[libc] Move fileno and fdopen to fullbuild only

[michaelrj-google]

Both fileno and fdopen require interfacing with the opaque FILE struct,
so they shouldn't be enabled in overlay mode. This patch moves both into
fullbuild only on all platforms.

Fixes #128643

[llvmbot]

@llvm/pr-subscribers-libc

Author: Michael Jones (michaelrj-google)

Changes

Both fileno and fdopen require interfacing with the opaque FILE struct,
so they shouldn't be enabled in overlay mode. This patch moves both into
fullbuild only on all platforms.

Fixes #128643

---

Full diff: https://github.com/llvm/llvm-project/pull/128762.diff

4 Files Affected:

• (modified) libc/config/linux/aarch64/entrypoints.txt (+2-2)
• (modified) libc/config/linux/riscv/entrypoints.txt (+2-2)
• (modified) libc/config/linux/x86_64/entrypoints.txt (+2-2)
• (modified) libc/src/stdio/generic/fileno.cpp (+1-2)

diff --git a/libc/config/linux/aarch64/entrypoints.txt b/libc/config/linux/aarch64/entrypoints.txt
index aac4017a0d845..6c2be4d3b0b99 100644
--- a/libc/config/linux/aarch64/entrypoints.txt
+++ b/libc/config/linux/aarch64/entrypoints.txt
@@ -212,8 +212,6 @@ set(TARGET_LIBC_ENTRYPOINTS
     libc.src.stdlib.realloc
 
     # stdio.h entrypoints
-    libc.src.stdio.fdopen
-    libc.src.stdio.fileno
     libc.src.stdio.fprintf
     libc.src.stdio.fscanf
     libc.src.stdio.vfscanf
@@ -918,6 +916,7 @@ if(LLVM_LIBC_FULL_BUILD)
     libc.src.stdio.clearerr
     libc.src.stdio.clearerr_unlocked
     libc.src.stdio.fclose
+    libc.src.stdio.fdopen
     libc.src.stdio.feof
     libc.src.stdio.feof_unlocked
     libc.src.stdio.ferror
@@ -926,6 +925,7 @@ if(LLVM_LIBC_FULL_BUILD)
     libc.src.stdio.fgetc
     libc.src.stdio.fgetc_unlocked
     libc.src.stdio.fgets
+    libc.src.stdio.fileno
     libc.src.stdio.flockfile
     libc.src.stdio.fopen
     libc.src.stdio.fopencookie
diff --git a/libc/config/linux/riscv/entrypoints.txt b/libc/config/linux/riscv/entrypoints.txt
index 6b006f0ecca89..fa1e48f901a90 100644
--- a/libc/config/linux/riscv/entrypoints.txt
+++ b/libc/config/linux/riscv/entrypoints.txt
@@ -211,8 +211,6 @@ set(TARGET_LIBC_ENTRYPOINTS
     libc.src.stdlib.realloc
 
     # stdio.h entrypoints
-    libc.src.stdio.fdopen
-    libc.src.stdio.fileno
     libc.src.stdio.fprintf
     libc.src.stdio.fscanf
     libc.src.stdio.vfscanf
@@ -857,6 +855,7 @@ if(LLVM_LIBC_FULL_BUILD)
     libc.src.stdio.clearerr
     libc.src.stdio.clearerr_unlocked
     libc.src.stdio.fclose
+    libc.src.stdio.fdopen
     libc.src.stdio.feof
     libc.src.stdio.feof_unlocked
     libc.src.stdio.ferror
@@ -865,6 +864,7 @@ if(LLVM_LIBC_FULL_BUILD)
     libc.src.stdio.fgetc
     libc.src.stdio.fgetc_unlocked
     libc.src.stdio.fgets
+    libc.src.stdio.fileno
     libc.src.stdio.flockfile
     libc.src.stdio.fopen
     libc.src.stdio.fopencookie
diff --git a/libc/config/linux/x86_64/entrypoints.txt b/libc/config/linux/x86_64/entrypoints.txt
index eaceb15c47291..5bc793db6d3b4 100644
--- a/libc/config/linux/x86_64/entrypoints.txt
+++ b/libc/config/linux/x86_64/entrypoints.txt
@@ -211,8 +211,6 @@ set(TARGET_LIBC_ENTRYPOINTS
     libc.src.stdlib.realloc
 
     # stdio.h entrypoints
-    libc.src.stdio.fdopen
-    libc.src.stdio.fileno
     libc.src.stdio.fprintf
     libc.src.stdio.fscanf
     libc.src.stdio.vfscanf
@@ -1018,6 +1016,7 @@ if(LLVM_LIBC_FULL_BUILD)
     libc.src.stdio.clearerr
     libc.src.stdio.clearerr_unlocked
     libc.src.stdio.fclose
+    libc.src.stdio.fdopen
     libc.src.stdio.feof
     libc.src.stdio.feof_unlocked
     libc.src.stdio.ferror
@@ -1026,6 +1025,7 @@ if(LLVM_LIBC_FULL_BUILD)
     libc.src.stdio.fgetc
     libc.src.stdio.fgetc_unlocked
     libc.src.stdio.fgets
+    libc.src.stdio.fileno
     libc.src.stdio.flockfile
     libc.src.stdio.fopen
     libc.src.stdio.fopencookie
diff --git a/libc/src/stdio/generic/fileno.cpp b/libc/src/stdio/generic/fileno.cpp
index 0bec180dd20ac..8fa73d17e1fe1 100644
--- a/libc/src/stdio/generic/fileno.cpp
+++ b/libc/src/stdio/generic/fileno.cpp
@@ -1,5 +1,4 @@
-//===-- Implementation of fileno
-//-------------------------------------------===//
+//===-- Implementation of fileno ------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.