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Siva Chandra Reddy
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[libc] Add GNU extention functions fread_unlocked and fwrite_unlocked.
POSIX locking and unlocking functions flockfile and funlockfile have also been added. The locking is not recursive yet. A future patch will make the underlying lock a recursive lock. Reviewed By: lntue Differential Revision: https://reviews.llvm.org/D123986
1 parent 009048a commit 945e022

18 files changed

+352
-14
lines changed

‎libc/config/linux/x86_64/entrypoints.txt

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@@ -252,10 +252,14 @@ if(LLVM_LIBC_FULL_BUILD)
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# stdio.h entrypoints
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libc.src.stdio.fclose
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libc.src.stdio.flockfile
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libc.src.stdio.fopen
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libc.src.stdio.fread
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libc.src.stdio.fread_unlocked
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libc.src.stdio.fseek
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libc.src.stdio.funlockfile
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libc.src.stdio.fwrite
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libc.src.stdio.fwrite_unlocked
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# signal.h entrypoints
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# TODO: Enable signal.h entrypoints after fixing signal.h

‎libc/spec/gnu_ext.td

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@@ -65,10 +65,36 @@ def GnuExtensions : StandardSpec<"GNUExtensions"> {
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]
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>;
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HeaderSpec StdIO = HeaderSpec<
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"stdio.h",
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[], // Macros
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[], // Types
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[], // Enumerations
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[
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FunctionSpec<
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"fread_unlocked",
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RetValSpec<SizeTType>,
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[ArgSpec<VoidRestrictedPtr>,
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ArgSpec<SizeTType>,
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ArgSpec<SizeTType>,
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ArgSpec<FILERestrictedPtr>]
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>,
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FunctionSpec<
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"fwrite_unlocked",
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RetValSpec<SizeTType>,
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[ArgSpec<ConstVoidRestrictedPtr>,
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ArgSpec<SizeTType>,
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ArgSpec<SizeTType>,
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ArgSpec<FILERestrictedPtr>]
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>,
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]
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>;
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let Headers = [
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CType,
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FEnv,
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Math,
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Math,
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StdIO,
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String,
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];
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}

‎libc/spec/posix.td

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@@ -502,12 +502,32 @@ def POSIX : StandardSpec<"POSIX"> {
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]
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>;
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HeaderSpec StdIO = HeaderSpec<
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"stdio.h",
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[], // Macros
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[], // Types
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[], // Enumerations
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[
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FunctionSpec<
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"flockfile",
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RetValSpec<VoidType>,
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[ArgSpec<FILEPtr>]
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>,
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FunctionSpec<
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"funlockfile",
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RetValSpec<VoidType>,
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[ArgSpec<FILEPtr>]
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>,
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]
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>;
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let Headers = [
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CType,
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Errno,
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FCntl,
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PThread,
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Signal,
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StdIO,
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StdLib,
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SysMMan,
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SysStat,

‎libc/spec/spec.td

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@@ -103,6 +103,10 @@ def QSortCompareT : NamedType<"__qsortcompare_t">;
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def AtexitHandlerT : NamedType<"__atexithandler_t">;
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def FILE : NamedType<"FILE">;
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def FILEPtr : PtrType<FILE>;
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def FILERestrictedPtr : RestrictedPtrType<FILE>;
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//added because __assert_fail needs it.
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def UnsignedType : NamedType<"unsigned">;
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‎libc/spec/stdc.td

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@@ -1,8 +1,5 @@
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def StdC : StandardSpec<"stdc"> {
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NamedType FILE = NamedType<"FILE">;
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PtrType FILEPtr = PtrType<FILE>;
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RestrictedPtrType FILERestrictedPtr = RestrictedPtrType<FILE>;
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NamedType StructTmType = NamedType<"struct tm">;
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PtrType StructTmPtr = PtrType<StructTmType>;
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PtrType TimeTTypePtr = PtrType<TimeTType>;

‎libc/src/__support/File/file.cpp

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@@ -16,9 +16,7 @@
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namespace __llvm_libc {
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size_t File::write(const void *data, size_t len) {
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FileLock lock(this);
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size_t File::write_unlocked(const void *data, size_t len) {
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if (!write_allowed()) {
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errno = EBADF;
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err = true;
@@ -76,9 +74,7 @@ size_t File::write(const void *data, size_t len) {
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return len;
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}
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size_t File::read(void *data, size_t len) {
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FileLock lock(this);
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size_t File::read_unlocked(void *data, size_t len) {
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if (!read_allowed()) {
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errno = EBADF;
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err = true;

‎libc/src/__support/File/file.h

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@@ -145,11 +145,27 @@ class File {
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f->eof = f->err = false;
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}
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// Buffered write of |len| bytes from |data|.
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size_t write(const void *data, size_t len);
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// Buffered write of |len| bytes from |data| without the file lock.
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size_t write_unlocked(const void *data, size_t len);
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// Buffered write of |len| bytes from |data| under the file lock.
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size_t write(const void *data, size_t len) {
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lock();
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size_t ret = write_unlocked(data, len);
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unlock();
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return ret;
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}
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// Buffered read of |len| bytes into |data| without the file lock.
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size_t read_unlocked(void *data, size_t len);
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// Buffered read of |len| bytes into |data|.
152-
size_t read(void *data, size_t len);
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// Buffered read of |len| bytes into |data| under the file lock.
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size_t read(void *data, size_t len) {
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lock();
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size_t ret = read_unlocked(data, len);
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unlock();
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return ret;
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}
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int seek(long offset, int whence);
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‎libc/src/stdio/CMakeLists.txt

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@@ -24,6 +24,42 @@ add_entrypoint_object(
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libc.src.__support.File.platform_file
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)
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add_entrypoint_object(
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flockfile
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SRCS
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flockfile.cpp
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HDRS
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flockfile.h
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DEPENDS
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libc.include.stdio
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libc.src.__support.File.file
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libc.src.__support.File.platform_file
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)
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add_entrypoint_object(
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funlockfile
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SRCS
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funlockfile.cpp
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HDRS
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funlockfile.h
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DEPENDS
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libc.include.stdio
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libc.src.__support.File.file
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libc.src.__support.File.platform_file
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)
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add_entrypoint_object(
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fread_unlocked
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SRCS
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fread_unlocked.cpp
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HDRS
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fread_unlocked.h
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DEPENDS
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libc.include.stdio
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libc.src.__support.File.file
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libc.src.__support.File.platform_file
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)
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add_entrypoint_object(
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fread
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SRCS
@@ -36,6 +72,18 @@ add_entrypoint_object(
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libc.src.__support.File.platform_file
3773
)
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add_entrypoint_object(
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fwrite_unlocked
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SRCS
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fwrite_unlocked.cpp
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HDRS
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fwrite_unlocked.h
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DEPENDS
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libc.include.stdio
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libc.src.__support.File.file
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libc.src.__support.File.platform_file
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)
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add_entrypoint_object(
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fwrite
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SRCS

‎libc/src/stdio/flockfile.cpp

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@@ -0,0 +1,20 @@
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//===-- Implementation of flockfile ---------------------------------------===//
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//
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
5+
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===----------------------------------------------------------------------===//
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9+
#include "src/stdio/flockfile.h"
10+
#include "src/__support/File/file.h"
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12+
#include <stdio.h>
13+
14+
namespace __llvm_libc {
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16+
LLVM_LIBC_FUNCTION(void, flockfile, (::FILE * stream)) {
17+
reinterpret_cast<__llvm_libc::File *>(stream)->lock();
18+
}
19+
20+
} // namespace __llvm_libc

‎libc/src/stdio/flockfile.h

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@@ -0,0 +1,20 @@
1+
//===-- Implementation header of flockfile ----------------------*- C++ -*-===//
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//
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4+
// See https://llvm.org/LICENSE.txt for license information.
5+
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
7+
//===----------------------------------------------------------------------===//
8+
9+
#ifndef LLVM_LIBC_SRC_STDIO_FLOCKFILE_H
10+
#define LLVM_LIBC_SRC_STDIO_FLOCKFILE_H
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#include <stdio.h>
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14+
namespace __llvm_libc {
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16+
void flockfile(::FILE *stream);
17+
18+
} // namespace __llvm_libc
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#endif // LLVM_LIBC_SRC_STDIO_FLOCKFILE_H

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