[Crash-utility] [PATCH v2] struct: Allow -r with a single member-specific output

[Dave Anderson]

----- Original Message -----
> Using struct -r allows much faster execution when iterating through a file;
> on 3909 elements struct struct.member takes 192s vs. 3s with -r
> ---
> Sorry for the delay, here's another take at allowing struct -r with a
> specific field specified.
> 
> I didn't post that v2 back in Feb because I wasn't totally happy with
> it; I can't say I now am but might as well get your take on it...

What part of this patch aren't you happy about?

Dave




> Thanks!
> 
>  defs.h    |  2 ++
>  symbols.c | 69 ++++++++++++++++++++++++++++++++++++++++++++++++-------
>  2 files changed, 63 insertions(+), 8 deletions(-)
> 
> diff --git a/defs.h b/defs.h
> index e852ddf..a3f828d 100644
> --- a/defs.h
> +++ b/defs.h
> @@ -2283,6 +2283,7 @@ struct array_table {
>  #define MEMBER_TYPE_REQUEST ((struct datatype_member *)(-3))
>  #define STRUCT_SIZE_REQUEST ((struct datatype_member *)(-4))
>  #define MEMBER_TYPE_NAME_REQUEST ((struct datatype_member *)(-5))
> +#define ANON_MEMBER_SIZE_REQUEST ((struct datatype_member *)(-6))
>  
>  #define STRUCT_SIZE(X)      datatype_info((X), NULL, STRUCT_SIZE_REQUEST)
>  #define UNION_SIZE(X)       datatype_info((X), NULL, STRUCT_SIZE_REQUEST)
> @@ -2294,6 +2295,7 @@ struct array_table {
>  #define MEMBER_TYPE(X,Y)    datatype_info((X), (Y), MEMBER_TYPE_REQUEST)
>  #define MEMBER_TYPE_NAME(X,Y)    ((char *)datatype_info((X), (Y),
>  MEMBER_TYPE_NAME_REQUEST))
>  #define ANON_MEMBER_OFFSET(X,Y)    datatype_info((X), (Y),
>  ANON_MEMBER_OFFSET_REQUEST)
> +#define ANON_MEMBER_SIZE(X,Y)    datatype_info((X), (Y),
> ANON_MEMBER_SIZE_REQUEST)
>  
>  /*
>   *  The following set of macros can only be used with pre-intialized fields
> diff --git a/symbols.c b/symbols.c
> index 9c3032d..b32e480 100644
> --- a/symbols.c
> +++ b/symbols.c
> @@ -145,6 +145,7 @@ static void print_union(char *, ulong);
>  static void dump_datatype_member(FILE *, struct datatype_member *);
>  static void dump_datatype_flags(ulong, FILE *);
>  static long anon_member_offset(char *, char *);
> +static long anon_member_size(char *, char *);
>  static int gdb_whatis(char *);
>  static void do_datatype_declaration(struct datatype_member *, ulong);
>  static int member_to_datatype(char *, struct datatype_member *, ulong);
> @@ -5604,14 +5605,17 @@ long
>  datatype_info(char *name, char *member, struct datatype_member *dm)
>  {
>  	struct gnu_request *req;
> -        long offset, size, member_size;
> +	long offset, size, member_size;
>  	int member_typecode;
> -        ulong type_found;
> +	ulong type_found;
>  	char buf[BUFSIZE];
>  
> -        if (dm == ANON_MEMBER_OFFSET_REQUEST)
> +	if (dm == ANON_MEMBER_OFFSET_REQUEST)
>  		return anon_member_offset(name, member);
>  
> +	if (dm == ANON_MEMBER_SIZE_REQUEST)
> +		return anon_member_size(name, member);
> +
>  	strcpy(buf, name);
>  
>  	req = (struct gnu_request *)GETBUF(sizeof(struct gnu_request));
> @@ -5828,6 +5832,46 @@ retry:
>  	return value;
>  }
>  
> +/*
> + *  Determine the size of a member in an anonymous union
> + *  in a structure or union.
> + */
> +static long
> +anon_member_size(char *name, char *member)
> +{
> +	char buf[BUFSIZE];
> +	ulong value;
> +	int type;
> +
> +	value = -1;
> +	type = STRUCT_REQUEST;
> +	sprintf(buf, "printf \"%%ld\", (u64)(&((struct %s*)0)->%s + 1) -
> (u64)&((struct %s*)0)->%s",
> +		name, member, name, member);
> +	open_tmpfile2();
> +retry:
> +	if (gdb_pass_through(buf, pc->tmpfile2, GNU_RETURN_ON_ERROR)) {
> +		rewind(pc->tmpfile2);
> +		if (fgets(buf, BUFSIZE, pc->tmpfile2)) {
> +			if (hexadecimal(buf, 0))
> +				value = htol(buf, RETURN_ON_ERROR|QUIET, NULL);
> +			else if (STRNEQ(buf, "(nil)"))
> +				value = 0;
> +		}
> +	}
> +
> +	if ((value == -1) && (type == STRUCT_REQUEST)) {
> +		type = UNION_REQUEST;
> +		sprintf(buf, "printf \"%%ld\", (u64)(&((union %s*)0)->%s + 1) -
> (u64)&((union %s*)0)->%s",
> +			name, member, name, member);
> +		rewind(pc->tmpfile2);
> +		goto retry;
> +	}
> +
> +	close_tmpfile2();
> +
> +	return value;
> +}
> +
>  /*
>   *  Get the basic type info for a symbol.  Let the caller pass in the
>   *  gnu_request structure to have access to the full response; in either
> @@ -6617,6 +6661,9 @@ do_datatype_addr(struct datatype_member *dm, ulong
> addr, int count,
>  		i = 0;
>          	do {
>                  	if (argc_members) {
> +				if (argc_members > 1 && flags & SHOW_RAW_DATA)
> +					error(FATAL,
> +					      "only up to one member-specific output allowed with -r\n");
>  				/* This call works fine with fields
>  				 * of the second, third, ... levels.
>  				 * There is no need to fix it
> @@ -6625,9 +6672,6 @@ do_datatype_addr(struct datatype_member *dm, ulong
> addr, int count,
>  							ANON_MEMBER_QUERY))
>  					error(FATAL, "invalid data structure reference: %s.%s\n",
>  					      dm->name, memberlist[i]);
> -				if (flags & SHOW_RAW_DATA)
> -        				error(FATAL,
> -					      "member-specific output not allowed with -r\n");
>  			}
>  
>  			/*
> @@ -6636,9 +6680,18 @@ do_datatype_addr(struct datatype_member *dm, ulong
> addr, int count,
>  			if (flags & SHOW_OFFSET) {
>  				dm->vaddr = addr;
>  				do_datatype_declaration(dm, flags | (dm->flags & TYPEDEF));
> -			} else if (flags & SHOW_RAW_DATA)
> +			} else if (flags & SHOW_RAW_DATA) {
> +				if (dm->member) {
> +					addr += dm->member_offset;
> +					len = MEMBER_SIZE(dm->name, dm->member);
> +					if (len < 0)
> +						len = ANON_MEMBER_SIZE(dm->name, dm->member);
> +					if (len < 0)
> +						error(FATAL, "invalid data structure reference: %s.%s\n",
> +						      dm->name, dm->member);
> +				}
>  				raw_data_dump(addr, len, flags & STRUCT_VERBOSE);
> -			else if ((flags & DEREF_POINTERS) && !dm->member) {
> +			} else if ((flags & DEREF_POINTERS) && !dm->member) {
>  				print_struct_with_dereference(addr, dm, flags);
>                  	} else {
>  	                        if (dm->member)
> --
> 2.26.0
> 
> 
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