[libc] Additional check for File support in scanf_core

[Caslyn]

This adds a check for TARGET libc.src.__support.File.file before appending libc.src.__support.File.file to file_deps.

[llvmbot]

@llvm/pr-subscribers-libc

Author: Caslyn Tonelli (Caslyn)

Changes

This adds a check for TARGET libc.src.__support.File.file before appending libc.src.__support.File.file to file_deps.

---

Full diff: https://github.com/llvm/llvm-project/pull/128079.diff

1 Files Affected:

• (modified) libc/src/stdio/scanf_core/CMakeLists.txt (+1-1)

diff --git a/libc/src/stdio/scanf_core/CMakeLists.txt b/libc/src/stdio/scanf_core/CMakeLists.txt
index ce639fe65a106..813f4213d160a 100644
--- a/libc/src/stdio/scanf_core/CMakeLists.txt
+++ b/libc/src/stdio/scanf_core/CMakeLists.txt
@@ -16,7 +16,7 @@ if(LIBC_TARGET_OS_IS_GPU)
     libc.src.stdio.ungetc
     libc.src.stdio.ferror
   )
-elseif(LLVM_LIBC_FULL_BUILD)
+elseif(TARGET libc.src.__support.File.file AND LLVM_LIBC_FULL_BUILD)
   list(APPEND file_deps
     libc.src.__support.File.file
   )

[Caslyn]

@michaelrj-google - I ought to have tested your previous patch locally. I think this might be the missing piece to resolve the error on our Fuchsia builder.

[michaelrj-google]

LGTM

[michaelrj-google]

I'm not sure if this will work for baremetal, since right now the fscanf scanner requires either the system's FILE or our own FILE. We might need to add a hook similar to what's in https://github.com/llvm/llvm-project/blob/main/libc/src/stdio/baremetal/printf.cpp, or alternately just add baremetal versions of getc and ungetc

[petrhosek]

I'm not sure if this will work for baremetal, since right now the fscanf scanner requires either the system's FILE or our own FILE. We might need to add a hook similar to what's in https://github.com/llvm/llvm-project/blob/main/libc/src/stdio/baremetal/printf.cpp, or alternately just add baremetal versions of getc and ungetc

I have a WIP implementation of that locally, I'll clean it up and send it for review.

[michaelrj-google]

I'm not sure if this will work for baremetal, since right now the fscanf scanner requires either the system's FILE or our own FILE. We might need to add a hook similar to what's in https://github.com/llvm/llvm-project/blob/main/libc/src/stdio/baremetal/printf.cpp, or alternately just add baremetal versions of getc and ungetc

I have a WIP implementation of that locally, I'll clean it up and send it for review.

Would it make sense to turn off scanf on baremetal temporarily to unbreak the bots then?

[petrhosek]

I'm not sure if this will work for baremetal, since right now the fscanf scanner requires either the system's FILE or our own FILE. We might need to add a hook similar to what's in https://github.com/llvm/llvm-project/blob/main/libc/src/stdio/baremetal/printf.cpp, or alternately just add baremetal versions of getc and ungetc

I have a WIP implementation of that locally, I'll clean it up and send it for review.

Would it make sense to turn off scanf on baremetal temporarily to unbreak the bots then?

It's not included in any of the baremetal entrypoints.txt files so I'm not sure why it's being pulled in.

[michaelrj-google]

I'm not sure if this will work for baremetal, since right now the fscanf scanner requires either the system's FILE or our own FILE. We might need to add a hook similar to what's in https://github.com/llvm/llvm-project/blob/main/libc/src/stdio/baremetal/printf.cpp, or alternately just add baremetal versions of getc and ungetc

I have a WIP implementation of that locally, I'll clean it up and send it for review.

Would it make sense to turn off scanf on baremetal temporarily to unbreak the bots then?

It's not included in any of the baremetal entrypoints.txt files so I'm not sure why it's being pulled in.

Ah, in that case this might fix the build. These aren't entrypoints so they're being built unconditionally, and if nothing is providing getc, ungetc, and ferror they should fail to link, but if nothing tries to link them it might just pass.

[Caslyn]

See #128097