lib_libvsprintf.c:Add buffer data type conversion interface.

Signed-off-by: likun17 <likun17@xiaomi.com>

include/nuttx/streams.h

@@ -685,6 +685,18 @@ int lib_snoflush(FAR struct lib_sostream_s *self);
 int lib_sprintf(FAR struct lib_outstream_s *stream,
                 FAR const IPTR char *fmt, ...) printf_like(2, 3);
 
+/****************************************************************************
+ * Name: lib_bsprintf
+ *
+ * Description:
+ *  Implementation of sprintf formatted output buffer data. Structure data
+ *  types must be one-byte aligned.
+ *
+ ****************************************************************************/
+
+int lib_bsprintf(FAR struct lib_outstream_s *s, FAR const IPTR char *fmt,
+                 FAR const void *buf);
+
 /****************************************************************************
  * Name: lib_sprintf_internal
  *

libs/libc/stdio/CMakeLists.txt

@@ -40,6 +40,7 @@ set(SRCS
     lib_sscanf.c
     lib_vsscanf.c
     lib_libvscanf.c
+    lib_libbsprintf.c
     lib_libvsprintf.c
     lib_remove.c
     lib_tempnam.c

libs/libc/stdio/Make.defs

@@ -28,7 +28,7 @@ CSRCS += lib_perror.c lib_putchar.c lib_getchar.c lib_puts.c
 CSRCS += lib_gets_s.c lib_gets.c lib_libdgets.c
 CSRCS += lib_sscanf.c lib_vsscanf.c lib_libvscanf.c lib_libvsprintf.c
 CSRCS += lib_remove.c lib_tempnam.c lib_tmpnam.c lib_ultoa_invert.c
-CSRCS += lib_renameat.c lib_putwchar.c
+CSRCS += lib_renameat.c lib_putwchar.c lib_libbsprintf.c
 
 ifeq ($(CONFIG_LIBC_FLOATINGPOINT),y)
 CSRCS += lib_dtoa_engine.c lib_dtoa_data.c

libs/libc/stdio/README.md

@@ -0,0 +1,95 @@
+# lib_libbsprintf
+  This function is mainly used to output the contents of the input structure. Most standards follow the standards of printf and scanf.
+  For detailed parameters, see:
+  1. https://en.cppreference.com/w/c/io/fprintf
+  2. https://en.cppreference.com/w/c/io/fscanf
+
+- **special**:
+  1. Float use %hf, and double for all others.
+  2. The char array is specified with %.xs. for example: "char t[30]" is specified with "%.30s", char a [20] - " %.20s "
+  3. "%u" is unsigned int.
+  4. "%d" is int.
+  5. When using %f to format a double data type, the double is truncated to 6 decimal places by default.
+  6. It is recommended that the "char[]" array be placed at the end of the structure to prevent parameter configuration errors such as "%.20s" from causing problems in parsing the entire buffer.
+- **demo**
+  1. **struct**:
+  ~~~
+  begin_packed_struct
+  struct test
+  {
+    uint8_t a;
+    uint16_t b;
+    uint32_t c;
+    int8_t d;
+    int16_t e;
+    int32_t f;
+    float g;
+    double h;
+    char i[32];
+    uint64_t j;
+    int64_t k;
+    char l;
+    unsigned char m;
+    short int n;
+    unsigned short int o;
+    int p;
+    unsigned int q;
+    long r;
+    unsigned long s;
+    long long t;
+    unsigned long long u;
+    size_t v;
+    long double w;
+  }end_packed_struct;
+  ~~~
+  1. **format string**:
+  ~~~
+  const char* sg = "           uint8_t:[%hhu]\n" \
+                   "          uint16_t:[%hu]\n" \
+                   "          uint32_t:[%u]\n" \
+                   "            int8_t:[%hhd]\n" \
+                   "           int16_t:[%hd]\n" \
+                   "           int32_t:[%d]\n" \
+                   "             float:[%hf]\n" \
+                   "            double:[%f]\n" \
+                   "            char[]:[%.32s]\n" \
+                   "          uint64_t:[%lu]\n" \
+                   "           int64_t:[%ld]\n" \
+                   "              char:[%hhd]\n" \
+                   "     unsigned char:[%hhu]\n" \
+                   "         short int:[%hd]\n" \
+                   "unsigned short int:[%hu]\n" \
+                   "               int:[%d]\n" \
+                   "      unsigned int:[%u]\n" \
+                   "              long:[%ld]\n" \
+                   "     unsigned long:[%lu]\n" \
+                   "         long long:[%lld]\n" \
+                   "unsigned long long:[%llu]\n" \
+                   "            size_t:[%uz]\n" \
+                   "       long double:[%Lf]\n";
+  ~~~
+  1. **use**:
+    -  output to terminal:
+   ~~~
+  #ifdef CONFIG_FILE_STREAM
+    struct lib_stdoutstream_s stdoutstream;
+
+    lib_stdoutstream(&stdoutstream, stdout);
+
+    flockfile(stdout);
+    lib_bsprintf(&stdoutstream.common, sv, &test_v);
+    lib_bsprintf(&stdoutstream.common, sg, &test_g);
+    funlockfile(stdout);
+  #else
+    struct lib_rawoutstream_s rawoutstream;
+    struct lib_bufferedoutstream_s outstream;
+
+    lib_rawoutstream(&rawoutstream, STDOUT_FILENO);
+    lib_bufferedoutstream(&outstream, &rawoutstream.common);
+
+    lib_bsprintf(&outstream.common, sv, &test_v);
+    lib_bsprintf(&outstream.common, sg, &test_g);
+
+    lib_stream_flush(&outstream.common);
+  #endif
+   ~~~

libs/libc/stdio/lib_libbsprintf.c

@@ -0,0 +1,207 @@
+/****************************************************************************
+ * libs/libc/stdio/lib_libbsprintf.c
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.  The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+#include <nuttx/streams.h>
+#include <nuttx/compiler.h>
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+int lib_bsprintf(FAR struct lib_outstream_s *s, FAR const IPTR char *fmt,
+                 FAR const void *buf)
+{
+  begin_packed_struct union
+    {
+      char c;
+      short int si;
+      int i;
+      long l;
+#ifdef CONFIG_HAVE_LONG_LONG
+      long long ll;
+#endif
+      intmax_t im;
+      size_t sz;
+      ptrdiff_t pd;
+      uintptr_t p;
+#ifdef CONFIG_HAVE_DOUBLE
+      float f;
+      double d;
+#  ifdef CONFIG_HAVE_LONG_DOUBLE
+      long double ld;
+#  endif
+#endif
+    }
+
+  end_packed_struct *var;
+  FAR const char *prec = NULL;
+  FAR const char *data = buf;
+  char fmtstr[64];
+  bool infmt = false;
+  size_t offset = 0;
+  size_t ret = 0;
+  size_t len = 0;
+  char c;
+
+  while ((c = *fmt++) != '\0')
+    {
+      if (c != '%' && !infmt)
+        {
+          lib_stream_putc(s, c);
+          ret++;
+          continue;
+        }
+
+      if (!infmt)
+        {
+          len = 0;
+          infmt = true;
+          memset(fmtstr, 0, sizeof(fmtstr));
+        }
+
+      var = (FAR void *)((char *)buf + offset);
+      fmtstr[len++] = c;
+
+      if (c == 'c' || c == 'd' || c == 'i' || c == 'u' ||
+          c == 'o' || c == 'x' || c == 'X')
+        {
+          if (*(fmt - 2) == 'j')
+            {
+              offset += sizeof(var->im);
+              ret += lib_sprintf(s, fmtstr, var->im);
+            }
+#ifdef CONFIG_HAVE_LONG_LONG
+          else if (*(fmt - 2) == 'l' && *(fmt - 3) == 'l')
+            {
+              offset += sizeof(var->ll);
+              ret += lib_sprintf(s, fmtstr, var->ll);
+            }
+#endif
+          else if (*(fmt - 2) == 'l')
+            {
+              offset += sizeof(var->l);
+              ret += lib_sprintf(s, fmtstr, var->l);
+            }
+          else if (*(fmt - 2) == 'z')
+            {
+              offset += sizeof(var->sz);
+              ret += lib_sprintf(s, fmtstr, var->sz);
+            }
+          else if (*(fmt - 2) == 't')
+            {
+              offset += sizeof(var->pd);
+              ret += lib_sprintf(s, fmtstr, var->pd);
+            }
+          else if (*(fmt - 2) == 'h' && *(fmt - 3) == 'h')
+            {
+              offset += sizeof(var->c);
+              ret += lib_sprintf(s, fmtstr, var->c);
+            }
+          else if (*(fmt - 2) == 'h')
+            {
+              offset += sizeof(var->si);
+              ret += lib_sprintf(s, fmtstr, var->si);
+            }
+          else
+            {
+              offset += sizeof(var->i);
+              ret += lib_sprintf(s, fmtstr, var->i);
+            }
+
+          infmt = false;
+        }
+      else if (c == 'e' || c == 'f' || c == 'g' || c == 'a' ||
+               c == 'A' || c == 'E' || c == 'F' || c == 'G')
+        {
+#ifdef CONFIG_HAVE_DOUBLE
+          if (*(fmt - 2) == 'h')
+            {
+              offset += sizeof(var->f);
+              ret += lib_sprintf(s, fmtstr, var->f);
+            }
+#  ifdef CONFIG_HAVE_LONG_DOUBLE
+          else if (*(fmt - 2) == 'L')
+            {
+              offset += sizeof(var->ld);
+              ret += lib_sprintf(s, fmtstr, var->ld);
+            }
+#  endif
+          else
+            {
+              offset += sizeof(var->d);
+              ret += lib_sprintf(s, fmtstr, var->d);
+            }
+
+          infmt = false;
+#endif
+        }
+      else if (c == '*')
+        {
+          itoa(var->i, fmtstr + len - 1, 10);
+          len = strlen(fmtstr);
+          offset += sizeof(var->i);
+        }
+      else if (c == 's')
+        {
+          FAR const char *value = data + offset;
+
+          if (prec != NULL)
+            {
+              offset += strtol(prec, NULL, 10);
+              prec = NULL;
+            }
+          else
+            {
+              offset += strlen(value) + 1;
+            }
+
+          ret += lib_sprintf(s, fmtstr, value);
+          infmt = false;
+        }
+      else if (c == 'p')
+        {
+          offset += sizeof(var->p);
+          ret += lib_sprintf(s, fmtstr, var->p);
+          infmt = false;
+        }
+      else if (c == '.')
+        {
+          prec = fmt;
+        }
+    }
+
+  if (*(fmt - 2) != '\n')
+    {
+      lib_stream_putc(s, '\n');
+      ret++;
+    }
+
+  return ret;
+}