[libc] Implement strftime

Author: tszhin-swe

libc/src/stdio/CMakeLists.txt

@@ -239,7 +239,6 @@ add_entrypoint_object(
 
 add_subdirectory(printf_core)
 add_subdirectory(scanf_core)
-add_subdirectory(strftime_core)
 
 add_entrypoint_object(
   remove

libc/src/stdio/strftime_core/CMakeLists.txt

@@ -103,28 +103,6 @@ add_entrypoint_object(
     libc.src.errno.errno
 )
 
-
-add_entrypoint_object(
-  strftime
-  SRCS
-    strftime.cpp
-  HDRS
-    strftime.h
-  DEPENDS
-    libc.include.time
-)
-
-add_entrypoint_object(
-  strftime_l
-  SRCS
-    strftime_l.cpp
-  HDRS
-    strftime_l.h
-  DEPENDS
-    libc.include.time
-    libc.include.locale
-)
-
 add_entrypoint_object(
   time
   ALIAS
@@ -159,3 +137,30 @@ add_entrypoint_object(
   DEPENDS
     .${LIBC_TARGET_OS}.gettimeofday
 )
+
+add_subdirectory(strftime_core)
+
+add_entrypoint_object(
+  strftime
+  SRCS
+    strftime.cpp
+  HDRS
+    strftime.h
+  DEPENDS
+    libc.include.time
+    libc.src.time.strftime_core.strftime_main
+    libc.src.stdio.printf_core.writer
+)
+
+add_entrypoint_object(
+  strftime_l
+  SRCS
+    strftime_l.cpp
+  HDRS
+    strftime_l.h
+  DEPENDS
+    libc.include.time
+    libc.include.locale
+    libc.src.time.strftime_core.strftime_main
+    libc.src.stdio.printf_core.writer
+)

libc/src/time/CMakeLists.txt

@@ -12,14 +12,16 @@
 #include "src/errno/libc_errno.h"
 #include "src/time/time_utils.h"
 
+#include "src/stdio/printf_core/writer.h"
+#include "src/time/strftime_core/strftime_main.h"
 namespace LIBC_NAMESPACE_DECL {
 
-using LIBC_NAMESPACE::time_utils::TimeConstants;
+size_t strftime(char *__restrict buffer, size_t buffsz, const char *__restrict format,
+                const struct tm *timeptr) {
 
-LLVM_LIBC_FUNCTION(size_t, strftime,
-                   (char *__restrict, size_t, const char *__restrict,
-                    const struct tm *)) {
-  // TODO: Implement this for the default locale.
+  printf_core::WriteBuffer wb(buffer, (buffsz > 0 ? buffsz - 1 : 0));
+  printf_core::Writer writer(&wb);
+  strftime_core::strftime_main(&writer, format, timeptr);
   return -1;
 }
 

libc/src/time/strftime.cpp

@@ -0,0 +1,46 @@
+
+add_header_library(
+  core_structs
+  HDRS
+    core_structs.h
+  DEPENDS
+    libc.src.__support.CPP.string_view
+)
+
+add_header_library(
+  parser
+  HDRS
+    parser.h
+)
+
+add_object_library(
+  converter
+  SRCS
+    converter.cpp
+  HDRS
+    converter.h
+  DEPENDS
+    .core_structs
+    .parser
+    libc.src.stdio.printf_core.writer
+    libc.src.__support.big_int
+    libc.src.math.log10
+    libc.src.__support.CPP.string_view
+    libc.src.__support.float_to_string
+    libc.src.__support.integer_to_string
+    libc.src.__support.uint128
+    libc.src.__support.StringUtil.error_to_string
+)
+
+add_object_library(
+  strftime_main
+  SRCS
+    strftime_main.cpp
+  HDRS
+    strftime_main.h
+  DEPENDS
+    .core_structs
+    .parser
+    .converter
+    libc.src.stdio.printf_core.writer
+)

libc/src/time/strftime_core/CMakeLists.txt

@@ -15,8 +15,8 @@
 #include "src/__support/macros/config.h"
 #include "src/math/log10.h"
 #include "src/stdio/printf_core/writer.h"
-#include "src/stdio/strftime_core/core_structs.h"
-#include "src/stdio/strftime_core/time_internal_def.h"
+#include "src/time/strftime_core/core_structs.h"
+#include "src/time/strftime_core/time_internal_def.h"
 #include <time.h>
 
 namespace LIBC_NAMESPACE_DECL {

libc/src/stdio/strftime_core/converter.cpp renamed to libc/src/time/strftime_core/converter.cpp

@@ -9,9 +9,8 @@
 #ifndef LLVM_LIBC_SRC_STDIO_STRFTIME_CORE_CONVERTER_H
 #define LLVM_LIBC_SRC_STDIO_STRFTIME_CORE_CONVERTER_H
 
-#include "src/__support/macros/config.h"
 #include "src/stdio/printf_core/writer.h"
-#include "src/stdio/strftime_core/core_structs.h"
+#include "src/time/strftime_core/core_structs.h"
 
 #include <stddef.h>
 

libc/src/stdio/strftime_core/converter.h renamed to libc/src/time/strftime_core/converter.h

@@ -9,14 +9,7 @@
 #ifndef LLVM_LIBC_SRC_STDIO_STRFTIME_CORE_CORE_STRUCTS_H
 #define LLVM_LIBC_SRC_STDIO_STRFTIME_CORE_CORE_STRUCTS_H
 
-#include "src/__support/macros/config.h"
-
 #include "src/__support/CPP/string_view.h"
-#include "src/__support/CPP/type_traits.h"
-#include "src/__support/FPUtil/FPBits.h"
-
-#include <inttypes.h>
-#include <stddef.h>
 
 namespace LIBC_NAMESPACE_DECL {
 namespace strftime_core {
@@ -44,43 +37,6 @@ struct FormatSection {
   const struct tm *time;
 };
 
-enum PrimaryType : uint8_t {
-  Unknown = 0,
-  Float = 1,
-  Pointer = 2,
-  Integer = 3,
-  FixedPoint = 4,
-};
-
-// TypeDesc stores the information about a type that is relevant to printf in
-// a relatively compact manner.
-struct TypeDesc {
-  uint8_t size;
-  PrimaryType primary_type;
-  LIBC_INLINE constexpr bool operator==(const TypeDesc &other) const {
-    return (size == other.size) && (primary_type == other.primary_type);
-  }
-};
-
-template <typename T> LIBC_INLINE constexpr TypeDesc type_desc_from_type() {
-  if constexpr (cpp::is_same_v<T, void>) {
-    return TypeDesc{0, PrimaryType::Unknown};
-  } else {
-    constexpr bool IS_POINTER = cpp::is_pointer_v<T>;
-    constexpr bool IS_FLOAT = cpp::is_floating_point_v<T>;
-#ifdef LIBC_INTERNAL_STRFTIME_HAS_FIXED_POINT
-    constexpr bool IS_FIXED_POINT = cpp::is_fixed_point_v<T>;
-#else
-    constexpr bool IS_FIXED_POINT = false;
-#endif // LIBC_INTERNAL_STRFTIME_HAS_FIXED_POINT
-
-    return TypeDesc{sizeof(T), IS_POINTER       ? PrimaryType::Pointer
-                               : IS_FLOAT       ? PrimaryType::Float
-                               : IS_FIXED_POINT ? PrimaryType::FixedPoint
-                                                : PrimaryType::Integer};
-  }
-}
-
 // This is the value to be returned by conversions when no error has occurred.
 constexpr int WRITE_OK = 0;
 // These are the printf return values for when an error has occurred. They are

libc/src/stdio/strftime_core/core_structs.h renamed to libc/src/time/strftime_core/core_structs.h

@@ -9,24 +9,7 @@
 #ifndef LLVM_LIBC_SRC_STDIO_STRFTIME_CORE_PARSER_H
 #define LLVM_LIBC_SRC_STDIO_STRFTIME_CORE_PARSER_H
 
-#include "include/llvm-libc-macros/stdfix-macros.h"
-#include "src/__support/CPP/algorithm.h" // max
-#include "src/__support/CPP/limits.h"
-#include "src/__support/CPP/optional.h"
-#include "src/__support/CPP/type_traits.h"
-#include "src/__support/macros/config.h"
-#include "src/__support/str_to_integer.h"
-#include "src/stdio/strftime_core/core_structs.h"
-// #include "src/stdio/strftime_core/printf_config.h"
-
-#include <stddef.h>
-
-#ifdef LIBC_INTERNAL_PRINTF_HAS_FIXED_POINT
-#include "src/__support/fixed_point/fx_rep.h"
-#endif // LIBC_INTERNAL_PRINTF_HAS_FIXED_POINT
-#ifndef LIBC_COPT_PRINTF_DISABLE_STRERROR
-#include "src/errno/libc_errno.h"
-#endif // LIBC_COPT_PRINTF_DISABLE_STRERROR
+#include <time.h>
 
 namespace LIBC_NAMESPACE_DECL {
 namespace strftime_core {

libc/src/stdio/strftime_core/parser.h renamed to libc/src/time/strftime_core/parser.h

@@ -0,0 +1,42 @@
+//===-- Starting point for strftime -------------------------------*- 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/time/strftime_core/strftime_main.h"
+
+#include "src/stdio/printf_core/writer.h"
+#include "src/time/strftime_core/converter.h"
+#include "src/time/strftime_core/core_structs.h"
+#include "src/time/strftime_core/parser.h"
+
+#include <stddef.h>
+
+namespace LIBC_NAMESPACE_DECL {
+namespace strftime_core {
+
+int strftime_main(Writer *writer, const char *__restrict str,
+                  const struct tm *timeptr) {
+  Parser parser(str, timeptr);
+  int result = 0;
+  for (FormatSection cur_section = parser.get_next_section();
+       !cur_section.raw_string.empty();
+       cur_section = parser.get_next_section()) {
+    if (cur_section.has_conv)
+      result = convert(writer, cur_section);
+    else
+      result = writer->write(cur_section.raw_string);
+
+    if (result < 0)
+      return result;
+  }
+
+  return writer->get_chars_written();
+}
+
+} // namespace strftime_core
+} // namespace LIBC_NAMESPACE_DECL

libc/src/time/strftime_core/strftime_main.cpp

@@ -0,0 +1,26 @@
+//===-- Starting point for strftime -------------------------------*- 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
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LIBC_SRC_STDIO_STRFTIME_CORE_STRFTIME_MAIN_H
+#define LLVM_LIBC_SRC_STDIO_STRFTIME_CORE_STRFTIME_MAIN_H
+
+#include "src/__support/macros/config.h"
+#include "src/stdio/printf_core/writer.h"
+
+#include <stddef.h>
+#include <time.h>
+
+namespace LIBC_NAMESPACE_DECL {
+namespace strftime_core {
+
+int strftime_main(printf_core::Writer *writer, const char *__restrict str, const struct tm *timeptr);
+
+} // namespace strftime_core
+} // namespace LIBC_NAMESPACE_DECL
+
+#endif // LLVM_LIBC_SRC_STDIO_STRFTIME_CORE_STRFTIME_MAIN_H

libc/src/time/strftime_core/strftime_main.h

@@ -542,5 +542,4 @@ endif()
 
 add_subdirectory(printf_core)
 add_subdirectory(scanf_core)
-add_subdirectory(strftime_core)
 add_subdirectory(testdata)

libc/src/stdio/strftime_core/time_internal_def.h renamed to libc/src/time/strftime_core/time_internal_def.h

@@ -173,3 +173,5 @@ add_libc_test(
     libc.src.time.clock
     libc.src.errno.errno
 )
+
+add_subdirectory(strftime_core)

libc/test/src/stdio/CMakeLists.txt

@@ -1,11 +1,11 @@
 add_libc_unittest(
   converter_test
   SUITE
-    libc_stdio_unittests
+    libc_time_unittests
   SRCS
     converter_test.cpp
   DEPENDS
-    libc.src.stdio.strftime_core.converter
+    libc.src.time.strftime_core.converter
     libc.src.stdio.printf_core.writer
-    libc.src.stdio.strftime_core.core_structs
+    libc.src.time.strftime_core.core_structs
 )