[libc] Support for scanf on baremetal #131043
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@llvm/pr-subscribers-libc Author: Petr Hosek (petrhosek) ChangesThis uses the templatized scanf Reader interface introduced in #131037. Full diff: https://github.com/llvm/llvm-project/pull/131043.diff 13 Files Affected:
diff --git a/libc/config/baremetal/aarch64/entrypoints.txt b/libc/config/baremetal/aarch64/entrypoints.txt
index 2c226ef176c08..ffe7e622279a0 100644
--- a/libc/config/baremetal/aarch64/entrypoints.txt
+++ b/libc/config/baremetal/aarch64/entrypoints.txt
@@ -128,13 +128,15 @@ set(TARGET_LIBC_ENTRYPOINTS
libc.src.stdio.putchar
libc.src.stdio.puts
libc.src.stdio.remove
+ libc.src.stdio.scanf
libc.src.stdio.snprintf
libc.src.stdio.sprintf
- libc.src.stdio.asprintf
+ libc.src.stdio.sscanf
libc.src.stdio.vprintf
+ libc.src.stdio.vscanf
libc.src.stdio.vsnprintf
libc.src.stdio.vsprintf
- libc.src.stdio.vasprintf
+ libc.src.stdio.vsscanf
# stdbit.h entrypoints
libc.src.stdbit.stdc_bit_ceil_uc
diff --git a/libc/config/baremetal/arm/entrypoints.txt b/libc/config/baremetal/arm/entrypoints.txt
index d7a01bdf90b3f..a6628d1c56219 100644
--- a/libc/config/baremetal/arm/entrypoints.txt
+++ b/libc/config/baremetal/arm/entrypoints.txt
@@ -128,13 +128,15 @@ set(TARGET_LIBC_ENTRYPOINTS
libc.src.stdio.putchar
libc.src.stdio.puts
libc.src.stdio.remove
+ libc.src.stdio.scanf
libc.src.stdio.snprintf
libc.src.stdio.sprintf
- libc.src.stdio.asprintf
+ libc.src.stdio.sscanf
libc.src.stdio.vprintf
+ libc.src.stdio.vscanf
libc.src.stdio.vsnprintf
libc.src.stdio.vsprintf
- libc.src.stdio.vasprintf
+ libc.src.stdio.vsscanf
# stdbit.h entrypoints
libc.src.stdbit.stdc_bit_ceil_uc
diff --git a/libc/config/baremetal/riscv/entrypoints.txt b/libc/config/baremetal/riscv/entrypoints.txt
index ae00803dd0def..ccbcb85a216a8 100644
--- a/libc/config/baremetal/riscv/entrypoints.txt
+++ b/libc/config/baremetal/riscv/entrypoints.txt
@@ -124,13 +124,15 @@ set(TARGET_LIBC_ENTRYPOINTS
libc.src.stdio.putchar
libc.src.stdio.puts
libc.src.stdio.remove
+ libc.src.stdio.scanf
libc.src.stdio.snprintf
libc.src.stdio.sprintf
- libc.src.stdio.asprintf
+ libc.src.stdio.sscanf
libc.src.stdio.vprintf
+ libc.src.stdio.vscanf
libc.src.stdio.vsnprintf
libc.src.stdio.vsprintf
- libc.src.stdio.vasprintf
+ libc.src.stdio.vsscanf
# stdbit.h entrypoints
libc.src.stdbit.stdc_bit_ceil_uc
diff --git a/libc/src/stdio/CMakeLists.txt b/libc/src/stdio/CMakeLists.txt
index b9bc904471df9..23c103c1d6465 100644
--- a/libc/src/stdio/CMakeLists.txt
+++ b/libc/src/stdio/CMakeLists.txt
@@ -95,20 +95,6 @@ add_entrypoint_object(
libc.src.__support.File.platform_file
)
-list(APPEND scanf_deps
- libc.src.__support.arg_list
- libc.src.stdio.scanf_core.vfscanf_internal
- libc.hdr.types.FILE
-)
-
-if(LLVM_LIBC_FULL_BUILD AND NOT LIBC_TARGET_OS_IS_GPU)
- list(APPEND scanf_deps
- libc.src.__support.File.file
- libc.src.__support.File.platform_file
- libc.src.__support.File.platform_stdin
- )
-endif()
-
add_entrypoint_object(
sscanf
SRCS
@@ -133,46 +119,6 @@ add_entrypoint_object(
libc.src.stdio.scanf_core.scanf_main
)
-add_entrypoint_object(
- fscanf
- SRCS
- fscanf.cpp
- HDRS
- fscanf.h
- DEPENDS
- ${scanf_deps}
-)
-
-add_entrypoint_object(
- vfscanf
- SRCS
- vfscanf.cpp
- HDRS
- vfscanf.h
- DEPENDS
- ${scanf_deps}
-)
-
-add_entrypoint_object(
- scanf
- SRCS
- scanf.cpp
- HDRS
- scanf.h
- DEPENDS
- ${scanf_deps}
-)
-
-add_entrypoint_object(
- vscanf
- SRCS
- vscanf.cpp
- HDRS
- vscanf.h
- DEPENDS
- ${scanf_deps}
-)
-
add_entrypoint_object(
sprintf
SRCS
@@ -295,8 +241,12 @@ add_stdio_entrypoint_object(getchar)
add_stdio_entrypoint_object(getchar_unlocked)
add_stdio_entrypoint_object(fgets)
add_stdio_entrypoint_object(ungetc)
+add_stdio_entrypoint_object(scanf)
+add_stdio_entrypoint_object(fscanf)
add_stdio_entrypoint_object(stdin)
add_stdio_entrypoint_object(stdout)
add_stdio_entrypoint_object(stderr)
add_stdio_entrypoint_object(vprintf)
add_stdio_entrypoint_object(vfprintf)
+add_stdio_entrypoint_object(vscanf)
+add_stdio_entrypoint_object(vfscanf)
diff --git a/libc/src/stdio/baremetal/CMakeLists.txt b/libc/src/stdio/baremetal/CMakeLists.txt
index c5cf4a8e0e5b5..4abe8bc66b25b 100644
--- a/libc/src/stdio/baremetal/CMakeLists.txt
+++ b/libc/src/stdio/baremetal/CMakeLists.txt
@@ -55,6 +55,19 @@ add_entrypoint_object(
libc.src.__support.CPP.string_view
)
+add_entrypoint_object(
+ scanf
+ SRCS
+ scanf.cpp
+ HDRS
+ ../scanf.h
+ DEPENDS
+ libc.src.stdio.scanf_core.scanf_main
+ libc.src.stdio.scanf_core.reader
+ libc.src.__support.arg_list
+ libc.src.__support.OSUtil.osutil
+)
+
add_entrypoint_object(
vprintf
SRCS
@@ -67,3 +80,16 @@ add_entrypoint_object(
libc.src.__support.arg_list
libc.src.__support.OSUtil.osutil
)
+
+add_entrypoint_object(
+ vscanf
+ SRCS
+ vscanf.cpp
+ HDRS
+ ../vscanf.h
+ DEPENDS
+ libc.src.stdio.scanf_core.scanf_main
+ libc.src.stdio.scanf_core.reader
+ libc.src.__support.arg_list
+ libc.src.__support.OSUtil.osutil
+)
diff --git a/libc/src/stdio/fscanf.cpp b/libc/src/stdio/fscanf.cpp
deleted file mode 100644
index 94b843978749e..0000000000000
--- a/libc/src/stdio/fscanf.cpp
+++ /dev/null
@@ -1,36 +0,0 @@
-//===-- Implementation of fscanf --------------------------------*- C++ -*-===//
-//
-// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-// See https://llvm.org/LICENSE.txt for license information.
-// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-//
-//===----------------------------------------------------------------------===//
-
-#include "src/stdio/fscanf.h"
-
-#include "src/__support/File/file.h"
-#include "src/__support/arg_list.h"
-#include "src/__support/macros/config.h"
-#include "src/stdio/scanf_core/vfscanf_internal.h"
-
-#include "hdr/types/FILE.h"
-#include <stdarg.h>
-
-namespace LIBC_NAMESPACE_DECL {
-
-LLVM_LIBC_FUNCTION(int, fscanf,
- (::FILE *__restrict stream, const char *__restrict format,
- ...)) {
- va_list vlist;
- va_start(vlist, format);
- internal::ArgList args(vlist); // This holder class allows for easier copying
- // and pointer semantics, as well as handling
- // destruction automatically.
- va_end(vlist);
- int ret_val = scanf_core::vfscanf_internal(stream, format, args);
- // This is done to avoid including stdio.h in the internals. On most systems
- // EOF is -1, so this will be transformed into just "return ret_val".
- return (ret_val == -1) ? EOF : ret_val;
-}
-
-} // namespace LIBC_NAMESPACE_DECL
diff --git a/libc/src/stdio/generic/CMakeLists.txt b/libc/src/stdio/generic/CMakeLists.txt
index bf301a6b0cb3c..9f568c5ab8d3a 100644
--- a/libc/src/stdio/generic/CMakeLists.txt
+++ b/libc/src/stdio/generic/CMakeLists.txt
@@ -425,6 +425,60 @@ add_entrypoint_object(
${fprintf_deps}
)
+list(APPEND scanf_deps
+ libc.src.__support.arg_list
+ libc.src.stdio.scanf_core.vfscanf_internal
+ libc.hdr.types.FILE
+)
+
+if(LLVM_LIBC_FULL_BUILD AND NOT LIBC_TARGET_OS_IS_GPU)
+ list(APPEND scanf_deps
+ libc.src.__support.File.file
+ libc.src.__support.File.platform_file
+ libc.src.__support.File.platform_stdin
+ )
+endif()
+
+add_entrypoint_object(
+ fscanf
+ SRCS
+ fscanf.cpp
+ HDRS
+ ../fscanf.h
+ DEPENDS
+ ${scanf_deps}
+)
+
+add_entrypoint_object(
+ vfscanf
+ SRCS
+ vfscanf.cpp
+ HDRS
+ ../vfscanf.h
+ DEPENDS
+ ${scanf_deps}
+)
+
+add_entrypoint_object(
+ scanf
+ SRCS
+ scanf.cpp
+ HDRS
+ ../scanf.h
+ DEPENDS
+ ${scanf_deps}
+)
+
+add_entrypoint_object(
+ vscanf
+ SRCS
+ vscanf.cpp
+ HDRS
+ ../vscanf.h
+ DEPENDS
+ ${scanf_deps}
+)
+
add_entrypoint_object(
fgets
SRCS
diff --git a/libc/src/stdio/scanf.cpp b/libc/src/stdio/scanf.cpp
deleted file mode 100644
index 86a8851df2886..0000000000000
--- a/libc/src/stdio/scanf.cpp
+++ /dev/null
@@ -1,41 +0,0 @@
-//===-- Implementation of scanf ---------------------------------*- C++ -*-===//
-//
-// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-// See https://llvm.org/LICENSE.txt for license information.
-// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-//
-//===----------------------------------------------------------------------===//
-
-#include "src/stdio/scanf.h"
-
-#include "src/__support/File/file.h"
-#include "src/__support/arg_list.h"
-#include "src/__support/macros/config.h"
-#include "src/stdio/scanf_core/vfscanf_internal.h"
-
-#include "hdr/types/FILE.h"
-#include <stdarg.h>
-
-#ifndef LIBC_COPT_STDIO_USE_SYSTEM_FILE
-#define SCANF_STDIN LIBC_NAMESPACE::stdin
-#else // LIBC_COPT_STDIO_USE_SYSTEM_FILE
-#define SCANF_STDIN ::stdin
-#endif // LIBC_COPT_STDIO_USE_SYSTEM_FILE
-
-namespace LIBC_NAMESPACE_DECL {
-
-LLVM_LIBC_FUNCTION(int, scanf, (const char *__restrict format, ...)) {
- va_list vlist;
- va_start(vlist, format);
- internal::ArgList args(vlist); // This holder class allows for easier copying
- // and pointer semantics, as well as handling
- // destruction automatically.
- va_end(vlist);
- int ret_val = scanf_core::vfscanf_internal(
- reinterpret_cast<::FILE *>(SCANF_STDIN), format, args);
- // This is done to avoid including stdio.h in the internals. On most systems
- // EOF is -1, so this will be transformed into just "return ret_val".
- return (ret_val == -1) ? EOF : ret_val;
-}
-
-} // namespace LIBC_NAMESPACE_DECL
diff --git a/libc/src/stdio/scanf_core/CMakeLists.txt b/libc/src/stdio/scanf_core/CMakeLists.txt
index 014413ccaa8da..714b174892504 100644
--- a/libc/src/stdio/scanf_core/CMakeLists.txt
+++ b/libc/src/stdio/scanf_core/CMakeLists.txt
@@ -16,6 +16,8 @@ if(LIBC_TARGET_OS_IS_GPU)
libc.src.stdio.ungetc
libc.src.stdio.ferror
)
+elseif(LIBC_TARGET_OS_IS_BAREMETAL)
+ # There's no FILE* for baremetal.
elseif(LLVM_LIBC_FULL_BUILD)
list(APPEND file_deps
libc.src.__support.File.file
@@ -54,13 +56,6 @@ add_header_library(
libc.src.__support.CPP.string_view
)
-if(NOT(TARGET libc.src.__support.File.file) AND LLVM_LIBC_FULL_BUILD AND
- (NOT LIBC_TARGET_OS_IS_GPU))
- # Not all platforms have a file implementation. If file is unvailable, and a
- # full build is requested, then we must skip all file based scanf sections.
- return()
-endif()
-
add_object_library(
scanf_main
SRCS
diff --git a/libc/src/stdio/sscanf.cpp b/libc/src/stdio/sscanf.cpp
index 82de8a29f6ad1..ec4e10caf6cb5 100644
--- a/libc/src/stdio/sscanf.cpp
+++ b/libc/src/stdio/sscanf.cpp
@@ -29,8 +29,8 @@ LLVM_LIBC_FUNCTION(int, sscanf,
// and pointer semantics, as well as handling
// destruction automatically.
va_end(vlist);
- scanf_core::ReadBuffer rb{buffer, cpp::numeric_limits<size_t>::max()};
- scanf_core::Reader reader(&rb);
+ scanf_core::StringBuffer rb(buffer, cpp::numeric_limits<size_t>::max());
+ scanf_core::Reader<scanf_core::StringBuffer> reader(&rb);
int ret_val = scanf_core::scanf_main(&reader, format, args);
// This is done to avoid including stdio.h in the internals. On most systems
// EOF is -1, so this will be transformed into just "return ret_val".
diff --git a/libc/src/stdio/vfscanf.cpp b/libc/src/stdio/vfscanf.cpp
deleted file mode 100644
index 220576522d0fd..0000000000000
--- a/libc/src/stdio/vfscanf.cpp
+++ /dev/null
@@ -1,34 +0,0 @@
-//===-- Implementation of vfscanf -------------------------------*- C++ -*-===//
-//
-// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-// See https://llvm.org/LICENSE.txt for license information.
-// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-//
-//===----------------------------------------------------------------------===//
-
-#include "src/stdio/vfscanf.h"
-
-#include "src/__support/File/file.h"
-#include "src/__support/arg_list.h"
-#include "src/__support/macros/config.h"
-#include "src/stdio/scanf_core/vfscanf_internal.h"
-
-#include "hdr/types/FILE.h"
-#include <stdarg.h>
-
-namespace LIBC_NAMESPACE_DECL {
-
-LLVM_LIBC_FUNCTION(int, vfscanf,
- (::FILE *__restrict stream, const char *__restrict format,
- va_list vlist)) {
- internal::ArgList args(vlist); // This holder class allows for easier copying
- // and pointer semantics, as well as handling
- // destruction automatically.
- va_end(vlist);
- int ret_val = scanf_core::vfscanf_internal(stream, format, args);
- // This is done to avoid including stdio.h in the internals. On most systems
- // EOF is -1, so this will be transformed into just "return ret_val".
- return (ret_val == -1) ? EOF : ret_val;
-}
-
-} // namespace LIBC_NAMESPACE_DECL
diff --git a/libc/src/stdio/vscanf.cpp b/libc/src/stdio/vscanf.cpp
deleted file mode 100644
index 64f5cc1d6962a..0000000000000
--- a/libc/src/stdio/vscanf.cpp
+++ /dev/null
@@ -1,40 +0,0 @@
-//===-- Implementation of vscanf --------------------------------*- C++ -*-===//
-//
-// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-// See https://llvm.org/LICENSE.txt for license information.
-// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-//
-//===----------------------------------------------------------------------===//
-
-#include "src/stdio/vscanf.h"
-
-#include "src/__support/File/file.h"
-#include "src/__support/arg_list.h"
-#include "src/__support/macros/config.h"
-#include "src/stdio/scanf_core/vfscanf_internal.h"
-
-#include "hdr/types/FILE.h"
-#include <stdarg.h>
-
-#ifndef LIBC_COPT_STDIO_USE_SYSTEM_FILE
-#define SCANF_STDIN LIBC_NAMESPACE::stdin
-#else // LIBC_COPT_STDIO_USE_SYSTEM_FILE
-#define SCANF_STDIN ::stdin
-#endif // LIBC_COPT_STDIO_USE_SYSTEM_FILE
-
-namespace LIBC_NAMESPACE_DECL {
-
-LLVM_LIBC_FUNCTION(int, vscanf,
- (const char *__restrict format, va_list vlist)) {
- internal::ArgList args(vlist); // This holder class allows for easier copying
- // and pointer semantics, as well as handling
- // destruction automatically.
- va_end(vlist);
- int ret_val = scanf_core::vfscanf_internal(
- reinterpret_cast<::FILE *>(SCANF_STDIN), format, args);
- // This is done to avoid including stdio.h in the internals. On most systems
- // EOF is -1, so this will be transformed into just "return ret_val".
- return (ret_val == -1) ? EOF : ret_val;
-}
-
-} // namespace LIBC_NAMESPACE_DECL
diff --git a/libc/src/stdio/vsscanf.cpp b/libc/src/stdio/vsscanf.cpp
index f3f56bce64292..e3e2fe34c32ec 100644
--- a/libc/src/stdio/vsscanf.cpp
+++ b/libc/src/stdio/vsscanf.cpp
@@ -21,9 +21,9 @@ namespace LIBC_NAMESPACE_DECL {
LLVM_LIBC_FUNCTION(int, vsscanf,
(const char *buffer, const char *format, va_list vlist)) {
internal::ArgList args(vlist);
- scanf_core::ReadBuffer rb{const_cast<char *>(buffer),
- cpp::numeric_limits<size_t>::max()};
- scanf_core::Reader reader(&rb);
+ scanf_core::StringBuffer rb{const_cast<char *>(buffer),
+ cpp::numeric_limits<size_t>::max()};
+ scanf_core::Reader<scanf_core::StringBuffer> reader(&rb);
int ret_val = scanf_core::scanf_main(&reader, format, args);
// This is done to avoid including stdio.h in the internals. On most systems
// EOF is -1, so this will be transformed into just "return ret_val".
|
This uses the templatized scanf Reader interface introduced in llvm#131037.
petrhosek
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@michaelrj-google This is ready for review now. |
jhuber6
reviewed
Mar 18, 2025
| libc.hdr.types.FILE | ||
| ) | ||
|
|
||
| if(LLVM_LIBC_FULL_BUILD AND NOT LIBC_TARGET_OS_IS_GPU) |
There was a problem hiding this comment.
Is this not needed anymore?
There was a problem hiding this comment.
It was moved to libc/src/stdio/generic/CMakeLists.txt.
jhuber6
approved these changes
Mar 18, 2025
libc/src/stdio/baremetal/vscanf.cpp
Outdated
|
|
||
| namespace { | ||
|
|
||
| struct StreamReader : scanf_core::Reader<StreamReader> { |
There was a problem hiding this comment.
nit: this should be named BaremetalReader or something other than StreamReader to keep it clear which is which.
There was a problem hiding this comment.
Done, I went with StdinReader.
libc/src/stdio/baremetal/scanf.cpp
Outdated
Comment on lines
24
to
33
| struct StreamReader : scanf_core::Reader<StreamReader> { | ||
| LIBC_INLINE char getc() { | ||
| char buf[1]; | ||
| auto result = read_from_stdin(buf, sizeof(buf)); | ||
| if (result <= 0) | ||
| return EOF; | ||
| return buf[0]; | ||
| } | ||
| LIBC_INLINE void ungetc(int) {} | ||
| }; |
There was a problem hiding this comment.
would it make sense to have a shared header that defines this? Similar to fvscanf_internal.h
There was a problem hiding this comment.
Done, I moved the implementation to scanf_internal.h.
I did, it should be included now. |
|
LLVM Buildbot has detected a new failure on builder Full details are available at: https://lab.llvm.org/buildbot/#/builders/10/builds/1791 Here is the relevant piece of the build log for the reference |
michaelrj-google
added a commit
to michaelrj-google/llvm-project
that referenced
this pull request
Mar 20, 2025
The scanf and fscanf implementations were moved into /generic, update the bazel targets.
michaelrj-google
added a commit
that referenced
this pull request
Mar 21, 2025
|
This broke the libc on AMDGPU bot https://lab.llvm.org/buildbot/#/builders/10/builds/1791 |
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This uses the templatized scanf Reader interface introduced in #131037.