That will be great!  Last time we were more aggressive about normalizing paths 
we caused a decent performance regression by normalizing all the paths every 
time we did a file-name compare for setting breakpoints.  If you look at 
FileSpec::Equal we added some "is it worth doing this work" preparatory work.  
I don't know where you'll find the additional places this needed to be done, 
but it's worth keeping an eye out for not putting GetNormalizedPath on a hot 
path.

Jim



> On Aug 28, 2017, at 1:19 AM, karnajit wangkhem <karnaj...@gmail.com> wrote:
> 
> Thanks Jim for the help. I would definitely like to work on this PR soon.
> 
> Filed the PR here
> https://bugs.llvm.org/show_bug.cgi?id=34341
> 
> Regards,
> Karan
> 
> On Thu, Aug 24, 2017 at 11:17 PM, Jim Ingham <jing...@apple.com> wrote:
> 
> > On Aug 24, 2017, at 10:06 AM, karnajit wangkhem <karnaj...@gmail.com> wrote:
> >
> > Hi Jim,
> >
> > Thanks for the valuable reply. Please find my comments inline.
> >
> > Regards,
> > Karan
> >
> > On Wed, Aug 23, 2017 at 12:32 AM, Jim Ingham <jing...@apple.com> wrote:
> >
> > > On Aug 21, 2017, at 12:02 PM, karnajit wangkhem via lldb-dev 
> > > <lldb-dev@lists.llvm.org> wrote:
> > >
> > > Hi All,
> > >
> > > Below is a sample example, where target.source-map seems to have a 
> > > limitation. The limitation seems to be because
> > > 1. lldb does not have an equivalent command like directory in gdb
> >
> > The gdb "dir" command seemed always to be more annoying than useful in real 
> > situations.  If your project had any complexity in the directory structure 
> > you ended up having to add dir commands for all the subdirectories, which 
> > got tedious quickly.  Since you pretty much always move your sources around 
> > rigidly, "source maps" are a more natural way to specify this.
> >
> > Note, we could add a recursive "dir" command, but you can't do the 
> > simpleminded recursive search or you'll mess up when the sources have same 
> > named files in different directories.  Because of this, again the source 
> > maps seem more suited.
> >
> >
> > -- Really a good info to know. Thanks!
> >
> > > 2. target.source-map does not accept multiple mapping entries. I checked 
> > > this only with freebsd.
> > >
> > > (lldb) settings show target.source-map
> > > target.source-map (path-map) =
> > > [0] "/home/karnajitw/lldb_test_execs/test_source_line1" -> 
> > > "/u/test/test_source_line1"
> >
> > That is not correct:
> >
> > (lldb) settings set target.source-map /some/source/path /tmp 
> > /some/other/source/path /tmp
> > (lldb) settings show target.source-map
> > target.source-map (path-map) =
> > [0] "/some/source/path" -> "/tmp"
> > [1] "/some/other/source/path" -> "/tmp"
> >
> > or
> >
> > (lldb) set set target.source-map /some/source/path /tmp
> > (lldb) set append target.source-map /some/other/source/path /tmp
> > (lldb) set show target.source-map
> > target.source-map (path-map) =
> > [0] "/some/source/path" -> "/tmp"
> > [1] "/some/other/source/path" -> "/tmp"
> >
> > - Thanks! This helped.
> >
> > >
> > > 3. Haven't checked in the code yet, but if we see the mappings of 
> > > scenario 1, they all point to a single real path 
> > > /home/karnajitw/lldb_test_execs/test_source_line1. But looks like the 
> > > mapping logic only considers strings into account. But, at the same time, 
> > > I am not claiming that they should be interpreted as path from a 
> > > different machine during the mapping.
> > >
> >
> > I'm not sure what you mean here.  lldb does what it can to unwind the 
> > source path, but it doesn't assume that those paths actually exist locally, 
> > so the most it can do is remove redundant "/"-s and "/./"-s and unwind 
> > ".."-s.  We do this before most source path comparisons (it's part of the 
> > FileSpec Equals method).  We've been tinkering with this over time so make 
> > sure you are using a recent version of lldb.  If there are places where we 
> > don't do this, then that's easily fixed.
> >
> >
> > - Your answer is in line with what I wanted to know. My lldb should be 
> > quite recent. But I used it only for freebsd currently.
> >
> > % ./lldb --version
> > lldb version 5.0.0 (http://llvm.org/svn/llvm-project/lldb/trunk revision 
> > 305778)
> >   clang revision 305546
> >   llvm revision 305548
> >
> >
> > > I want to check on this issue in-depth. But before that, want to confirm 
> > > if this is real issue or there are other ways to deal these scenarios 
> > > which I am not aware of?
> > >
> > > I am referring below link for the lldb commands.
> > > https://lldb.llvm.org/lldb-gdb.html
> > >
> > > 1. First scenario: Different souce file path representation
> > >
> > > [/home/karnajitw/lldb_test_execs/test_source_line1] $ clang -O0 -g 
> > > /home/karnajitw/lldb_test_execs///test_source_line1/main.c 
> > > /home/karnajitw/lldb_test_execs/../lldb_test_execs/test_source_line1/a/ainc.c
> > >  /home/karnajitw/lldb_test_execs/test_source_line1/a/b/binc.c
> > >
> > > Machine 1: /home/karnajitw/lldb_test_execs/test_source_line1 -> Machine 
> > > 2: /u/test/test_source_line1
> > >
> > > test_source_line1
> > > |-- a
> > > |   |-- ainc.c
> > > |   |-- ainc.h
> > > |   `-- b
> > > |       |-- binc.c
> > > |       `-- binc.h
> > > |-- a.out
> > > `-- main.c
> > >
> > > % ./lldb test_source_line1/a.out
> > >
> > > (lldb) target create "test_source_line1/a.out"
> > > Current executable set to 'test_source_line1/a.out' (x86_64).
> > > (lldb) l main
> > > File: /home/karnajitw/lldb_test_execs///test_source_line1/main.c
> > > (lldb) l afn
> > > File: 
> > > /home/karnajitw/lldb_test_execs/../lldb_test_execs/test_source_line1/a/ainc.c
> > > (lldb) l bfn
> > > File: /home/karnajitw/lldb_test_execs/test_source_line1/a/b/binc.c
> > >
> > > (lldb) settings set target.source-map 
> > > /home/karnajitw/lldb_test_execs///test_source_line1 
> > > /u/test/test_source_line1
> > >
> > > (lldb) l main
> > > File: /home/karnajitw/lldb_test_execs///test_source_line1/main.c
> > >    1    #include "a/ainc.h"
> > >    2
> > >    3    int main()
> > >    4    {
> > >    5      afn();
> > >    6
> > >    7      bfn();
> > >    8
> > >    9      return 0;
> > >    10   }
> > > (lldb) l afn
> > > File: 
> > > /home/karnajitw/lldb_test_execs/../lldb_test_execs/test_source_line1/a/ainc.c
> > > (lldb) l bfn
> > > File: /home/karnajitw/lldb_test_execs/test_source_line1/a/b/binc.c
> > >
> > > (lldb) settings set target.source-map 
> > > /home/karnajitw/lldb_test_execs/../lldb_test_execs/test_source_line1 
> > > /u/test/test_source_line1
> > >
> > > (lldb) l main
> > > File: /home/karnajitw/lldb_test_execs///test_source_line1/main.c
> > > (lldb) l afn
> > > File: 
> > > /home/karnajitw/lldb_test_execs/../lldb_test_execs/test_source_line1/a/ainc.c
> > >    1    #include <stdio.h>
> > >    2    #include "ainc.h"
> > >    3
> > >    4    void afn()
> > >    5    {
> > >    6      printf("Hello this is afn...\n");
> > >    7    }
> > > (lldb) l bfn
> > > File: /home/karnajitw/lldb_test_execs/test_source_line1/a/b/binc.c
> > >
> > > (lldb) settings set target.source-map 
> > > /home/karnajitw/lldb_test_execs/test_source_line1 
> > > /u/test/test_source_line1
> > >
> > > (lldb) l main
> > > File: /home/karnajitw/lldb_test_execs///test_source_line1/main.c
> > > (lldb) l afn
> > > File: 
> > > /home/karnajitw/lldb_test_execs/../lldb_test_execs/test_source_line1/a/ainc.c
> > > (lldb) l bfn
> > > File: /home/karnajitw/lldb_test_execs/test_source_line1/a/b/binc.c
> > >    1    #include <stdio.h>
> > >    2    #include "binc.h"
> > >    3
> > >    4    void bfn()
> > >    5    {
> > >    6      printf("Hello this is bfn...\n");
> > >    7    }
> >
> > I can't test the "///" part of this, clang seems to always collapse these 
> > for me.  But with a recent lldb, I see:
> >
> > $ clang -g -O0 -c '/tmp/sources/build/../files/hello.c'
> > $ dwarfdump hello.o
> > ...
> > 0x0000000b: TAG_compile_unit [1] *
> >              AT_producer( "Apple LLVM version 9.0.0 (clang-900.0.31)" )
> >              AT_language( DW_LANG_C99 )
> >              AT_name( "/tmp/sources/build/../files/hello.c" )
> >
> > So we did get a compile unit name with .. in it, but:
> >
> > lldbrulez:/tmp/sources/build > clang -g -O0 -o hello hello.o
> > lldbrulez:/tmp/sources/build > lldb
> > (lldb) file hello
> > Current executable set to 'hello' (x86_64).
> > (lldb) source list -n main
> > File: /tmp/sources/build/../files/hello.c
> >    1    #include <stdio.h>
> >    2
> >    3    int
> >    4    main()
> >    5    {
> >    6      printf ("Hello there.\n");
> >    7      return 0;
> >    8    }
> >
> > So we do unwind the ..'s in this case.  This example doesn't have 
> > source-maps, but the same thing works if I move the sources and add just a 
> > <build-top> -> <debug-top> mapping.  As I say, we have been working these 
> > ".." aware comparisons through all the file compares recently, so you may 
> > just need to get a newer lldb.
> >
> > - Lets say in my above example, the function is this way
> > main -> afn  -> bfn
> >
> > Now, I breakpoint on bfn, now to get source list on all the 3 frames, I 
> > will need this below mapping
> >
> > (lldb)
> > target.source-map (path-map) =
> > [0] "/home/karnajitw/lldb_test_execs///test_source_line1" -> 
> > "/u/test/test_source_line1"
> > [1] "/home/karnajitw/lldb_test_execs/../lldb_test_execs/test_source_line1" 
> > -> "/u/test/test_source_line1"
> > [2] "/home/karnajitw/lldb_test_execs/test_source_line1" -> 
> > "/u/test/test_source_line1"
> >
> > Like the previous discussion, All the LHS and RHS actually refers to the 
> > same path. So why we need 3 mappings here? But, as I have mentioned 
> > previously the problem could be just in the freebsd version also.
> >
> >
> > >
> > > 2. Scenario 2: Deep directory structure
> > >
> > > <top>/obj/a/b/c/d/e/app/sub/../../../../../../../../src/a/b/c/d/e/app/sub/file
> > > <top>/obj/a/b/c/d/e/app/../../../../../../../src/a/b/c/d/e/app/file
> > >
> > > - If we carry the copy the source file to machine 2, we cannot easily map 
> > > the source file without creating dummy <top>/obj/a/b/c/d/e/f/g.
> > >
> > You should only need to map <top> to <top>.  The only reason you would have 
> > to start specifying subdirectories is you have ones specified with ".."-s, 
> > but that problem is properly handled by making the file comparisons aware 
> > of backup operators.  So if the comparisons are working right (again check 
> > a more recent lldb) you should not need to deal with all these dots.
> >
> >
> > - Checked with latest lldb build, its the same
> >
> > (lldb) version
> > lldb version 6.0.0 (http://llvm.org/svn/llvm-project/lldb/trunk revision 
> > 311075)
> >   clang revision 311072
> >   llvm revision 311071
> >
> > $ build/bin/lldb a.out
> > (lldb) target create "a.out"
> > Current executable set to 'a.out' (x86_64).
> > (lldb) settings set target.source-map 
> > /home/karnajitw/lldbtest/obj/a/b/c/d/e/app/../../../../../../../src/a/b/c/d/e/app
> >  /home/karnajitw/app
> > (lldb) l main
> > File: 
> > /home/karnajitw/lldbtest/obj/a/b/c/d/e/app/../../../../../../../src/a/b/c/d/e/app/main.c
> >    1    #include "sub/subfile.h"
> >    2
> >    3    int main()
> >    4    {
> >    5      subfn();
> >    6
> >    7      return 0;
> >    8    }
> >    9
> > (lldb) l subfn
> > File: 
> > /home/karnajitw/lldbtest/obj/a/b/c/d/e/app/sub/../../../../../../../../src/a/b/c/d/e/app/sub/subfile.c
> > (lldb) settings append target.source-map 
> > /home/karnajitw/lldbtest/obj/a/b/c/d/e/app/sub/../../../../../../../../src/a/b/c/d/e/app
> >  /home/karnajitw/app
> > (lldb) l subfn
> > File: 
> > /home/karnajitw/lldbtest/obj/a/b/c/d/e/app/sub/../../../../../../../../src/a/b/c/d/e/app/sub/subfile.c
> >    1    #include <stdio.h>
> >    2    #include "subfile.h"
> >    3
> >    4    void subfn()
> >    5    {
> >    6      printf("This is subfn...\n");
> >    7    }
> >    8
> >
> > It still needs both the mappings
> > (lldb) settings show target.source-map
> > target.source-map (path-map) =
> > [0] 
> > "/home/karnajitw/lldbtest/obj/a/b/c/d/e/app/../../../../../../../src/a/b/c/d/e/app"
> >  -> "/home/karnajitw/app"
> > [1] 
> > "/home/karnajitw/lldbtest/obj/a/b/c/d/e/app/sub/../../../../../../../../src/a/b/c/d/e/app"
> >  -> "/home/karnajitw/app"
> 
> That does seem wrong.  Please file a PR about this.
> 
> There's a method in FileSpec (GetNormalizedPath) that canonicalizes paths by 
> doing the obvious text substitution (unwinding ..'s and removing /./ and /// 
> -> /, etc.)  Somewhere in the comparison of the source and build paths we 
> aren't using this when we should do.  There's also a FileSpec::Equal method 
> that allows a canonicalized comparison.  It might be that there's just some 
> obvious place we should have been using that.
> 
> I'm in the middle of something else right now, but if you have some time to 
> dig into this, it would probably be straightforward to track down where we 
> aren't using the right comparison.  But if there's a PR, then even if you 
> don't have time, somebody else will get to the PR when they have a chance.
> 
> Thanks for chasing this down!
> 
> Jim
> 
> 
> 
> >
> >
> > > 3. Scenario 3: External libraries
> > > - I haven't exactly tested this yet. But I belive in scenario too we 
> > > might need to change the source-map.
> >
> > External libraries should be no different from your project.  I don't see 
> > anything different needed here.
> >
> >
> > - Agreed.
> >
> > Jim
> >
> >
> > >
> > > Please look into this and guide me for the same.
> > >
> > > Regards,
> > > Karan
> > > _______________________________________________
> > > lldb-dev mailing list
> > > lldb-dev@lists.llvm.org
> > > http://lists.llvm.org/cgi-bin/mailman/listinfo/lldb-dev
> 
> 

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