[gcc r13-1235] libstdc++: testsuite: skip fs space tests on dummy implementations

[Alexandre Oliva <aoliva@gcc.gnu.org>]

https://gcc.gnu.org/g:b931c6874e846cd4eba1c31112593d33ff4bf1f1

commit r13-1235-gb931c6874e846cd4eba1c31112593d33ff4bf1f1
Author: Alexandre Oliva <oliva@adacore.com>
Date:   Thu Jun 23 23:20:51 2022 -0300

    libstdc++: testsuite: skip fs space tests on dummy implementations
    
    The do_space function is defined in ways that are useful, or that fail
    immediately, depending on various macros.  When it fails immediately,
    the filesystem space.cc tests fail noisily, but the fail is entirely
    expected.
    
    Define NO_SPACE in testsuite_fs.h, according to the macros that select
    implementations of do_space, and use it to skip tests that are
    expected to fail, through a new dg-require.
    
    
    for  libstdc++-v3/ChangeLog
    
            * testsuite/util/testsuite_fs.h (NO_SPACE): Define if
            appropriate.
            * testsuite/lib/libstdc++.exp (check_v3_target_fs_space): New.
            * testsuite/lib/dg-options.exp (dg-require-target-fs-space):
            New.
            * testsuite/27_io/filesystem/operations/space.cc: Require
            target-fs-space.
            * testsuite/experimental/filesystem/operations/space.cc:
            Likewise.

Diff:
---
 libstdc++-v3/testsuite/27_io/filesystem/operations/space.cc      | 1 +
 .../testsuite/experimental/filesystem/operations/space.cc        | 1 +
 libstdc++-v3/testsuite/lib/dg-options.exp                        | 9 +++++++++
 libstdc++-v3/testsuite/lib/libstdc++.exp                         | 8 ++++++++
 libstdc++-v3/testsuite/util/testsuite_fs.h                       | 5 +++++
 5 files changed, 24 insertions(+)

diff --git a/libstdc++-v3/testsuite/27_io/filesystem/operations/space.cc b/libstdc++-v3/testsuite/27_io/filesystem/operations/space.cc
index 05997cac1df..daa1ce439f3 100644
--- a/libstdc++-v3/testsuite/27_io/filesystem/operations/space.cc
+++ b/libstdc++-v3/testsuite/27_io/filesystem/operations/space.cc
@@ -17,6 +17,7 @@
 
 // { dg-do run { target c++17 } }
 // { dg-require-filesystem-ts "" }
+// { dg-require-target-fs-space "" }
 
 // 30.10.14.3 Permissions [fs.op.space]
 
diff --git a/libstdc++-v3/testsuite/experimental/filesystem/operations/space.cc b/libstdc++-v3/testsuite/experimental/filesystem/operations/space.cc
index 10ee0f06871..c3745a26866 100644
--- a/libstdc++-v3/testsuite/experimental/filesystem/operations/space.cc
+++ b/libstdc++-v3/testsuite/experimental/filesystem/operations/space.cc
@@ -18,6 +18,7 @@
 // { dg-options "-DUSE_FILESYSTEM_TS -lstdc++fs" }
 // { dg-do run { target c++11 } }
 // { dg-require-filesystem-ts "" }
+// { dg-require-target-fs-space "" }
 
 // 30.10.14.3 Permissions [fs.op.space]
 
diff --git a/libstdc++-v3/testsuite/lib/dg-options.exp b/libstdc++-v3/testsuite/lib/dg-options.exp
index e624a69460e..81bb8f448bd 100644
--- a/libstdc++-v3/testsuite/lib/dg-options.exp
+++ b/libstdc++-v3/testsuite/lib/dg-options.exp
@@ -250,6 +250,15 @@ proc dg-require-target-fs-symlinks { args } {
     return
 }
 
+proc dg-require-target-fs-space { args } {
+    if { ![ check_v3_target_fs_space ] } {
+	upvar dg-do-what dg-do-what
+	set dg-do-what [list [lindex ${dg-do-what} 0] "N" "P"]
+	return
+    }
+    return
+}
+
 proc add_options_for_no_pch { flags } {
     # This forces any generated and possibly included PCH to be invalid.
     return "-D__GLIBCXX__=99999999"
diff --git a/libstdc++-v3/testsuite/lib/libstdc++.exp b/libstdc++-v3/testsuite/lib/libstdc++.exp
index 03f47e8d772..4305ec60994 100644
--- a/libstdc++-v3/testsuite/lib/libstdc++.exp
+++ b/libstdc++-v3/testsuite/lib/libstdc++.exp
@@ -1278,6 +1278,14 @@ proc check_v3_target_fs_symlinks { } {
     return [v3_check_preprocessor_condition fs_symlinks $cond $inc]
 }
 
+# Return 1 if the libstdc++ filesystem implementation of space is not an
+# always-failing dummy.
+proc check_v3_target_fs_space { } {
+    set inc "#include <testsuite_fs.h>"
+    set cond "!defined NO_SPACE"
+    return [v3_check_preprocessor_condition fs_space $cond $inc]
+}
+
 # Return 1 if the "cxx11" ABI is in use using the current flags, 0 otherwise.
 # Any flags provided by RUNTESTFLAGS or a target board will be used here.
 # Flags added in the test by dg-options or dg-add-options will not be used.
diff --git a/libstdc++-v3/testsuite/util/testsuite_fs.h b/libstdc++-v3/testsuite/util/testsuite_fs.h
index 03af7ae96e3..e9fb4fff8f2 100644
--- a/libstdc++-v3/testsuite/util/testsuite_fs.h
+++ b/libstdc++-v3/testsuite/util/testsuite_fs.h
@@ -46,6 +46,11 @@ namespace test_fs = std::experimental::filesystem;
 #define NO_SYMLINKS
 #endif
 
+#if !defined (_GLIBCXX_HAVE_SYS_STATVFS_H) \
+  && !defined (_GLIBCXX_FILESYSTEM_IS_WINDOWS)
+#define NO_SPACE
+#endif
+
 namespace __gnu_test
 {
 #define PATH_CHK(p1, p2, fn) \