[Gdb] Debugging Symbols Question

[Vickie Eigel-Danielson]

Hi all.  I am a GDB novice developing embedded ARM software using a host i686 Linux PC and the GNU tool chain.  For some reason when I cross-compile my embedded program on the PC and link it with the ARM C run-time library (which was apparently compiled without debugging symbols) I get a bunch of bogus symbols in my minimal symbol table.  The bogus symbols are all compiler-generated line labels for my source files such as “L2” and “L5”. 

 

The problem I am having is as follows:

 

for ( i = 0; i < nLoops; i++ )

{

   printf( “%d\n”, i );

}

 

This source code generates a line label (“L5”) for the line that contains the printf() call.  Upon return from the call to printf(), the GDB function find_pc_sect_partial_function() looks the current PC value up both in the symbol table and in the minimal symbol table.  In my case, the symbol table says that the PC is in the function “main” (which is correct) but the minimal symbol table says that the PC is in the function “L5” (which is incorrect).  GDB compares the addresses for the conflicting “functions” and chooses “L5”!  Yikes!  Things go steadily downhill from there as GDB proceeds to execute the “prologue” at the address of “L5”…

 

My question is: why/how are these bogus symbols being added to my minimal symbol table?  I have temporarily “patched” this problem by hacking my copy of dbxread.c so that the function record_minimal_symbol() refuses to record any mst_file_text symbols!  Rut-Row George!  Obviously, this “solution” worries me greatly.

 

Thanks,

 

Vickie