[libc-commits] [libc] [wip] [libc] Implement vasprintf (PR #98824)

Tsz Chan via libc-commits libc-commits at lists.llvm.org
Sat Jul 20 09:12:32 PDT 2024


https://github.com/tszhin-swe updated https://github.com/llvm/llvm-project/pull/98824

>From 98059bab8557e839c6e5564ebb3d02e0ece87365 Mon Sep 17 00:00:00 2001
From: Izaak Schroeder <izaak.schroeder at gmail.com>
Date: Tue, 2 Jul 2024 23:53:14 -0700
Subject: [PATCH 1/2] [libc] Add `vasprintf` function stubs

---
 libc/spec/stdc.td             |  7 +++++++
 libc/src/stdio/CMakeLists.txt | 31 +++++++++++++++++++++++++++++++
 libc/src/stdio/vasprintf.cpp  | 26 ++++++++++++++++++++++++++
 libc/src/stdio/vasprintf.h    | 21 +++++++++++++++++++++
 4 files changed, 85 insertions(+)
 create mode 100644 libc/src/stdio/vasprintf.cpp
 create mode 100644 libc/src/stdio/vasprintf.h

diff --git a/libc/spec/stdc.td b/libc/spec/stdc.td
index aa56152aee141..e5e0900cce8c6 100644
--- a/libc/spec/stdc.td
+++ b/libc/spec/stdc.td
@@ -967,6 +967,13 @@ def StdC : StandardSpec<"stdc"> {
               RetValSpec<IntType>,
               [ArgSpec<IntType>, ArgSpec<FILEPtr>]
           >,
+          FunctionSpec<
+              "vasprintf",
+              RetValSpec<IntType>,
+              [ArgSpec<CharRestrictedPtrPtr>,
+               ArgSpec<ConstCharPtr>,
+               ArgSpec<VaListType>]
+          >,
       ],
       [
           ObjectSpec<
diff --git a/libc/src/stdio/CMakeLists.txt b/libc/src/stdio/CMakeLists.txt
index 2d528a903cc2f..0582c96d320b3 100644
--- a/libc/src/stdio/CMakeLists.txt
+++ b/libc/src/stdio/CMakeLists.txt
@@ -185,6 +185,37 @@ add_entrypoint_object(
     libc.src.stdio.printf_core.writer
 )
 
+add_entrypoint_object(
+  vfprintf
+  SRCS
+    vfprintf.cpp
+  HDRS
+    vfprintf.h
+  DEPENDS
+    libc.src.__support.arg_list
+    libc.src.stdio.printf_core.vfprintf_internal
+)
+
+add_entrypoint_object(
+  vasprintf
+  SRCS
+    vasprintf.cpp
+  HDRS
+    vasprintf.h
+  DEPENDS
+    libc.src.__support.arg_list
+)
+
+add_stdio_entrypoint_object(
+  fileno
+  SRCS
+    fileno.cpp
+  HDRS
+    fileno.h
+  DEPENDS
+    libc.src.stdio.fileno
+)
+
 add_subdirectory(printf_core)
 add_subdirectory(scanf_core)
 
diff --git a/libc/src/stdio/vasprintf.cpp b/libc/src/stdio/vasprintf.cpp
new file mode 100644
index 0000000000000..712a3f72ab62d
--- /dev/null
+++ b/libc/src/stdio/vasprintf.cpp
@@ -0,0 +1,26 @@
+//===-- Implementation of vasprintf -----------------------------*- 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/vasprintf.h"
+
+#include "src/__support/arg_list.h"
+
+#include <stdarg.h>
+#include <stdio.h>
+
+namespace LIBC_NAMESPACE {
+
+LLVM_LIBC_FUNCTION(int, vasprintf,
+                   (char **__restrict, const char *, va_list vlist)) {
+  internal::ArgList args(vlist); // This holder class allows for easier copying
+                                 // and pointer semantics, as well as handling
+                                 // destruction automatically.
+  return -1;
+}
+
+} // namespace LIBC_NAMESPACE
diff --git a/libc/src/stdio/vasprintf.h b/libc/src/stdio/vasprintf.h
new file mode 100644
index 0000000000000..c11675461e3fb
--- /dev/null
+++ b/libc/src/stdio/vasprintf.h
@@ -0,0 +1,21 @@
+//===-- Implementation header of vasprintf ----------------------*- 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_VASPRINTF_H
+#define LLVM_LIBC_SRC_STDIO_VASPRINTF_H
+
+#include <stdarg.h>
+#include <stdio.h>
+
+namespace LIBC_NAMESPACE {
+
+int vasprintf(char **__restrict s, const char *format, va_list vlist);
+
+} // namespace LIBC_NAMESPACE
+
+#endif // LLVM_LIBC_SRC_STDIO_VASPRINTF_H

>From 0cc2f20ddad1e6151b48a44a2f3e23bdec708ffc Mon Sep 17 00:00:00 2001
From: Tsz Chan <keithcth2001 at gmail.com>
Date: Sat, 20 Jul 2024 15:41:08 +0800
Subject: [PATCH 2/2] [libc][WIP] Implement vasprint

---
 libc/config/baremetal/arm/entrypoints.txt   |   1 +
 libc/config/baremetal/riscv/entrypoints.txt |   1 +
 libc/config/darwin/arm/entrypoints.txt      |   8 ++
 libc/config/linux/aarch64/entrypoints.txt   |   1 +
 libc/config/linux/riscv/entrypoints.txt     |   1 +
 libc/config/linux/x86_64/entrypoints.txt    |   1 +
 libc/spec/stdc.td                           |   2 +-
 libc/src/stdio/CMakeLists.txt               |  25 +----
 libc/src/stdio/printf_core/core_structs.h   |   2 +-
 libc/src/stdio/printf_core/writer.h         | 103 ++++++++++++--------
 libc/src/stdio/vasprintf.cpp                |  57 ++++++++++-
 libc/test/src/stdio/CMakeLists.txt          |   9 ++
 libc/test/src/stdio/vasprintf_test.cpp      |  78 +++++++++++++++
 13 files changed, 225 insertions(+), 64 deletions(-)
 create mode 100644 libc/test/src/stdio/vasprintf_test.cpp

diff --git a/libc/config/baremetal/arm/entrypoints.txt b/libc/config/baremetal/arm/entrypoints.txt
index 4f2462abc7452..d262941c12cf9 100644
--- a/libc/config/baremetal/arm/entrypoints.txt
+++ b/libc/config/baremetal/arm/entrypoints.txt
@@ -93,6 +93,7 @@ set(TARGET_LIBC_ENTRYPOINTS
     libc.src.stdio.vprintf
     libc.src.stdio.vsnprintf
     libc.src.stdio.vsprintf
+    libc.src.stdio.vasprintf
 
     # stdbit.h entrypoints
     libc.src.stdbit.stdc_bit_ceil_uc
diff --git a/libc/config/baremetal/riscv/entrypoints.txt b/libc/config/baremetal/riscv/entrypoints.txt
index c2ab9d7f19921..d5e08af9c6c76 100644
--- a/libc/config/baremetal/riscv/entrypoints.txt
+++ b/libc/config/baremetal/riscv/entrypoints.txt
@@ -89,6 +89,7 @@ set(TARGET_LIBC_ENTRYPOINTS
     libc.src.stdio.vprintf
     libc.src.stdio.vsnprintf
     libc.src.stdio.vsprintf
+    libc.src.stdio.vasprintf
 
     # stdbit.h entrypoints
     libc.src.stdbit.stdc_bit_ceil_uc
diff --git a/libc/config/darwin/arm/entrypoints.txt b/libc/config/darwin/arm/entrypoints.txt
index 383118dc781e5..0205411ac73ba 100644
--- a/libc/config/darwin/arm/entrypoints.txt
+++ b/libc/config/darwin/arm/entrypoints.txt
@@ -94,6 +94,14 @@ set(TARGET_LIBC_ENTRYPOINTS
     libc.src.stdlib.calloc
     libc.src.stdlib.realloc
     libc.src.stdlib.free
+
+    # stdio.h external entrypoints
+    libc.src.stdio.snprintf
+    libc.src.stdio.sprintf
+    libc.src.stdio.vprintf
+    libc.src.stdio.vsnprintf
+    libc.src.stdio.vsprintf
+    libc.src.stdio.vasprintf
 )
 
 set(TARGET_LIBM_ENTRYPOINTS
diff --git a/libc/config/linux/aarch64/entrypoints.txt b/libc/config/linux/aarch64/entrypoints.txt
index dee6ac673643e..919f6f95661c9 100644
--- a/libc/config/linux/aarch64/entrypoints.txt
+++ b/libc/config/linux/aarch64/entrypoints.txt
@@ -211,6 +211,7 @@ set(TARGET_LIBC_ENTRYPOINTS
     #libc.src.stdio.sscanf
     libc.src.stdio.vsnprintf
     libc.src.stdio.vsprintf
+    libc.src.stdio.vasprintf
 
     # sys/mman.h entrypoints
     libc.src.sys.mman.madvise
diff --git a/libc/config/linux/riscv/entrypoints.txt b/libc/config/linux/riscv/entrypoints.txt
index 516a4b6ce3433..7545811817ec9 100644
--- a/libc/config/linux/riscv/entrypoints.txt
+++ b/libc/config/linux/riscv/entrypoints.txt
@@ -210,6 +210,7 @@ set(TARGET_LIBC_ENTRYPOINTS
     libc.src.stdio.vprintf
     libc.src.stdio.vsnprintf
     libc.src.stdio.vsprintf
+    libc.src.stdio.vasprintf
 
     # sys/mman.h entrypoints
     libc.src.sys.mman.madvise
diff --git a/libc/config/linux/x86_64/entrypoints.txt b/libc/config/linux/x86_64/entrypoints.txt
index b6c55e7aa3033..e1d603b30355d 100644
--- a/libc/config/linux/x86_64/entrypoints.txt
+++ b/libc/config/linux/x86_64/entrypoints.txt
@@ -221,6 +221,7 @@ set(TARGET_LIBC_ENTRYPOINTS
     libc.src.stdio.vprintf
     libc.src.stdio.vsnprintf
     libc.src.stdio.vsprintf
+    libc.src.stdio.vasprintf
 
     # sys/epoll.h entrypoints
     libc.src.sys.epoll.epoll_create
diff --git a/libc/spec/stdc.td b/libc/spec/stdc.td
index e5e0900cce8c6..af48bf13fa2e4 100644
--- a/libc/spec/stdc.td
+++ b/libc/spec/stdc.td
@@ -971,7 +971,7 @@ def StdC : StandardSpec<"stdc"> {
               "vasprintf",
               RetValSpec<IntType>,
               [ArgSpec<CharRestrictedPtrPtr>,
-               ArgSpec<ConstCharPtr>,
+               ArgSpec<ConstCharRestrictedPtr>,
                ArgSpec<VaListType>]
           >,
       ],
diff --git a/libc/src/stdio/CMakeLists.txt b/libc/src/stdio/CMakeLists.txt
index 0582c96d320b3..ea98e5757ca43 100644
--- a/libc/src/stdio/CMakeLists.txt
+++ b/libc/src/stdio/CMakeLists.txt
@@ -185,17 +185,6 @@ add_entrypoint_object(
     libc.src.stdio.printf_core.writer
 )
 
-add_entrypoint_object(
-  vfprintf
-  SRCS
-    vfprintf.cpp
-  HDRS
-    vfprintf.h
-  DEPENDS
-    libc.src.__support.arg_list
-    libc.src.stdio.printf_core.vfprintf_internal
-)
-
 add_entrypoint_object(
   vasprintf
   SRCS
@@ -204,16 +193,10 @@ add_entrypoint_object(
     vasprintf.h
   DEPENDS
     libc.src.__support.arg_list
-)
-
-add_stdio_entrypoint_object(
-  fileno
-  SRCS
-    fileno.cpp
-  HDRS
-    fileno.h
-  DEPENDS
-    libc.src.stdio.fileno
+    libc.src.stdio.printf_core.printf_main
+    libc.src.stdio.printf_core.writer
+    libc.src.stdlib.malloc
+    libc.src.stdlib.realloc
 )
 
 add_subdirectory(printf_core)
diff --git a/libc/src/stdio/printf_core/core_structs.h b/libc/src/stdio/printf_core/core_structs.h
index 76d006b813dd1..4c3b81ff018ab 100644
--- a/libc/src/stdio/printf_core/core_structs.h
+++ b/libc/src/stdio/printf_core/core_structs.h
@@ -134,7 +134,7 @@ constexpr int FILE_STATUS_ERROR = -2;
 constexpr int NULLPTR_WRITE_ERROR = -3;
 constexpr int INT_CONVERSION_ERROR = -4;
 constexpr int FIXED_POINT_CONVERSION_ERROR = -5;
-
+constexpr int ALLOCATION_ERROR = -6;
 } // namespace printf_core
 } // namespace LIBC_NAMESPACE_DECL
 
diff --git a/libc/src/stdio/printf_core/writer.h b/libc/src/stdio/printf_core/writer.h
index 89421561f3b2e..a893c1f2b464a 100644
--- a/libc/src/stdio/printf_core/writer.h
+++ b/libc/src/stdio/printf_core/writer.h
@@ -22,60 +22,87 @@ namespace LIBC_NAMESPACE_DECL {
 namespace printf_core {
 
 struct WriteBuffer {
+  enum class WriteMode {
+    FILL_BUFF_AND_DROP_OVERFLOW,
+    FLUSH_TO_STREAM,
+    RESIZE_AND_FILL_BUFF,
+    BUTT,
+  };
   using StreamWriter = int (*)(cpp::string_view, void *);
+  using OverflowWriter = int (WriteBuffer::*)(cpp::string_view);
   char *buff;
-  const size_t buff_len;
+  const char *init_buff; // for checking when resize.
+  size_t buff_len;
   size_t buff_cur = 0;
 
   // The stream writer will be called when the buffer is full. It will be passed
   // string_views to write to the stream.
   StreamWriter stream_writer;
   void *output_target;
+  WriteMode write_mode{WriteMode::BUTT};
 
   LIBC_INLINE WriteBuffer(char *Buff, size_t Buff_len, StreamWriter hook,
                           void *target)
-      : buff(Buff), buff_len(Buff_len), stream_writer(hook),
-        output_target(target) {}
+      : buff(Buff), init_buff(Buff), buff_len(Buff_len), stream_writer(hook),
+        output_target(target), write_mode(WriteMode::FLUSH_TO_STREAM) {}
 
   LIBC_INLINE WriteBuffer(char *Buff, size_t Buff_len)
-      : buff(Buff), buff_len(Buff_len), stream_writer(nullptr),
-        output_target(nullptr) {}
+      : buff(Buff), init_buff(Buff), buff_len(Buff_len), stream_writer(nullptr),
+        output_target(nullptr),
+        write_mode(WriteMode::FILL_BUFF_AND_DROP_OVERFLOW) {}
+
+  LIBC_INLINE WriteBuffer(char *Buff, size_t Buff_len, StreamWriter hook)
+      : buff(Buff), init_buff(Buff), buff_len(Buff_len), stream_writer(hook),
+        output_target(this), write_mode(WriteMode::RESIZE_AND_FILL_BUFF) {}
+
+  LIBC_INLINE int flush_to_stream(cpp::string_view new_str) {
+    if (buff_cur > 0) {
+      int retval = stream_writer({buff, buff_cur}, output_target);
+      if (retval < 0)
+        return retval;
+    }
+    if (new_str.size() > 0) {
+      int retval = stream_writer(new_str, output_target);
+      if (retval < 0)
+        return retval;
+    }
+    buff_cur = 0;
+    return WRITE_OK;
+  }
+
+  LIBC_INLINE int fill_remaining_to_buff(cpp::string_view new_str) {
+    if (buff_cur < buff_len) {
+      size_t bytes_to_write = buff_len - buff_cur;
+      if (bytes_to_write > new_str.size()) {
+        bytes_to_write = new_str.size();
+      }
+      inline_memcpy(buff + buff_cur, new_str.data(), bytes_to_write);
+      buff_cur += bytes_to_write;
+    }
+    return WRITE_OK;
+  }
+
+  LIBC_INLINE int resize_and_write(cpp::string_view new_str) {
+    return stream_writer(new_str, output_target);
+  }
 
   // The overflow_write method is intended to be called to write the contents of
-  // the buffer and new_str to the stream_writer if it exists, else it will
-  // write as much of new_str to the buffer as it can. The current position in
-  // the buffer will be reset iff stream_writer is called. Calling this with an
-  // empty string will flush the buffer if relevant.
+  // the buffer and new_str to the stream_writer if it exists. If a resizing
+  // hook is provided, it will resize the buffer and write the contents. If
+  // neither a stream_writer nor a resizing hook is provided, it will fill the
+  // remaining space in the buffer with new_str and drop the overflow. Calling
+  // this with an empty string will flush the buffer if relevant.
+
   LIBC_INLINE int overflow_write(cpp::string_view new_str) {
-    // If there is a stream_writer, write the contents of the buffer, then
-    // new_str, then clear the buffer.
-    if (stream_writer != nullptr) {
-      if (buff_cur > 0) {
-        int retval = stream_writer({buff, buff_cur}, output_target);
-        if (retval < 0) {
-          return retval;
-        }
-      }
-      if (new_str.size() > 0) {
-        int retval = stream_writer(new_str, output_target);
-        if (retval < 0) {
-          return retval;
-        }
-      }
-      buff_cur = 0;
-      return WRITE_OK;
-    } else {
-      // We can't flush to the stream, so fill the rest of the buffer, then drop
-      // the overflow.
-      if (buff_cur < buff_len) {
-        size_t bytes_to_write = buff_len - buff_cur;
-        if (bytes_to_write > new_str.size()) {
-          bytes_to_write = new_str.size();
-        }
-        inline_memcpy(buff + buff_cur, new_str.data(), bytes_to_write);
-        buff_cur += bytes_to_write;
-      }
-      return WRITE_OK;
+    switch (write_mode) {
+    case WriteMode::FILL_BUFF_AND_DROP_OVERFLOW:
+      return fill_remaining_to_buff(new_str);
+    case WriteMode::FLUSH_TO_STREAM:
+      return flush_to_stream(new_str);
+    case WriteMode::RESIZE_AND_FILL_BUFF:
+      return resize_and_write(new_str);
+    default:
+      return -1;
     }
   }
 };
diff --git a/libc/src/stdio/vasprintf.cpp b/libc/src/stdio/vasprintf.cpp
index 712a3f72ab62d..eae1348f41bc7 100644
--- a/libc/src/stdio/vasprintf.cpp
+++ b/libc/src/stdio/vasprintf.cpp
@@ -8,19 +8,70 @@
 
 #include "src/stdio/vasprintf.h"
 
+#include "src/__support/OSUtil/io.h"
 #include "src/__support/arg_list.h"
-
+#include "src/stdio/printf.h"
+#include "src/stdio/printf_core/core_structs.h"
+#include "src/stdio/printf_core/printf_main.h"
+#include "src/stdio/printf_core/writer.h"
 #include <stdarg.h>
 #include <stdio.h>
+#include <stdlib.h> // malloc, realloc, free
 
 namespace LIBC_NAMESPACE {
+namespace {
+
+LIBC_INLINE int resize_overflow_hook(cpp::string_view new_str, void *target) {
+  printf_core::WriteBuffer *wb =
+      reinterpret_cast<printf_core::WriteBuffer *>(target);
+  size_t new_size = new_str.size() + wb->buff_cur;
+  // init_buff is a stack ptr, needs to call malloc first.
+  char *TmpBuf =
+      static_cast<char *>((wb->buff == wb->init_buff)
+                              ? malloc(new_size + 1)
+                              : realloc(wb->buff, new_size + 1)); // +1 for null
+  if (TmpBuf == nullptr) {
+    if (wb->buff != wb->init_buff) {
+      free(wb->buff);
+    }
+    return printf_core::ALLOCATION_ERROR;
+  }
+  wb->buff = TmpBuf;
+  inline_memcpy(wb->buff + wb->buff_cur, new_str.data(), new_str.size());
+  wb->buff_cur = new_size;
+  wb->buff_len = new_size;
+  return printf_core::WRITE_OK;
+}
+
+} // namespace
+inline constexpr size_t DEFAULT_BUFFER_SIZE = 200;
 
 LLVM_LIBC_FUNCTION(int, vasprintf,
-                   (char **__restrict, const char *, va_list vlist)) {
+                   (char **__restrict ret, const char *format, va_list vlist)) {
   internal::ArgList args(vlist); // This holder class allows for easier copying
                                  // and pointer semantics, as well as handling
                                  // destruction automatically.
-  return -1;
+  char init_buff_on_stack[DEFAULT_BUFFER_SIZE];
+  printf_core::WriteBuffer wb(init_buff_on_stack, DEFAULT_BUFFER_SIZE,
+                              resize_overflow_hook);
+  printf_core::Writer writer(&wb);
+
+  auto ret_val = printf_core::printf_main(&writer, format, args);
+  if (ret_val < 0) {
+    *ret = nullptr;
+    return -1;
+  }
+  if (wb.buff == init_buff_on_stack) {
+    *ret = static_cast<char *>(malloc(ret_val + 1));
+    if (ret == nullptr) {
+      return -1;
+    }
+    inline_memcpy(*ret, wb.buff, ret_val);
+  } else {
+    *ret = wb.buff;
+  }
+  (*ret)[ret_val] = '\0';
+  return ret_val;
 }
 
 } // namespace LIBC_NAMESPACE
diff --git a/libc/test/src/stdio/CMakeLists.txt b/libc/test/src/stdio/CMakeLists.txt
index 5eb8c9577893b..8a2b109e51a43 100644
--- a/libc/test/src/stdio/CMakeLists.txt
+++ b/libc/test/src/stdio/CMakeLists.txt
@@ -236,6 +236,15 @@ add_libc_test(
     libc.src.stdio.vprintf
 )
 
+add_libc_test(
+   vasprintf_test
+   SUITE
+     libc_stdio_unittests
+   SRCS
+     vasprintf_test.cpp
+   DEPENDS
+     libc.src.stdio.vasprintf
+ )
 
 if(LLVM_LIBC_FULL_BUILD)
   # In fullbuild mode, fscanf's tests use the internal FILE for other functions.
diff --git a/libc/test/src/stdio/vasprintf_test.cpp b/libc/test/src/stdio/vasprintf_test.cpp
new file mode 100644
index 0000000000000..a8260375dcf17
--- /dev/null
+++ b/libc/test/src/stdio/vasprintf_test.cpp
@@ -0,0 +1,78 @@
+//===-- Unittests for vasprintf--------------------------------------------===//
+//
+// 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 <iostream>
+#include "src/stdio/vasprintf.h"
+#include "test/UnitTest/Test.h"
+#include "src/string/memset.h"
+
+int call_vasprintf(char **__restrict buffer, const char *__restrict format,
+                   ...) {
+  va_list vlist;
+  va_start(vlist, format);
+  int ret = LIBC_NAMESPACE::vasprintf(buffer, format, vlist);
+  va_end(vlist);
+  return ret;
+}
+
+TEST(LlvmLibcVASPrintfTest, SimpleNoConv) {
+  char *buff = nullptr;
+  int written;
+  written = call_vasprintf(&buff, "A simple string with no conversions.");
+  EXPECT_EQ(written, 36);
+  ASSERT_STREQ(buff, "A simple string with no conversions.");
+  free(buff);
+}
+
+TEST(LlvmLibcVASPrintfTest, PercentConv) {
+  char *buff = nullptr;
+  int written;
+
+  written = call_vasprintf(&buff, "%%");
+  EXPECT_EQ(written, 1);
+  ASSERT_STREQ(buff, "%");
+
+  written = call_vasprintf(&buff, "abc %% def");
+  EXPECT_EQ(written, 9);
+  ASSERT_STREQ(buff, "abc % def");
+
+  written = call_vasprintf(&buff, "%%%%%%");
+  EXPECT_EQ(written, 3);
+  ASSERT_STREQ(buff, "%%%");
+  free(buff);
+}
+
+TEST(LlvmLibcVASPrintfTest, CharConv) {
+  char *buff = nullptr;
+  int written;
+
+  written = call_vasprintf(&buff, "%c", 'a');
+  EXPECT_EQ(written, 1);
+  ASSERT_STREQ(buff, "a");
+
+  written = call_vasprintf(&buff, "%3c %-3c", '1', '2');
+  EXPECT_EQ(written, 7);
+  ASSERT_STREQ(buff, "  1 2  ");
+
+  written = call_vasprintf(&buff, "%*c", 2, '3');
+  EXPECT_EQ(written, 2);
+  ASSERT_STREQ(buff, " 3");
+  free(buff);
+}
+
+TEST(LlvmLibcVASPrintfTest, LargeStringNoConv) {
+  char *buff = nullptr;
+  char long_str[1001];
+  memset(long_str, 'a', 1000);
+  long_str[1000] = '\0';
+  int written;
+  written = call_vasprintf(&buff, long_str);
+  EXPECT_EQ(written, 1000);
+  ASSERT_STREQ(buff, long_str);
+  free(buff);
+}



More information about the libc-commits mailing list