[libc-commits] [libc] [libc] implement pathconf/fpathconf (PR #87165)

[Schrodinger ZHU Yifan via libc-commits]

SchrodingerZhu wrote:

@changkhothuychung locally under full build, there is another error (which I believe should be my fault).
```
[294/446] Building CXX object projects/libc/src/unis...std.linux.fpathconf.__internal__.dir/fpathconf.cpp.o
FAILED: projects/libc/src/unistd/linux/CMakeFiles/libc.src.unistd.linux.fpathconf.__internal__.dir/fpathconf.cpp.o 
ccache /usr/bin/clang++ -DLIBC_NAMESPACE=__llvm_libc_19_0_0_git -I/home/yifanzhu/llvm-project/build/projects/libc/src/unistd/linux -I/home/yifanzhu/llvm-project/libc/src/unistd/linux -I/home/yifanzhu/llvm-project/libc -isystem /home/yifanzhu/llvm-project/build/projects/libc/include -fPIC -fno-semantic-interposition -fvisibility-inlines-hidden -Werror=date-time -Werror=unguarded-availability-new -Wall -Wextra -Wno-unused-parameter -Wwrite-strings -Wcast-qual -Wmissing-field-initializers -pedantic -Wno-long-long -Wc++98-compat-extra-semi -Wimplicit-fallthrough -Wcovered-switch-default -Wno-noexcept-type -Wnon-virtual-dtor -Wdelete-non-virtual-dtor -Wsuggest-override -Wstring-conversion -Wmisleading-indentation -Wctad-maybe-unsupported -fdiagnostics-color -ffunction-sections -fdata-sections -O2 -g -DNDEBUG -std=c++17 -fpie -DLIBC_FULL_BUILD -ffreestanding -fno-builtin -fno-exceptions -fno-lax-vector-conversions -fno-unwind-tables -fno-asynchronous-unwind-tables -fno-rtti -ftrivial-auto-var-init=pattern -fno-omit-frame-pointer -Wall -Wextra -Werror -Wconversion -Wno-sign-conversion -Wimplicit-fallthrough -Wwrite-strings -Wextra-semi -Wnewline-eof -Wnonportable-system-include-path -Wstrict-prototypes -Wthread-safety -Wglobal-constructors -MD -MT projects/libc/src/unistd/linux/CMakeFiles/libc.src.unistd.linux.fpathconf.__internal__.dir/fpathconf.cpp.o -MF projects/libc/src/unistd/linux/CMakeFiles/libc.src.unistd.linux.fpathconf.__internal__.dir/fpathconf.cpp.o.d -o projects/libc/src/unistd/linux/CMakeFiles/libc.src.unistd.linux.fpathconf.__internal__.dir/fpathconf.cpp.o -c /home/yifanzhu/llvm-project/libc/src/unistd/linux/fpathconf.cpp
In file included from /home/yifanzhu/llvm-project/libc/src/unistd/linux/fpathconf.cpp:12:
/home/yifanzhu/llvm-project/libc/src/sys/statvfs/linux/statfs_utils.h:12:10: fatal error: 'llvm-libc-types/struct_statvfs.h' file not found
   12 | #include "llvm-libc-types/struct_statvfs.h"
      |          ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
1 error generated.
[300/446] Building CXX object projects/libc/src/unis...rc.unistd.linux.isatty.__internal__.dir/isatty.cpp.o
ninja: build stopped: subcommand failed.
```
Other than that everything looks good to me now. 

A small patch for the fix:
```diff
>From 66b281bc70410b7359c64dd2f2600f5878c51d6b Mon Sep 17 00:00:00 2001
From: Schrodinger ZHU Yifan <i at zhuyi.fan>
Date: Mon, 17 Jun 2024 22:49:46 -0700
Subject: [PATCH] fix build issue

---
 libc/src/sys/statvfs/linux/CMakeLists.txt | 1 +
 1 file changed, 1 insertion(+)

diff --git a/libc/src/sys/statvfs/linux/CMakeLists.txt b/libc/src/sys/statvfs/linux/CMakeLists.txt
index f818863bb470..a6660c02badf 100644
--- a/libc/src/sys/statvfs/linux/CMakeLists.txt
+++ b/libc/src/sys/statvfs/linux/CMakeLists.txt
@@ -8,6 +8,7 @@ add_header_library(
     libc.src.__support.common
     libc.src.__support.CPP.optional
     libc.include.sys_syscall
+    libc.include.llvm-libc-types.struct_statvfs
 )
 
 add_entrypoint_object(
-- 
2.45.2


``` 

https://github.com/llvm/llvm-project/pull/87165