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[libc] add scanf entrypoints
This patch adds scanf, sscanf, and fscanf entrypoints. It also adds unit tests for sscanf and a basic test to fscanf. The scanf function is basically impossible to test in an automated fashion due to it recieving user input. Reviewed By: sivachandra, lntue Differential Revision: https://reviews.llvm.org/D138076
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15 files changed

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15 files changed

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‎libc/config/linux/x86_64/entrypoints.txt

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@@ -394,6 +394,9 @@ if(LLVM_LIBC_FULL_BUILD)
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libc.src.stdio.getc
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libc.src.stdio.getc_unlocked
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libc.src.stdio.printf
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libc.src.stdio.sscanf
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libc.src.stdio.scanf
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libc.src.stdio.fscanf
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libc.src.stdio.putc
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libc.src.stdio.putchar
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libc.src.stdio.puts

‎libc/spec/stdc.td

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@@ -633,6 +633,26 @@ def StdC : StandardSpec<"stdc"> {
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RetValSpec<IntType>,
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[ArgSpec<FILERestrictedPtr>, ArgSpec<CharRestrictedPtr>, ArgSpec<IntType>, ArgSpec<SizeTType>]
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>,
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FunctionSpec<
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"sscanf",
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RetValSpec<IntType>,
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[ArgSpec<ConstCharRestrictedPtr>,
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ArgSpec<ConstCharRestrictedPtr>,
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ArgSpec<VarArgType>]
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>,
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FunctionSpec<
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"scanf",
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RetValSpec<IntType>,
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[ArgSpec<ConstCharRestrictedPtr>,
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ArgSpec<VarArgType>]
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>,
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FunctionSpec<
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"fscanf",
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RetValSpec<IntType>,
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[ArgSpec<FILERestrictedPtr>,
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ArgSpec<ConstCharRestrictedPtr>,
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ArgSpec<VarArgType>]
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>,
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FunctionSpec<
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"sprintf",
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RetValSpec<IntType>,

‎libc/src/stdio/CMakeLists.txt

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@@ -403,6 +403,41 @@ 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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sscanf
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SRCS
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sscanf.cpp
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HDRS
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sscanf.h
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DEPENDS
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libc.src.__support.arg_list
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libc.src.stdio.scanf_core.string_reader
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libc.src.stdio.scanf_core.reader
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libc.src.stdio.scanf_core.scanf_main
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)
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add_entrypoint_object(
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fscanf
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SRCS
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fscanf.cpp
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HDRS
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fscanf.h
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DEPENDS
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libc.src.__support.arg_list
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libc.src.stdio.scanf_core.vfscanf_internal
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)
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add_entrypoint_object(
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scanf
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SRCS
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scanf.cpp
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HDRS
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scanf.h
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DEPENDS
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libc.src.__support.arg_list
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libc.src.stdio.scanf_core.vfscanf_internal
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)
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add_entrypoint_object(
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sprintf
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SRCS

‎libc/src/stdio/fscanf.cpp

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//===-- Implementation of fscanf --------------------------------*- C++ -*-===//
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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.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===----------------------------------------------------------------------===//
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#include "src/stdio/fscanf.h"
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#include "src/__support/File/file.h"
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#include "src/__support/arg_list.h"
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#include "src/stdio/scanf_core/vfscanf_internal.h"
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#include <stdarg.h>
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#include <stdio.h>
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namespace __llvm_libc {
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LLVM_LIBC_FUNCTION(int, fscanf,
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(::FILE *__restrict stream, const char *__restrict format,
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...)) {
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va_list vlist;
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va_start(vlist, format);
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internal::ArgList args(vlist); // This holder class allows for easier copying
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// and pointer semantics, as well as handling
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// destruction automatically.
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va_end(vlist);
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int ret_val = scanf_core::vfscanf_internal(stream, format, args);
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// This is done to avoid including stdio.h in the internals. On most systems
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// EOF is -1, so this will be transformed into just "return ret_val".
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return (ret_val == -1) ? EOF : ret_val;
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}
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} // namespace __llvm_libc

‎libc/src/stdio/fscanf.h

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//===-- Implementation header of fscanf -------------------------*- C++ -*-===//
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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.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===----------------------------------------------------------------------===//
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#ifndef LLVM_LIBC_SRC_STDIO_FSCANF_H
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#define LLVM_LIBC_SRC_STDIO_FSCANF_H
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#include <stdio.h>
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namespace __llvm_libc {
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int fscanf(::FILE *__restrict stream, const char *__restrict format, ...);
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} // namespace __llvm_libc
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#endif // LLVM_LIBC_SRC_STDIO_FSCANF_H

‎libc/src/stdio/scanf.cpp

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//===-- Implementation of scanf ---------------------------------*- C++ -*-===//
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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.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===----------------------------------------------------------------------===//
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#include "src/stdio/scanf.h"
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#include "src/__support/File/file.h"
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#include "src/__support/arg_list.h"
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#include "src/stdio/scanf_core/vfscanf_internal.h"
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#include <stdarg.h>
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#include <stdio.h>
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namespace __llvm_libc {
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LLVM_LIBC_FUNCTION(int, scanf, (const char *__restrict format, ...)) {
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va_list vlist;
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va_start(vlist, format);
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internal::ArgList args(vlist); // This holder class allows for easier copying
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// and pointer semantics, as well as handling
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// destruction automatically.
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va_end(vlist);
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int ret_val = scanf_core::vfscanf_internal(
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reinterpret_cast<::FILE *>(__llvm_libc::stdin), format, args);
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// This is done to avoid including stdio.h in the internals. On most systems
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// EOF is -1, so this will be transformed into just "return ret_val".
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return (ret_val == -1) ? EOF : ret_val;
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}
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} // namespace __llvm_libc

‎libc/src/stdio/scanf.h

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//===-- Implementation header of scanf --------------------------*- C++ -*-===//
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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.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===----------------------------------------------------------------------===//
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#ifndef LLVM_LIBC_SRC_STDIO_SCANF_H
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#define LLVM_LIBC_SRC_STDIO_SCANF_H
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namespace __llvm_libc {
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int scanf(const char *__restrict format, ...);
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} // namespace __llvm_libc
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#endif // LLVM_LIBC_SRC_STDIO_SCANF_H

‎libc/src/stdio/scanf_core/CMakeLists.txt

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@@ -89,3 +89,16 @@ add_object_library(
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libc.src.__support.CPP.string_view
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libc.src.__support.CPP.limits
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)
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add_object_library(
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vfscanf_internal
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SRCS
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vfscanf_internal.cpp
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HDRS
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vfscanf_internal.h
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DEPENDS
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.reader
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.file_reader
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.scanf_main
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libc.src.__support.arg_list
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)

‎libc/src/stdio/scanf_core/vfscanf_internal.cpp

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//===-- Internal implementation of vfscanf ---------------------*- C++ -*-===//
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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.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===----------------------------------------------------------------------===//
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#include "src/stdio/scanf_core/vfscanf_internal.h"
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#include "src/__support/arg_list.h"
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#include "src/stdio/scanf_core/file_reader.h"
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#include "src/stdio/scanf_core/reader.h"
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#include "src/stdio/scanf_core/scanf_main.h"
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#include <stdio.h>
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namespace __llvm_libc {
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namespace scanf_core {
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int vfscanf_internal(::FILE *__restrict stream, const char *__restrict format,
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internal::ArgList &args) {
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FileReader file_reader(stream);
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scanf_core::Reader reader(&file_reader);
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return scanf_core::scanf_main(&reader, format, args);
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}
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} // namespace scanf_core
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} // namespace __llvm_libc

‎libc/src/stdio/scanf_core/vfscanf_internal.h

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//===-- Internal implementation header of vfscanf ---------------*- C++ -*-===//
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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.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===----------------------------------------------------------------------===//
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#ifndef LLVM_LIBC_SRC_STDIO_SCANF_CORE_VFSCANF_INTERNAL_H
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#define LLVM_LIBC_SRC_STDIO_SCANF_CORE_VFSCANF_INTERNAL_H
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#include "src/__support/arg_list.h"
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#include <stdio.h>
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namespace __llvm_libc {
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namespace scanf_core {
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int vfscanf_internal(::FILE *__restrict stream, const char *__restrict format,
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internal::ArgList &args);
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} // namespace scanf_core
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} // namespace __llvm_libc
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#endif // LLVM_LIBC_SRC_STDIO_SCANF_CORE_VFSCANF_INTERNAL_H

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