is followed by @samp{=} and one of the following:
@table @code
-@item b@var{value}
+@item b @var{value}
Boolean constant. @var{value} is a numeric value; I assume it is 0 for
false or 1 for true.
-@item c@var{value}
+@item c @var{value}
Character constant. @var{value} is the numeric value of the constant.
-@item e@var{type-information},@var{value}
-Enumeration constant. @var{type-information} is the type of the
-constant, as it would appear after a symbol descriptor
-(@pxref{Stabs Format}). @var{value} is the numeric value of the constant.
-
-@item i@var{value}
-Integer constant. @var{value} is the numeric value.
-
-@item r@var{value}
+@item e @var{type-information} , @var{value}
+Constant whose value can be represented as integral.
+@var{type-information} is the type of the constant, as it would appear
+after a symbol descriptor (@pxref{Stabs Format}). @var{value} is the
+numeric value of the constant. GDB 4.9 does not actually get the right
+value if @var{value} does not fit in a host @code{int}, but it does not
+do anything violent, and future debuggers could be extended to accept
+integers of any size (whether unsigned or not). This constant type is
+usually documented as being only for enumeration constants, but GDB has
+never imposed that restriction; I don't know about other debuggers.
+
+@item i @var{value}
+Integer constant. @var{value} is the numeric value. The type is some
+sort of generic integer type (for GDB, a host @code{int}); to specify
+the type explicitly, use @samp{e} instead.
+
+@item r @var{value}
Real constant. @var{value} is the real value, which can be @samp{INF}
(optionally preceded by a sign) for infinity, @samp{QNAN} for a quiet
NaN (not-a-number), or @samp{SNAN} for a signalling NaN. If it is a
normal number the format is that accepted by the C library function
@code{atof}.
-@item s@var{string}
+@item s @var{string}
String constant. @var{string} is a string enclosed in either @samp{'}
(in which case @samp{'} characters within the string are represented as
@samp{\'} or @samp{"} (in which case @samp{"} characters within the
string are represented as @samp{\"}).
-@item S@var{type-information},@var{elements},@var{bits},@var{pattern}
+@item S @var{type-information} , @var{elements} , @var{bits} , @var{pattern}
Set constant. @var{type-information} is the type of the constant, as it
would appear after a symbol descriptor (@pxref{Stabs Format}).
@var{elements} is the number of elements in the set (is this just the
it specifies the length of @var{pattern}, I think), and @var{pattern} is
a hexadecimal representation of the set. AIX documentation refers to a
limit of 32 bytes, but I see no reason why this limit should exist.
+This form could probably be used for arbitrary constants, not just sets;
+the only catch is that @var{pattern} should be understood to be target,
+not host, byte order and format.
@end table
The boolean, character, string, and set constants are not supported by
.stabs "unsigned short:t6=r1;0;65535;",128,0,0,0
@end example
-If the upper bound of a subrange is -1, it means that the type is an
-integral type whose bounds are too big to describe in an int.
-Traditionally this is only used for @code{unsigned int} and
-@code{unsigned long}; GCC also uses it for @code{long long} and
-@code{unsigned long long}, and the only way to tell those types apart is
-to look at their names. On other machines GCC puts out bounds in octal,
-with a leading 0. In this case a negative bound consists of a number
-which is a 1 bit followed by a bunch of 0 bits, and a positive bound is
-one in which a bunch of bits are 1.
+If the lower bound of a subrange is 0 and the upper bound is -1, it
+means that the type is an unsigned integral type whose bounds are too
+big to describe in an int. Traditionally this is only used for
+@code{unsigned int} and @code{unsigned long}; GCC also sometimes uses it
+for @code{long long} and @code{unsigned long long}, and the only way to
+tell those types apart is to look at their names. On other machines GCC
+puts out bounds in octal, with a leading 0. In this case a negative
+bound consists of a number which is a 1 bit followed by a bunch of 0
+bits, and a positive bound is one in which a bunch of bits are 1.
@example
.stabs "unsigned int:t4=r1;0;-1;",128,0,0,0
.stabs "long long int:t7=r1;0;-1;",128,0,0,0
@end example
+If the lower bound of a subrange is 0 and the upper bound is negative,
+it means that it is an unsigned integral type whose size in bytes is the
+absolute value of the upper bound. I believe this is a Convex
+convention for @code{unsigned long long}.
+
+If the lower bound of a subrange is negative and the upper bound is 0,
+it means that the type is a signed integral type whose size in bytes is
+the absolute value of the lower bound. I believe this is a Convex
+convention for @code{long long}. To distinguish this from a legitimate
+subrange, the type should be a subrange of itself. I'm not sure whether
+this is the case for Convex.
+
If the upper bound of a subrange is 0, it means that this is a floating
point type, and the lower bound of the subrange indicates the number of
bytes in the type:
suspect the correct thing to do is to define a new number in cases where
a type does not have the size and format indicated below.
+Also note that part of the definition of the negative type number is
+the name of the type. Types with identical size and format but
+different names have different negative type numbers.
+
@table @code
@item -1
@code{int}, 32 bit signed integral type.
@code{double}, IEEE double precision.
@item -14
-@code{long double}, IEEE extended, RS6000 format.
+@code{long double}, IEEE double precision. The compiler claims the size
+will increase in a future release, and for binary compatibility you have
+to avoid using @code{long double}. I hope when they increase it they
+use a new negative type number.
@item -15
-@code{integer}. Pascal, I assume. 32 bit signed integral type.
+@code{integer}. 32 bit signed integral type.
@item -16
-Boolean. Only one bit is used, not sure about the actual size of the
+@code{boolean}. Only one bit is used, not sure about the actual size of the
type.
@item -17
-@code{short real}. Pascal, I assume. IEEE single precision.
+@code{short real}. IEEE single precision.
@item -18
-@code{real}. Pascal, I assume. IEEE double precision.
+@code{real}. IEEE double precision.
@item -19
-A Pascal Stringptr. @xref{Strings}.
+@code{stringptr}. @xref{Strings}.
@item -20
@code{character}, 8 bit unsigned type.
@code{logical}, 32 bit unsigned integral type.
@item -25
-A complex type consisting of two IEEE single-precision floating point values.
+@code{complex}. A complex type consisting of two IEEE single-precision
+floating point values.
@item -26
-A complex type consisting of two IEEE double-precision floating point values.
+@code{complex}. A complex type consisting of two IEEE double-precision
+floating point values.
@item -27
@code{integer*1}, 8 bit signed integral type.
@code{integer*4}, 32 bit signed integral type.
@item -30
-Wide character. AIX appears not to use this for the C type
-@code{wchar_t}; instead it uses an integral type of the appropriate
-size.
+@code{wchar}. Wide character, 16 bits wide (Unicode format?). This is
+not used for the C type @code{wchar_t}.
@end table
@node Miscellaneous Types
projects / binutils-gdb.git / commitdiff