:\Users\aballman\OneDrive - Intel Corporation\Desktop\conf2.cfg" "C:\Users\aballman\OneDrive - Intel Corporation\Desktop\test.cpp" -###
clang version 21.0.0git (https://github.com/llvm/llvm-project.git f9b9e817082a8745ac34db2939273f05270fdbf5)
Target: i386-pc-windows-msvc
Thread model: posix
InstalledDir: F:\source\llvm-project\llvm\out\build\x64-Debug\bin
Build config: +unoptimized, +assertions
Configuration file: C:\Users\aballman\OneDrive - Intel Corporation\Desktop\conf1.cfg
Configuration file: C:\Users\aballman\OneDrive - Intel Corporation\Desktop\conf2.cfg
 (in-process)
 "F:\\source\\llvm-project\\llvm\\out\\build\\x64-Debug\\bin\\clang.exe" "-cc1" "-triple" "i386-pc-windows-msvc19.43.34810" "-fsyntax-only" "-disable-free" "-clear-ast-before-backend" "-main-file-name" "test.cpp" "-mrelocation-model" "static" "-mframe-pointer=all" "-relaxed-aliasing" "-fmath-errno" "-ffp-contract=on" "-fno-rounding-math" "-mconstructor-aliases" "-fms-volatile" "-target-cpu" "pentium4" "-tune-cpu" "generic" "-fdebug-compilation-dir=F:\\source\\llvm-project" "-fcoverage-compilation-dir=F:\\source\\llvm-project" "-resource-dir" "F:\\source\\llvm-project\\llvm\\out\\build\\x64-Debug\\lib\\clang\\21" "-internal-isystem" "F:\\source\\llvm-project\\llvm\\out\\build\\x64-Debug\\lib\\clang\\21\\include" "-internal-isystem" "C:\\Program Files\\Microsoft Visual Studio\\2022\\Professional\\VC\\Tools\\MSVC\\14.43.34808\\include" "-internal-isystem" "C:\\Program Files\\Microsoft Visual Studio\\2022\\Professional\\VC\\Tools\\MSVC\\14.43.34808\\ATLMFC\\include" "-internal-isystem" "C:\\Program Files\\Microsoft Visual Studio\\2022\\Professional\\VC\\Auxiliary\\VS\\include" "-internal-isystem" "C:\\Program Files (x86)\\Windows Kits\\10\\include\\10.0.19041.0\\ucrt" "-internal-isystem" "C:\\Program Files (x86)\\Windows Kits\\10\\\\include\\10.0.19041.0\\\\um" "-internal-isystem" "C:\\Program Files (x86)\\Windows Kits\\10\\\\include\\10.0.19041.0\\\\shared" "-internal-isystem" "C:\\Program Files (x86)\\Windows Kits\\10\\\\include\\10.0.19041.0\\\\winrt" "-internal-isystem" "C:\\Program Files (x86)\\Windows Kits\\10\\\\include\\10.0.19041.0\\\\cppwinrt" "-internal-isystem" "C:\\Program Files\\Microsoft Visual Studio\\2022\\Professional\\VC\\Tools\\MSVC\\14.43.34808\\include" "-internal-isystem" "C:\\Program Files\\Microsoft Visual Studio\\2022\\Professional\\VC\\Tools\\MSVC\\14.43.34808\\ATLMFC\\include" "-internal-isystem" "C:\\Program Files\\Microsoft Visual Studio\\2022\\Professional\\VC\\Auxiliary\\VS\\include" "-internal-isystem" "C:\\Program Files (x86)\\Windows Kits\\10\\include\\10.0.19041.0\\ucrt" "-internal-isystem" "C:\\Program Files (x86)\\Windows Kits\\10\\\\include\\10.0.19041.0\\\\um" "-internal-isystem" "C:\\Program Files (x86)\\Windows Kits\\10\\\\include\\10.0.19041.0\\\\shared" "-internal-isystem" "C:\\Program Files (x86)\\Windows Kits\\10\\\\include\\10.0.19041.0\\\\winrt" "-internal-isystem" "C:\\Program Files (x86)\\Windows Kits\\10\\\\include\\10.0.19041.0\\\\cppwinrt" "-std=c++23" "-fdeprecated-macro" "-ferror-limit" "19" "-fmessage-length=120" "-fno-use-cxa-atexit" "-fms-extensions" "-fms-compatibility" "-fms-compatibility-version=19.43.34810" "-fno-implicit-modules" "-fskip-odr-check-in-gmf" "-fcxx-exceptions" "-fexceptions" "-fcolor-diagnostics" "-faddrsig" "-x" "c++" "C:\\Users\\aballman\\OneDrive - Intel Corporation\\Desktop\\test.cpp"

[etiennemlb]

It does not do the trick. My usecase revolves around ROCm, see:

$ amdclang --verbose --hip-link test.c
AMD clang version 17.0.0 (https://github.com/RadeonOpenCompute/llvm-project roc-6.1.2 24193 669db884972e769450470020c06a6f132a8a065b)
Target: x86_64-unknown-linux-gnu
Thread model: posix
InstalledDir: /lus/home/softs/rocm/6.1.2/lib/llvm/bin
Configuration file: /lus/home/softs/rocm/6.1.2/lib/llvm/bin/clang.cfg
Found candidate GCC installation: /opt/rh/gcc-toolset-12/root/usr/lib/gcc/x86_64-redhat-linux/12
Selected GCC installation: /opt/rh/gcc-toolset-12/root/usr/lib/gcc/x86_64-redhat-linux/12
Candidate multilib: .;@m64
Candidate multilib: 32;@m32
Selected multilib: .;@m64
Found HIP installation: /lus/home/softs/rocm/6.1.2/lib/llvm/bin/../../.., version 6.1.40093
 "/lus/home/softs/rocm/6.1.2/lib/llvm/bin/clang-17" -cc1 -triple x86_64-unknown-linux-gnu -emit-obj -mrelax-all -dumpdir a- -disable-free -clear-ast-before-backend -disable-llvm-verifier -discard-value-names -main-file-name test.c -mrelocation-model static -mframe-pointer=all -fmath-errno -ffp-contract=on -fno-rounding-math -mconstructor-aliases -funwind-tables=2 -target-cpu x86-64 -tune-cpu generic -debugger-tuning=gdb -v -fcoverage-compilation-dir=/tmp/teeet -resource-dir /lus/home/softs/rocm/6.1.2/lib/llvm/lib/clang/17 -internal-isystem /lus/home/softs/rocm/6.1.2/lib/llvm/lib/clang/17/include -internal-isystem /usr/local/include -internal-isystem /opt/rh/gcc-toolset-12/root/usr/lib/gcc/x86_64-redhat-linux/12/../../../../x86_64-redhat-linux/include -internal-externc-isystem /include -internal-externc-isystem /usr/include -fdebug-compilation-dir=/tmp/teeet -ferror-limit 19 -fgnuc-version=4.2.1 -faddrsig -D__GCC_HAVE_DWARF2_CFI_ASM=1 -o /tmp/test-2b62d1.o -x c test.c
clang -cc1 version 17.0.0 based upon LLVM 17.0.0git default target x86_64-unknown-linux-gnu
ignoring nonexistent directory "/opt/rh/gcc-toolset-12/root/usr/lib/gcc/x86_64-redhat-linux/12/../../../../x86_64-redhat-linux/include"
ignoring nonexistent directory "/include"
#include "..." search starts here:
#include <...> search starts here:
 /lus/home/softs/rocm/6.1.2/lib/llvm/lib/clang/17/include
 /usr/local/include
 /usr/include
End of search list.
 "/lus/home/softs/rocm/6.1.2/lib/llvm/bin/ld.lld" --hash-style=gnu --eh-frame-hdr -m elf_x86_64 -dynamic-linker /lib64/ld-linux-x86-64.so.2 -o a.out /lib/../lib64/crt1.o /lib/../lib64/crti.o /lus/home/softs/rocm/6.1.2/lib/llvm/lib/clang/17/lib/linux/clang_rt.crtbegin-x86_64.o -L/opt/rh/gcc-toolset-12/root/usr/lib/gcc/x86_64-redhat-linux/12 -L/opt/rh/gcc-toolset-12/root/usr/lib/gcc/x86_64-redhat-linux/12/../../../../lib64 -L/lib/../lib64 -L/usr/lib/../lib64 -L/lib -L/usr/lib --enable-new-dtags /tmp/test-2b62d1.o -L/lus/home/softs/rocm/6.1.2/lib/llvm/bin/../../../lib -rpath /lus/home/softs/rocm/6.1.2/lib/llvm/bin/../../../lib -lamdhip64 /lus/home/softs/rocm/6.1.2/lib/llvm/lib/clang/17/lib/linux/libclang_rt.builtins-x86_64.a --as-needed -lgcc_s --no-as-needed -lc /lus/home/softs/rocm/6.1.2/lib/llvm/lib/clang/17/lib/linux/libclang_rt.builtins-x86_64.a --as-needed -lgcc_s --no-as-needed /lus/home/softs/rocm/6.1.2/lib/llvm/lib/clang/17/lib/linux/clang_rt.crtend-x86_64.o /lib/../lib64/crtn.o
$ amdclang --verbose --hip-link test.c -###
AMD clang version 17.0.0 (https://github.com/RadeonOpenCompute/llvm-project roc-6.1.2 24193 669db884972e769450470020c06a6f132a8a065b)
Target: x86_64-unknown-linux-gnu
Thread model: posix
InstalledDir: /lus/home/softs/rocm/6.1.2/lib/llvm/bin
Configuration file: /lus/home/softs/rocm/6.1.2/lib/llvm/bin/clang.cfg
Found candidate GCC installation: /opt/rh/gcc-toolset-12/root/usr/lib/gcc/x86_64-redhat-linux/12
Selected GCC installation: /opt/rh/gcc-toolset-12/root/usr/lib/gcc/x86_64-redhat-linux/12
Candidate multilib: .;@m64
Candidate multilib: 32;@m32
Selected multilib: .;@m64
Found HIP installation: /lus/home/softs/rocm/6.1.2/lib/llvm/bin/../../.., version 6.1.40093
 "/lus/home/softs/rocm/6.1.2/lib/llvm/bin/clang-17" "-cc1" "-triple" "x86_64-unknown-linux-gnu" "-emit-obj" "-mrelax-all" "-dumpdir" "a-" "-disable-free" "-clear-ast-before-backend" "-disable-llvm-verifier" "-discard-value-names" "-main-file-name" "test.c" "-mrelocation-model" "static" "-mframe-pointer=all" "-fmath-errno" "-ffp-contract=on" "-fno-rounding-math" "-mconstructor-aliases" "-funwind-tables=2" "-target-cpu" "x86-64" "-tune-cpu" "generic" "-debugger-tuning=gdb" "-v" "-fcoverage-compilation-dir=/tmp/teeet" "-resource-dir" "/lus/home/softs/rocm/6.1.2/lib/llvm/lib/clang/17" "-internal-isystem" "/lus/home/softs/rocm/6.1.2/lib/llvm/lib/clang/17/include" "-internal-isystem" "/usr/local/include" "-internal-isystem" "/opt/rh/gcc-toolset-12/root/usr/lib/gcc/x86_64-redhat-linux/12/../../../../x86_64-redhat-linux/include" "-internal-externc-isystem" "/include" "-internal-externc-isystem" "/usr/include" "-fdebug-compilation-dir=/tmp/teeet" "-ferror-limit" "19" "-fgnuc-version=4.2.1" "-faddrsig" "-D__GCC_HAVE_DWARF2_CFI_ASM=1" "-o" "/tmp/test-b12f5a.o" "-x" "c" "test.c"
 "/lus/home/softs/rocm/6.1.2/lib/llvm/bin/ld.lld" "--hash-style=gnu" "--eh-frame-hdr" "-m" "elf_x86_64" "-dynamic-linker" "/lib64/ld-linux-x86-64.so.2" "-o" "a.out" "/lib/../lib64/crt1.o" "/lib/../lib64/crti.o" "/lus/home/softs/rocm/6.1.2/lib/llvm/lib/clang/17/lib/linux/clang_rt.crtbegin-x86_64.o" "-L/opt/rh/gcc-toolset-12/root/usr/lib/gcc/x86_64-redhat-linux/12" "-L/opt/rh/gcc-toolset-12/root/usr/lib/gcc/x86_64-redhat-linux/12/../../../../lib64" "-L/lib/../lib64" "-L/usr/lib/../lib64" "-L/lib" "-L/usr/lib" "--enable-new-dtags" "/tmp/test-b12f5a.o" "-L/lus/home/softs/rocm/6.1.2/lib/llvm/bin/../../../lib" "-rpath" "/lus/home/softs/rocm/6.1.2/lib/llvm/bin/../../../lib" "-lamdhip64" "/lus/home/softs/rocm/6.1.2/lib/llvm/lib/clang/17/lib/linux/libclang_rt.builtins-x86_64.a" "--as-needed" "-lgcc_s" "--no-as-needed" "-lc" "/lus/home/softs/rocm/6.1.2/lib/llvm/lib/clang/17/lib/linux/libclang_rt.builtins-x86_64.a" "--as-needed" "-lgcc_s" "--no-as-needed" "/lus/home/softs/rocm/6.1.2/lib/llvm/lib/clang/17/lib/linux/clang_rt.crtend-x86_64.o" "/lib/../lib64/crtn.o"

So I would say that "-###" is even less verbose.

The config file contains:

-Wl,--enable-new-dtags
--rocm-path='<CFGDIR>/../../..'
-frtlib-add-rpath

Which we see applied to lld (the rpath to the amd hip runtime) but clearly, this lld flags appear out of nowhere, the driver cmd line has not changed.

[AaronBallman]

But it still specifies the configuration file?

Configuration file: /lus/home/softs/rocm/6.1.2/lib/llvm/bin/clang.cfg

no other configuration file is being passed on the command line. So it does have the information, just not expanded out? So an improvement could be to list the file contents under the Configuration file line? Or is there a different configuration file you're talking about and I'm just not seeing it?

[etiennemlb]

What I meant by Configuration flags do not show up when --verbose was that, as you guessed, I would expect the config file's option to be expanded and shown somewhere.

So indeed, an improvement would be to show the injected flags.