[libc] Add putc, fputc, and fprintf to stdio/baremetal

libc/config/baremetal/aarch64/entrypoints.txt

@@ -124,8 +124,11 @@ set(TARGET_LIBC_ENTRYPOINTS
 
     # stdio.h entrypoints
     libc.src.stdio.asprintf
+    libc.src.stdio.fprintf
+    libc.src.stdio.fputc
     libc.src.stdio.getchar
     libc.src.stdio.printf
+    libc.src.stdio.putc
     libc.src.stdio.putchar
     libc.src.stdio.puts
     libc.src.stdio.remove

libc/config/baremetal/arm/entrypoints.txt

@@ -124,8 +124,11 @@ set(TARGET_LIBC_ENTRYPOINTS
 
     # stdio.h entrypoints
     libc.src.stdio.asprintf
+    libc.src.stdio.fprintf
+    libc.src.stdio.fputc
     libc.src.stdio.getchar
     libc.src.stdio.printf
+    libc.src.stdio.putc
     libc.src.stdio.putchar
     libc.src.stdio.puts
     libc.src.stdio.remove

libc/config/baremetal/riscv/entrypoints.txt

@@ -124,8 +124,11 @@ set(TARGET_LIBC_ENTRYPOINTS
 
     # stdio.h entrypoints
     libc.src.stdio.asprintf
+    libc.src.stdio.fprintf
+    libc.src.stdio.fputc
     libc.src.stdio.getchar
     libc.src.stdio.printf
+    libc.src.stdio.putc
     libc.src.stdio.putchar
     libc.src.stdio.puts
     libc.src.stdio.remove

libc/src/stdio/baremetal/CMakeLists.txt

@@ -1,3 +1,27 @@
+add_entrypoint_object(
+  fprintf
+  SRCS
+    fprintf.cpp
+  HDRS
+    ../fprintf.h
+    write_utils.h
+  DEPENDS
+    libc.src.__support.OSUtil.osutil
+    libc.src.__support.CPP.string_view
+    libc.src.stdio.printf_core.printf_main
+)
+
+add_entrypoint_object(
+  fputc
+  SRCS
+    fputc.cpp
+  HDRS
+    ../fputc.h
+    write_utils.h
+  DEPENDS
+    libc.src.__support.CPP.string_view
+)
+
 add_entrypoint_object(
   getchar
   SRCS
@@ -20,12 +44,24 @@ add_entrypoint_object(
     libc.include.stdio
 )
 
+add_entrypoint_object(
+  putc
+  SRCS
+    putc.cpp
+  HDRS
+    ../putc.h
+    write_utils.h
+  DEPENDS
+    libc.src.__support.CPP.string_view
+)
+
 add_entrypoint_object(
   printf
   SRCS
     printf.cpp
   HDRS
     ../printf.h
+    write_utils.h
   DEPENDS
     libc.src.stdio.printf_core.printf_main
     libc.src.stdio.printf_core.writer
@@ -102,3 +138,16 @@ add_entrypoint_object(
     libc.src.__support.arg_list
     libc.src.__support.OSUtil.osutil
 )
+
+add_header_library(
+  baremetal_write_utils
+  HDRS
+    write_utils.h
+  DEPENDS
+    libc.hdr.types.FILE
+    libc.hdr.stdio_macros
+    libc.src.__support.OSUtil.osutil
+    libc.src.__support.CPP.string_view
+    .stdout
+    .stderr
+)

libc/src/stdio/baremetal/fprintf.cpp

@@ -0,0 +1,46 @@
+//===-- Implementation of fprintf for baremetal -----------------*- 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/fprintf.h"
+
+#include "hdr/types/FILE.h"
+#include "src/__support/arg_list.h"
+#include "src/__support/macros/config.h"
+#include "src/stdio/baremetal/write_utils.h"
+#include "src/stdio/printf_core/printf_main.h"
+
+#include <stdarg.h>
+
+namespace LIBC_NAMESPACE_DECL {
+
+LLVM_LIBC_FUNCTION(int, fprintf,
+                   (::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);
+  static constexpr size_t BUFF_SIZE = 1024;
+  char buffer[BUFF_SIZE];
+
+  printf_core::WriteBuffer<printf_core::WriteMode::FLUSH_TO_STREAM> wb(
+      buffer, BUFF_SIZE, get_write_hook(stream), nullptr);
+  printf_core::Writer<printf_core::WriteMode::FLUSH_TO_STREAM> writer(wb);
+
+  int retval = printf_core::printf_main(&writer, format, args);
+
+  int flushval = wb.overflow_write("");
+  if (flushval != printf_core::WRITE_OK)
+    retval = flushval;
+
+  return retval;
+}
+
+} // namespace LIBC_NAMESPACE_DECL

libc/src/stdio/baremetal/fputc.cpp

@@ -0,0 +1,25 @@
+//===-- Baremetal Implementation of fputc ---------------------------------===//
+//
+// 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/fputc.h"
+
+#include "src/__support/CPP/string_view.h"
+#include "src/__support/macros/config.h"
+#include "src/stdio/baremetal/write_utils.h"
+
+namespace LIBC_NAMESPACE_DECL {
+
+LLVM_LIBC_FUNCTION(int, fputc, (int c, ::FILE *stream)) {
+  char uc = static_cast<char>(c);
+
+  write(stream, cpp::string_view(&uc, 1));
+
+  return 0;
+}
+
+} // namespace LIBC_NAMESPACE_DECL

libc/src/stdio/baremetal/printf.cpp

@@ -7,27 +7,17 @@
 //===----------------------------------------------------------------------===//
 
 #include "src/stdio/printf.h"
-#include "src/__support/OSUtil/io.h"
+
 #include "src/__support/arg_list.h"
 #include "src/__support/macros/config.h"
-#include "src/stdio/printf_core/core_structs.h"
+#include "src/stdio/baremetal/write_utils.h"
 #include "src/stdio/printf_core/printf_main.h"
-#include "src/stdio/printf_core/writer.h"
 
 #include <stdarg.h>
 #include <stddef.h>
 
 namespace LIBC_NAMESPACE_DECL {
 
-namespace {
-
-LIBC_INLINE int stdout_write_hook(cpp::string_view new_str, void *) {
-  write_to_stdout(new_str);
-  return printf_core::WRITE_OK;
-}
-
-} // namespace
-
 LLVM_LIBC_FUNCTION(int, printf, (const char *__restrict format, ...)) {
   va_list vlist;
   va_start(vlist, format);

libc/src/stdio/baremetal/putc.cpp

@@ -0,0 +1,25 @@
+//===-- Baremetal Implementation of putc ----------------------------------===//
+//
+// 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/putc.h"
+
+#include "src/__support/CPP/string_view.h"
+#include "src/__support/macros/config.h"
+#include "src/stdio/baremetal/write_utils.h"
+
+namespace LIBC_NAMESPACE_DECL {
+
+LLVM_LIBC_FUNCTION(int, putc, (int c, ::FILE *stream)) {
+  char uc = static_cast<char>(c);
+
+  write(stream, cpp::string_view(&uc, 1));
+
+  return 0;
+}
+
+} // namespace LIBC_NAMESPACE_DECL

libc/src/stdio/baremetal/putchar.cpp

@@ -7,14 +7,15 @@
 //===----------------------------------------------------------------------===//
 
 #include "src/stdio/putchar.h"
+
 #include "src/__support/CPP/string_view.h"
 #include "src/__support/OSUtil/io.h"
 #include "src/__support/macros/config.h"
 
 namespace LIBC_NAMESPACE_DECL {
 
 LLVM_LIBC_FUNCTION(int, putchar, (int c)) {
-  char uc = static_cast<char>(c);
+  char uc = static_cast<unsigned char>(c);
 
   write_to_stdout(cpp::string_view(&uc, 1));
 

libc/src/stdio/baremetal/vprintf.cpp

@@ -7,9 +7,11 @@
 //===----------------------------------------------------------------------===//
 
 #include "src/stdio/vprintf.h"
+
 #include "src/__support/OSUtil/io.h"
 #include "src/__support/arg_list.h"
 #include "src/__support/macros/config.h"
+#include "src/stdio/baremetal/write_utils.h"
 #include "src/stdio/printf_core/core_structs.h"
 #include "src/stdio/printf_core/printf_main.h"
 #include "src/stdio/printf_core/writer.h"
@@ -19,15 +21,6 @@
 
 namespace LIBC_NAMESPACE_DECL {
 
-namespace {
-
-LIBC_INLINE int stdout_write_hook(cpp::string_view new_str, void *) {
-  write_to_stdout(new_str);
-  return printf_core::WRITE_OK;
-}
-
-} // namespace
-
 LLVM_LIBC_FUNCTION(int, vprintf,
                    (const char *__restrict format, va_list vlist)) {
   internal::ArgList args(vlist); // This holder class allows for easier copying

libc/src/stdio/baremetal/write_utils.h

@@ -0,0 +1,48 @@
+//===-- Baremetal helper functions for writing to stdout/stderr -*- 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 "hdr/stdio_macros.h" // For stdout/err
+#include "hdr/types/FILE.h"
+#include "src/__support/CPP/string_view.h"
+#include "src/__support/OSUtil/io.h"
+#include "src/__support/macros/config.h"
+#include "src/stdio/printf_core/core_structs.h" // For printf_core::WRITE_OK
+
+#include <stddef.h>
+
+namespace LIBC_NAMESPACE_DECL {
+namespace {
+
+LIBC_INLINE int stdout_write_hook(cpp::string_view new_str, void *) {
+  write_to_stdout(new_str);
+  return printf_core::WRITE_OK;
+}
+
+LIBC_INLINE int stderr_write_hook(cpp::string_view new_str, void *) {
+  write_to_stderr(new_str);
+  return printf_core::WRITE_OK;
+}
+
+LIBC_INLINE void write(::FILE *f, cpp::string_view new_str) {
+  if (f == stdout) {
+    write_to_stdout(new_str);
+  } else {
+    write_to_stderr(new_str);
+  }
+}
+
+LIBC_INLINE decltype(&stdout_write_hook) get_write_hook(::FILE *f) {
+  if (f == stdout) {
+    return &stdout_write_hook;
+  }
+
+  return &stderr_write_hook;
+}
+
+} // namespace
+} // namespace LIBC_NAMESPACE_DECL