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* Stabs: (stabs).                 The "stabs" debugging information format.

END-INFO-DIR-ENTRY

   This document describes the stabs debugging symbol tables.

   Copyright 1992, 93, 94, 95, 97, 1998 Free Software Foundation, Inc.

Contributed by Cygnus Support.  Written by Julia Menapace, Jim Kingdon,

and David MacKenzie.

   Permission is granted to make and distribute verbatim copies of this

manual provided the copyright notice and this permission notice are

preserved on all copies.

   Permission is granted to copy or distribute modified versions of this

manual under the terms of the GPL (for which purpose this text may be

regarded as a program in the language TeX).

File: stabs.info,  Node: Class Instance,  Next: Methods,  Prev: Simple Classes,  Up: Cplusplus

Class Instance

==============

   As shown above, describing even a simple C++ class definition is

accomplished by massively extending the stab format used in C to

describe structure types.  However, once the class is defined, C stabs

with no modifications can be used to describe class instances.  The

following source:

     main () {

             baseA AbaseA;

     }

yields the following stab describing the class instance.  It looks no

different from a standard C stab describing a local variable.

     .stabs "name:type_ref(baseA)", N_LSYM, NIL, NIL, frame_ptr_offset

     .stabs "AbaseA:20",128,0,0,-20

File: stabs.info,  Node: Methods,  Next: Method Type Descriptor,  Prev: Class Instance,  Up: Cplusplus

Method Definition

=================

   The class definition shown above declares Ameth.  The C++ source

below defines Ameth:

     int

     baseA::Ameth(int in, char other)

     {

             return in;

     };

   This method definition yields three stabs following the code of the

method.  One stab describes the method itself and following two describe

its parameters.  Although there is only one formal argument all methods

have an implicit argument which is the `this' pointer.  The `this'

pointer is a pointer to the object on which the method was called.  Note

that the method name is mangled to encode the class name and argument

types.  Name mangling is described in the ARM (`The Annotated C++

Reference Manual', by Ellis and Stroustrup, ISBN 0-201-51459-1);

`gpcompare.texi' in Cygnus GCC distributions describes the differences

between GNU mangling and ARM mangling.

     .stabs "name:symbol_desriptor(global function)return_type(int)",

             N_FUN, NIL, NIL, code_addr_of_method_start

     .stabs "Ameth__5baseAic:F1",36,0,0,_Ameth__5baseAic

   Here is the stab for the `this' pointer implicit argument.  The name

of the `this' pointer is always `this'.  Type 19, the `this' pointer is

defined as a pointer to type 20, `baseA', but a stab defining `baseA'

has not yet been emited.  Since the compiler knows it will be emited

shortly, here it just outputs a cross reference to the undefined

symbol, by prefixing the symbol name with `xs'.

     .stabs "name:sym_desc(register param)type_def(19)=

             type_desc(ptr to)type_ref(baseA)=

             type_desc(cross-reference to)baseA:",N_RSYM,NIL,NIL,register_number

     .stabs "this:P19=*20=xsbaseA:",64,0,0,8

   The stab for the explicit integer argument looks just like a

parameter to a C function.  The last field of the stab is the offset

from the argument pointer, which in most systems is the same as the

frame pointer.

     .stabs "name:sym_desc(value parameter)type_ref(int)",

             N_PSYM,NIL,NIL,offset_from_arg_ptr

     .stabs "in:p1",160,0,0,72

   << The examples that follow are based on A1.C >>

File: stabs.info,  Node: Method Type Descriptor,  Next: Member Type Descriptor,  Prev: Methods,  Up: Cplusplus

The `#' Type Descriptor

=======================

   This is used to describe a class method.  This is a function which

takes an extra argument as its first argument, for the `this' pointer.

   If the `#' is immediately followed by another `#', the second one

will be followed by the return type and a semicolon.  The class and

argument types are not specified, and must be determined by demangling

the name of the method if it is available.

   Otherwise, the single `#' is followed by the class type, a comma,

the return type, a comma, and zero or more parameter types separated by

commas.  The list of arguments is terminated by a semicolon.  In the

debugging output generated by gcc, a final argument type of `void'

indicates a method which does not take a variable number of arguments.

If the final argument type of `void' does not appear, the method was

declared with an ellipsis.

   Note that although such a type will normally be used to describe

fields in structures, unions, or classes, for at least some versions of

the compiler it can also be used in other contexts.

File: stabs.info,  Node: Member Type Descriptor,  Next: Protections,  Prev: Method Type Descriptor,  Up: Cplusplus

The `@' Type Descriptor

=======================

   The `@' type descriptor is for a member (class and variable) type.

It is followed by type information for the offset basetype, a comma, and

type information for the type of the field being pointed to.  (FIXME:

this is acknowledged to be gibberish.  Can anyone say what really goes

here?).

   Note that there is a conflict between this and type attributes

(*note String Field::); both use type descriptor `@'.  Fortunately, the

`@' type descriptor used in this C++ sense always will be followed by a

digit, `(', or `-', and type attributes never start with those things.

File: stabs.info,  Node: Protections,  Next: Method Modifiers,  Prev: Member Type Descriptor,  Up: Cplusplus

Protections

===========

   In the simple class definition shown above all member data and

functions were publicly accessable.  The example that follows contrasts

public, protected and privately accessable fields and shows how these

protections are encoded in C++ stabs.

   If the character following the `FIELD-NAME:' part of the string is

`/', then the next character is the visibility.  `0' means private, `1'

means protected, and `2' means public.  Debuggers should ignore

visibility characters they do not recognize, and assume a reasonable

default (such as public) (GDB 4.11 does not, but this should be fixed

in the next GDB release).  If no visibility is specified the field is

public.  The visibility `9' means that the field has been optimized out

and is public (there is no way to specify an optimized out field with a

private or protected visibility).  Visibility `9' is not supported by

GDB 4.11; this should be fixed in the next GDB release.

   The following C++ source:

     class vis {

     private:

             int   priv;

     protected:

             char  prot;

     public:

             float pub;

     };

generates the following stab:

     # 128 is N_LSYM

     .stabs "vis:T19=s12priv:/01,0,32;prot:/12,32,8;pub:12,64,32;;",128,0,0,0

   `vis:T19=s12' indicates that type number 19 is a 12 byte structure

named `vis' The `priv' field has public visibility (`/0'), type int

(`1'), and offset and size `,0,32;'.  The `prot' field has protected

visibility (`/1'), type char (`2') and offset and size `,32,8;'.  The

`pub' field has type float (`12'), and offset and size `,64,32;'.

   Protections for member functions are signified by one digit embeded

in the field part of the stab describing the method.  The digit is 0 if

private, 1 if protected and 2 if public.  Consider the C++ class

definition below:

     class all_methods {

     private:

             int   priv_meth(int in){return in;};

     protected:

             char  protMeth(char in){return in;};

     public:

             float pubMeth(float in){return in;};

     };

   It generates the following stab.  The digit in question is to the

left of an `A' in each case.  Notice also that in this case two symbol

descriptors apply to the class name struct tag and struct type.

     .stabs "class_name:sym_desc(struct tag&type)type_def(21)=

             sym_desc(struct)struct_bytes(1)

             meth_name::type_def(22)=sym_desc(method)returning(int);

             :args(int);protection(private)modifier(normal)virtual(no);

             meth_name::type_def(23)=sym_desc(method)returning(char);

             :args(char);protection(protected)modifier(normal)virual(no);

             meth_name::type_def(24)=sym_desc(method)returning(float);

             :args(float);protection(public)modifier(normal)virtual(no);;",

             N_LSYM,NIL,NIL,NIL

     .stabs "all_methods:Tt21=s1priv_meth::22=##1;:i;0A.;protMeth::23=##2;:c;1A.;

             pubMeth::24=##12;:f;2A.;;",128,0,0,0

File: stabs.info,  Node: Method Modifiers,  Next: Virtual Methods,  Prev: Protections,  Up: Cplusplus

Method Modifiers (`const', `volatile', `const volatile')

========================================================

   << based on a6.C >>

   In the class example described above all the methods have the normal

modifier.  This method modifier information is located just after the

protection information for the method.  This field has four possible

character values.  Normal methods use `A', const methods use `B',

volatile methods use `C', and const volatile methods use `D'.  Consider

the class definition below:

     class A {

     public:

             int ConstMeth (int arg) const { return arg; };

             char VolatileMeth (char arg) volatile { return arg; };

             float ConstVolMeth (float arg) const volatile {return arg; };

     };

   This class is described by the following stab:

     .stabs "class(A):sym_desc(struct)type_def(20)=type_desc(struct)struct_bytes(1)

             meth_name(ConstMeth)::type_def(21)sym_desc(method)

             returning(int);:arg(int);protection(public)modifier(const)virtual(no);

             meth_name(VolatileMeth)::type_def(22)=sym_desc(method)

             returning(char);:arg(char);protection(public)modifier(volatile)virt(no)

             meth_name(ConstVolMeth)::type_def(23)=sym_desc(method)

             returning(float);:arg(float);protection(public)modifer(const volatile)

             virtual(no);;", ...

     .stabs "A:T20=s1ConstMeth::21=##1;:i;2B.;VolatileMeth::22=##2;:c;2C.;

                  ConstVolMeth::23=##12;:f;2D.;;",128,0,0,0

File: stabs.info,  Node: Virtual Methods,  Next: Inheritence,  Prev: Method Modifiers,  Up: Cplusplus

Virtual Methods

===============

   << The following examples are based on a4.C >>

   The presence of virtual methods in a class definition adds additional

data to the class description.  The extra data is appended to the

description of the virtual method and to the end of the class

description.  Consider the class definition below:

     class A {

     public:

             int Adat;

             virtual int A_virt (int arg) { return arg; };

     };

   This results in the stab below describing class A.  It defines a new

type (20) which is an 8 byte structure.  The first field of the class

struct is `Adat', an integer, starting at structure offset 0 and

occupying 32 bits.

   The second field in the class struct is not explicitly defined by the

C++ class definition but is implied by the fact that the class contains

a virtual method.  This field is the vtable pointer.  The name of the

vtable pointer field starts with `$vf' and continues with a type

reference to the class it is part of.  In this example the type

reference for class A is 20 so the name of its vtable pointer field is

`$vf20', followed by the usual colon.

   Next there is a type definition for the vtable pointer type (21).

This is in turn defined as a pointer to another new type (22).

   Type 22 is the vtable itself, which is defined as an array, indexed

by a range of integers between 0 and 1, and whose elements are of type

17.  Type 17 was the vtable record type defined by the boilerplate C++

type definitions, as shown earlier.

   The bit offset of the vtable pointer field is 32.  The number of bits

in the field are not specified when the field is a vtable pointer.

   Next is the method definition for the virtual member function

`A_virt'.  Its description starts out using the same format as the

non-virtual member functions described above, except instead of a dot

after the `A' there is an asterisk, indicating that the function is

virtual.  Since is is virtual some addition information is appended to

the end of the method description.

   The first number represents the vtable index of the method.  This is

a 32 bit unsigned number with the high bit set, followed by a

semi-colon.

   The second number is a type reference to the first base class in the

inheritence hierarchy defining the virtual member function.  In this

case the class stab describes a base class so the virtual function is

not overriding any other definition of the method.  Therefore the

reference is to the type number of the class that the stab is

describing (20).

   This is followed by three semi-colons.  One marks the end of the

current sub-section, one marks the end of the method field, and the

third marks the end of the struct definition.

   For classes containing virtual functions the very last section of the

string part of the stab holds a type reference to the first base class.

This is preceeded by `~%' and followed by a final semi-colon.

     .stabs "class_name(A):type_def(20)=sym_desc(struct)struct_bytes(8)

             field_name(Adat):type_ref(int),bit_offset(0),field_bits(32);

             field_name(A virt func ptr):type_def(21)=type_desc(ptr to)type_def(22)=

             sym_desc(array)index_type_ref(range of int from 0 to 1);

             elem_type_ref(vtbl elem type),

             bit_offset(32);

             meth_name(A_virt)::typedef(23)=sym_desc(method)returning(int);

             :arg_type(int),protection(public)normal(yes)virtual(yes)

             vtable_index(1);class_first_defining(A);;;~%first_base(A);",

             N_LSYM,NIL,NIL,NIL

     .stabs "A:t20=s8Adat:1,0,32;$vf20:21=*22=ar1;0;1;17,32;

             A_virt::23=##1;:i;2A*-2147483647;20;;;~%20;",128,0,0,0

File: stabs.info,  Node: Inheritence,  Next: Virtual Base Classes,  Prev: Virtual Methods,  Up: Cplusplus

Inheritence

===========

   Stabs describing C++ derived classes include additional sections that

describe the inheritence hierarchy of the class.  A derived class stab

also encodes the number of base classes.  For each base class it tells

if the base class is virtual or not, and if the inheritence is private

or public.  It also gives the offset into the object of the portion of

the object corresponding to each base class.

   This additional information is embeded in the class stab following

the number of bytes in the struct.  First the number of base classes

appears bracketed by an exclamation point and a comma.

   Then for each base type there repeats a series: a virtual character,

a visibilty character, a number, a comma, another number, and a

semi-colon.

   The virtual character is `1' if the base class is virtual and `0' if

not.  The visibility character is `2' if the derivation is public, `1'

if it is protected, and `0' if it is private.  Debuggers should ignore

virtual or visibility characters they do not recognize, and assume a

reasonable default (such as public and non-virtual) (GDB 4.11 does not,

but this should be fixed in the next GDB release).

   The number following the virtual and visibility characters is the

offset from the start of the object to the part of the object

pertaining to the base class.

   After the comma, the second number is a type_descriptor for the base

type.  Finally a semi-colon ends the series, which repeats for each

base class.

   The source below defines three base classes `A', `B', and `C' and

the derived class `D'.

     class A {

     public:

             int Adat;

             virtual int A_virt (int arg) { return arg; };

     };

     class B {

     public:

             int B_dat;

             virtual int B_virt (int arg) {return arg; };

     };

     class C {

     public:

             int Cdat;

             virtual int C_virt (int arg) {return arg; };

     };

     class D : A, virtual B, public C {

     public:

             int Ddat;

             virtual int A_virt (int arg ) { return arg+1; };

             virtual int B_virt (int arg)  { return arg+2; };

             virtual int C_virt (int arg)  { return arg+3; };

             virtual int D_virt (int arg)  { return arg; };

     };

   Class stabs similar to the ones described earlier are generated for

each base class.

     .stabs "A:T20=s8Adat:1,0,32;$vf20:21=*22=ar1;0;1;17,32;

             A_virt::23=##1;:i;2A*-2147483647;20;;;~%20;",128,0,0,0

     .stabs "B:Tt25=s8Bdat:1,0,32;$vf25:21,32;B_virt::26=##1;

             :i;2A*-2147483647;25;;;~%25;",128,0,0,0

     .stabs "C:Tt28=s8Cdat:1,0,32;$vf28:21,32;C_virt::29=##1;

             :i;2A*-2147483647;28;;;~%28;",128,0,0,0

   In the stab describing derived class `D' below, the information about

the derivation of this class is encoded as follows.

     .stabs "derived_class_name:symbol_descriptors(struct tag&type)=

             type_descriptor(struct)struct_bytes(32)!num_bases(3),

             base_virtual(no)inheritence_public(no)base_offset(0),

             base_class_type_ref(A);

             base_virtual(yes)inheritence_public(no)base_offset(NIL),

             base_class_type_ref(B);

             base_virtual(no)inheritence_public(yes)base_offset(64),

             base_class_type_ref(C); ...

     .stabs "D:Tt31=s32!3,000,20;100,25;0264,28;$vb25:24,128;Ddat:

             1,160,32;A_virt::32=##1;:i;2A*-2147483647;20;;B_virt:

             :32:i;2A*-2147483647;25;;C_virt::32:i;2A*-2147483647;

             28;;D_virt::32:i;2A*-2147483646;31;;;~%20;",128,0,0,0

File: stabs.info,  Node: Virtual Base Classes,  Next: Static Members,  Prev: Inheritence,  Up: Cplusplus

Virtual Base Classes

====================

   A derived class object consists of a concatenation in memory of the

data areas defined by each base class, starting with the leftmost and

ending with the rightmost in the list of base classes.  The exception

to this rule is for virtual inheritence.  In the example above, class

`D' inherits virtually from base class `B'.  This means that an

instance of a `D' object will not contain its own `B' part but merely a

pointer to a `B' part, known as a virtual base pointer.

   In a derived class stab, the base offset part of the derivation

information, described above, shows how the base class parts are

ordered.  The base offset for a virtual base class is always given as 0.

Notice that the base offset for `B' is given as 0 even though `B' is

not the first base class.  The first base class `A' starts at offset 0.

   The field information part of the stab for class `D' describes the

field which is the pointer to the virtual base class `B'. The vbase

pointer name is `$vb' followed by a type reference to the virtual base

class.  Since the type id for `B' in this example is 25, the vbase

pointer name is `$vb25'.

     .stabs "D:Tt31=s32!3,000,20;100,25;0264,28;$vb25:24,128;Ddat:1,

            160,32;A_virt::32=##1;:i;2A*-2147483647;20;;B_virt::32:i;

            2A*-2147483647;25;;C_virt::32:i;2A*-2147483647;28;;D_virt:

            :32:i;2A*-2147483646;31;;;~%20;",128,0,0,0

   Following the name and a semicolon is a type reference describing the

type of the virtual base class pointer, in this case 24.  Type 24 was

defined earlier as the type of the `B' class `this' pointer.  The

`this' pointer for a class is a pointer to the class type.

     .stabs "this:P24=*25=xsB:",64,0,0,8

   Finally the field offset part of the vbase pointer field description

shows that the vbase pointer is the first field in the `D' object,

before any data fields defined by the class.  The layout of a `D' class

object is a follows, `Adat' at 0, the vtable pointer for `A' at 32,

`Cdat' at 64, the vtable pointer for C at 96, the virtual base pointer

for `B' at 128, and `Ddat' at 160.

File: stabs.info,  Node: Static Members,  Prev: Virtual Base Classes,  Up: Cplusplus

Static Members

==============

   The data area for a class is a concatenation of the space used by the

data members of the class.  If the class has virtual methods, a vtable

pointer follows the class data.  The field offset part of each field

description in the class stab shows this ordering.

   << How is this reflected in stabs?  See Cygnus bug #677 for some

info.  >>

File: stabs.info,  Node: Stab Types,  Next: Symbol Descriptors,  Prev: Cplusplus,  Up: Top

Table of Stab Types

*******************

   The following are all the possible values for the stab type field,

for a.out files, in numeric order.  This does not apply to XCOFF, but

it does apply to stabs in sections (*note Stab Sections::).  Stabs in

ECOFF use these values but add 0x8f300 to distinguish them from non-stab

symbols.

   The symbolic names are defined in the file `include/aout/stabs.def'.

* Menu:

* Non-Stab Symbol Types::       Types from 0 to 0x1f

* Stab Symbol Types::           Types from 0x20 to 0xff

File: stabs.info,  Node: Non-Stab Symbol Types,  Next: Stab Symbol Types,  Up: Stab Types

Non-Stab Symbol Types

=====================

   The following types are used by the linker and assembler, not by stab

directives.  Since this document does not attempt to describe aspects of

object file format other than the debugging format, no details are

given.

`0x0     N_UNDF'

     Undefined symbol

`0x2     N_ABS'

     File scope absolute symbol

`0x3     N_ABS | N_EXT'

     External absolute symbol

`0x4     N_TEXT'

     File scope text symbol

`0x5     N_TEXT | N_EXT'

     External text symbol

`0x6     N_DATA'

     File scope data symbol

`0x7     N_DATA | N_EXT'

     External data symbol

`0x8     N_BSS'

     File scope BSS symbol

`0x9     N_BSS | N_EXT'

     External BSS symbol

`0x0c    N_FN_SEQ'

     Same as `N_FN', for Sequent compilers

`0x0a    N_INDR'

     Symbol is indirected to another symbol

`0x12    N_COMM'

     Common--visible after shared library dynamic link

`0x14 N_SETA'

`0x15 N_SETA | N_EXT'

     Absolute set element

`0x16 N_SETT'

`0x17 N_SETT | N_EXT'

     Text segment set element

`0x18 N_SETD'

`0x19 N_SETD | N_EXT'

     Data segment set element

`0x1a N_SETB'

`0x1b N_SETB | N_EXT'

     BSS segment set element

`0x1c N_SETV'

`0x1d N_SETV | N_EXT'

     Pointer to set vector

`0x1e N_WARNING'

     Print a warning message during linking

`0x1f    N_FN'

     File name of a `.o' file

File: stabs.info,  Node: Stab Symbol Types,  Prev: Non-Stab Symbol Types,  Up: Stab Types

Stab Symbol Types

=================

   The following symbol types indicate that this is a stab.  This is the

full list of stab numbers, including stab types that are used in

languages other than C.

`0x20     N_GSYM'

     Global symbol; see *Note Global Variables::.

`0x22     N_FNAME'

     Function name (for BSD Fortran); see *Note Procedures::.

`0x24     N_FUN'

     Function name (*note Procedures::) or text segment variable (*note

     Statics::).

`0x26 N_STSYM'

     Data segment file-scope variable; see *Note Statics::.

`0x28 N_LCSYM'

     BSS segment file-scope variable; see *Note Statics::.

`0x2a N_MAIN'

     Name of main routine; see *Note Main Program::.

`0x2c N_ROSYM'

     Variable in `.rodata' section; see *Note Statics::.

`0x30     N_PC'

     Global symbol (for Pascal); see *Note N_PC::.

`0x32     N_NSYMS'

     Number of symbols (according to Ultrix V4.0); see *Note N_NSYMS::.

`0x34     N_NOMAP'

     No DST map; see *Note N_NOMAP::.

`0x38 N_OBJ'

     Object file (Solaris2).

`0x3c N_OPT'

     Debugger options (Solaris2).

`0x40     N_RSYM'

     Register variable; see *Note Register Variables::.

`0x42     N_M2C'

     Modula-2 compilation unit; see *Note N_M2C::.

`0x44     N_SLINE'

     Line number in text segment; see *Note Line Numbers::.

`0x46     N_DSLINE'

     Line number in data segment; see *Note Line Numbers::.

`0x48     N_BSLINE'

     Line number in bss segment; see *Note Line Numbers::.

`0x48     N_BROWS'

     Sun source code browser, path to `.cb' file; see *Note N_BROWS::.

`0x4a     N_DEFD'

     GNU Modula2 definition module dependency; see *Note N_DEFD::.

`0x4c N_FLINE'

     Function start/body/end line numbers (Solaris2).

`0x50     N_EHDECL'

     GNU C++ exception variable; see *Note N_EHDECL::.

`0x50     N_MOD2'

     Modula2 info "for imc" (according to Ultrix V4.0); see *Note

     N_MOD2::.

`0x54     N_CATCH'

     GNU C++ `catch' clause; see *Note N_CATCH::.

`0x60     N_SSYM'

     Structure of union element; see *Note N_SSYM::.

`0x62 N_ENDM'

     Last stab for module (Solaris2).

`0x64     N_SO'

     Path and name of source file; see *Note Source Files::.

`0x80 N_LSYM'

     Stack variable (*note Stack Variables::) or type (*note

     Typedefs::).

`0x82     N_BINCL'

     Beginning of an include file (Sun only); see *Note Include Files::.

`0x84     N_SOL'

     Name of include file; see *Note Include Files::.

`0xa0     N_PSYM'

     Parameter variable; see *Note Parameters::.

`0xa2     N_EINCL'

     End of an include file; see *Note Include Files::.

`0xa4     N_ENTRY'

     Alternate entry point; see *Note Alternate Entry Points::.

`0xc0     N_LBRAC'

     Beginning of a lexical block; see *Note Block Structure::.

`0xc2     N_EXCL'

     Place holder for a deleted include file; see *Note Include Files::.

`0xc4     N_SCOPE'

     Modula2 scope information (Sun linker); see *Note N_SCOPE::.

`0xe0     N_RBRAC'

     End of a lexical block; see *Note Block Structure::.

`0xe2     N_BCOMM'

     Begin named common block; see *Note Common Blocks::.

`0xe4     N_ECOMM'

     End named common block; see *Note Common Blocks::.

`0xe8     N_ECOML'

     Member of a common block; see *Note Common Blocks::.

`0xea N_WITH'

     Pascal `with' statement: type,,0,0,offset (Solaris2).

`0xf0     N_NBTEXT'

     Gould non-base registers; see *Note Gould::.

`0xf2     N_NBDATA'

     Gould non-base registers; see *Note Gould::.

`0xf4     N_NBBSS'

     Gould non-base registers; see *Note Gould::.

`0xf6     N_NBSTS'

     Gould non-base registers; see *Note Gould::.

`0xf8     N_NBLCS'

     Gould non-base registers; see *Note Gould::.

File: stabs.info,  Node: Symbol Descriptors,  Next: Type Descriptors,  Prev: Stab Types,  Up: Top

Table of Symbol Descriptors

***************************

   The symbol descriptor is the character which follows the colon in

many stabs, and which tells what kind of stab it is.  *Note String

Field::, for more information about their use.

`DIGIT'

`('

`-'

     Variable on the stack; see *Note Stack Variables::.

`:'

     C++ nested symbol; see *Note Nested Symbols::.

`a'

     Parameter passed by reference in register; see *Note Reference

     Parameters::.

`b'

     Based variable; see *Note Based Variables::.

`c'

     Constant; see *Note Constants::.

`C'

     Conformant array bound (Pascal, maybe other languages); *Note

     Conformant Arrays::.  Name of a caught exception (GNU C++).  These

     can be distinguished because the latter uses `N_CATCH' and the

     former uses another symbol type.

`d'

     Floating point register variable; see *Note Register Variables::.

`D'

     Parameter in floating point register; see *Note Register

     Parameters::.

`f'

     File scope function; see *Note Procedures::.

`F'

     Global function; see *Note Procedures::.

`G'

     Global variable; see *Note Global Variables::.

`i'

     *Note Register Parameters::.

`I'

     Internal (nested) procedure; see *Note Nested Procedures::.

`J'

     Internal (nested) function; see *Note Nested Procedures::.

`L'

     Label name (documented by AIX, no further information known).

`m'

     Module; see *Note Procedures::.

`p'

     Argument list parameter; see *Note Parameters::.

`pP'

     *Note Parameters::.

`pF'

     Fortran Function parameter; see *Note Parameters::.

`P'

     Unfortunately, three separate meanings have been independently

     invented for this symbol descriptor.  At least the GNU and Sun

     uses can be distinguished by the symbol type.  Global Procedure

     (AIX) (symbol type used unknown); see *Note Procedures::.

     Register parameter (GNU) (symbol type `N_PSYM'); see *Note

     Parameters::.  Prototype of function referenced by this file (Sun

     `acc') (symbol type `N_FUN').

`Q'

     Static Procedure; see *Note Procedures::.

`R'

     Register parameter; see *Note Register Parameters::.

`r'

     Register variable; see *Note Register Variables::.

`S'

     File scope variable; see *Note Statics::.

`s'

     Local variable (OS9000).

`t'

     Type name; see *Note Typedefs::.

`T'

     Enumeration, structure, or union tag; see *Note Typedefs::.

`v'

     Parameter passed by reference; see *Note Reference Parameters::.

`V'

     Procedure scope static variable; see *Note Statics::.

`x'

     Conformant array; see *Note Conformant Arrays::.

`X'

     Function return variable; see *Note Parameters::.

File: stabs.info,  Node: Type Descriptors,  Next: Expanded Reference,  Prev: Symbol Descriptors,  Up: Top

Table of Type Descriptors

*************************

   The type descriptor is the character which follows the type number

and an equals sign.  It specifies what kind of type is being defined.

*Note String Field::, for more information about their use.

`DIGIT'

`('

     Type reference; see *Note String Field::.

`-'

     Reference to builtin type; see *Note Negative Type Numbers::.

`#'

     Method (C++); see *Note Method Type Descriptor::.

`*'

     Pointer; see *Note Miscellaneous Types::.

`&'

     Reference (C++).

`@'

     Type Attributes (AIX); see *Note String Field::.  Member (class

     and variable) type (GNU C++); see *Note Member Type Descriptor::.

`a'

     Array; see *Note Arrays::.

`A'

     Open array; see *Note Arrays::.

`b'

     Pascal space type (AIX); see *Note Miscellaneous Types::.  Builtin

     integer type (Sun); see *Note Builtin Type Descriptors::.  Const

     and volatile qualfied type (OS9000).

`B'

     Volatile-qualified type; see *Note Miscellaneous Types::.

`c'

     Complex builtin type (AIX); see *Note Builtin Type Descriptors::.

     Const-qualified type (OS9000).

`C'

     COBOL Picture type.  See AIX documentation for details.

`d'

     File type; see *Note Miscellaneous Types::.

`D'

     N-dimensional dynamic array; see *Note Arrays::.

`e'

     Enumeration type; see *Note Enumerations::.

`E'

     N-dimensional subarray; see *Note Arrays::.

`f'

     Function type; see *Note Function Types::.

`F'

     Pascal function parameter; see *Note Function Types::

`g'

     Builtin floating point type; see *Note Builtin Type Descriptors::.

`G'

     COBOL Group.  See AIX documentation for details.

`i'

     Imported type (AIX); see *Note Cross-References::.

     Volatile-qualified type (OS9000).

`k'

     Const-qualified type; see *Note Miscellaneous Types::.

`K'

     COBOL File Descriptor.  See AIX documentation for details.

`M'

     Multiple instance type; see *Note Miscellaneous Types::.

`n'

     String type; see *Note Strings::.