[libc] Implement strftime and strftime_l

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

@@ -1,6 +1,6 @@
-if(EXISTS ${CMAKE_CURRENT_SOURCE_DIR}/${LIBC_TARGET_OS})
-  add_subdirectory(${CMAKE_CURRENT_SOURCE_DIR}/${LIBC_TARGET_OS})
-endif()
+# if(EXISTS ${CMAKE_CURRENT_SOURCE_DIR}/${LIBC_TARGET_OS})
+#   add_subdirectory(${CMAKE_CURRENT_SOURCE_DIR}/${LIBC_TARGET_OS})
+# endif()
 
 add_object_library(
   time_utils
@@ -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/stdio/strftime_core/core_structs.h

@@ -12,15 +12,17 @@
 #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.
-  return -1;
+  printf_core::WriteBuffer wb(buffer, (buffsz > 0 ? buffsz - 1 : 0));
+  printf_core::Writer writer(&wb);
+  strftime_core::strftime_main(&writer, format, timeptr);
+  return writer.get_chars_written();
 }
 
 } // namespace LIBC_NAMESPACE_DECL

libc/src/time/CMakeLists.txt

@@ -0,0 +1,52 @@
+add_header_library(
+  core_structs
+  HDRS
+    core_structs.h
+  DEPENDS
+    libc.src.__support.CPP.string_view
+    libc.include.time
+)
+
+add_header_library(
+  parser
+  HDRS
+    parser.h
+  DEPENDS
+    .core_structs
+    libc.src.string.string_utils
+    libc.include.time
+
+)
+
+add_object_library(
+  converter
+  SRCS
+    converter.cpp
+  HDRS
+    converter.h
+  DEPENDS
+    .core_structs
+    libc.src.stdio.printf_core.writer
+    libc.src.__support.big_int
+    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
+    libc.include.time
+
+)
+
+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.include.time
+)