[gcc/devel/rust/master] 'gcc/testsuite/rust/link/link.exp': Fix 'runtest_file_p' usage

[gcc/devel/rust/master] 'gcc/testsuite/rust/link/link.exp': Fix 'runtest_file_p' usage

[Thomas Schwinge]

https://gcc.gnu.org/g:51f03d9d697b0f3fed65f85e88ce41d424c844fb

commit 51f03d9d697b0f3fed65f85e88ce41d424c844fb
Author: Thomas Schwinge <thomas@codesourcery.com>
Date:   Wed Jul 20 12:03:39 2022 +0200

    'gcc/testsuite/rust/link/link.exp': Fix 'runtest_file_p' usage
    
    The recent commit 418aef1b006182e84266dcf4f31ee721ed04301a
    "Support extern crate" (merged in
    commit fd2bd659e44e5b7fea92bc34a4864f057f387490 "Merge #1362"), added
    'gcc/testsuite/rust/link/link.exp', which I understand to be a hacked up
    variant of the LTO multi-file testing harness (not reviewed in detail).
    
    Since that commit, there are issues in parallel testing, so that, for example
    with:
    
        $ make -j12 check-rust RUNTESTFLAGS='--target_board=unix\{,-m32,-mx32\}'
    
    ..., the first variant does test as expected:
    
        @@ -6490,9 +6490,31 @@ PASS: rust/execute/torture/trait9.rs   -Os   at line 13 (test for warnings, line
         PASS: rust/execute/torture/trait9.rs   -Os  (test for excess errors)
         PASS: rust/execute/torture/trait9.rs   -Os  execution test
         PASS: rust/execute/torture/trait9.rs   -Os  output pattern test
        +Running /home/thomas/tmp/source/gcc/rust/build/trace-slim/source-gcc/gcc/testsuite/rust/link/link.exp ...
        +PASS: rust/link/generic_function_0.rs   -O0  (test for excess errors)
        +[...]
        +PASS: rust/link/trait_import_0.rs   -Os  (test for excess errors)
                        === rust Summary for unix ===
    
        -# of expected passes           6445
        +# of expected passes           6466
         # of expected failures         31
    
    ..., but we then get undesired changes for the second and following variants:
    
         Running target unix/-m32
         Running /home/thomas/tmp/source/gcc/rust/build/trace-slim/source-gcc/gcc/testsuite/rust/compile/compile.exp ...
         PASS: rust/compile/abi-options1.rs  at line 2 (test for errors, line 1)
         PASS: rust/compile/abi-options1.rs  at line 7 (test for errors, line 6)
         PASS: rust/compile/abi-options1.rs (test for excess errors)
        -PASS: rust/compile/array3.rs  at line 2 (test for warnings, line 1)
        -PASS: rust/compile/array3.rs (test for excess errors)
        -PASS: rust/compile/array_empty_list.rs  at line 3 (test for errors, line 2)
        -PASS: rust/compile/array_empty_list.rs (test for excess errors)
        -PASS: rust/compile/arrays1.rs  (test for errors, line 3)
        -PASS: rust/compile/arrays1.rs (test for excess errors)
         PASS: rust/compile/arrays2.rs  at line 4 (test for errors, line 3)
         PASS: rust/compile/arrays2.rs (test for excess errors)
         PASS: rust/compile/attr-mismatch-crate-name.rs (test for excess errors)
        @@ -8355,110 +8371,215 @@ PASS: rust/compile/torture/generics17.rs   -O3 -g  (test for excess errors)
         PASS: rust/compile/torture/generics17.rs   -Os   at line 18 (test for warnings, line 17)
         PASS: rust/compile/torture/generics17.rs   -Os  (test for excess errors)
         PASS: rust/compile/torture/generics18.rs   -O0   at line 19 (test for warnings, line 18)
        +PASS: rust/compile/torture/generics18.rs   -O0   at line 19 (test for warnings, line 18)
        +PASS: rust/compile/torture/generics18.rs   -O0   at line 5 (test for warnings, line 4)
         PASS: rust/compile/torture/generics18.rs   -O0   at line 5 (test for warnings, line 4)
         PASS: rust/compile/torture/generics18.rs   -O0  (test for excess errors)
        +PASS: rust/compile/torture/generics18.rs   -O0  (test for excess errors)
    
    ..., and so on.
    
    This has been determined to be due to repetitive 'runtest_file_p' calls (it's
    a mess...), thusly fixed (some would call it a "hack", no doubt), and verified
    that, for example:
    
        $ make -j12 check-rust RUNTESTFLAGS='--target_board=unix\{,-m32,-mx32\} link.exp=simple_function_0.rs'
    
    ... only runs the one test as indicated.

Diff:
---
 gcc/testsuite/rust/link/link.exp | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/gcc/testsuite/rust/link/link.exp b/gcc/testsuite/rust/link/link.exp
index b504e4c4cd1..8b2e93ceab6 100644
--- a/gcc/testsuite/rust/link/link.exp
+++ b/gcc/testsuite/rust/link/link.exp
@@ -154,7 +154,16 @@ foreach src [lsort [find $srcdir/$subdir *_0.rs]] {
 	continue
     }
 
+    # To prevent 'runtest_file_p' being tested again (for example, via
+    # 'gcc-dg-runtest'), with undesirable consequences due to its side effects,
+    # interpose a dummy:
+    rename runtest_file_p saved_runtest_file_p
+    proc runtest_file_p { runtests testcase } {
+	return 1
+    }
     rs-link-execute $src
+    rename runtest_file_p {}
+    rename saved_runtest_file_p runtest_file_p
 }
 
 set dg-do-what-default ${saved-dg-do-what-default}