[LIBC] Invalid token in LIBC_NAMESPACE macro expansion

[samvangysegem]

When building the libc library based on the release/20.x branch, the compilation fails due to an invalid token in the LIBC_NAMESPACE macro expansion. This problem is rooted in the definition of LLVM_VERSION_SUFFIX

llvm-project/cmake/Modules/LLVMVersion.cmake

Lines 12 to 14 in d185bd9

	if(NOT DEFINED LLVM_VERSION_SUFFIX)
	set(LLVM_VERSION_SUFFIX -rc1)
	endif()

and its usage to configure the default_namespace field

llvm-project/libc/CMakeLists.txt

Lines 52 to 58 in d185bd9

	set(default_namespace "__llvm_libc")
	if(LLVM_VERSION_MAJOR)
	set(default_namespace "__llvm_libc_${LLVM_VERSION_MAJOR}_${LLVM_VERSION_MINOR}_${LLVM_VERSION_PATCH}_${LLVM_VERSION_SUFFIX}")
	endif()
	set(LIBC_NAMESPACE ${default_namespace}
	CACHE STRING "The namespace to use to enclose internal implementations. Must start with '__llvm_libc'."
	)

For the release/20.x branch, LIBC_NAMESPACE is expanded to __llvm_libc_20_1_0_-rc1 with the invalid token -. This can be fixed relatively easy by either updating the LLVM_VERSION_SUFFIX definition to not use the - token or by removing the LLVM_VERSION_SUFFIX from the libc default_namespace.

[llvmbot]

@llvm/issue-subscribers-libc

Author: s.vgys (samvangysegem)

When building the libc library based on the `release/20.x`, the compilation fails due to an invalid token in the LIBC_NAMESPACE macro expansion. This problem is rooted in the definition of `LLVM_VERSION_SUFFIX` in the `cmake/Modules/LLVMVersion.cmake` file: ``` if(NOT DEFINED LLVM_VERSION_SUFFIX) set(LLVM_VERSION_SUFFIX -rc1) endif() ``` and its usage in `libc/CMakeLists.txt` to configure the `default_namespace` field as shown below: ``` # Defining a global namespace to enclose all libc functions. set(default_namespace "__llvm_libc") if(LLVM_VERSION_MAJOR) set(default_namespace "__llvm_libc_${LLVM_VERSION_MAJOR}_${LLVM_VERSION_MINOR}_${LLVM_VERSION_PATCH}_${LLVM_VERSION_SUFFIX}") endif() set(LIBC_NAMESPACE ${default_namespace} CACHE STRING "The namespace to use to enclose internal implementations. Must start with '__llvm_libc'." ) ``` For the `release/20.x` branch, `LIBC_NAMESPACE` is expanded to `__llvm_libc_20_1_0_-rc1` with the invalid token `-`. This can be fixed relatively easy by either updating the `LLVM_VERSION_SUFFIX` definition to not use the `-` token or by removing the `LLVM_VERSION_SUFFIX` from the libc default_namespace.

[nickdesaulniers]

Thanks for the report! It sounds like we could use cmakes's string(REPLACE functionality on LLVM_VERSION_SUFFIX to replace - with ``.

[llvmbot]

Hi!

This issue may be a good introductory issue for people new to working on LLVM. If you would like to work on this issue, your first steps are:

1. Check that no other contributor has already been assigned to this issue. If you believe that no one is actually working on it despite an assignment, ping the person. After one week without a response, the assignee may be changed.
2. In the comments of this issue, request for it to be assigned to you, or just create a pull request after following the steps below. Mention this issue in the description of the pull request.
3. Fix the issue locally.
4. Run the test suite locally. Remember that the subdirectories under test/ create fine-grained testing targets, so you can e.g. use make check-clang-ast to only run Clang's AST tests.
5. Create a Git commit.
6. Run git clang-format HEAD~1 to format your changes.
7. Open a pull request to the upstream repository on GitHub. Detailed instructions can be found in GitHub's documentation. Mention this issue in the description of the pull request.

If you have any further questions about this issue, don't hesitate to ask via a comment in the thread below.

[llvmbot]

@llvm/issue-subscribers-good-first-issue

Author: s.vgys (samvangysegem)

When building the libc library based on the `release/20.x` branch, the compilation fails due to an invalid token in the LIBC_NAMESPACE macro expansion. This problem is rooted in the definition of `LLVM_VERSION_SUFFIX`

llvm-project/cmake/Modules/LLVMVersion.cmake

Lines 12 to 14 in d185bd9

	if(NOT DEFINED LLVM_VERSION_SUFFIX)
	set(LLVM_VERSION_SUFFIX -rc1)
	endif()

and its usage to configure the default_namespace field

llvm-project/libc/CMakeLists.txt

Lines 52 to 58 in d185bd9

	set(default_namespace "__llvm_libc")
	if(LLVM_VERSION_MAJOR)
	set(default_namespace "__llvm_libc_${LLVM_VERSION_MAJOR}_${LLVM_VERSION_MINOR}_${LLVM_VERSION_PATCH}_${LLVM_VERSION_SUFFIX}")
	endif()
	set(LIBC_NAMESPACE ${default_namespace}
	CACHE STRING "The namespace to use to enclose internal implementations. Must start with '__llvm_libc'."
	)

For the release/20.x branch, LIBC_NAMESPACE is expanded to __llvm_libc_20_1_0_-rc1 with the invalid token -. This can be fixed relatively easy by either updating the LLVM_VERSION_SUFFIX definition to not use the - token or by removing the LLVM_VERSION_SUFFIX from the libc default_namespace.

[samvangysegem]

Sounds good! I'll make a PR with the fix.

[samvangysegem]

@nickdesaulniers Could we mark this issue to be included in the next patch release for the release/20.x branch? Then I can add the cherry-pick message for backporting...

[nickdesaulniers]

done