[flang-commits] [flang] [llvm] [flang][cuda] Fix CUDA Fortran device-variable memory leaks, and allow `cudaDeviceReset()` before program end (PR #207843)

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github-actions[bot] wrote:

<!--PREMERGE ADVISOR COMMENT: Windows-->
# :window: Windows x64 Test Results

* 4525 tests passed
* 250 tests skipped
* 1 test failed

## Failed Tests
(click on a test name to see its output)

### Flang
<details>
<summary>Flang.Lower/CUDA/cuda-return02.cuf</summary>

```
Exit Code: 1

Command Output (stdout):
--
# RUN: at line 1
c:\_work\llvm-project\llvm-project\build\bin\bbc.exe -fintrinsic-modules-path=C:\_work\llvm-project\llvm-project\build\lib\clang\24\finclude\flang\x86_64-pc-windows-msvc -emit-hlfir -fcuda C:\_work\llvm-project\llvm-project\flang\test\Lower\CUDA\cuda-return02.cuf -o - | c:\_work\llvm-project\llvm-project\build\bin\filecheck.exe C:\_work\llvm-project\llvm-project\flang\test\Lower\CUDA\cuda-return02.cuf
# executed command: 'c:\_work\llvm-project\llvm-project\build\bin\bbc.exe' '-fintrinsic-modules-path=C:\_work\llvm-project\llvm-project\build\lib\clang\24\finclude\flang\x86_64-pc-windows-msvc' -emit-hlfir -fcuda 'C:\_work\llvm-project\llvm-project\flang\test\Lower\CUDA\cuda-return02.cuf' -o -
# note: command had no output on stdout or stderr
# executed command: 'c:\_work\llvm-project\llvm-project\build\bin\filecheck.exe' 'C:\_work\llvm-project\llvm-project\flang\test\Lower\CUDA\cuda-return02.cuf'
# .---command stderr------------
# | C:\_work\llvm-project\llvm-project\flang\test\Lower\CUDA\cuda-return02.cuf:20:15: error: CHECK-NEXT: is not on the line after the previous match
# | ! CHECK-NEXT: cuf.free %[[DECL]]#0 : !fir.ref<!fir.array<10xi32>>
# |               ^
# | <stdin>:16:2: note: 'next' match was here
# |  cuf.free %3#0 : !fir.ref<!fir.array<10xi32>> {data_attr = #cuf.cuda<device>}
# |  ^
# | <stdin>:13:7: note: previous match ended here
# |  ^bb1: // pred: ^bb0
# |       ^
# | <stdin>:14:1: note: non-matching line after previous match is here
# |  %8 = fir.call @_FortranACUFDeviceIsActive() fastmath<contract> : () -> i1
# | ^
# | 
# | Input file: <stdin>
# | Check file: C:\_work\llvm-project\llvm-project\flang\test\Lower\CUDA\cuda-return02.cuf
# | 
# | -dump-input=help explains the following input dump.
# | 
# | Input was:
# | <<<<<<
# |            .
# |            .
# |            .
# |            8:  %4 = fir.alloca !fir.logical<4> {bindc_name = "l", uniq_name = "_QFEl"} 
# |            9:  %5:2 = hlfir.declare %4 {uniq_name = "_QFEl"} : (!fir.ref<!fir.logical<4>>) -> (!fir.ref<!fir.logical<4>>, !fir.ref<!fir.logical<4>>) 
# |           10:  %6 = fir.load %5#0 : !fir.ref<!fir.logical<4>> 
# |           11:  %7 = fir.convert %6 : (!fir.logical<4>) -> i1 
# |           12:  cf.cond_br %7, ^bb1, ^bb2 
# |           13:  ^bb1: // pred: ^bb0 
# | next:20'0          {                 search range start (exclusive)
# |           14:  %8 = fir.call @_FortranACUFDeviceIsActive() fastmath<contract> : () -> i1 
# |           15:  fir.if %8 { 
# |           16:  cuf.free %3#0 : !fir.ref<!fir.array<10xi32>> {data_attr = #cuf.cuda<device>} 
# | next:20'1      !~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~                                   error: match on wrong line
# |           17:  } 
# |           18:  return 
# |           19:  ^bb2: // pred: ^bb0 
# |           20:  %9 = fir.call @_FortranACUFDeviceIsActive() fastmath<contract> : () -> i1 
# |           21:  fir.if %9 { 
# |            .
# |            .
# |            .
# |           55:  %c0_i32 = arith.constant 0 : i32 
# |           56:  fir.call @_FortranAProgramEndStatement() fastmath<contract> : () -> () 
# |           57:  return %c0_i32 : i32 
# |           58:  } 
# |           59:  func.func private @_FortranACUFInit() 
# |           60: } 
# | next:20'2       } search range end (exclusive)
# | >>>>>>
# `-----------------------------
# error: command failed with exit status: 1

--

```
</details>

If these failures are unrelated to your changes (for example tests are broken or flaky at HEAD), please open an issue at https://github.com/llvm/llvm-project/issues and add the `infrastructure` label.

https://github.com/llvm/llvm-project/pull/207843