Re: [PATCH] -fdump-tree, -save-temps=obj & subdirs

[Jeff Law <law at redhat dot com>]

On 12/07/2017 05:10 AM, Nathan Sidwell wrote:
> There's an unfortunate interaction between -save-temps=obj and
> -fdump-tree-<whatever> when subdirectories are in play.
> 
> Consider:
>   g++ -fdump-tree-all -save-temps=obj -c -o tgt/x.o sub/x.cc
> we end up with a bunch of errors of the form:
>  sub/x.cc:1:0: error: could not open dump file
> ‘tgt/tgt/x.046t.profile_estimate’: No such file or directory
> 
> you'll see it's added the 'tgt' sub directory twice.  The reason is that
> cc1plus is invoked as:
> 
>  /usr/libexec/gcc/x86_64-redhat-linux/7/cc1plus -E -quiet -v
> -D_GNU_SOURCE sub/x.cc -mtune=generic -march=x86-64 -ansi
> -Woverloaded-virtual -Wall -Wpointer-arith -Wwrite-strings
> -felide-constructors -fdump-tree-all -fpch-preprocess -o tgt/x.ii
> 
> to generate the preprocessed output, and then as:
> 
>  /usr/libexec/gcc/x86_64-redhat-linux/7/cc1plus -fpreprocessed tgt/x.ii
> -quiet -dumpbase tgt/x -mtune=generic -march=x86-64 -auxbase-strip
> tgt/x.o -Woverloaded-virtual -Wall -Wpointer-arith -Wwrite-strings -ansi
> -version -felide-constructors -fdump-tree-all -o tgt/x.s
> 
> for the compilation itself.  That has '-dumpbase tgt/x' and
> '-auxbase-strip tgt/x.o' passed in.
> 
> The options processing checks if dump-base is absolute, and if not
> prefixes dump_dir_name or aux_base_name's directory components.
> 
> It seems to me that the absolute path check is incomplete.  We should
> check if dump-base has /any/ directory components.  If it does, we
> shouldn't touch it.  That's what this patch does:
> 
> 1) remove the absolute dir check.  That's subsumed into ...
> 2) look for any DIR_SEPARATOR in the dump-base.  If so, no prefixing
> 3 & 4) existing prefix code
> 5) always set dump_base_name_prefixed, so we don't repeat #2 on a
> subsequent invocation.
> 
> With this patch we now get a successful compilation:
> 
> nathans@lyta:7>egcs/trunk/obj/x86_64/gcc/xg++ -B
> egcs/trunk/obj/x86_64/gcc/ -fdump-tree-all -save-temps=obj -c -o tgt/x.o
> sub/x.cc
> nathans@lyta:8>ls tgt
> total 100
> 4 x.003t.original  4 x.010t.eh              4 x.020t.ssa             4
> x.049t.release_ssa    4 x.220t.switchlower  4 x.o
> 4 x.004t.gimple    4 x.011t.cfg              4 x.027t.fixup_cfg3        
> 4 x.050t.local-fnsummary2    4 x.226t.resx          4 x.s
> 4 x.006t.omplower  4 x.012t.ompexp          4 x.028t.local-fnsummary1  4
> x.087t.fixup_cfg4    4 x.228t.optimized
> 4 x.007t.lower       4 x.013t.printf-return-value1  4
> x.029t.einline         4 x.218t.veclower        0 x.313t.statistics
> 4 x.009t.ehopt       4 x.019t.fixup_cfg1          0
> x.046t.profile_estimate  4 x.219t.cplxlower0    4 x.ii
> 
> ok?
> 
> nathan
> -- 
> Nathan Sidwell
> 
> pfx.diff
> 
> 
> 2017-12-06  Nathan Sidwell  <nathan@acm.org>
> 
> 	* opts.c (finish_options): Don't prefix dump_base_name if it
> 	already contains directories.
OK.
jeff