LIBDWARF How to obtain die attributes .....

webquinty · 10-31-2012, 04:37 AM

Hello,

I would like to make a small version of dwarfdump to obtain the desired debug information of process.

libdwarf has a example called "simplereader" to read dwarf information but I have not enought information about how to make it.

For example:
dwarfdump give me this information......

Quote:

< 1><0x000000b9> DW_TAG_base_type
DW_AT_byte_size 0x00000004
DW_AT_encoding DW_ATE_float
DW_AT_name "float"

And simplereader example return me the follow line....

Quote:

<1> tag: 36 DW_TAG_base_type name: "float"

How can I obtain, for example byte size?

Other example...

Quote:

< 1><0x00001523> DW_TAG_variable
DW_AT_name "INDEX_TXPDO"
DW_AT_decl_file 0x0000000a
DW_AT_decl_line 0x00000011
DW_AT_type <0x00001513>
DW_AT_external yes(1)
DW_AT_location DW_OP_addr 0x08171e40

And simplereader return me.......

Quote:

<1> tag: 52 DW_TAG_variable name: "INDEX_TXPDO"

How can I obtain name, type and location??

Best regards
John Martin.

webquinty · 11-02-2012, 09:47 AM

Hello,

I know that the question is somewhat general and I apologize for that.

I would like to change my question for better one.
I have make some test with gdb, but i would like to use it in my process ( write a piece of code inside my own process, for example, to request a value of some vars ).

is it posible to do it?
For example in gdb, if i print "p myvar" return me a value.
Could I execute this command inside a C programm and capture value?

Best regards
John Martin.