[libc] Templatize the scanf Reader interface #131037
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@llvm/pr-subscribers-libc Author: Petr Hosek (petrhosek) ChangesThis allows specializing the implementation for different targets without including unnecessary logic and is similar to #111559 which did the same for printf Writer interface. Patch is 76.96 KiB, truncated to 20.00 KiB below, full version: https://github.com/llvm/llvm-project/pull/131037.diff 32 Files Affected:
diff --git a/libc/config/baremetal/aarch64/entrypoints.txt b/libc/config/baremetal/aarch64/entrypoints.txt
index 2c226ef176c08..8b51942d30fe8 100644
--- a/libc/config/baremetal/aarch64/entrypoints.txt
+++ b/libc/config/baremetal/aarch64/entrypoints.txt
@@ -123,18 +123,22 @@ set(TARGET_LIBC_ENTRYPOINTS
libc.src.inttypes.strtoumax
# stdio.h entrypoints
+ libc.src.stdio.asprintf
libc.src.stdio.getchar
libc.src.stdio.printf
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.vasprintf
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..511d9d22f1450 100644
--- a/libc/config/baremetal/arm/entrypoints.txt
+++ b/libc/config/baremetal/arm/entrypoints.txt
@@ -123,18 +123,22 @@ set(TARGET_LIBC_ENTRYPOINTS
libc.src.inttypes.strtoumax
# stdio.h entrypoints
+ libc.src.stdio.asprintf
libc.src.stdio.getchar
libc.src.stdio.printf
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.vasprintf
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..bbefb75ee16b5 100644
--- a/libc/config/baremetal/riscv/entrypoints.txt
+++ b/libc/config/baremetal/riscv/entrypoints.txt
@@ -119,18 +119,22 @@ set(TARGET_LIBC_ENTRYPOINTS
libc.src.inttypes.strtoumax
# stdio.h entrypoints
+ libc.src.stdio.asprintf
libc.src.stdio.getchar
libc.src.stdio.printf
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.vasprintf
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/baremetal/scanf.cpp b/libc/src/stdio/baremetal/scanf.cpp
new file mode 100644
index 0000000000000..1b0bf3e3afd54
--- /dev/null
+++ b/libc/src/stdio/baremetal/scanf.cpp
@@ -0,0 +1,52 @@
+//===-- 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 "hdr/stdio_macros.h"
+#include "src/__support/OSUtil/io.h"
+#include "src/__support/arg_list.h"
+#include "src/__support/macros/config.h"
+#include "src/stdio/scanf_core/reader.h"
+#include "src/stdio/scanf_core/scanf_main.h"
+
+#include <stdarg.h>
+
+namespace LIBC_NAMESPACE_DECL {
+
+namespace {
+
+struct StreamBuffer : scanf_core::ReadBuffer<StreamBuffer> {
+ LIBC_INLINE char getc() {
+ char buf[1];
+ read_from_stdin(buf, sizeof(buf));
+ return buf[0];
+ }
+ LIBC_INLINE void ungetc(int) {}
+};
+
+} // namespace
+
+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);
+
+ StreamBuffer buffer;
+ scanf_core::Reader<StreamBuffer> reader(&buffer);
+
+ int retval = 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 retval".
+ return (retval == -1) ? EOF : retval;
+}
+
+} // namespace LIBC_NAMESPACE_DECL
diff --git a/libc/src/stdio/baremetal/vscanf.cpp b/libc/src/stdio/baremetal/vscanf.cpp
new file mode 100644
index 0000000000000..e0119d6146d89
--- /dev/null
+++ b/libc/src/stdio/baremetal/vscanf.cpp
@@ -0,0 +1,51 @@
+//===-- 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 "hdr/stdio_macros.h"
+#include "src/__support/OSUtil/io.h"
+#include "src/__support/arg_list.h"
+#include "src/__support/macros/config.h"
+#include "src/stdio/scanf_core/reader.h"
+#include "src/stdio/scanf_core/scanf_main.h"
+
+#include <stdarg.h>
+
+namespace LIBC_NAMESPACE_DECL {
+
+namespace {
+
+struct StreamBuffer : scanf_core::ReadBuffer<StreamBuffer> {
+ LIBC_INLINE char getc() {
+ char buf[1];
+ read_from_stdin(buf, sizeof(buf));
+ return buf[0];
+ }
+ LIBC_INLINE void ungetc(int) {}
+};
+
+} // namespace
+
+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);
+
+ StreamBuffer buffer;
+ scanf_core::Reader<StreamBuffer> reader(&buffer);
+
+ int retval = 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 retval".
+ return (retval == -1) ? EOF : retval;
+}
+
+} // 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/fscanf.cpp b/libc/src/stdio/generic/fscanf.cpp
similarity index 100%
rename from libc/src/stdio/fscanf.cpp
rename to libc/src/stdio/generic/fscanf.cpp
diff --git a/libc/src/stdio/scanf.cpp b/libc/src/stdio/generic/scanf.cpp
similarity index 100%
rename from libc/src/stdio/scanf.cpp
rename to libc/src/stdio/generic/scanf.cpp
diff --git a/libc/src/stdio/vfscanf.cpp b/libc/src/stdio/generic/vfscanf.cpp
similarity index 100%
rename from libc/src/stdio/vfscanf.cpp
rename to libc/src/stdio/generic/vfscanf.cpp
diff --git a/libc/src/stdio/vscanf.cpp b/libc/src/stdio/generic/vscanf.cpp
similarity index 100%
rename from libc/src/stdio/vscanf.cpp
rename to libc/src/stdio/generic/vscanf.cpp
diff --git a/libc/src/stdio/scanf_core/CMakeLists.txt b/libc/src/stdio/scanf_core/CMakeLists.txt
index 014413ccaa8da..3de1e6a6eea37 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
@@ -54,17 +56,8 @@ 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(
+add_header_library(
scanf_main
- SRCS
- scanf_main.cpp
HDRS
scanf_main.h
DEPENDS
@@ -87,14 +80,8 @@ add_header_library(
${use_system_file}
)
-add_object_library(
+add_header_library(
converter
- SRCS
- converter.cpp
- string_converter.cpp
- int_converter.cpp
- float_converter.cpp
- ptr_converter.cpp
HDRS
converter.h
converter_utils.h
diff --git a/libc/src/stdio/scanf_core/converter.cpp b/libc/src/stdio/scanf_core/converter.cpp
index b1ee8cd1e74bb..fb234ce7864cf 100644
--- a/libc/src/stdio/scanf_core/converter.cpp
+++ b/libc/src/stdio/scanf_core/converter.cpp
@@ -26,78 +26,5 @@
namespace LIBC_NAMESPACE_DECL {
namespace scanf_core {
-int convert(Reader *reader, const FormatSection &to_conv) {
- int ret_val = 0;
- switch (to_conv.conv_name) {
- case '%':
- return raw_match(reader, "%");
- case 's':
- ret_val = raw_match(reader, " ");
- if (ret_val != READ_OK)
- return ret_val;
- return convert_string(reader, to_conv);
- case 'c':
- case '[':
- return convert_string(reader, to_conv);
- case 'd':
- case 'i':
- case 'u':
- case 'o':
- case 'x':
- case 'X':
- ret_val = raw_match(reader, " ");
- if (ret_val != READ_OK)
- return ret_val;
- return convert_int(reader, to_conv);
-#ifndef LIBC_COPT_SCANF_DISABLE_FLOAT
- case 'f':
- case 'F':
- case 'e':
- case 'E':
- case 'a':
- case 'A':
- case 'g':
- case 'G':
- ret_val = raw_match(reader, " ");
- if (ret_val != READ_OK)
- return ret_val;
- return convert_float(reader, to_conv);
-#endif // LIBC_COPT_SCANF_DISABLE_FLOAT
- case 'n':
- return convert_current_pos(reader, to_conv);
- case 'p':
- ret_val = raw_match(reader, " ");
- if (ret_val != READ_OK)
- return ret_val;
- return convert_pointer(reader, to_conv);
- default:
- return raw_match(reader, to_conv.raw_string);
- }
- return -1;
-}
-
-// raw_string is assumed to have a positive size.
-int raw_match(Reader *reader, cpp::string_view raw_string) {
- char cur_char = reader->getc();
- int ret_val = READ_OK;
- for (size_t i = 0; i < raw_string.size(); ++i) {
- // Any space character matches any number of space characters.
- if (internal::isspace(raw_string[i])) {
- while (internal::isspace(cur_char)) {
- cur_char = reader->getc();
- }
- } else {
- if (raw_string[i] == cur_char) {
- cur_char = reader->getc();
- } else {
- ret_val = MATCHING_FAILURE;
- break;
- }
- }
- }
- reader->ungetc(cur_char);
- return ret_val;
-}
-
} // namespace scanf_core
} // namespace LIBC_NAMESPACE_DECL
diff --git a/libc/src/stdio/scanf_core/converter.h b/libc/src/stdio/scanf_core/converter.h
index 3f514eeb75bdf..3df43e9de1e25 100644
--- a/libc/src/stdio/scanf_core/converter.h
+++ b/libc/src/stdio/scanf_core/converter.h
@@ -10,10 +10,19 @@
#define LLVM_LIBC_SRC_STDIO_SCANF_CORE_CONVERTER_H
#include "src/__support/CPP/string_view.h"
+#include "src/__support/ctype_utils.h"
#include "src/__support/macros/config.h"
#include "src/stdio/scanf_core/core_structs.h"
#include "src/stdio/scanf_core/reader.h"
+#ifndef LIBC_COPT_SCANF_DISABLE_FLOAT
+#include "src/stdio/scanf_core/float_converter.h"
+#endif // LIBC_COPT_SCANF_DISABLE_FLOAT
+#include "src/stdio/scanf_core/current_pos_converter.h"
+#include "src/stdio/scanf_core/int_converter.h"
+#include "src/stdio/scanf_core/ptr_converter.h"
+#include "src/stdio/scanf_core/string_converter.h"
+
#include <stddef.h>
namespace LIBC_NAMESPACE_DECL {
@@ -22,11 +31,81 @@ namespace scanf_core {
// convert will call a conversion function to convert the FormatSection into
// its string representation, and then that will write the result to the
// reader.
-int convert(Reader *reader, const FormatSection &to_conv);
+template <typename T>
+int convert(Reader<T> *reader, const FormatSection &to_conv) {
+ int ret_val = 0;
+ switch (to_conv.conv_name) {
+ case '%':
+ return raw_match(reader, "%");
+ case 's':
+ ret_val = raw_match(reader, " ");
+ if (ret_val != READ_OK)
+ return ret_val;
+ return convert_string(reader, to_conv);
+ case 'c':
+ case '[':
+ return convert_string(reader, to_conv);
+ case 'd':
+ case 'i':
+ case 'u':
+ case 'o':
+ case 'x':
+ case 'X':
+ ret_val = raw_match(reader, " ");
+ if (ret_val != READ_OK)
+ return ret_val;
+ return convert_int(reader, to_conv);
+#ifndef LIBC_COPT_SCANF_DISABLE_FLOAT
+ case 'f':
+ case 'F':
+ case 'e':
+ case 'E':
+ case 'a':
+ case 'A':
+ case 'g':
+ case 'G':
+ ret_val = raw_match(reader, " ");
+ if (ret_val != READ_OK)
+ return ret_val;
+ return convert_float(reader, to_conv);
+#endif // LIBC_COPT_SCANF_DISABLE_FLOAT
+ case 'n':
+ return convert_current_pos(reader, to_conv);
+ case 'p':
+ ret_val = raw_match(reader, " ");
+ if (ret_val != READ_OK)
+ return ret_val;
+ return convert_pointer(reader, to_conv);
+ default:
+ return raw_match(reader, to_conv.raw_string);
+ }
+ return -1;
+}
// raw_match takes a raw string and matches it to the characters obtained from
// the reader.
-int raw_match(Reader *reader, cpp::string_view raw_string);
+template <typename T>
+int raw_match(Reader<T> *reader, cpp::string_view raw_string) {
+ char cur_char = reader->getc();
+ int ret_val = READ_OK;
+ for (size_t i = 0; i < raw_string.size(); ++i) {
+ // Any space character matches any number of space characters.
+ if (internal::isspace(raw_string[i])) {
+ while (internal::isspace(cur_char)) {
+ cur_char = reader->getc();
+ }
+ } else {
+ if (raw_string[i] == cur_char) {
+ cur_char = reader->getc();
+ } else {
+ ret_val = MATCHING_FAILURE;
+ break;
+ }
+ }
+ }
+ reader->ungetc(cur_char);
+ return ret_val;
+}
} // namespace scanf_core
} // namespace LIBC_NAMESPACE_DECL
diff --git a/libc/src/stdio/scanf_core/current_pos_converter.h b/libc/src/stdio/scanf_core/current_pos_converter.h
index 8af1cc0ca0c27..8708490c82d3e 100644
--- a/libc/src/stdio/scanf_core/current_pos_converter.h
+++ b/libc/src/stdio/scanf_core/current_pos_converter.h
@@ -19,7 +19,8 @@
namespace LIBC_NAMESPACE_DECL {
namespace scanf_core {
-LIBC_INLINE int convert_current_pos(Reader *reader,
+template <typename T>
+LIBC_INLINE int convert_current_pos(Reader<T> *reader,
const FormatSection &to_conv) {
write_int_with_length(reader->chars_read(), to_conv);
return READ_OK;
diff --git a/libc/src/stdio/scanf_core/float_converter.cpp b/libc/src/stdio/scanf_core/float_converter.cpp
deleted file mode 100644
index 9c714d0727214..0000000000000
--- a/libc/src/stdio/scanf_core/float_converter.cpp
+++ /dev/null
@@ -1,229 +0,0 @@
-//===-- Int type specifier converters for 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_core/float_converter.h"
-
-#include "src/__support/CPP/limits.h"
-#include "src/__support/char_vector.h"
-#include "src/__support/ctype_utils.h"
-#include "src/__support/macros/config.h"
-#include "src/stdio/scanf_core/converter_utils.h"
-#include "src/stdio/scanf_core/core_structs.h"
-#include "src/stdio/scanf_core/reader.h"
-
-#include <stddef.h>
-
-namespace LIBC_NAMESPACE_DECL {
-namespace scanf_core {
-
-// All of the floating point conversions are the same for scanf, every name will
-// accept every style.
-int convert_float(Reader *reader, const FormatSection &to_conv) {
- // %a/A/e/E/f/F/g/G "Matches an optionally signed floating-point number,
- // infinity, or NaN, whose format is the same as expected for the subject
- // sequence of the strtod function. The corresponding argument shall be a
- // pointer to floating."
-
- CharVector out_str = CharVector();
- bool is_number = false;
-
- size_t max_width = cpp::numeric_limits<size_t>::max();
- if (to_conv.max_width > 0) {
- max_width = to_conv.max_width;
- }
-
- char cur_char = reader->getc();
- // Handle the sign.
- if (cur_char == '+' || cur_char == '-') {
- if (!...
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This PR currently also includes support for |
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@michaelrj-google Do you have any opinion on keeping |
This allows specializing the implementation for different targets without including unnecessary logic and is similar to llvm#111559 which did the same for printf Writer interface.
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This uses the templatized scanf Reader interface introduced in llvm#131037.
I moved the baremetal implementation of |
| @@ -26,78 +26,5 @@ | |||
| namespace LIBC_NAMESPACE_DECL { | |||
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this file can be deleted.
libc/src/stdio/scanf_core/reader.h
Outdated
| class Reader { | ||
| ReadBuffer *rb; | ||
| void *input_stream = nullptr; | ||
| // TODO: We should be able to fold ReadBuffer into Reader. |
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How about this:
template <typename Derived> class Reader {
size_t cur_chars_read = 0;
public:
// This returns the next character from the input and advances it by one
// character. When it hits the end of the string or file it returns '\0' to
// signal to stop parsing.
LIBC_INLINE char getc() {
++cur_chars_read;
return static_cast<Derived *>(this)->getc();
}
// This moves the input back by one character, placing c into the buffer if
// this is a file reader, else c is ignored.
LIBC_INLINE void ungetc(char c) {
--cur_chars_read;
static_cast<Derived *>(this)->ungetc(c);
}
LIBC_INLINE size_t chars_read() { return cur_chars_read; }
};
class StringReader : public Reader<StringReader> {
const char *buffer;
[[maybe_unused]] size_t buff_len;
size_t buff_cur = 0;
public:
LIBC_INLINE StringReader(const char *buffer, size_t buff_len)
: buffer(buffer), buff_len(buff_len) {}
LIBC_INLINE char getc() {
char output = buffer[buff_cur];
++buff_cur;
return output;
}
LIBC_INLINE void ungetc(int) {
if (buff_cur > 0) {
// While technically c should be written back to the buffer, in scanf we
// always write the character that was already there. Additionally, the
// buffer is most likely to contain a string that isn't part of a file,
// which may not be writable.
--buff_cur;
}
}
};I'm fine with merging them in this way since the subclass already needs to track state, so making it fully static wouldn't work.
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| class StreamBuffer : public ReadBuffer<StreamBuffer> { | ||
| ::FILE *stream; | ||
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| public: | ||
| LIBC_INLINE StreamBuffer(::FILE *stream) : stream(stream) {} | ||
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| LIBC_INLINE char getc() { | ||
| return static_cast<char>(internal::getc(static_cast<FILE *>(stream))); | ||
| } | ||
| LIBC_INLINE void ungetc(int c) { | ||
| internal::ungetc(c, static_cast<FILE *>(stream)); | ||
| } | ||
| }; | ||
|
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I'd like to also add a dynamic dispatch reader that stores a union of StringReader and StreamReader so to make that simpler I'd like to move each reader subclass into its own file.
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✅ With the latest revision this PR passed the C/C++ code formatter. |
|
LLVM Buildbot has detected a new failure on builder Full details are available at: https://lab.llvm.org/buildbot/#/builders/10/builds/1542 Here is the relevant piece of the build log for the reference |
|
LLVM Buildbot has detected a new failure on builder Full details are available at: https://lab.llvm.org/buildbot/#/builders/73/builds/14781 Here is the relevant piece of the build log for the reference |
petrhosek
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This uses the templatized scanf Reader interface introduced in #131037.
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This allows specializing the implementation for different targets without including unnecessary logic and is similar to #111559 which did the same for printf Writer interface.