[libc-commits] [PATCH] D127995: [libc] add printf pointer conv

[Michael Jones via Phabricator via libc-commits]

michaelrj created this revision.
michaelrj added reviewers: sivachandra, lntue.
Herald added subscribers: libc-commits, ecnelises, tschuett.
Herald added projects: libc-project, All.
michaelrj requested review of this revision.

The pointer converter handles the %p conversion. It uses the hex
converter for most of the conversion.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D127995

Files:
  libc/src/stdio/printf_core/converter.cpp
  libc/src/stdio/printf_core/converter_atlas.h
  libc/src/stdio/printf_core/ptr_converter.h
  libc/test/src/stdio/sprintf_test.cpp


Index: libc/test/src/stdio/sprintf_test.cpp
===================================================================
--- libc/test/src/stdio/sprintf_test.cpp
+++ libc/test/src/stdio/sprintf_test.cpp
@@ -346,6 +346,22 @@
   ASSERT_STREQ(buff, "007F 0x1000000000 002   ");
 }
 
+TEST(LlvmLibcSPrintfTest, PointerConv) {
+  char buff[64];
+  int written;
+
+  written = __llvm_libc::sprintf(buff, "%p", nullptr);
+  EXPECT_EQ(written, 9);
+  ASSERT_STREQ(buff, "(nullptr)");
+
+  written = __llvm_libc::sprintf(buff, "%p", 0x1a2b3c4d);
+  EXPECT_EQ(written, 10);
+  ASSERT_STREQ(buff, "0x1a2b3c4d");
+
+  written = __llvm_libc::sprintf(buff, "%p", buff);
+  EXPECT_GT(written, 0);
+}
+
 #ifndef LLVM_LIBC_PRINTF_DISABLE_INDEX_MODE
 TEST(LlvmLibcSPrintfTest, IndexModeParsing) {
   char buff[64];
Index: libc/src/stdio/printf_core/ptr_converter.h
===================================================================
--- /dev/null
+++ libc/src/stdio/printf_core/ptr_converter.h
@@ -0,0 +1,39 @@
+//===-- Pointer Converter for 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_CORE_PTR_CONVERTER_H
+#define LLVM_LIBC_SRC_STDIO_PRINTF_CORE_PTR_CONVERTER_H
+
+#include "src/stdio/printf_core/converter_utils.h"
+#include "src/stdio/printf_core/core_structs.h"
+#include "src/stdio/printf_core/hex_converter.h"
+#include "src/stdio/printf_core/writer.h"
+
+namespace __llvm_libc {
+namespace printf_core {
+
+int inline convert_pointer(Writer *writer, const FormatSection &to_conv) {
+  if (to_conv.conv_val_ptr == (void *)(nullptr)) {
+    const char ZERO_STR[] = "(nullptr)";
+    // subtract 1 from sizeof to remove the null byte at the end.
+    RET_IF_RESULT_NEGATIVE(writer->write(ZERO_STR, sizeof(ZERO_STR) - 1));
+  } else {
+    FormatSection hex_conv;
+    hex_conv.has_conv = true;
+    hex_conv.conv_name = 'x';
+    hex_conv.flags = FormatFlags::ALTERNATE_FORM;
+    hex_conv.conv_val_raw = reinterpret_cast<uintptr_t>(to_conv.conv_val_ptr);
+    return convert_hex(writer, hex_conv);
+  }
+  return 0;
+}
+
+} // namespace printf_core
+} // namespace __llvm_libc
+
+#endif // LLVM_LIBC_SRC_STDIO_PRINTF_CORE_PTR_CONVERTER_H
Index: libc/src/stdio/printf_core/converter_atlas.h
===================================================================
--- libc/src/stdio/printf_core/converter_atlas.h
+++ libc/src/stdio/printf_core/converter_atlas.h
@@ -36,5 +36,6 @@
 // defines convert_write_int
 
 // defines convert_pointer
+#include "src/stdio/printf_core/ptr_converter.h"
 
 #endif // LLVM_LIBC_SRC_STDIO_PRINTF_CORE_CONVERTER_ATLAS_H
Index: libc/src/stdio/printf_core/converter.cpp
===================================================================
--- libc/src/stdio/printf_core/converter.cpp
+++ libc/src/stdio/printf_core/converter.cpp
@@ -61,7 +61,7 @@
   case 'n':
     // return convert_write_int(writer, to_conv);
   case 'p':
-    // return convert_pointer(writer, to_conv);
+    return convert_pointer(writer, to_conv);
   default:
     return writer->write(to_conv.raw_string, to_conv.raw_len);
   }


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