From fce30fa15eea044144b50e3896d72cb167472ad7 Mon Sep 17 00:00:00 2001 From: Jim Kingdon Date: Thu, 22 Apr 1993 16:12:31 +0000 Subject: [PATCH] * symtab.h: Clean up SYMBOL_VALUE comments. --- gdb/ChangeLog | 4 ++++ gdb/symtab.h | 67 ++++++++++++++++++++++++++--------------------------------- 2 files changed, 34 insertions(+), 37 deletions(-) diff --git a/gdb/ChangeLog b/gdb/ChangeLog index 38b2e1d..b9caec4 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,3 +1,7 @@ +Thu Apr 22 09:07:24 1993 Jim Kingdon (kingdon@cygnus.com) + + * symtab.h: Clean up SYMBOL_VALUE comments. + Wed Apr 21 14:29:57 1993 Jim Kingdon (kingdon@cygnus.com) * stack.c (print_frame_arg_vars), printcmd.c (print_frame_args): diff --git a/gdb/symtab.h b/gdb/symtab.h index 0661c5a..82ad961 100644 --- a/gdb/symtab.h +++ b/gdb/symtab.h @@ -37,32 +37,20 @@ struct general_symbol_info char *name; - /* Constant value, or address if static, or register number, - or offset in arguments, or offset in stack frame. All of - these are in host byte order (though what they point to might - be in target byte order, e.g. LOC_CONST_BYTES). - - Note that the address of a function is SYMBOL_VALUE_ADDRESS (pst) - in a partial symbol table, but BLOCK_START (SYMBOL_BLOCK_VALUE (st)) - in a symbol table. */ + /* Value of the symbol. Which member of this union to use, and what + it means, depends on what kind of symbol this is and its + SYMBOL_CLASS. See comments there for more details. All of these + are in host byte order (though what they point to might be in + target byte order, e.g. LOC_CONST_BYTES). */ union { - /* for LOC_CONST, LOC_REGISTER, LOC_ARG, LOC_REF_ARG, LOC_REGPARM, - LOC_LOCAL */ - long value; - /* for LOC_BLOCK */ - struct block *block; - /* for LOC_CONST_BYTES */ - char *bytes; - /* for LOC_STATIC, LOC_LABEL */ - CORE_ADDR address; /* for opaque typedef struct chain */ @@ -267,7 +255,10 @@ extern int demangle; /* We reference it, so go ahead and declare it. */ struct minimal_symbol { - /* The general symbol info required for all types of symbols. */ + /* The general symbol info required for all types of symbols. + + The SYMBOL_VALUE_ADDRESS contains the address that this symbol + corresponds to. */ struct general_symbol_info ginfo; @@ -449,25 +440,26 @@ enum address_class LOC_STATIC, - /* Value is in register */ + /* Value is in register. SYMBOL_VALUE is the register number. */ LOC_REGISTER, - /* Value is at spec'd offset in arglist */ + /* It's an argument; the value is at SYMBOL_VALUE offset in arglist. */ LOC_ARG, - /* Value address is at spec'd offset in arglist. Currently this is used - for C++ references (and presumably will be used for Pascal VAR - parameters), and is only dereferenced in certain contexts. */ + /* Value address is at SYMBOL_VALUE offset in arglist. Currently + this is used for C++ references (and presumably will be used for + Pascal VAR parameters), and is only dereferenced in certain + contexts. */ LOC_REF_ARG, - /* Value is in specified register. Just like LOC_REGISTER except this is - an argument. Probably the cleaner way to handle this would be to - separate address_class (which would include separate ARG and LOCAL - to deal with FRAME_ARGS_ADDRESS versus FRAME_LOCALS_ADDRESS), and - an is_argument flag. + /* Value is in register number SYMBOL_VALUE. Just like LOC_REGISTER + except this is an argument. Probably the cleaner way to handle + this would be to separate address_class (which would include + separate ARG and LOCAL to deal with FRAME_ARGS_ADDRESS versus + FRAME_LOCALS_ADDRESS), and an is_argument flag. For some symbol formats (stabs, for some compilers at least), gdb generates a LOC_ARG and a LOC_REGISTER rather than a LOC_REGPARM. @@ -477,7 +469,7 @@ enum address_class LOC_REGPARM, - /* Value is at spec'd offset in stack frame */ + /* Value is a local variable at SYMBOL_VALUE offset in stack frame. */ LOC_LOCAL, @@ -490,8 +482,9 @@ enum address_class LOC_LABEL, - /* Value is address SYMBOL_VALUE_BLOCK of a `struct block'. Function names - have this class. */ + /* In a symbol table, value is SYMBOL_BLOCK_VALUE of a `struct block'. + In a partial symbol table, SYMBOL_VALUE_ADDRESS is the start address + of the block. Function names have this class. */ LOC_BLOCK, @@ -500,16 +493,16 @@ enum address_class LOC_CONST_BYTES, - /* Value is arg at spec'd offset in stack frame. Differs from LOC_LOCAL in - that symbol is an argument; differs from LOC_ARG in that we find it - in the frame (FRAME_LOCALS_ADDRESS), not in the arglist - (FRAME_ARGS_ADDRESS). Added for i960, which passes args in regs then - copies to frame. */ + /* Value is arg at SYMBOL_VALUE offset in stack frame. Differs from + LOC_LOCAL in that symbol is an argument; differs from LOC_ARG in + that we find it in the frame (FRAME_LOCALS_ADDRESS), not in the + arglist (FRAME_ARGS_ADDRESS). Added for i960, which passes args + in regs then copies to frame. */ LOC_LOCAL_ARG, /* The variable does not actually exist in the program. - The SYMBOL_VALUE is ignored. */ + The value is ignored. */ LOC_OPTIMIZED_OUT }; -- 2.7.4