Bug 16576 - mcs does not handle relative #line filenames
Summary: mcs does not handle relative #line filenames
Alias: None
Product: Compilers
Classification: Mono
Component: C# ()
Version: unspecified
Hardware: PC Mac OS
: --- normal
Target Milestone: ---
Assignee: Marek Safar
Depends on:
Reported: 2013-12-03 17:25 UTC by Mikayla Hutchinson [MSFT]
Modified: 2013-12-09 08:41 UTC (History)
1 user (show)

Is this bug a regression?: ---
Last known good build:

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Description Mikayla Hutchinson [MSFT] 2013-12-03 17:25:45 UTC
mcs does not handle relative #line filenames, csc does

For example in the following project layout:


Both the following directives in the file Bar.cs work fine in csc and are resolved to correct absolute paths in the build output and the debug symbols:

#line 1 "B.cs"
#line 1 "../A.cs"

However, mcs outputs them verbatim and thus they do not work correctly.
Comment 1 Mikayla Hutchinson [MSFT] 2013-12-03 17:33:39 UTC
By "build output" I mean file/line info in build errors.

VS somehow screws this up, probably the in-process compiler - it ends up with two near-identical versions of each error, one with the verbatim paths and one with the correct path. But csc and msbuild work fine.
Comment 2 Mikayla Hutchinson [MSFT] 2013-12-03 17:35:03 UTC
I would like this to be able to generate razor / t4 output that does not contain machine/user-specific paths, since they output files are always checked into source control.
Comment 3 Mikayla Hutchinson [MSFT] 2013-12-03 17:58:29 UTC
Okay, looks like mcs generates correct debug info but incorrect build output.
Comment 4 Marek Safar 2013-12-05 14:07:30 UTC
Do you need this for error/warning messages? There is command line option /fullpaths which does it.
Comment 5 Mikayla Hutchinson [MSFT] 2013-12-05 17:50:06 UTC
I guess I would work around it with /fullpaths, but it's still an issue of compat. csc works fine without the option, mcs does not.
Comment 6 Marek Safar 2013-12-06 07:37:57 UTC
I don't see any reason why pollute error message with full source path. If you need it just use the option for it.
Comment 7 Mikayla Hutchinson [MSFT] 2013-12-06 17:54:56 UTC
I'm not asking for the full path. I'm asking for the CORRECT relative path.

If I have a file Foo/Bar.cs, errors are reported in Foo/Bar.cs. If it includes #line 1 "Baz.t4", mcs reports errors in Baz.t4 (which is useless), csc reports errors in Foo/Baz.t4 (which is useful).
Comment 8 Marek Safar 2013-12-09 08:41:31 UTC
Fixed in master