Re: stabs.texinfo update for macro define/undefine

David Taylor
2006-10-30T22:25:38Z

Patch to add information about recording macro define and undefine
information in stabs.

Index: stabs.texinfo
===================================================================
RCS file: /cvs/src/src/gdb/doc/stabs.texinfo,v
retrieving revision 1.18
diff -u -r1.18 stabs.texinfo
--- stabs.texinfo 2 Aug 2006 03:31:21 -0000 1.18
+++ stabs.texinfo 30 Oct 2006 22:19:10 -0000
@@ -67,6 +67,7 @@
* Constants:: Constants
* Variables::
* Types:: Type definitions
+* Macro define and undefine:: Representation of #define and #undef
* Symbol Tables:: Symbol information in symbol tables
* Cplusplus:: Stabs specific to C++
* Stab Types:: Symbol types in a.out files
@@ -2220,6 +2221,69 @@
The variable defines a new type, 24, which is a pointer to another new
type, 25, which is a function returning @code{int}.

+@node Macro define and undefine
+@chapter Representation of #define and #undef
+
+Macro define and undefine.
+
+This section describes the stabs support for macro define and undefine
+information, supported on some systems. (e.g., with -g3 -gstabs when
+using gcc).
+
+A @code{#define @var{macro-name} @var{macro-body}} is represented with
+an @code{N_MAC_DEFINE} stab with a string field of
+@code{@var{macro-name} @var{macro-body}}.
+@findex N_MAC_DEFINE
+
+An @code{#undef @var{macro-name}} is represented with an
+@code{N_MAC_UNDEF} stabs with a string field of simply
+@code{@var{macro-name}}.
+@findex N_MAC_UNDEF
+
+For both @code{N_MAC_DEFINE} and @code{N_MAC_UNDEF}, the desc field is
+the line number within the file where the corresponding @code{#define}
+or @code{#undef} occurred.
+@findex N_MAC_DEFINE
+@findex N_MAC_UNDEF
+
+For example, the following C code:
+
+@example
+ #define NONE 42
+ #define TWO(a, b) (a + (a) + 2 * b)
+ #define ONE(c) (c + 19)
+
+ main(int argc, char *argv[])
+ @{
+ func(NONE, TWO(10, 11));
+ func(NONE, ONE(23));
+
+ #undef ONE
+ #define ONE(c) (c + 23)
+
+ func(NONE, ONE(-23));
+
+ return (0);
+ @}
+
+ int global;
+
+ func(int arg1, int arg2)
+ @{
+ global = arg1 + arg2;
+ @}
+@end example
+
+produces the following stabs (as well as many others):
+
+@example
+ .stabs "NONE 42",54,0,1,0 # 54 is N_MAC_DEFINE
+ .stabs "TWO(a,b) (a + (a) + 2 * b)",54,0,2,0 # 54 is N_MAC_DEFINE
+ .stabs "ONE(c) (c + 19)",54,0,3,0 # 54 is N_MAC_DEFINE
+ .stabs "ONE",58,0,10,0 # 58 is N_MAC_UNDEF
+ .stabs "ONE(c) (c + 23)",54,0,11,0 # 54 is N_MAC_DEFINE
+@end example
+
@node Symbol Tables
@chapter Symbol Information in Symbol Tables

@@ -3276,11 +3340,17 @@
@item 0x34 N_NOMAP
No DST map; see @ref{N_NOMAP}.

+@item 0x36 N_MAC_DEFINE
+Name and body of a @code{#define}d macro; see @ref{Macro define and undefine}.
+
@c FIXME: describe this solaris feature in the body of the text (see
@c comments in include/aout/stab.def).
@item 0x38 N_OBJ
Object file (Solaris2).

+@item 0x3a N_MAC_UNDEF
+Name of an @code{#undef}ed macro; see @ref{Macro define and undefine}.
+
@c See include/aout/stab.def for (a little) more info.
@item 0x3c N_OPT
Debugger options (Solaris2).