[PATCH] Improve printf DFP support

[PATCH] Improve printf DFP support

[Luis Machado]

[-- Attachment #1: Type: text/plain, Size: 492 bytes --]

Hi folks,

This is an improvement over the last patch i have submited to add DFP
support for GDB's printf command.

The DFP modifiers are now being treated as length modifiers, and not
type modifiers. This puts us in agreement with what the C99 standard's
DFP annex says.

The parsing of the string is a bit more robust than the last version.

A documentation and testcase updated is attached as well.

Comments?

Best regards,
-- 
Luis Machado
Software Engineer 
IBM Linux Technology Center

[-- Attachment #2: dfp-printf.diff --]
[-- Type: text/x-patch, Size: 13412 bytes --]

2008-08-01  Luis Machado  <luisgpm@br.ibm.com>

	* printcmd.c (printf_command): Add seen_big_h, seen_big_d and 
	seen_double_big_d, treat the new H, D, and DD modifiers as length
	modifiers.
	* doc/gdb.texinfo: Update documentation on using printf with DFP
	types.
	* testsuite/gdb.base/printcmds.exp (test_printf_with_dfp): Update 
	printf calls with required float modifiers.

Index: gdb/printcmd.c
===================================================================
--- gdb.orig/printcmd.c	2008-01-08 04:52:15.000000000 -0800
+++ gdb/printcmd.c	2008-01-08 05:23:52.000000000 -0800
@@ -1837,7 +1837,8 @@
 	{
 	  int seen_hash = 0, seen_zero = 0, lcount = 0, seen_prec = 0;
 	  int seen_space = 0, seen_plus = 0;
-	  int seen_big_l = 0, seen_h = 0;
+	  int seen_big_l = 0, seen_h = 0, seen_big_h = 0;
+	  int seen_big_d = 0, seen_double_big_d = 0;
 	  int bad = 0;
 
 	  /* Check the validity of the format specifier, and work
@@ -1901,6 +1902,26 @@
 	      seen_big_l = 1;
 	      f++;
 	    }
+	  /* Decimal32 modifier.  */
+	  else if (*f == 'H')
+	    {
+	      seen_big_h = 1;
+	      f++;
+	    }
+	  /* Decimal64 and Decimal128 modifiers.  */
+	  else if (*f == 'D')
+	    {
+	      f++;
+
+              /* Check for a Decimal128.  */
+              if (*f == 'D')
+	      {
+                f++;
+		seen_double_big_d = 1;
+	      }
+	      else
+		seen_big_d = 1;
+	    }
 
 	  switch (*f)
 	    {
@@ -1929,34 +1950,6 @@
 		bad = 1;
 	      break;
 
-	    /* DFP Decimal32 types.  */
-	    case 'H':
-	      this_argclass = decfloat_arg;
-
-#ifndef PRINTF_HAS_DECFLOAT
-              if (lcount || seen_h || seen_big_l)
-                bad = 1;
-              if (seen_prec || seen_zero || seen_space || seen_plus)
-                bad = 1;
-#endif
-	      break;
-
-	    /* DFP Decimal64 and Decimal128 types.  */
-	    case 'D':
-	      this_argclass = decfloat_arg;
-
-#ifndef PRINTF_HAS_DECFLOAT
-              if (lcount || seen_h || seen_big_l)
-                bad = 1;
-              if (seen_prec || seen_zero || seen_space || seen_plus)
-                bad = 1;
-#endif
-	      /* Check for a Decimal128.  */
-	      if (*(f + 1) == 'D')
-		f++;
-
-	      break;
-
 	    case 'c':
 	      this_argclass = int_arg;
 	      if (lcount || seen_h || seen_big_l)
@@ -1986,7 +1979,9 @@
 	    case 'g':
 	    case 'E':
 	    case 'G':
-	      if (seen_big_l)
+              if (seen_big_h || seen_big_d || seen_double_big_d)
+                this_argclass = decfloat_arg;
+	      else if (seen_big_l)
 		this_argclass = long_double_arg;
 	      else
 		this_argclass = double_arg;
@@ -2124,50 +2119,103 @@
 	      break;
 	    }
 
-	  /* Handles decimal floating point values.  */
+	  /* Handles decimal floating values.  */
 	  case decfloat_arg:
 	    {
-	      char *eos;
-	      char decstr[MAX_DECIMAL_STRING];
-	      unsigned int dfp_len = TYPE_LENGTH (value_type (val_args[i]));
-	      unsigned char *dfp_value_ptr = (unsigned char *) value_contents_all (val_args[i])
+	      gdb_byte *param_ptr = (gdb_byte *) value_contents_all (val_args[i])
                                       + value_offset (val_args[i]);
-
 #if defined (PRINTF_HAS_DECFLOAT)
-	      printf_filtered (current_substring, dfp_value_ptr);
+	      /* If we have native support for Decimal floating
+		 printing, handle it here.  */
+	      printf_filtered (current_substring, param_ptr);
 #else
-	      if (TYPE_CODE (value_type (val_args[i])) != TYPE_CODE_DECFLOAT)
-		error (_("Cannot convert parameter to decfloat."));
 
-	      /* As a workaround until vasprintf has native support for DFP
-		 we convert the DFP values to string and print them using
-		 the %s format specifier.  */
-	      decimal_to_string (dfp_value_ptr, dfp_len, decstr);
-
-	      /* Points to the end of the string so that we can go back
-		 and check for DFP format specifiers.  */
-	      eos = current_substring + strlen (current_substring);
-
-	      /* Replace %H, %D and %DD with %s's.  */
-	      while (*--eos != '%')
-		if (*eos == 'D' && *(eos - 1) == 'D')
-		  {
-		    *(eos - 1) = 's';
-
-		    /* If we've found a %DD format specifier we need to go
-		       through the whole string pulling back one character
-		       since this format specifier has two chars.  */
-		    while (eos < last_arg)
-		      {
-			*eos = *(eos + 1);
-			eos++;
-		      }
-		  }
-		else if (*eos == 'D' || *eos == 'H')
-		  *eos = 's';
+            /* As a workaround until vasprintf has native support for DFP
+               we convert the DFP values to string and print them using
+               the %s format specifier.  */
+
+              char *eos, *sos;
+	      int nnull_chars = 0;
+
+              /* Parameter data.  */
+              struct type *param_type = value_type (val_args[i]);
+              unsigned int param_len = TYPE_LENGTH (param_type);
+
+              /* DFP output data.  */
+              struct value *dfp_value = NULL;
+              gdb_byte *dfp_ptr;
+              int dfp_len = 16;
+              gdb_byte dec[16];
+              struct type *dfp_type = NULL;
+              char decstr[MAX_DECIMAL_STRING];
+
+              /* Points to the end of the string so that we can go back
+                 and check for DFP length modifiers.  */
+              eos = current_substring + strlen (current_substring);
+
+	      /* Look for the float/double format specifier.  */
+              while (*eos != 'f' && *eos != 'e' && *eos != 'E'
+		     && *eos != 'g' && *eos != 'G')
+		  eos--;
+
+              sos = eos;
+
+	      /* Search for the '%' char and extract the size and type of
+		 the output decimal value based on its modifiers
+		 (%Hf, %Df, %DDf).  */
+              while (*--sos != '%')
+                {
+                  if (*sos == 'H')
+                    {
+                      dfp_len = 4;
+                      dfp_type = builtin_type (current_gdbarch)->builtin_decfloat;
+                    }
+                  else if (*sos == 'D' && *(sos - 1) == 'D')
+                    {
+                      dfp_len = 16;
+                      dfp_type = builtin_type (current_gdbarch)->builtin_declong;
+		      sos--;
+                    }
+                  else
+                    {
+                      dfp_len = 8;
+                      dfp_type = builtin_type (current_gdbarch)->builtin_decdouble;
+                    }
+                }
+
+	      /* Replace %Hf, %Df and %DDf with %s's.  */
+              *++sos = 's';
+
+              /* Go through the whole format string and pull the correct
+		 number of chars back to compensate for the change in the
+		 format specifier.  */
+	      while (nnull_chars < nargs - i)
+		{
+		  if (*eos == '\0')
+		    nnull_chars++;
+
+		  *++sos = *++eos;
+		}
+
+	      /* Conversion between different DFP types.  */
+	      if (TYPE_CODE (param_type) == TYPE_CODE_DECFLOAT)
+		decimal_convert (param_ptr, param_len, dec, dfp_len);
+	      else
+		/* If this is a non-trivial conversion, just output 0.
+		   A correct converted value can be displayed by explicitly
+		   casting to a DFP type.  */
+		decimal_from_string (dec, dfp_len, "0");
+
+	      dfp_value = value_from_decfloat (dfp_type, dec);
+
+	      dfp_ptr = (gdb_byte *) value_contents_all (dfp_value)
+				      + value_offset (dfp_value);
+
+	      decimal_to_string (dfp_ptr, dfp_len, decstr);
 
 	      /* Print the DFP value.  */
 	      printf_filtered (current_substring, decstr);
+
 	      break;
 #endif
 	    }
Index: gdb/doc/gdb.texinfo
===================================================================
--- gdb.orig/doc/gdb.texinfo	2008-01-08 04:52:15.000000000 -0800
+++ gdb/doc/gdb.texinfo	2008-01-08 04:56:54.000000000 -0800
@@ -16693,7 +16693,8 @@
 supported.
 
 Additionally, @code{printf} supports conversion specifications for DFP
-(@dfn{Decimal Floating Point}) types using the following conversion
+(@dfn{Decimal Floating Point}) types using the following length modifiers
+together with a floating point specifier.
 letters:
 
 @itemize @bullet
@@ -16708,7 +16709,7 @@
 @end itemize
 
 If the underlying @code{C} implementation used to build @value{GDBN} has
-support for the three conversion letters for DFP types, other modifiers
+support for the three length modifiers for DFP types, other modifiers
 such as width and precision will also be available for @value{GDBN} to use.
 
 In case there is no such @code{C} support, no additional modifiers will be
@@ -16716,7 +16717,7 @@
 
 Here's an example of printing DFP types using the above conversion letters:
 @smallexample
-printf "D32: %H - D64: %D - D128: %DD\n",1.2345df,1.2E10dd,1.2E1dl
+printf "D32: %Hf - D64: %Df - D128: %DDf\n",1.2345df,1.2E10dd,1.2E1dl
 @end smallexample
 
 @end table
Index: gdb/testsuite/gdb.base/printcmds.exp
===================================================================
--- gdb.orig/testsuite/gdb.base/printcmds.exp	2008-01-08 04:52:15.000000000 -0800
+++ gdb/testsuite/gdb.base/printcmds.exp	2008-01-08 04:56:54.000000000 -0800
@@ -674,49 +674,49 @@
     # Test various dfp values, covering 32-bit, 64-bit and 128-bit ones
 
     # _Decimal32 constants, which can support up to 7 digits
-    gdb_test "printf \"%H\\n\",1.2df" "1.2"
-    gdb_test "printf \"%H\\n\",-1.2df" "-1.2"
-    gdb_test "printf \"%H\\n\",1.234567df" "1.234567"
-    gdb_test "printf \"%H\\n\",-1.234567df" "-1.234567"
-    gdb_test "printf \"%H\\n\",1234567.df" "1234567"
-    gdb_test "printf \"%H\\n\",-1234567.df" "-1234567"
-
-    gdb_test "printf \"%H\\n\",1.2E1df" "12"
-    gdb_test "printf \"%H\\n\",1.2E10df" "1.2E\\+10"
-    gdb_test "printf \"%H\\n\",1.2E-10df" "1.2E-10"
+    gdb_test "printf \"%Hf\\n\",1.2df" "1.2"
+    gdb_test "printf \"%Hf\\n\",-1.2df" "-1.2"
+    gdb_test "printf \"%Hf\\n\",1.234567df" "1.234567"
+    gdb_test "printf \"%Hf\\n\",-1.234567df" "-1.234567"
+    gdb_test "printf \"%Hf\\n\",1234567.df" "1234567"
+    gdb_test "printf \"%Hf\\n\",-1234567.df" "-1234567"
+
+    gdb_test "printf \"%Hf\\n\",1.2E1df" "12"
+    gdb_test "printf \"%Hf\\n\",1.2E10df" "1.2E\\+10"
+    gdb_test "printf \"%Hf\\n\",1.2E-10df" "1.2E-10"
 
     # The largest exponent for 32-bit dfp value is 96.
-    gdb_test "printf \"%H\\n\",1.2E96df" "1.200000E\\+96"
+    gdb_test "printf \"%Hf\\n\",1.2E96df" "1.200000E\\+96"
 
     # _Decimal64 constants, which can support up to 16 digits
-    gdb_test "printf \"%D\\n\",1.2dd" "1.2"
-    gdb_test "printf \"%D\\n\",-1.2dd" "-1.2"
-    gdb_test "printf \"%D\\n\",1.234567890123456dd" "1.234567890123456"
-    gdb_test "printf \"%D\\n\",-1.234567890123456dd" "-1.234567890123456"
-    gdb_test "printf \"%D\\n\",1234567890123456.dd" "1234567890123456"
-    gdb_test "printf \"%D\\n\",-1234567890123456.dd" "-1234567890123456"
-
-    gdb_test "printf \"%D\\n\",1.2E1dd" "12"
-    gdb_test "printf \"%D\\n\",1.2E10dd" "1.2E\\+10"
-    gdb_test "printf \"%D\\n\",1.2E-10dd" "1.2E-10"
+    gdb_test "printf \"%Df\\n\",1.2dd" "1.2"
+    gdb_test "printf \"%Df\\n\",-1.2dd" "-1.2"
+    gdb_test "printf \"%Df\\n\",1.234567890123456dd" "1.234567890123456"
+    gdb_test "printf \"%Df\\n\",-1.234567890123456dd" "-1.234567890123456"
+    gdb_test "printf \"%Df\\n\",1234567890123456.dd" "1234567890123456"
+    gdb_test "printf \"%Df\\n\",-1234567890123456.dd" "-1234567890123456"
+
+    gdb_test "printf \"%Df\\n\",1.2E1dd" "12"
+    gdb_test "printf \"%Df\\n\",1.2E10dd" "1.2E\\+10"
+    gdb_test "printf \"%Df\\n\",1.2E-10dd" "1.2E-10"
 
     # The largest exponent for 64-bit dfp value is 384.
-    gdb_test "printf \"%D\\n\",1.2E384dd" "1.200000000000000E\\+384"
+    gdb_test "printf \"%Df\\n\",1.2E384dd" "1.200000000000000E\\+384"
 
     # _Decimal128 constants, which can support up to 34 digits
-    gdb_test "printf \"%DD\\n\",1.2dl" "1.2"
-    gdb_test "printf \"%DD\\n\",-1.2dl" "-1.2"
-    gdb_test "printf \"%DD\\n\",1.234567890123456789012345678901234dl" "1.234567890123456789012345678901234"
-    gdb_test "printf \"%DD\\n\",-1.234567890123456789012345678901234dl" "-1.234567890123456789012345678901234"
-    gdb_test "printf \"%DD\\n\",1234567890123456789012345678901234.dl" "1234567890123456789012345678901234"
-    gdb_test "printf \"%DD\\n\",-1234567890123456789012345678901234.dl" "-1234567890123456789012345678901234"
-
-    gdb_test "printf \"%DD\\n\",1.2E1dl" "12"
-    gdb_test "printf \"%DD\\n\",1.2E10dl" "1.2E\\+10"
-    gdb_test "printf \"%DD\\n\",1.2E-10dl" "1.2E-10"
+    gdb_test "printf \"%DDf\\n\",1.2dl" "1.2"
+    gdb_test "printf \"%DDf\\n\",-1.2dl" "-1.2"
+    gdb_test "printf \"%DDf\\n\",1.234567890123456789012345678901234dl" "1.234567890123456789012345678901234"
+    gdb_test "printf \"%DDf\\n\",-1.234567890123456789012345678901234dl" "-1.234567890123456789012345678901234"
+    gdb_test "printf \"%DDf\\n\",1234567890123456789012345678901234.dl" "1234567890123456789012345678901234"
+    gdb_test "printf \"%DDf\\n\",-1234567890123456789012345678901234.dl" "-1234567890123456789012345678901234"
+
+    gdb_test "printf \"%DDf\\n\",1.2E1dl" "12"
+    gdb_test "printf \"%DDf\\n\",1.2E10dl" "1.2E\\+10"
+    gdb_test "printf \"%DDf\\n\",1.2E-10dl" "1.2E-10"
 
     # The largest exponent for 128-bit dfp value is 6144.
-    gdb_test "printf \"%DD\\n\",1.2E6144dl" "1.200000000000000000000000000000000E\\+6144"
+    gdb_test "printf \"%DDf\\n\",1.2E6144dl" "1.200000000000000000000000000000000E\\+6144"
 }
 
 # Escape a left curly brace to prevent it from being interpreted as 

Re: [PATCH] Improve printf DFP support

[Thiago Jung Bauermann]

On Tue, 2008-01-08 at 11:27 -0200, Luis Machado wrote:
> Comments?

> +	      gdb_byte *param_ptr = (gdb_byte *) value_contents_all >
(val_args[i])
>                                        + value_offset (val_args[i]);

param_ptr should be a const gdb_byte *, and the cast here should be
removed. In addition, I believe the use of value_offset here is wrong.
Other uses of value_offset are to obtain a memory address in the
inferior address space, not in GDB's. Also, I think that value_contents
should be used intead of value_contents_all so that the value's
embedded_offset can be taken into account.

> +	      dfp_ptr = (gdb_byte *) value_contents_all (dfp_value)
> +				      + value_offset (dfp_value);

Same here.

PS: I don't have deep understaing of GDB's value mechanism so if someone
sees I am saying something wrong here please correct me.
-- 
[]'s
Thiago Jung Bauermann
Software Engineer
IBM Linux Technology Center

Re: [PATCH] Improve printf DFP support

[Daniel Jacobowitz]

On Tue, Jan 08, 2008 at 01:19:06PM -0200, Thiago Jung Bauermann wrote:
> param_ptr should be a const gdb_byte *, and the cast here should be
> removed. In addition, I believe the use of value_offset here is wrong.
> Other uses of value_offset are to obtain a memory address in the
> inferior address space, not in GDB's. Also, I think that value_contents
> should be used intead of value_contents_all so that the value's
> embedded_offset can be taken into account.

I believe that you are correct.  The value handling is another area of
GDB that could do with some cleaning up; I am not convinced the
multiple offsets dance is necessary...

-- 
Daniel Jacobowitz
CodeSourcery

Re: [PATCH] Improve printf DFP support

[Luis Machado]

[-- Attachment #1: Type: text/plain, Size: 660 bytes --]

On Tue, 2008-01-08 at 13:19 -0200, Thiago Jung Bauermann wrote:
> param_ptr should be a const gdb_byte *, and the cast here should be
> removed. In addition, I believe the use of value_offset here is wrong.
> Other uses of value_offset are to obtain a memory address in the
> inferior address space, not in GDB's. Also, I think that value_contents
> should be used intead of value_contents_all so that the value's
> embedded_offset can be taken into account.
> 
> > +	      dfp_ptr = (gdb_byte *) value_contents_all (dfp_value)
> > +				      + value_offset (dfp_value);
> 
> Same here.

Fixed.

-- 
Luis Machado
Software Engineer 
IBM Linux Technology Center

[-- Attachment #2: dfp-printf.diff --]
[-- Type: text/x-patch, Size: 13360 bytes --]

2008-08-01  Luis Machado  <luisgpm@br.ibm.com>

	* printcmd.c (printf_command): Add seen_big_h, seen_big_d and 
	seen_double_big_d, treat the new H, D, and DD modifiers as length
	modifiers.
	* doc/gdb.texinfo: Update documentation on using printf with DFP
	types.
	* testsuite/gdb.base/printcmds.exp (test_printf_with_dfp): Update 
	printf calls with required float modifiers.

Index: gdb/printcmd.c
===================================================================
--- gdb.orig/printcmd.c	2008-01-08 07:03:19.000000000 -0800
+++ gdb/printcmd.c	2008-01-08 07:26:28.000000000 -0800
@@ -1837,7 +1837,8 @@
 	{
 	  int seen_hash = 0, seen_zero = 0, lcount = 0, seen_prec = 0;
 	  int seen_space = 0, seen_plus = 0;
-	  int seen_big_l = 0, seen_h = 0;
+	  int seen_big_l = 0, seen_h = 0, seen_big_h = 0;
+	  int seen_big_d = 0, seen_double_big_d = 0;
 	  int bad = 0;
 
 	  /* Check the validity of the format specifier, and work
@@ -1901,6 +1902,26 @@
 	      seen_big_l = 1;
 	      f++;
 	    }
+	  /* Decimal32 modifier.  */
+	  else if (*f == 'H')
+	    {
+	      seen_big_h = 1;
+	      f++;
+	    }
+	  /* Decimal64 and Decimal128 modifiers.  */
+	  else if (*f == 'D')
+	    {
+	      f++;
+
+              /* Check for a Decimal128.  */
+              if (*f == 'D')
+	      {
+                f++;
+		seen_double_big_d = 1;
+	      }
+	      else
+		seen_big_d = 1;
+	    }
 
 	  switch (*f)
 	    {
@@ -1929,34 +1950,6 @@
 		bad = 1;
 	      break;
 
-	    /* DFP Decimal32 types.  */
-	    case 'H':
-	      this_argclass = decfloat_arg;
-
-#ifndef PRINTF_HAS_DECFLOAT
-              if (lcount || seen_h || seen_big_l)
-                bad = 1;
-              if (seen_prec || seen_zero || seen_space || seen_plus)
-                bad = 1;
-#endif
-	      break;
-
-	    /* DFP Decimal64 and Decimal128 types.  */
-	    case 'D':
-	      this_argclass = decfloat_arg;
-
-#ifndef PRINTF_HAS_DECFLOAT
-              if (lcount || seen_h || seen_big_l)
-                bad = 1;
-              if (seen_prec || seen_zero || seen_space || seen_plus)
-                bad = 1;
-#endif
-	      /* Check for a Decimal128.  */
-	      if (*(f + 1) == 'D')
-		f++;
-
-	      break;
-
 	    case 'c':
 	      this_argclass = int_arg;
 	      if (lcount || seen_h || seen_big_l)
@@ -1986,7 +1979,9 @@
 	    case 'g':
 	    case 'E':
 	    case 'G':
-	      if (seen_big_l)
+              if (seen_big_h || seen_big_d || seen_double_big_d)
+                this_argclass = decfloat_arg;
+	      else if (seen_big_l)
 		this_argclass = long_double_arg;
 	      else
 		this_argclass = double_arg;
@@ -2124,50 +2119,101 @@
 	      break;
 	    }
 
-	  /* Handles decimal floating point values.  */
+	  /* Handles decimal floating values.  */
 	  case decfloat_arg:
 	    {
-	      char *eos;
-	      char decstr[MAX_DECIMAL_STRING];
-	      unsigned int dfp_len = TYPE_LENGTH (value_type (val_args[i]));
-	      unsigned char *dfp_value_ptr = (unsigned char *) value_contents_all (val_args[i])
-                                      + value_offset (val_args[i]);
-
+	      const gdb_byte *param_ptr = value_contents (val_args[i]);
 #if defined (PRINTF_HAS_DECFLOAT)
-	      printf_filtered (current_substring, dfp_value_ptr);
+	      /* If we have native support for Decimal floating
+		 printing, handle it here.  */
+	      printf_filtered (current_substring, param_ptr);
 #else
-	      if (TYPE_CODE (value_type (val_args[i])) != TYPE_CODE_DECFLOAT)
-		error (_("Cannot convert parameter to decfloat."));
 
-	      /* As a workaround until vasprintf has native support for DFP
-		 we convert the DFP values to string and print them using
-		 the %s format specifier.  */
-	      decimal_to_string (dfp_value_ptr, dfp_len, decstr);
-
-	      /* Points to the end of the string so that we can go back
-		 and check for DFP format specifiers.  */
-	      eos = current_substring + strlen (current_substring);
-
-	      /* Replace %H, %D and %DD with %s's.  */
-	      while (*--eos != '%')
-		if (*eos == 'D' && *(eos - 1) == 'D')
-		  {
-		    *(eos - 1) = 's';
-
-		    /* If we've found a %DD format specifier we need to go
-		       through the whole string pulling back one character
-		       since this format specifier has two chars.  */
-		    while (eos < last_arg)
-		      {
-			*eos = *(eos + 1);
-			eos++;
-		      }
-		  }
-		else if (*eos == 'D' || *eos == 'H')
-		  *eos = 's';
+            /* As a workaround until vasprintf has native support for DFP
+               we convert the DFP values to string and print them using
+               the %s format specifier.  */
+
+              char *eos, *sos;
+	      int nnull_chars = 0;
+
+              /* Parameter data.  */
+              struct type *param_type = value_type (val_args[i]);
+              unsigned int param_len = TYPE_LENGTH (param_type);
+
+              /* DFP output data.  */
+              struct value *dfp_value = NULL;
+              gdb_byte *dfp_ptr;
+              int dfp_len = 16;
+              gdb_byte dec[16];
+              struct type *dfp_type = NULL;
+              char decstr[MAX_DECIMAL_STRING];
+
+              /* Points to the end of the string so that we can go back
+                 and check for DFP length modifiers.  */
+              eos = current_substring + strlen (current_substring);
+
+	      /* Look for the float/double format specifier.  */
+              while (*eos != 'f' && *eos != 'e' && *eos != 'E'
+		     && *eos != 'g' && *eos != 'G')
+		  eos--;
+
+              sos = eos;
+
+	      /* Search for the '%' char and extract the size and type of
+		 the output decimal value based on its modifiers
+		 (%Hf, %Df, %DDf).  */
+              while (*--sos != '%')
+                {
+                  if (*sos == 'H')
+                    {
+                      dfp_len = 4;
+                      dfp_type = builtin_type (current_gdbarch)->builtin_decfloat;
+                    }
+                  else if (*sos == 'D' && *(sos - 1) == 'D')
+                    {
+                      dfp_len = 16;
+                      dfp_type = builtin_type (current_gdbarch)->builtin_declong;
+		      sos--;
+                    }
+                  else
+                    {
+                      dfp_len = 8;
+                      dfp_type = builtin_type (current_gdbarch)->builtin_decdouble;
+                    }
+                }
+
+	      /* Replace %Hf, %Df and %DDf with %s's.  */
+              *++sos = 's';
+
+              /* Go through the whole format string and pull the correct
+		 number of chars back to compensate for the change in the
+		 format specifier.  */
+	      while (nnull_chars < nargs - i)
+		{
+		  if (*eos == '\0')
+		    nnull_chars++;
+
+		  *++sos = *++eos;
+		}
+
+	      /* Conversion between different DFP types.  */
+	      if (TYPE_CODE (param_type) == TYPE_CODE_DECFLOAT)
+		decimal_convert (param_ptr, param_len, dec, dfp_len);
+	      else
+		/* If this is a non-trivial conversion, just output 0.
+		   A correct converted value can be displayed by explicitly
+		   casting to a DFP type.  */
+		decimal_from_string (dec, dfp_len, "0");
+
+	      dfp_value = value_from_decfloat (dfp_type, dec);
+
+	      dfp_ptr = (gdb_byte *) value_contents (dfp_value);
+
+	      decimal_to_string (dfp_ptr, dfp_len, decstr);
 
 	      /* Print the DFP value.  */
 	      printf_filtered (current_substring, decstr);
+
 	      break;
 #endif
 	    }
Index: gdb/doc/gdb.texinfo
===================================================================
--- gdb.orig/doc/gdb.texinfo	2008-01-08 07:03:19.000000000 -0800
+++ gdb/doc/gdb.texinfo	2008-01-08 07:03:39.000000000 -0800
@@ -16693,7 +16693,8 @@
 supported.
 
 Additionally, @code{printf} supports conversion specifications for DFP
-(@dfn{Decimal Floating Point}) types using the following conversion
+(@dfn{Decimal Floating Point}) types using the following length modifiers
+together with a floating point specifier.
 letters:
 
 @itemize @bullet
@@ -16708,7 +16709,7 @@
 @end itemize
 
 If the underlying @code{C} implementation used to build @value{GDBN} has
-support for the three conversion letters for DFP types, other modifiers
+support for the three length modifiers for DFP types, other modifiers
 such as width and precision will also be available for @value{GDBN} to use.
 
 In case there is no such @code{C} support, no additional modifiers will be
@@ -16716,7 +16717,7 @@
 
 Here's an example of printing DFP types using the above conversion letters:
 @smallexample
-printf "D32: %H - D64: %D - D128: %DD\n",1.2345df,1.2E10dd,1.2E1dl
+printf "D32: %Hf - D64: %Df - D128: %DDf\n",1.2345df,1.2E10dd,1.2E1dl
 @end smallexample
 
 @end table
Index: gdb/testsuite/gdb.base/printcmds.exp
===================================================================
--- gdb.orig/testsuite/gdb.base/printcmds.exp	2008-01-08 07:03:19.000000000 -0800
+++ gdb/testsuite/gdb.base/printcmds.exp	2008-01-08 07:03:39.000000000 -0800
@@ -674,49 +674,49 @@
     # Test various dfp values, covering 32-bit, 64-bit and 128-bit ones
 
     # _Decimal32 constants, which can support up to 7 digits
-    gdb_test "printf \"%H\\n\",1.2df" "1.2"
-    gdb_test "printf \"%H\\n\",-1.2df" "-1.2"
-    gdb_test "printf \"%H\\n\",1.234567df" "1.234567"
-    gdb_test "printf \"%H\\n\",-1.234567df" "-1.234567"
-    gdb_test "printf \"%H\\n\",1234567.df" "1234567"
-    gdb_test "printf \"%H\\n\",-1234567.df" "-1234567"
-
-    gdb_test "printf \"%H\\n\",1.2E1df" "12"
-    gdb_test "printf \"%H\\n\",1.2E10df" "1.2E\\+10"
-    gdb_test "printf \"%H\\n\",1.2E-10df" "1.2E-10"
+    gdb_test "printf \"%Hf\\n\",1.2df" "1.2"
+    gdb_test "printf \"%Hf\\n\",-1.2df" "-1.2"
+    gdb_test "printf \"%Hf\\n\",1.234567df" "1.234567"
+    gdb_test "printf \"%Hf\\n\",-1.234567df" "-1.234567"
+    gdb_test "printf \"%Hf\\n\",1234567.df" "1234567"
+    gdb_test "printf \"%Hf\\n\",-1234567.df" "-1234567"
+
+    gdb_test "printf \"%Hf\\n\",1.2E1df" "12"
+    gdb_test "printf \"%Hf\\n\",1.2E10df" "1.2E\\+10"
+    gdb_test "printf \"%Hf\\n\",1.2E-10df" "1.2E-10"
 
     # The largest exponent for 32-bit dfp value is 96.
-    gdb_test "printf \"%H\\n\",1.2E96df" "1.200000E\\+96"
+    gdb_test "printf \"%Hf\\n\",1.2E96df" "1.200000E\\+96"
 
     # _Decimal64 constants, which can support up to 16 digits
-    gdb_test "printf \"%D\\n\",1.2dd" "1.2"
-    gdb_test "printf \"%D\\n\",-1.2dd" "-1.2"
-    gdb_test "printf \"%D\\n\",1.234567890123456dd" "1.234567890123456"
-    gdb_test "printf \"%D\\n\",-1.234567890123456dd" "-1.234567890123456"
-    gdb_test "printf \"%D\\n\",1234567890123456.dd" "1234567890123456"
-    gdb_test "printf \"%D\\n\",-1234567890123456.dd" "-1234567890123456"
-
-    gdb_test "printf \"%D\\n\",1.2E1dd" "12"
-    gdb_test "printf \"%D\\n\",1.2E10dd" "1.2E\\+10"
-    gdb_test "printf \"%D\\n\",1.2E-10dd" "1.2E-10"
+    gdb_test "printf \"%Df\\n\",1.2dd" "1.2"
+    gdb_test "printf \"%Df\\n\",-1.2dd" "-1.2"
+    gdb_test "printf \"%Df\\n\",1.234567890123456dd" "1.234567890123456"
+    gdb_test "printf \"%Df\\n\",-1.234567890123456dd" "-1.234567890123456"
+    gdb_test "printf \"%Df\\n\",1234567890123456.dd" "1234567890123456"
+    gdb_test "printf \"%Df\\n\",-1234567890123456.dd" "-1234567890123456"
+
+    gdb_test "printf \"%Df\\n\",1.2E1dd" "12"
+    gdb_test "printf \"%Df\\n\",1.2E10dd" "1.2E\\+10"
+    gdb_test "printf \"%Df\\n\",1.2E-10dd" "1.2E-10"
 
     # The largest exponent for 64-bit dfp value is 384.
-    gdb_test "printf \"%D\\n\",1.2E384dd" "1.200000000000000E\\+384"
+    gdb_test "printf \"%Df\\n\",1.2E384dd" "1.200000000000000E\\+384"
 
     # _Decimal128 constants, which can support up to 34 digits
-    gdb_test "printf \"%DD\\n\",1.2dl" "1.2"
-    gdb_test "printf \"%DD\\n\",-1.2dl" "-1.2"
-    gdb_test "printf \"%DD\\n\",1.234567890123456789012345678901234dl" "1.234567890123456789012345678901234"
-    gdb_test "printf \"%DD\\n\",-1.234567890123456789012345678901234dl" "-1.234567890123456789012345678901234"
-    gdb_test "printf \"%DD\\n\",1234567890123456789012345678901234.dl" "1234567890123456789012345678901234"
-    gdb_test "printf \"%DD\\n\",-1234567890123456789012345678901234.dl" "-1234567890123456789012345678901234"
-
-    gdb_test "printf \"%DD\\n\",1.2E1dl" "12"
-    gdb_test "printf \"%DD\\n\",1.2E10dl" "1.2E\\+10"
-    gdb_test "printf \"%DD\\n\",1.2E-10dl" "1.2E-10"
+    gdb_test "printf \"%DDf\\n\",1.2dl" "1.2"
+    gdb_test "printf \"%DDf\\n\",-1.2dl" "-1.2"
+    gdb_test "printf \"%DDf\\n\",1.234567890123456789012345678901234dl" "1.234567890123456789012345678901234"
+    gdb_test "printf \"%DDf\\n\",-1.234567890123456789012345678901234dl" "-1.234567890123456789012345678901234"
+    gdb_test "printf \"%DDf\\n\",1234567890123456789012345678901234.dl" "1234567890123456789012345678901234"
+    gdb_test "printf \"%DDf\\n\",-1234567890123456789012345678901234.dl" "-1234567890123456789012345678901234"
+
+    gdb_test "printf \"%DDf\\n\",1.2E1dl" "12"
+    gdb_test "printf \"%DDf\\n\",1.2E10dl" "1.2E\\+10"
+    gdb_test "printf \"%DDf\\n\",1.2E-10dl" "1.2E-10"
 
     # The largest exponent for 128-bit dfp value is 6144.
-    gdb_test "printf \"%DD\\n\",1.2E6144dl" "1.200000000000000000000000000000000E\\+6144"
+    gdb_test "printf \"%DDf\\n\",1.2E6144dl" "1.200000000000000000000000000000000E\\+6144"
 }
 
 # Escape a left curly brace to prevent it from being interpreted as 

Re: [PATCH] Improve printf DFP support

[Eli Zaretskii]

> From: Luis Machado <luisgpm@linux.vnet.ibm.com>
> Date: Tue, 08 Jan 2008 11:27:36 -0200
> 
> This is an improvement over the last patch i have submited to add DFP
> support for GDB's printf command.
> 
> The DFP modifiers are now being treated as length modifiers, and not
> type modifiers. This puts us in agreement with what the C99 standard's
> DFP annex says.
> 
> The parsing of the string is a bit more robust than the last version.
> 
> A documentation and testcase updated is attached as well.

Thanks.  The documentation part of the patch is approved, but please
include in the ChangeLog entry the name of the node where you make the
change, as if it were a function.

Re: [PATCH] Improve printf DFP support

[Jim Blandy]

Daniel Jacobowitz <drow at false.org> writes:

> On Tue, Jan 08, 2008 at 01:19:06PM -0200, Thiago Jung Bauermann wrote:
>> param_ptr should be a const gdb_byte *, and the cast here should be
>> removed. In addition, I believe the use of value_offset here is wrong.
>> Other uses of value_offset are to obtain a memory address in the
>> inferior address space, not in GDB's. Also, I think that value_contents
>> should be used intead of value_contents_all so that the value's
>> embedded_offset can be taken into account.
>
> I believe that you are correct.  The value handling is another area of
> GDB that could do with some cleaning up; I am not convinced the
> multiple offsets dance is necessary...

I think the origin of GDB's confusion is that we didn't follow through
with any consistent decision about whether a value should act like an
instance of its static type or its dynamic type.  So value_type (v) is
v's static type, but value_address (v) returns the address of the
instance of the dynamic type --- thus the need to add
value_embedded_offset to it.

So, if I were going to take a shot at it, here are the decisions I
think would make sense:

1) Use the C++ terminology --- 'static type' and 'dynamic type' ---
   whereever the distinction needs to be made, instead of 'embedded'
   and 'enclosing'.  For example, value_enclosing_type should be
   value_dynamic_type.

2) Use the static type as the default for most value_ operations
   within GDB:
   - value_type should return the static type.
   - value_contents should return the contents of the portion of the
     object corresponding to the static type (i.e. it should have
     value_embedded_offset added in)
   - value_contents_all should be called value_dynamic_type_contents

3) Use the dynamic type by default when printing objects.  objectprint
   should be 1 by default.  We can count on run-time type information
   nowadays, right?

I don't know how much of this still applies, but this is what I wrote
on the topic a long time ago:

http://sourceware.org/ml/gdb/2001-05/msg00306.html

Re: [PATCH] Improve printf DFP support

[Luis Machado]

[-- Attachment #1: Type: text/plain, Size: 272 bytes --]

> Thanks.  The documentation part of the patch is approved, but please
> include in the ChangeLog entry the name of the node where you make the
> change, as if it were a function.

Thanks. Like so?

Regards,
-- 
Luis Machado
Software Engineer 
IBM Linux Technology Center

[-- Attachment #2: dfp-printf.diff --]
[-- Type: text/x-patch, Size: 13369 bytes --]

2008-08-01  Luis Machado  <luisgpm@br.ibm.com>

	* printcmd.c (printf_command): Add seen_big_h, seen_big_d and 
	seen_double_big_d, treat the new H, D, and DD modifiers as length
	modifiers.
	* doc/gdb.texinfo (Output): Update documentation on using printf with DFP
	types.
	* testsuite/gdb.base/printcmds.exp (test_printf_with_dfp): Update 
	printf calls with required float modifiers.

Index: gdb/printcmd.c
===================================================================
--- gdb.orig/printcmd.c	2008-01-08 07:03:19.000000000 -0800
+++ gdb/printcmd.c	2008-01-08 07:26:28.000000000 -0800
@@ -1837,7 +1837,8 @@
 	{
 	  int seen_hash = 0, seen_zero = 0, lcount = 0, seen_prec = 0;
 	  int seen_space = 0, seen_plus = 0;
-	  int seen_big_l = 0, seen_h = 0;
+	  int seen_big_l = 0, seen_h = 0, seen_big_h = 0;
+	  int seen_big_d = 0, seen_double_big_d = 0;
 	  int bad = 0;
 
 	  /* Check the validity of the format specifier, and work
@@ -1901,6 +1902,26 @@
 	      seen_big_l = 1;
 	      f++;
 	    }
+	  /* Decimal32 modifier.  */
+	  else if (*f == 'H')
+	    {
+	      seen_big_h = 1;
+	      f++;
+	    }
+	  /* Decimal64 and Decimal128 modifiers.  */
+	  else if (*f == 'D')
+	    {
+	      f++;
+
+              /* Check for a Decimal128.  */
+              if (*f == 'D')
+	      {
+                f++;
+		seen_double_big_d = 1;
+	      }
+	      else
+		seen_big_d = 1;
+	    }
 
 	  switch (*f)
 	    {
@@ -1929,34 +1950,6 @@
 		bad = 1;
 	      break;
 
-	    /* DFP Decimal32 types.  */
-	    case 'H':
-	      this_argclass = decfloat_arg;
-
-#ifndef PRINTF_HAS_DECFLOAT
-              if (lcount || seen_h || seen_big_l)
-                bad = 1;
-              if (seen_prec || seen_zero || seen_space || seen_plus)
-                bad = 1;
-#endif
-	      break;
-
-	    /* DFP Decimal64 and Decimal128 types.  */
-	    case 'D':
-	      this_argclass = decfloat_arg;
-
-#ifndef PRINTF_HAS_DECFLOAT
-              if (lcount || seen_h || seen_big_l)
-                bad = 1;
-              if (seen_prec || seen_zero || seen_space || seen_plus)
-                bad = 1;
-#endif
-	      /* Check for a Decimal128.  */
-	      if (*(f + 1) == 'D')
-		f++;
-
-	      break;
-
 	    case 'c':
 	      this_argclass = int_arg;
 	      if (lcount || seen_h || seen_big_l)
@@ -1986,7 +1979,9 @@
 	    case 'g':
 	    case 'E':
 	    case 'G':
-	      if (seen_big_l)
+              if (seen_big_h || seen_big_d || seen_double_big_d)
+                this_argclass = decfloat_arg;
+	      else if (seen_big_l)
 		this_argclass = long_double_arg;
 	      else
 		this_argclass = double_arg;
@@ -2124,50 +2119,101 @@
 	      break;
 	    }
 
-	  /* Handles decimal floating point values.  */
+	  /* Handles decimal floating values.  */
 	  case decfloat_arg:
 	    {
-	      char *eos;
-	      char decstr[MAX_DECIMAL_STRING];
-	      unsigned int dfp_len = TYPE_LENGTH (value_type (val_args[i]));
-	      unsigned char *dfp_value_ptr = (unsigned char *) value_contents_all (val_args[i])
-                                      + value_offset (val_args[i]);
-
+	      const gdb_byte *param_ptr = value_contents (val_args[i]);
 #if defined (PRINTF_HAS_DECFLOAT)
-	      printf_filtered (current_substring, dfp_value_ptr);
+	      /* If we have native support for Decimal floating
+		 printing, handle it here.  */
+	      printf_filtered (current_substring, param_ptr);
 #else
-	      if (TYPE_CODE (value_type (val_args[i])) != TYPE_CODE_DECFLOAT)
-		error (_("Cannot convert parameter to decfloat."));
 
-	      /* As a workaround until vasprintf has native support for DFP
-		 we convert the DFP values to string and print them using
-		 the %s format specifier.  */
-	      decimal_to_string (dfp_value_ptr, dfp_len, decstr);
-
-	      /* Points to the end of the string so that we can go back
-		 and check for DFP format specifiers.  */
-	      eos = current_substring + strlen (current_substring);
-
-	      /* Replace %H, %D and %DD with %s's.  */
-	      while (*--eos != '%')
-		if (*eos == 'D' && *(eos - 1) == 'D')
-		  {
-		    *(eos - 1) = 's';
-
-		    /* If we've found a %DD format specifier we need to go
-		       through the whole string pulling back one character
-		       since this format specifier has two chars.  */
-		    while (eos < last_arg)
-		      {
-			*eos = *(eos + 1);
-			eos++;
-		      }
-		  }
-		else if (*eos == 'D' || *eos == 'H')
-		  *eos = 's';
+            /* As a workaround until vasprintf has native support for DFP
+               we convert the DFP values to string and print them using
+               the %s format specifier.  */
+
+              char *eos, *sos;
+	      int nnull_chars = 0;
+
+              /* Parameter data.  */
+              struct type *param_type = value_type (val_args[i]);
+              unsigned int param_len = TYPE_LENGTH (param_type);
+
+              /* DFP output data.  */
+              struct value *dfp_value = NULL;
+              gdb_byte *dfp_ptr;
+              int dfp_len = 16;
+              gdb_byte dec[16];
+              struct type *dfp_type = NULL;
+              char decstr[MAX_DECIMAL_STRING];
+
+              /* Points to the end of the string so that we can go back
+                 and check for DFP length modifiers.  */
+              eos = current_substring + strlen (current_substring);
+
+	      /* Look for the float/double format specifier.  */
+              while (*eos != 'f' && *eos != 'e' && *eos != 'E'
+		     && *eos != 'g' && *eos != 'G')
+		  eos--;
+
+              sos = eos;
+
+	      /* Search for the '%' char and extract the size and type of
+		 the output decimal value based on its modifiers
+		 (%Hf, %Df, %DDf).  */
+              while (*--sos != '%')
+                {
+                  if (*sos == 'H')
+                    {
+                      dfp_len = 4;
+                      dfp_type = builtin_type (current_gdbarch)->builtin_decfloat;
+                    }
+                  else if (*sos == 'D' && *(sos - 1) == 'D')
+                    {
+                      dfp_len = 16;
+                      dfp_type = builtin_type (current_gdbarch)->builtin_declong;
+		      sos--;
+                    }
+                  else
+                    {
+                      dfp_len = 8;
+                      dfp_type = builtin_type (current_gdbarch)->builtin_decdouble;
+                    }
+                }
+
+	      /* Replace %Hf, %Df and %DDf with %s's.  */
+              *++sos = 's';
+
+              /* Go through the whole format string and pull the correct
+		 number of chars back to compensate for the change in the
+		 format specifier.  */
+	      while (nnull_chars < nargs - i)
+		{
+		  if (*eos == '\0')
+		    nnull_chars++;
+
+		  *++sos = *++eos;
+		}
+
+	      /* Conversion between different DFP types.  */
+	      if (TYPE_CODE (param_type) == TYPE_CODE_DECFLOAT)
+		decimal_convert (param_ptr, param_len, dec, dfp_len);
+	      else
+		/* If this is a non-trivial conversion, just output 0.
+		   A correct converted value can be displayed by explicitly
+		   casting to a DFP type.  */
+		decimal_from_string (dec, dfp_len, "0");
+
+	      dfp_value = value_from_decfloat (dfp_type, dec);
+
+	      dfp_ptr = (gdb_byte *) value_contents (dfp_value);
+
+	      decimal_to_string (dfp_ptr, dfp_len, decstr);
 
 	      /* Print the DFP value.  */
 	      printf_filtered (current_substring, decstr);
+
 	      break;
 #endif
 	    }
Index: gdb/doc/gdb.texinfo
===================================================================
--- gdb.orig/doc/gdb.texinfo	2008-01-08 07:03:19.000000000 -0800
+++ gdb/doc/gdb.texinfo	2008-01-08 07:03:39.000000000 -0800
@@ -16693,7 +16693,8 @@
 supported.
 
 Additionally, @code{printf} supports conversion specifications for DFP
-(@dfn{Decimal Floating Point}) types using the following conversion
+(@dfn{Decimal Floating Point}) types using the following length modifiers
+together with a floating point specifier.
 letters:
 
 @itemize @bullet
@@ -16708,7 +16709,7 @@
 @end itemize
 
 If the underlying @code{C} implementation used to build @value{GDBN} has
-support for the three conversion letters for DFP types, other modifiers
+support for the three length modifiers for DFP types, other modifiers
 such as width and precision will also be available for @value{GDBN} to use.
 
 In case there is no such @code{C} support, no additional modifiers will be
@@ -16716,7 +16717,7 @@
 
 Here's an example of printing DFP types using the above conversion letters:
 @smallexample
-printf "D32: %H - D64: %D - D128: %DD\n",1.2345df,1.2E10dd,1.2E1dl
+printf "D32: %Hf - D64: %Df - D128: %DDf\n",1.2345df,1.2E10dd,1.2E1dl
 @end smallexample
 
 @end table
Index: gdb/testsuite/gdb.base/printcmds.exp
===================================================================
--- gdb.orig/testsuite/gdb.base/printcmds.exp	2008-01-08 07:03:19.000000000 -0800
+++ gdb/testsuite/gdb.base/printcmds.exp	2008-01-08 07:03:39.000000000 -0800
@@ -674,49 +674,49 @@
     # Test various dfp values, covering 32-bit, 64-bit and 128-bit ones
 
     # _Decimal32 constants, which can support up to 7 digits
-    gdb_test "printf \"%H\\n\",1.2df" "1.2"
-    gdb_test "printf \"%H\\n\",-1.2df" "-1.2"
-    gdb_test "printf \"%H\\n\",1.234567df" "1.234567"
-    gdb_test "printf \"%H\\n\",-1.234567df" "-1.234567"
-    gdb_test "printf \"%H\\n\",1234567.df" "1234567"
-    gdb_test "printf \"%H\\n\",-1234567.df" "-1234567"
-
-    gdb_test "printf \"%H\\n\",1.2E1df" "12"
-    gdb_test "printf \"%H\\n\",1.2E10df" "1.2E\\+10"
-    gdb_test "printf \"%H\\n\",1.2E-10df" "1.2E-10"
+    gdb_test "printf \"%Hf\\n\",1.2df" "1.2"
+    gdb_test "printf \"%Hf\\n\",-1.2df" "-1.2"
+    gdb_test "printf \"%Hf\\n\",1.234567df" "1.234567"
+    gdb_test "printf \"%Hf\\n\",-1.234567df" "-1.234567"
+    gdb_test "printf \"%Hf\\n\",1234567.df" "1234567"
+    gdb_test "printf \"%Hf\\n\",-1234567.df" "-1234567"
+
+    gdb_test "printf \"%Hf\\n\",1.2E1df" "12"
+    gdb_test "printf \"%Hf\\n\",1.2E10df" "1.2E\\+10"
+    gdb_test "printf \"%Hf\\n\",1.2E-10df" "1.2E-10"
 
     # The largest exponent for 32-bit dfp value is 96.
-    gdb_test "printf \"%H\\n\",1.2E96df" "1.200000E\\+96"
+    gdb_test "printf \"%Hf\\n\",1.2E96df" "1.200000E\\+96"
 
     # _Decimal64 constants, which can support up to 16 digits
-    gdb_test "printf \"%D\\n\",1.2dd" "1.2"
-    gdb_test "printf \"%D\\n\",-1.2dd" "-1.2"
-    gdb_test "printf \"%D\\n\",1.234567890123456dd" "1.234567890123456"
-    gdb_test "printf \"%D\\n\",-1.234567890123456dd" "-1.234567890123456"
-    gdb_test "printf \"%D\\n\",1234567890123456.dd" "1234567890123456"
-    gdb_test "printf \"%D\\n\",-1234567890123456.dd" "-1234567890123456"
-
-    gdb_test "printf \"%D\\n\",1.2E1dd" "12"
-    gdb_test "printf \"%D\\n\",1.2E10dd" "1.2E\\+10"
-    gdb_test "printf \"%D\\n\",1.2E-10dd" "1.2E-10"
+    gdb_test "printf \"%Df\\n\",1.2dd" "1.2"
+    gdb_test "printf \"%Df\\n\",-1.2dd" "-1.2"
+    gdb_test "printf \"%Df\\n\",1.234567890123456dd" "1.234567890123456"
+    gdb_test "printf \"%Df\\n\",-1.234567890123456dd" "-1.234567890123456"
+    gdb_test "printf \"%Df\\n\",1234567890123456.dd" "1234567890123456"
+    gdb_test "printf \"%Df\\n\",-1234567890123456.dd" "-1234567890123456"
+
+    gdb_test "printf \"%Df\\n\",1.2E1dd" "12"
+    gdb_test "printf \"%Df\\n\",1.2E10dd" "1.2E\\+10"
+    gdb_test "printf \"%Df\\n\",1.2E-10dd" "1.2E-10"
 
     # The largest exponent for 64-bit dfp value is 384.
-    gdb_test "printf \"%D\\n\",1.2E384dd" "1.200000000000000E\\+384"
+    gdb_test "printf \"%Df\\n\",1.2E384dd" "1.200000000000000E\\+384"
 
     # _Decimal128 constants, which can support up to 34 digits
-    gdb_test "printf \"%DD\\n\",1.2dl" "1.2"
-    gdb_test "printf \"%DD\\n\",-1.2dl" "-1.2"
-    gdb_test "printf \"%DD\\n\",1.234567890123456789012345678901234dl" "1.234567890123456789012345678901234"
-    gdb_test "printf \"%DD\\n\",-1.234567890123456789012345678901234dl" "-1.234567890123456789012345678901234"
-    gdb_test "printf \"%DD\\n\",1234567890123456789012345678901234.dl" "1234567890123456789012345678901234"
-    gdb_test "printf \"%DD\\n\",-1234567890123456789012345678901234.dl" "-1234567890123456789012345678901234"
-
-    gdb_test "printf \"%DD\\n\",1.2E1dl" "12"
-    gdb_test "printf \"%DD\\n\",1.2E10dl" "1.2E\\+10"
-    gdb_test "printf \"%DD\\n\",1.2E-10dl" "1.2E-10"
+    gdb_test "printf \"%DDf\\n\",1.2dl" "1.2"
+    gdb_test "printf \"%DDf\\n\",-1.2dl" "-1.2"
+    gdb_test "printf \"%DDf\\n\",1.234567890123456789012345678901234dl" "1.234567890123456789012345678901234"
+    gdb_test "printf \"%DDf\\n\",-1.234567890123456789012345678901234dl" "-1.234567890123456789012345678901234"
+    gdb_test "printf \"%DDf\\n\",1234567890123456789012345678901234.dl" "1234567890123456789012345678901234"
+    gdb_test "printf \"%DDf\\n\",-1234567890123456789012345678901234.dl" "-1234567890123456789012345678901234"
+
+    gdb_test "printf \"%DDf\\n\",1.2E1dl" "12"
+    gdb_test "printf \"%DDf\\n\",1.2E10dl" "1.2E\\+10"
+    gdb_test "printf \"%DDf\\n\",1.2E-10dl" "1.2E-10"
 
     # The largest exponent for 128-bit dfp value is 6144.
-    gdb_test "printf \"%DD\\n\",1.2E6144dl" "1.200000000000000000000000000000000E\\+6144"
+    gdb_test "printf \"%DDf\\n\",1.2E6144dl" "1.200000000000000000000000000000000E\\+6144"
 }
 
 # Escape a left curly brace to prevent it from being interpreted as 

Re: [PATCH] Improve printf DFP support

[Eli Zaretskii]

> From: Luis Machado <luisgpm@linux.vnet.ibm.com>
> Cc: gdb-patches@sourceware.org
> Date: Tue, 08 Jan 2008 22:03:44 -0200
> 
> > Thanks.  The documentation part of the patch is approved, but please
> > include in the ChangeLog entry the name of the node where you make the
> > change, as if it were a function.
> 
> Thanks. Like so?

Yes, thanks.

Re: [PATCH] Improve printf DFP support

[Daniel Jacobowitz]

On Tue, Jan 08, 2008 at 10:03:44PM -0200, Luis Machado wrote:
> 2008-08-01  Luis Machado  <luisgpm@br.ibm.com>
> 
> 	* printcmd.c (printf_command): Add seen_big_h, seen_big_d and 
> 	seen_double_big_d, treat the new H, D, and DD modifiers as length
> 	modifiers.
> 	* doc/gdb.texinfo (Output): Update documentation on using printf with DFP
> 	types.
> 	* testsuite/gdb.base/printcmds.exp (test_printf_with_dfp): Update 
> 	printf calls with required float modifiers.

OK.  Remember that doc/ and testsuite/ entries go into their own
changelogs.  Also, please be careful with spaces versus tabs.  I see a
lot of strange indentation in this patch.

> +              /* Check for a Decimal128.  */
> +              if (*f == 'D')
> +	      {

Here, for instance.

-- 
Daniel Jacobowitz
CodeSourcery

Re: [PATCH] Improve printf DFP support

[Luis Machado]

[-- Attachment #1: Type: text/plain, Size: 309 bytes --]

> OK.  Remember that doc/ and testsuite/ entries go into their own
> changelogs.  Also, please be careful with spaces versus tabs.  I see a
> lot of strange indentation in this patch.

Thanks. Fixed those. Checked in this version now.

Regards,
-- 
Luis Machado
Software Engineer 
IBM Linux Technology Center

[-- Attachment #2: dfp-printf.diff --]
[-- Type: text/x-patch, Size: 12736 bytes --]

2008-01-09  Luis Machado  <luisgpm@br.ibm.com>

	* printcmd.c (printf_command): Add seen_big_h, seen_big_d and 
	seen_double_big_d, treat the new H, D, and DD modifiers as length
	modifiers.
	* doc/gdb.texinfo (Output): Update documentation on using printf with DFP
	types.
	* testsuite/gdb.base/printcmds.exp (test_printf_with_dfp): Update 
	printf calls with required float modifiers.

Index: gdb/printcmd.c
===================================================================
--- gdb.orig/printcmd.c	2008-01-09 05:07:08.000000000 -0800
+++ gdb/printcmd.c	2008-01-09 05:26:13.000000000 -0800
@@ -1837,7 +1837,8 @@
 	{
 	  int seen_hash = 0, seen_zero = 0, lcount = 0, seen_prec = 0;
 	  int seen_space = 0, seen_plus = 0;
-	  int seen_big_l = 0, seen_h = 0;
+	  int seen_big_l = 0, seen_h = 0, seen_big_h = 0;
+	  int seen_big_d = 0, seen_double_big_d = 0;
 	  int bad = 0;
 
 	  /* Check the validity of the format specifier, and work
@@ -1901,6 +1902,26 @@
 	      seen_big_l = 1;
 	      f++;
 	    }
+	  /* Decimal32 modifier.  */
+	  else if (*f == 'H')
+	    {
+	      seen_big_h = 1;
+	      f++;
+	    }
+	  /* Decimal64 and Decimal128 modifiers.  */
+	  else if (*f == 'D')
+	    {
+	      f++;
+
+	      /* Check for a Decimal128.  */
+	      if (*f == 'D')
+		{
+		  f++;
+		  seen_double_big_d = 1;
+		}
+	      else
+		seen_big_d = 1;
+	    }
 
 	  switch (*f)
 	    {
@@ -1929,34 +1950,6 @@
 		bad = 1;
 	      break;
 
-	    /* DFP Decimal32 types.  */
-	    case 'H':
-	      this_argclass = decfloat_arg;
-
-#ifndef PRINTF_HAS_DECFLOAT
-              if (lcount || seen_h || seen_big_l)
-                bad = 1;
-              if (seen_prec || seen_zero || seen_space || seen_plus)
-                bad = 1;
-#endif
-	      break;
-
-	    /* DFP Decimal64 and Decimal128 types.  */
-	    case 'D':
-	      this_argclass = decfloat_arg;
-
-#ifndef PRINTF_HAS_DECFLOAT
-              if (lcount || seen_h || seen_big_l)
-                bad = 1;
-              if (seen_prec || seen_zero || seen_space || seen_plus)
-                bad = 1;
-#endif
-	      /* Check for a Decimal128.  */
-	      if (*(f + 1) == 'D')
-		f++;
-
-	      break;
-
 	    case 'c':
 	      this_argclass = int_arg;
 	      if (lcount || seen_h || seen_big_l)
@@ -1986,7 +1979,9 @@
 	    case 'g':
 	    case 'E':
 	    case 'G':
-	      if (seen_big_l)
+	      if (seen_big_h || seen_big_d || seen_double_big_d)
+		this_argclass = decfloat_arg;
+	      else if (seen_big_l)
 		this_argclass = long_double_arg;
 	      else
 		this_argclass = double_arg;
@@ -2124,50 +2119,101 @@
 	      break;
 	    }
 
-	  /* Handles decimal floating point values.  */
-	  case decfloat_arg:
+	  /* Handles decimal floating values.  */
+	case decfloat_arg:
 	    {
-	      char *eos;
-	      char decstr[MAX_DECIMAL_STRING];
-	      unsigned int dfp_len = TYPE_LENGTH (value_type (val_args[i]));
-	      unsigned char *dfp_value_ptr = (unsigned char *) value_contents_all (val_args[i])
-                                      + value_offset (val_args[i]);
-
+	      const gdb_byte *param_ptr = value_contents (val_args[i]);
 #if defined (PRINTF_HAS_DECFLOAT)
-	      printf_filtered (current_substring, dfp_value_ptr);
+	      /* If we have native support for Decimal floating
+		 printing, handle it here.  */
+	      printf_filtered (current_substring, param_ptr);
 #else
-	      if (TYPE_CODE (value_type (val_args[i])) != TYPE_CODE_DECFLOAT)
-		error (_("Cannot convert parameter to decfloat."));
 
 	      /* As a workaround until vasprintf has native support for DFP
-		 we convert the DFP values to string and print them using
-		 the %s format specifier.  */
-	      decimal_to_string (dfp_value_ptr, dfp_len, decstr);
+	       we convert the DFP values to string and print them using
+	       the %s format specifier.  */
+
+	      char *eos, *sos;
+	      int nnull_chars = 0;
+
+	      /* Parameter data.  */
+	      struct type *param_type = value_type (val_args[i]);
+	      unsigned int param_len = TYPE_LENGTH (param_type);
+
+	      /* DFP output data.  */
+	      struct value *dfp_value = NULL;
+	      gdb_byte *dfp_ptr;
+	      int dfp_len = 16;
+	      gdb_byte dec[16];
+	      struct type *dfp_type = NULL;
+	      char decstr[MAX_DECIMAL_STRING];
 
 	      /* Points to the end of the string so that we can go back
-		 and check for DFP format specifiers.  */
+		 and check for DFP length modifiers.  */
 	      eos = current_substring + strlen (current_substring);
 
-	      /* Replace %H, %D and %DD with %s's.  */
-	      while (*--eos != '%')
-		if (*eos == 'D' && *(eos - 1) == 'D')
-		  {
-		    *(eos - 1) = 's';
-
-		    /* If we've found a %DD format specifier we need to go
-		       through the whole string pulling back one character
-		       since this format specifier has two chars.  */
-		    while (eos < last_arg)
-		      {
-			*eos = *(eos + 1);
-			eos++;
-		      }
-		  }
-		else if (*eos == 'D' || *eos == 'H')
-		  *eos = 's';
+	      /* Look for the float/double format specifier.  */
+	      while (*eos != 'f' && *eos != 'e' && *eos != 'E'
+		     && *eos != 'g' && *eos != 'G')
+		  eos--;
+
+	      sos = eos;
+
+	      /* Search for the '%' char and extract the size and type of
+		 the output decimal value based on its modifiers
+		 (%Hf, %Df, %DDf).  */
+	      while (*--sos != '%')
+		{
+		  if (*sos == 'H')
+		    {
+		      dfp_len = 4;
+		      dfp_type = builtin_type (current_gdbarch)->builtin_decfloat;
+		    }
+		  else if (*sos == 'D' && *(sos - 1) == 'D')
+		    {
+		      dfp_len = 16;
+		      dfp_type = builtin_type (current_gdbarch)->builtin_declong;
+		      sos--;
+		    }
+		  else
+		    {
+		      dfp_len = 8;
+		      dfp_type = builtin_type (current_gdbarch)->builtin_decdouble;
+		    }
+		}
+
+	      /* Replace %Hf, %Df and %DDf with %s's.  */
+	      *++sos = 's';
+
+	      /* Go through the whole format string and pull the correct
+		 number of chars back to compensate for the change in the
+		 format specifier.  */
+	      while (nnull_chars < nargs - i)
+		{
+		  if (*eos == '\0')
+		    nnull_chars++;
+
+		  *++sos = *++eos;
+		}
+
+	      /* Conversion between different DFP types.  */
+	      if (TYPE_CODE (param_type) == TYPE_CODE_DECFLOAT)
+		decimal_convert (param_ptr, param_len, dec, dfp_len);
+	      else
+		/* If this is a non-trivial conversion, just output 0.
+		   A correct converted value can be displayed by explicitly
+		   casting to a DFP type.  */
+		decimal_from_string (dec, dfp_len, "0");
+
+	      dfp_value = value_from_decfloat (dfp_type, dec);
+
+	      dfp_ptr = (gdb_byte *) value_contents (dfp_value);
+
+	      decimal_to_string (dfp_ptr, dfp_len, decstr);
 
 	      /* Print the DFP value.  */
 	      printf_filtered (current_substring, decstr);
+
 	      break;
 #endif
 	    }
Index: gdb/doc/gdb.texinfo
===================================================================
--- gdb.orig/doc/gdb.texinfo	2008-01-09 05:07:08.000000000 -0800
+++ gdb/doc/gdb.texinfo	2008-01-09 05:14:58.000000000 -0800
@@ -16693,7 +16693,8 @@
 supported.
 
 Additionally, @code{printf} supports conversion specifications for DFP
-(@dfn{Decimal Floating Point}) types using the following conversion
+(@dfn{Decimal Floating Point}) types using the following length modifiers
+together with a floating point specifier.
 letters:
 
 @itemize @bullet
@@ -16708,7 +16709,7 @@
 @end itemize
 
 If the underlying @code{C} implementation used to build @value{GDBN} has
-support for the three conversion letters for DFP types, other modifiers
+support for the three length modifiers for DFP types, other modifiers
 such as width and precision will also be available for @value{GDBN} to use.
 
 In case there is no such @code{C} support, no additional modifiers will be
@@ -16716,7 +16717,7 @@
 
 Here's an example of printing DFP types using the above conversion letters:
 @smallexample
-printf "D32: %H - D64: %D - D128: %DD\n",1.2345df,1.2E10dd,1.2E1dl
+printf "D32: %Hf - D64: %Df - D128: %DDf\n",1.2345df,1.2E10dd,1.2E1dl
 @end smallexample
 
 @end table
Index: gdb/testsuite/gdb.base/printcmds.exp
===================================================================
--- gdb.orig/testsuite/gdb.base/printcmds.exp	2008-01-09 05:07:08.000000000 -0800
+++ gdb/testsuite/gdb.base/printcmds.exp	2008-01-09 05:14:58.000000000 -0800
@@ -674,49 +674,49 @@
     # Test various dfp values, covering 32-bit, 64-bit and 128-bit ones
 
     # _Decimal32 constants, which can support up to 7 digits
-    gdb_test "printf \"%H\\n\",1.2df" "1.2"
-    gdb_test "printf \"%H\\n\",-1.2df" "-1.2"
-    gdb_test "printf \"%H\\n\",1.234567df" "1.234567"
-    gdb_test "printf \"%H\\n\",-1.234567df" "-1.234567"
-    gdb_test "printf \"%H\\n\",1234567.df" "1234567"
-    gdb_test "printf \"%H\\n\",-1234567.df" "-1234567"
-
-    gdb_test "printf \"%H\\n\",1.2E1df" "12"
-    gdb_test "printf \"%H\\n\",1.2E10df" "1.2E\\+10"
-    gdb_test "printf \"%H\\n\",1.2E-10df" "1.2E-10"
+    gdb_test "printf \"%Hf\\n\",1.2df" "1.2"
+    gdb_test "printf \"%Hf\\n\",-1.2df" "-1.2"
+    gdb_test "printf \"%Hf\\n\",1.234567df" "1.234567"
+    gdb_test "printf \"%Hf\\n\",-1.234567df" "-1.234567"
+    gdb_test "printf \"%Hf\\n\",1234567.df" "1234567"
+    gdb_test "printf \"%Hf\\n\",-1234567.df" "-1234567"
+
+    gdb_test "printf \"%Hf\\n\",1.2E1df" "12"
+    gdb_test "printf \"%Hf\\n\",1.2E10df" "1.2E\\+10"
+    gdb_test "printf \"%Hf\\n\",1.2E-10df" "1.2E-10"
 
     # The largest exponent for 32-bit dfp value is 96.
-    gdb_test "printf \"%H\\n\",1.2E96df" "1.200000E\\+96"
+    gdb_test "printf \"%Hf\\n\",1.2E96df" "1.200000E\\+96"
 
     # _Decimal64 constants, which can support up to 16 digits
-    gdb_test "printf \"%D\\n\",1.2dd" "1.2"
-    gdb_test "printf \"%D\\n\",-1.2dd" "-1.2"
-    gdb_test "printf \"%D\\n\",1.234567890123456dd" "1.234567890123456"
-    gdb_test "printf \"%D\\n\",-1.234567890123456dd" "-1.234567890123456"
-    gdb_test "printf \"%D\\n\",1234567890123456.dd" "1234567890123456"
-    gdb_test "printf \"%D\\n\",-1234567890123456.dd" "-1234567890123456"
-
-    gdb_test "printf \"%D\\n\",1.2E1dd" "12"
-    gdb_test "printf \"%D\\n\",1.2E10dd" "1.2E\\+10"
-    gdb_test "printf \"%D\\n\",1.2E-10dd" "1.2E-10"
+    gdb_test "printf \"%Df\\n\",1.2dd" "1.2"
+    gdb_test "printf \"%Df\\n\",-1.2dd" "-1.2"
+    gdb_test "printf \"%Df\\n\",1.234567890123456dd" "1.234567890123456"
+    gdb_test "printf \"%Df\\n\",-1.234567890123456dd" "-1.234567890123456"
+    gdb_test "printf \"%Df\\n\",1234567890123456.dd" "1234567890123456"
+    gdb_test "printf \"%Df\\n\",-1234567890123456.dd" "-1234567890123456"
+
+    gdb_test "printf \"%Df\\n\",1.2E1dd" "12"
+    gdb_test "printf \"%Df\\n\",1.2E10dd" "1.2E\\+10"
+    gdb_test "printf \"%Df\\n\",1.2E-10dd" "1.2E-10"
 
     # The largest exponent for 64-bit dfp value is 384.
-    gdb_test "printf \"%D\\n\",1.2E384dd" "1.200000000000000E\\+384"
+    gdb_test "printf \"%Df\\n\",1.2E384dd" "1.200000000000000E\\+384"
 
     # _Decimal128 constants, which can support up to 34 digits
-    gdb_test "printf \"%DD\\n\",1.2dl" "1.2"
-    gdb_test "printf \"%DD\\n\",-1.2dl" "-1.2"
-    gdb_test "printf \"%DD\\n\",1.234567890123456789012345678901234dl" "1.234567890123456789012345678901234"
-    gdb_test "printf \"%DD\\n\",-1.234567890123456789012345678901234dl" "-1.234567890123456789012345678901234"
-    gdb_test "printf \"%DD\\n\",1234567890123456789012345678901234.dl" "1234567890123456789012345678901234"
-    gdb_test "printf \"%DD\\n\",-1234567890123456789012345678901234.dl" "-1234567890123456789012345678901234"
-
-    gdb_test "printf \"%DD\\n\",1.2E1dl" "12"
-    gdb_test "printf \"%DD\\n\",1.2E10dl" "1.2E\\+10"
-    gdb_test "printf \"%DD\\n\",1.2E-10dl" "1.2E-10"
+    gdb_test "printf \"%DDf\\n\",1.2dl" "1.2"
+    gdb_test "printf \"%DDf\\n\",-1.2dl" "-1.2"
+    gdb_test "printf \"%DDf\\n\",1.234567890123456789012345678901234dl" "1.234567890123456789012345678901234"
+    gdb_test "printf \"%DDf\\n\",-1.234567890123456789012345678901234dl" "-1.234567890123456789012345678901234"
+    gdb_test "printf \"%DDf\\n\",1234567890123456789012345678901234.dl" "1234567890123456789012345678901234"
+    gdb_test "printf \"%DDf\\n\",-1234567890123456789012345678901234.dl" "-1234567890123456789012345678901234"
+
+    gdb_test "printf \"%DDf\\n\",1.2E1dl" "12"
+    gdb_test "printf \"%DDf\\n\",1.2E10dl" "1.2E\\+10"
+    gdb_test "printf \"%DDf\\n\",1.2E-10dl" "1.2E-10"
 
     # The largest exponent for 128-bit dfp value is 6144.
-    gdb_test "printf \"%DD\\n\",1.2E6144dl" "1.200000000000000000000000000000000E\\+6144"
+    gdb_test "printf \"%DDf\\n\",1.2E6144dl" "1.200000000000000000000000000000000E\\+6144"
 }
 
 # Escape a left curly brace to prevent it from being interpreted as