Run conform/ tests using newly built libc

Although the conform/ header tests are built using the headers of the
glibc under test, the execution tests from conformtest (a few tests of
the values of macros evaluating to string constants) are linked and
run with system libc, not the newly built libc.

Apart from preventing testing in cross environments, this can be a
problem even for native testing.  Specifically, it can be useful to do
native testing when building with a cross compiler that links with a
libc that is not the system libc; for example, on x86_64, you can test
all three ABIs that way if the kernel support is present, even if the
host OS lacks 32-bit or x32 libraries or they are older than the
libraries in the sysroot used by the compiler used to build glibc.
This works for almost all tests, but not for these conformtest tests.

Arrange for conformtest to link and run test programs similarly to
other tests, with consequent refactoring of various variables in
Makeconfig to allow passing relevant parts of the link-time command
lines down to conformtest.  In general, the parts of the link command
involving $@ or $^ are separated out from the parts that should be
passed to conformtest (the variables passed to conformtest still
involve various variables whose names involve $(@F), but those
variables simply won't be defined for the conformtest makefile rules
and I think their presence there is harmless).

This is also most of the support that would be needed to allow running
those tests of string constants for cross testing when test-wrapper is
defined.  That will also need changes to where conformtest.py puts the
test executables, so it puts them in the main object directory
(expected to be shared with a test system in cross testing) rather
than /tmp (not expected to be shared) as at present.

Tested for x86_64.

2 files changed, 20 insertions, 3 deletions

diff --git a/conform/Makefile b/conform/Makefile
index c64a83a905..296db818f0 100644
--- a/conform/Makefile
+++ b/conform/Makefile
@@ -176,6 +176,9 @@ $(conformtest-header-tests): $(objpfx)%/conform.out: \
 	(set -e; std_hdr=$*; std=$${std_hdr%%/*}; hdr=$${std_hdr#*/}; \
 	 mkdir -p $(@D); \
 	 $(PYTHON) $< --cc='$(CC)' --flags='$(conformtest-cc-flags)' \
+		   --ldflags='$(+link-tests-before-inputs)' \
+		   --libs='$(+link-tests-after-inputs)' \
+		   --run-program-prefix='$(run-program-prefix)' \
 		   --standard=$$std --header=$$hdr $(conformtest-xfail) \
 		   $(conformtest-cross) \
 		   > $@ 2>&1); \
diff --git a/conform/conformtest.py b/conform/conformtest.py
index b0ec8e7ed1..164cf2917d 100644
--- a/conform/conformtest.py
+++ b/conform/conformtest.py
@@ -381,12 +381,16 @@ class MacroStrTest(object):
 class HeaderTests(object):
     """The set of tests run for a header."""
 
-    def __init__(self, header, standard, cc, flags, cross, xfail):
+    def __init__(self, header, standard, cc, flags, ldflags, libs,
+                 run_program_prefix, cross, xfail):
         """Initialize a HeaderTests object."""
         self.header = header
         self.standard = standard
         self.cc = cc
         self.flags = flags
+        self.ldflags = ldflags
+        self.libs = libs
+        self.run_program_prefix = run_program_prefix
         self.cross = cross
         self.xfail_str = xfail
         self.cflags_namespace = ('%s -fno-builtin %s -D_ISOMAC'
@@ -590,7 +594,8 @@ class HeaderTests(object):
         exe_file = os.path.join(self.temp_dir, 'test')
         with open(c_file, 'w') as c_file_out:
             c_file_out.write('#include <%s>\n%s' % (self.header, text))
-        cmd = ('%s %s %s -o %s' % (self.cc, self.cflags, c_file, exe_file))
+        cmd = ('%s %s %s %s %s -o %s' % (self.cc, self.cflags, self.ldflags,
+                                         c_file, self.libs, exe_file))
         try:
             subprocess.check_call(cmd, shell=True)
         except subprocess.CalledProcessError:
@@ -600,7 +605,9 @@ class HeaderTests(object):
             self.note_skip(name)
             return
         try:
-            subprocess.check_call(exe_file, shell=True)
+            subprocess.check_call('%s %s' % (self.run_program_prefix,
+                                             exe_file),
+                                  shell=True)
         except subprocess.CalledProcessError:
             self.note_error(name, self.group_xfail)
             return
@@ -727,12 +734,19 @@ def main():
                         help='C compiler to use')
     parser.add_argument('--flags', metavar='CFLAGS',
                         help='Compiler flags to use with CC')
+    parser.add_argument('--ldflags', metavar='LDFLAGS',
+                        help='Compiler arguments for linking before inputs')
+    parser.add_argument('--libs', metavar='LIBS',
+                        help='Compiler arguments for linking after inputs')
+    parser.add_argument('--run-program-prefix', metavar='RUN-PROGRAM-PREFIX',
+                        help='Wrapper for running newly built program')
     parser.add_argument('--cross', action='store_true',
                         help='Do not run compiled test programs')
     parser.add_argument('--xfail', metavar='COND',
                         help='Name of condition for XFAILs')
     args = parser.parse_args()
     tests = HeaderTests(args.header, args.standard, args.cc, args.flags,
+                        args.ldflags, args.libs, args.run_program_prefix,
                         args.cross, args.xfail)
     tests.run()