[RFA 1/2] Fix two regressions in scalar printing

[Tom Tromey <tom at tromey dot com>]

PR gdb/21675 points out a few regressions in scalar printing.

One type of regression is due to not carrying over the old handling of
floating point printing -- where a format like "/x" causes a floating
point number to first be cast to integer.  While this behavior does not
seem very useful to me, apparently at least one person is testing for
it, and we did agree in the earlier thread to preserve this.  So, this
patch extends this behavior to the 'd' and 'u' formats.

The other regression is a longstanding bug in print_octal_chars: one of
the constants was wrong.  This patch fixes the constant and adds static
asserts to help catch this sort of error.

2017-07-13  Tom Tromey  <tom@tromey.com>

	PR gdb/21675
	* valprint.c (LOW_ZERO): Change value to 034.
	(print_octal_chars): Add static_asserts for octal constants.
	* printcmd.c (print_scalar_formatted): Add 'd' and 'u' to special
	cases for float types.

2017-07-13  Tom Tromey  <tom@tromey.com>

	PR gdb/21675:
	* gdb.base/printcmds.exp (test_radices): New function.
---
 gdb/ChangeLog                        |  8 ++++++++
 gdb/printcmd.c                       | 11 ++++++++---
 gdb/testsuite/ChangeLog              |  5 +++++
 gdb/testsuite/gdb.base/printcmds.exp |  8 ++++++++
 gdb/valprint.c                       |  8 +++++++-
 5 files changed, 36 insertions(+), 4 deletions(-)

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 012b3e4..5ac5bab 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,11 @@
+2017-07-13  Tom Tromey  <tom@tromey.com>
+
+	PR gdb/21675
+	* valprint.c (LOW_ZERO): Change value to 034.
+	(print_octal_chars): Add static_asserts for octal constants.
+	* printcmd.c (print_scalar_formatted): Add 'd' and 'u' to special
+	cases for float types.
+
 2017-07-11  John Baldwin  <jhb@FreeBSD.org>
 
 	* amd64-bsd-nat.c (amd64bsd_fetch_inferior_registers): Use
diff --git a/gdb/printcmd.c b/gdb/printcmd.c
index a8cc052..cd615ec 100644
--- a/gdb/printcmd.c
+++ b/gdb/printcmd.c
@@ -413,7 +413,9 @@ print_scalar_formatted (const gdb_byte *valaddr, struct type *type,
       && (options->format == 'o'
 	  || options->format == 'x'
 	  || options->format == 't'
-	  || options->format == 'z'))
+	  || options->format == 'z'
+	  || options->format == 'd'
+	  || options->format == 'u'))
     {
       LONGEST val_long = unpack_long (type, valaddr);
       converted_float_bytes.resize (TYPE_LENGTH (type));
@@ -427,11 +429,14 @@ print_scalar_formatted (const gdb_byte *valaddr, struct type *type,
     case 'o':
       print_octal_chars (stream, valaddr, len, byte_order);
       break;
+    case 'd':
     case 'u':
-      print_decimal_chars (stream, valaddr, len, false, byte_order);
+      {
+	bool is_signed = options->format != 'u' || !TYPE_UNSIGNED (type);
+	print_decimal_chars (stream, valaddr, len, is_signed, byte_order);
+      }
       break;
     case 0:
-    case 'd':
       if (TYPE_CODE (type) != TYPE_CODE_FLT)
 	{
 	  print_decimal_chars (stream, valaddr, len, !TYPE_UNSIGNED (type),
diff --git a/gdb/testsuite/ChangeLog b/gdb/testsuite/ChangeLog
index aa3dee3..0c8481b 100644
--- a/gdb/testsuite/ChangeLog
+++ b/gdb/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2017-07-13  Tom Tromey  <tom@tromey.com>
+
+	PR gdb/21675:
+	* gdb.base/printcmds.exp (test_radices): New function.
+
 2017-07-11  Iain Buclaw  <ibuclaw@gdcproject.org>
 
 	* gdb.dlang/demangle.exp: Update for demangling changes.
diff --git a/gdb/testsuite/gdb.base/printcmds.exp b/gdb/testsuite/gdb.base/printcmds.exp
index 323ca73..03275c3 100644
--- a/gdb/testsuite/gdb.base/printcmds.exp
+++ b/gdb/testsuite/gdb.base/printcmds.exp
@@ -155,6 +155,13 @@ proc test_float_rejected {} {
     test_print_reject "p 1.1ll"
 }
 
+# Regression test for PR gdb/21675
+proc test_radices {} {
+    gdb_test "print/o 16777211" " = 077777773"
+    gdb_test "print/d 1.5" " = 1\[^.\]"
+    gdb_test "print/u 1.5" " = 1\[^.\]"
+}
+
 proc test_print_all_chars {} {
     global gdb_prompt
 
@@ -981,3 +988,4 @@ test_printf
 test_printf_with_dfp
 test_print_symbol
 test_repeat_bytes
+test_radices
diff --git a/gdb/valprint.c b/gdb/valprint.c
index 1667882..9e216cf 100644
--- a/gdb/valprint.c
+++ b/gdb/valprint.c
@@ -1593,15 +1593,21 @@ print_octal_chars (struct ui_file *stream, const gdb_byte *valaddr,
    */
 #define BITS_IN_OCTAL 3
 #define HIGH_ZERO     0340
-#define LOW_ZERO      0016
+#define LOW_ZERO      0034
 #define CARRY_ZERO    0003
+  static_assert (HIGH_ZERO + LOW_ZERO + CARRY_ZERO == 0xff,
+		 "cycle zero constants are wrong");
 #define HIGH_ONE      0200
 #define MID_ONE       0160
 #define LOW_ONE       0016
 #define CARRY_ONE     0001
+  static_assert (HIGH_ONE + MID_ONE + LOW_ONE + CARRY_ONE == 0xff,
+		 "cycle one constants are wrong");
 #define HIGH_TWO      0300
 #define MID_TWO       0070
 #define LOW_TWO       0007
+  static_assert (HIGH_TWO + MID_TWO + LOW_TWO == 0xff,
+		 "cycle two constants are wrong");
 
   /* For 32 we start in cycle 2, with two bits and one bit carry;
      for 64 in cycle in cycle 1, with one bit and a two bit carry.  */
-- 
2.9.4