Re: [PATCH 3/8] Add support for non-contiguous blocks to find_pc_partial_function

[Kevin Buettner <kevinb@redhat.com>]

On Tue, 31 Jul 2018 21:59:57 -0400
Simon Marchi <simon.marchi@ericsson.com> wrote:

> >  int
> >  find_pc_partial_function (CORE_ADDR pc, const char **name, CORE_ADDR *address,
> > -			  CORE_ADDR *endaddr)
> > +			  CORE_ADDR *endaddr, const struct block **block)
> >  {
> >    struct obj_section *section;
> >    struct symbol *f;
> > @@ -232,13 +223,37 @@ find_pc_partial_function (CORE_ADDR pc, const char **name, CORE_ADDR *address,
> >        f = find_pc_sect_function (mapped_pc, section);
> >        if (f != NULL
> >  	  && (msymbol.minsym == NULL
> > -	      || (BLOCK_START (SYMBOL_BLOCK_VALUE (f))
> > +	      || (BLOCK_ENTRY_PC (SYMBOL_BLOCK_VALUE (f))  
> 
> I don't understand this change, can you explain it briefly?
> 
> >  		  >= BMSYMBOL_VALUE_ADDRESS (msymbol))))  
> >  	{

A function's minimal symbol generally (maybe even always) refers to
the entry pc.  Therefore, we want to compare the block's entry pc to
the minimal symbol address instead of the block start - which might
not be the same as the entry pc.  BLOCK_START will refer to the lowest
address in all of the ranges.

I'll add a comment to the code explaining this.

Kevin