[libc-commits] [libc] ad233c6 - [libc] add printf

[Michael Jones via libc-commits]

Author: Michael Jones
Date: 2022-06-15T11:45:38-07:00
New Revision: ad233c6047fc8702ddff833259fbe06364449dc1

URL: https://github.com/llvm/llvm-project/commit/ad233c6047fc8702ddff833259fbe06364449dc1
DIFF: https://github.com/llvm/llvm-project/commit/ad233c6047fc8702ddff833259fbe06364449dc1.diff

LOG: [libc] add printf

This patch adds the entrypoint for printf. With this, building a
"hello world" program with just LLVM-libc is possible.

Reviewed By: sivachandra

Differential Revision: https://reviews.llvm.org/D126831

Added: 
    libc/src/stdio/printf.cpp
    libc/src/stdio/printf.h
    libc/test/src/stdio/printf_test.cpp

Modified: 
    libc/config/linux/x86_64/entrypoints.txt
    libc/src/stdio/CMakeLists.txt
    libc/test/src/stdio/CMakeLists.txt

Removed: 
    


################################################################################
diff  --git a/libc/config/linux/x86_64/entrypoints.txt b/libc/config/linux/x86_64/entrypoints.txt
index 6e8cb2c1f1112..c744e37fae49d 100644
--- a/libc/config/linux/x86_64/entrypoints.txt
+++ b/libc/config/linux/x86_64/entrypoints.txt
@@ -280,6 +280,7 @@ if(LLVM_LIBC_FULL_BUILD)
     libc.src.stdio.sprintf
     libc.src.stdio.snprintf
     libc.src.stdio.fprintf
+    libc.src.stdio.printf
     libc.src.stdio.stderr
     libc.src.stdio.stdout
 

diff  --git a/libc/src/stdio/CMakeLists.txt b/libc/src/stdio/CMakeLists.txt
index 7432e0e3b1531..20e33498b07c8 100644
--- a/libc/src/stdio/CMakeLists.txt
+++ b/libc/src/stdio/CMakeLists.txt
@@ -261,3 +261,17 @@ add_entrypoint_object(
     libc.src.__support.arg_list
     libc.src.stdio.printf_core.vfprintf_internal
 )
+
+
+add_entrypoint_object(
+  printf
+  SRCS
+    printf.cpp
+  HDRS
+    printf.h
+  DEPENDS
+    libc.src.__support.File.file
+    libc.src.__support.File.platform_file
+    libc.src.__support.arg_list
+    libc.src.stdio.printf_core.vfprintf_internal
+)

diff  --git a/libc/src/stdio/printf.cpp b/libc/src/stdio/printf.cpp
new file mode 100644
index 0000000000000..8fd8b9cc57fad
--- /dev/null
+++ b/libc/src/stdio/printf.cpp
@@ -0,0 +1,31 @@
+//===-- Implementation of printf --------------------------------*- 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/printf.h"
+
+#include "src/__support/File/file.h"
+#include "src/__support/arg_list.h"
+#include "src/stdio/printf_core/vfprintf_internal.h"
+
+#include <stdarg.h>
+
+namespace __llvm_libc {
+
+LLVM_LIBC_FUNCTION(int, printf, (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 = printf_core::vfprintf_internal(
+      reinterpret_cast<::FILE *>(__llvm_libc::stdout), format, args);
+  return ret_val;
+}
+
+} // namespace __llvm_libc

diff  --git a/libc/src/stdio/printf.h b/libc/src/stdio/printf.h
new file mode 100644
index 0000000000000..c568b04adb7c5
--- /dev/null
+++ b/libc/src/stdio/printf.h
@@ -0,0 +1,20 @@
+//===-- Implementation header of printf -------------------------*- 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_PRINTF_H
+#define LLVM_LIBC_SRC_STDIO_PRINTF_H
+
+#include <stdio.h>
+
+namespace __llvm_libc {
+
+int printf(const char *__restrict format, ...);
+
+} // namespace __llvm_libc
+
+#endif // LLVM_LIBC_SRC_STDIO_PRINTF_H

diff  --git a/libc/test/src/stdio/CMakeLists.txt b/libc/test/src/stdio/CMakeLists.txt
index e0e7357620a7c..caf7f4264cae0 100644
--- a/libc/test/src/stdio/CMakeLists.txt
+++ b/libc/test/src/stdio/CMakeLists.txt
@@ -97,6 +97,17 @@ add_libc_unittest(
     libc.src.stdio.fread
 )
 
+
+add_libc_unittest(
+  printf_test
+  SUITE
+    libc_stdio_unittests
+  SRCS
+    printf_test.cpp
+  DEPENDS
+    libc.src.stdio.printf
+)
+
 add_subdirectory(printf_core)
 
 add_subdirectory(testdata)

diff  --git a/libc/test/src/stdio/printf_test.cpp b/libc/test/src/stdio/printf_test.cpp
new file mode 100644
index 0000000000000..f781d90403b59
--- /dev/null
+++ b/libc/test/src/stdio/printf_test.cpp
@@ -0,0 +1,29 @@
+//===-- Unittests for printf ---------------------------------------------===//
+//
+// 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/printf.h"
+
+#include "utils/UnitTest/Test.h"
+
+TEST(LlvmLibcPrintfTest, PrintOut) {
+  int written;
+
+  constexpr char simple[] = "A simple string with no conversions.\n";
+  written = __llvm_libc::printf(simple);
+  EXPECT_EQ(written, static_cast<int>(sizeof(simple) - 1));
+
+  constexpr char numbers[] = "1234567890\n";
+  written = __llvm_libc::printf("%s", numbers);
+  EXPECT_EQ(written, static_cast<int>(sizeof(numbers) - 1));
+
+  constexpr char format_more[] = "%s and more\n";
+  constexpr char short_numbers[] = "1234";
+  written = __llvm_libc::printf(format_more, short_numbers);
+  EXPECT_EQ(written,
+            static_cast<int>(sizeof(format_more) + sizeof(short_numbers) - 4));
+}