On 6/30/21 11:53 PM, Sandra Loosemore wrote:
> For the past several months I've been working on developing a set of 
> tests for the Fortran/C interoperability features added to Fortran via 
> TS 29113, "Further Interoperability of Fortran with C":
> 
> https://wg5-fortran.org/N1901-N1950/N1942.pdf
> 
> The goal here is to exercise gfortran's implementation in a more 
> systematic and complete way, including conformance with error detection 
> requirements and the like as well as making sure correct programs run 
> correctly.
> 
> I'm posting this as work-in-progress at this time because, well, there 
> are a lot of bugs in the implementation causing lots of the tests to 
> fail.  :-(  I know maintainers don't like patches that deliberately add 
> FAILs to the test results and the normal practice seems to be to XFAIL 
> known bugs with references to a PR.  Some of the bugs already have PRs 
> open, but others don't.  What I plan to work on next is filing or 
> updating the PRs with reference to the testcases that demonstrate the 
> bugs, add the XFAILs, and then resubmit the patch for approval.  A few 
> of these tests also still have some excessively verbose debugging output 
> enabled which I'll also try to clean up before resubmitting.
> 
> I have a trivial patch for one set of failures (incorrect initialization 
> of version fields) that I'll be posting shortly.  A couple of José's 
> recent not-yet-committed patches also fix some of the bugs I've run 
> into; I will note those in the corresponding PRs as I work through the 
> list.

Here's the patch for the cleaned-up testsuite with xfails added. 
Besides disabling the more verbose output, I fixed some issues with 
comments and whitespace.

This is the list of issues I've tagged for the failing tests:

PR 54753
   assumed-rank dummies: Reject assumed-size actuals in in some cases
   (C535c; in F2018: C839)

PR 92482
   BIND(C) with array-descriptor mishandled for type character

PR 92621
   Problems with memory handling with allocatable intent(out) arrays
   with bind(c)

PR 93308
   bind(c) subroutine changes lower bound of array argument in caller

PR 94070
   Assumed-rank arrays – bounds mishandled, SIZE/SHAPE/UBOUND/LBOUND

PR 101304
   Bind(C): CONTIGUOUS attribute not handled correctly in Fortran routines
   called from C with discontiguous argument

PR 101305
   Bind(C): Problems with incorrect kinds/sizes in ISO_Fortran_binding.h
   and CFI_establish

PR 101308
   Bind(C): gfortran does not create C descriptors for scalar
   pointer/allocatable arguments

PR 101309
   Bind(C): gfortran creates invalid C descriptor for result of TRANSPOSE
   intrinsic

PR 101310
   Bind(C): CFI_section seems confused by pointer arrays

PR 101317
   Bind(C): improve error checking in CFI_* functions declared in
   ISO_Fortran_binding.h

PR 101319
   Missing diagnostic for argument with type parameters for assumed-type 
dummy

PR 101320
   Bind(C): Missing diagnostic for constraint C1557 on allocatable/pointer
   arguments

PR 101333
   gfortran fails to enforce C711 on assumed-type actual arguments

PR 101334
   gfortran fails to enforce C838 on disallowed uses of assumed-rank
   variable names + bogus errors

PR 101337
   gfortran doesn't diagnose all operands with constraint violations

There was a question in one of the issues about why this testsuite 
references TS29113 instead of the 2018 standard.  Well, that is what our 
customer is interested in: finding out what parts of the TS29113 
functionality remain unimplemented or broken, and fixing them, so that 
gfortran can say that it implements that specification.

I tested on both x86_64-linux-gnu and i686-pc-linux-gnu (32-bit), and 
verified that there are no FAILing tests left, just ~300 new XFAILs.

OK to check in?

-Sandra