Replace conform/list-header-symbols.pl with a Python script.

Continuing the move of test code from Perl to Python (which seems
uncontroversial, unlike dependencies on Python in the actual build of
glibc), this patch replaces conform/list-header-symbols.pl with a
Python script, as a first step in converting the conform/ tests.
(conform/glibcconform.py is an equivalent to GlibcConform.pm,
containing code that will be relevant to move than one of the conform/
scripts.)

Tested for x86_64, including verifying that the symbol lists generated
are identical to those generated by the Perl version.

	* conform/glibcconform.py: New file.
	* conform/list-header-symbols.py: Likewise.
	* conform/list-header-symbols.pl: Remove.
	* conform/Makefile (tests-special): Only add linknamespace tests
	if [PYTHON].
	($(linknamespace-symlists-tests)): Use list-header-symbols.py.

4 files changed, 163 insertions, 88 deletions

diff --git a/conform/Makefile b/conform/Makefile
index d43093171b..71e58a46c8 100644
--- a/conform/Makefile
+++ b/conform/Makefile
@@ -120,7 +120,9 @@ linknamespace-symlists-base := $(foreach std,$(conformtest-standards),\
 					     symlist-$(std))
 linknamespace-symlists-tests := $(addprefix $(objpfx),\
 					    $(linknamespace-symlists-base))
+ifdef PYTHON
 tests-special += $(linknamespace-symlists-tests)
+endif
 
 linknamespace-symlist-stdlibs-base := $(foreach std,$(conformtest-standards),\
 						    symlist-stdlibs-$(std))
@@ -128,7 +130,9 @@ linknamespace-symlist-stdlibs-tests := \
 	$(addprefix $(objpfx),\
 		    $(linknamespace-symlist-stdlibs-base))
 
+ifdef PYTHON
 tests-special += $(linknamespace-symlist-stdlibs-tests)
+endif
 
 linknamespace-header-base := $(foreach std,\
 				       $(conformtest-standards),\
@@ -137,7 +141,9 @@ linknamespace-header-base := $(foreach std,\
 						 $(std)/$(h)/linknamespace.out))
 linknamespace-header-tests := $(addprefix $(objpfx),\
 					  $(linknamespace-header-base))
+ifdef PYTHON
 tests-special += $(linknamespace-header-tests)
+endif
 
 include ../Rules
 
@@ -181,11 +187,10 @@ $(conformtest-header-tests): $(objpfx)%/conform.out: \
 		 > $@); \
 	$(evaluate-test)
 
-$(linknamespace-symlists-tests): $(objpfx)symlist-%: list-header-symbols.pl
-	$(PERL) -I. -w $< --tmpdir=$(objpfx) --cc='$(CC)' \
-		--flags='$(conformtest-cc-flags)' --standard=$* \
-		--headers="$(strip $(conformtest-headers-$*))" \
-		> $@ 2> $@.err; \
+$(linknamespace-symlists-tests): $(objpfx)symlist-%: list-header-symbols.py
+	$(PYTHON) $< --cc='$(CC)' --flags='$(conformtest-cc-flags)' \
+		  --standard=$* --headers="$(strip $(conformtest-headers-$*))" \
+		  > $@ 2> $@.err; \
 	$(evaluate-test)
 
 linknamespace-libs-isoc = $(common-objpfx)libc.a $(common-objpfx)math/libm.a
diff --git a/conform/glibcconform.py b/conform/glibcconform.py
new file mode 100644
index 0000000000..31ad4a9f9f
--- /dev/null
+++ b/conform/glibcconform.py
@@ -0,0 +1,77 @@
+#!/usr/bin/python
+# Shared code for glibc conformance tests.
+# Copyright (C) 2018 Free Software Foundation, Inc.
+# This file is part of the GNU C Library.
+#
+# The GNU C Library is free software; you can redistribute it and/or
+# modify it under the terms of the GNU Lesser General Public
+# License as published by the Free Software Foundation; either
+# version 2.1 of the License, or (at your option) any later version.
+#
+# The GNU C Library is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+# Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public
+# License along with the GNU C Library; if not, see
+# <http://www.gnu.org/licenses/>.
+
+import os.path
+import re
+import shutil
+import subprocess
+import tempfile
+
+
+# Compiler options for each standard.
+CFLAGS = {'ISO': '-ansi',
+          'ISO99': '-std=c99',
+          'ISO11': '-std=c11',
+          'POSIX': '-D_POSIX_C_SOURCE=199506L -ansi',
+          'XPG4': '-ansi -D_XOPEN_SOURCE',
+          'XPG42': '-ansi -D_XOPEN_SOURCE -D_XOPEN_SOURCE_EXTENDED',
+          'UNIX98': '-ansi -D_XOPEN_SOURCE=500',
+          'XOPEN2K': '-std=c99 -D_XOPEN_SOURCE=600',
+          'XOPEN2K8': '-std=c99 -D_XOPEN_SOURCE=700',
+          'POSIX2008': '-std=c99 -D_POSIX_C_SOURCE=200809L'}
+
+
+def list_exported_functions(cc, standard, header):
+    """Return the set of functions exported by a header, empty if an
+    include of the header does not compile.
+
+    """
+    cc_all = '%s -D_ISOMAC %s' % (cc, CFLAGS[standard])
+    # tempfile.TemporaryDirectory requires Python 3.2, so use mkdtemp.
+    temp_dir = tempfile.mkdtemp()
+    c_file_name = os.path.join(temp_dir, 'test.c')
+    aux_file_name = os.path.join(temp_dir, 'test.c.aux')
+    try:
+        with open(c_file_name, 'w') as c_file:
+            c_file.write('#include <%s>\n' % header)
+        fns = set()
+        cmd = ('%s -c %s -o /dev/null -aux-info %s'
+               % (cc_all, c_file_name, aux_file_name))
+        try:
+            subprocess.check_call(cmd, shell=True)
+        except subprocess.CalledProcessError:
+            return fns
+        with open(aux_file_name, 'r') as aux_file:
+            for line in aux_file:
+                line = re.sub(r'/\*.*?\*/', '', line)
+                line = line.strip()
+                if line:
+                    # The word before a '(' that isn't '(*' is the
+                    # function name before the argument list (not
+                    # fully general, but sufficient for -aux-info
+                    # output on standard headers).
+                    m = re.search(r'([A-Za-z0-9_]+) *\([^*]', line)
+                    if m:
+                        fns.add(m.group(1))
+                    else:
+                        raise ValueError("couldn't parse -aux-info output: %s"
+                                         % line)
+    finally:
+        shutil.rmtree(temp_dir)
+    return fns
diff --git a/conform/list-header-symbols.pl b/conform/list-header-symbols.pl
deleted file mode 100644
index 0db61bfe86..0000000000
--- a/conform/list-header-symbols.pl
+++ /dev/null
@@ -1,83 +0,0 @@
-#!/usr/bin/perl
-
-# Print a list of symbols exported by some headers that would
-# otherwise be in the user's namespace.
-
-# Copyright (C) 2014-2018 Free Software Foundation, Inc.
-# This file is part of the GNU C Library.
-
-# The GNU C Library is free software; you can redistribute it and/or
-# modify it under the terms of the GNU Lesser General Public
-# License as published by the Free Software Foundation; either
-# version 2.1 of the License, or (at your option) any later version.
-
-# The GNU C Library is distributed in the hope that it will be useful,
-# but WITHOUT ANY WARRANTY; without even the implied warranty of
-# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
-# Lesser General Public License for more details.
-
-# You should have received a copy of the GNU Lesser General Public
-# License along with the GNU C Library; if not, see
-# <http://www.gnu.org/licenses/>.
-
-use GlibcConform;
-use Getopt::Long;
-
-GetOptions ('headers=s' => \$headers, 'standard=s' => \$standard,
-	    'flags=s' => \$flags, 'cc=s' => \$CC, 'tmpdir=s' => \$tmpdir);
-@headers = split (/\s+/, $headers);
-
-# Extra symbols possibly not found through -aux-info but still
-# reserved by the standard: either data symbols, or symbols where the
-# standard leaves unspecified whether the identifier is a macro or
-# defined with external linkage.
-$extra_syms{"ISO"} = ["errno", "setjmp", "va_end"];
-$extra_syms{"ISO99"} = ["errno", "math_errhandling", "setjmp", "va_end"];
-# stdatomic.h not yet covered by conformance tests; as per DR#419, all
-# the generic functions there or may not be defined with external
-# linkage (but are reserved in any case).
-$extra_syms{"ISO11"} = ["errno", "math_errhandling", "setjmp", "va_end"];
-# The following lists may not be exhaustive.
-$extra_syms{"POSIX"} = ["errno", "setjmp", "va_end", "environ", "sigsetjmp",
-			"optarg", "optind", "opterr", "optopt", "tzname"];
-$extra_syms{"XPG4"} = ["errno", "setjmp", "va_end", "environ", "signgam",
-		       "loc1", "loc2", "locs", "sigsetjmp", "optarg",
-		       "optind", "opterr", "optopt", "daylight", "timezone",
-		       "tzname"];
-$extra_syms{"XPG42"} = ["errno", "setjmp", "va_end", "environ", "signgam",
-		       "loc1", "loc2", "locs", "sigsetjmp", "optarg",
-		       "optind", "opterr", "optopt", "daylight", "timezone",
-		       "tzname", "getdate_err", "h_errno"];
-$extra_syms{"UNIX98"} = ["errno", "setjmp", "va_end", "environ", "signgam",
-			 "loc1", "loc2", "locs", "sigsetjmp", "optarg",
-			 "optind", "opterr", "optopt", "daylight", "timezone",
-			 "tzname", "getdate_err", "h_errno"];
-$extra_syms{"XOPEN2K"} = ["errno", "setjmp", "va_end", "environ", "signgam",
-			  "sigsetjmp", "optarg", "optind", "opterr", "optopt",
-			  "daylight", "timezone", "tzname", "getdate_err",
-			  "h_errno", "in6addr_any", "in6addr_loopback"];
-$extra_syms{"XOPEN2K8"} = ["errno", "setjmp", "va_end", "environ", "signgam",
-			   "sigsetjmp", "optarg", "optind", "opterr", "optopt",
-			   "daylight", "timezone", "tzname", "getdate_err",
-			   "in6addr_any", "in6addr_loopback"];
-$extra_syms{"POSIX2008"} = ["errno", "setjmp", "va_end", "environ",
-			    "sigsetjmp", "optarg", "optind", "opterr", "optopt",
-			    "tzname", "in6addr_any", "in6addr_loopback"];
-
-%user_syms = ();
-
-foreach my $header (@headers) {
-  @syms = list_exported_functions ("$CC $flags", $standard, $header, $tmpdir);
-  foreach my $sym (@syms) {
-    if ($sym !~ /^_/) {
-      $user_syms{$sym} = 1;
-    }
-  }
-}
-foreach my $sym (@{$extra_syms{$standard}}) {
-  $user_syms{$sym} = 1;
-}
-
-foreach my $sym (sort keys %user_syms) {
-  print "$sym\n";
-}
diff --git a/conform/list-header-symbols.py b/conform/list-header-symbols.py
new file mode 100644
index 0000000000..5dd0a51605
--- /dev/null
+++ b/conform/list-header-symbols.py
@@ -0,0 +1,76 @@
+#!/usr/bin/python
+# Print a list of symbols exported by some headers that would
+# otherwise be in the user's namespace.
+# Copyright (C) 2018 Free Software Foundation, Inc.
+# This file is part of the GNU C Library.
+#
+# The GNU C Library is free software; you can redistribute it and/or
+# modify it under the terms of the GNU Lesser General Public
+# License as published by the Free Software Foundation; either
+# version 2.1 of the License, or (at your option) any later version.
+#
+# The GNU C Library is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+# Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public
+# License along with the GNU C Library; if not, see
+# <http://www.gnu.org/licenses/>.
+
+import argparse
+
+import glibcconform
+
+# Extra symbols possibly not found through -aux-info but still
+# reserved by the standard: either data symbols, or symbols where the
+# standard leaves unspecified whether the identifier is a macro or
+# defined with external linkage.
+EXTRA_SYMS = {}
+EXTRA_SYMS['ISO'] = {'errno', 'setjmp', 'va_end'}
+EXTRA_SYMS['ISO99'] = EXTRA_SYMS['ISO'] | {'math_errhandling'}
+# stdatomic.h not yet covered by conformance tests; as per DR#419, all
+# the generic functions there or may not be defined with external
+# linkage (but are reserved in any case).
+EXTRA_SYMS['ISO11'] = EXTRA_SYMS['ISO99']
+# The following lists may not be exhaustive.
+EXTRA_SYMS['POSIX'] = (EXTRA_SYMS['ISO']
+                       | {'environ', 'sigsetjmp', 'optarg', 'optind', 'opterr',
+                          'optopt', 'tzname'})
+EXTRA_SYMS['XPG4'] = (EXTRA_SYMS['POSIX']
+                      | {'signgam', 'loc1', 'loc2', 'locs', 'daylight',
+                         'timezone'})
+EXTRA_SYMS['XPG42'] = EXTRA_SYMS['XPG4'] | {'getdate_err', 'h_errno'}
+EXTRA_SYMS['UNIX98'] = EXTRA_SYMS['XPG42']
+EXTRA_SYMS['XOPEN2K'] = (EXTRA_SYMS['POSIX']
+                         | {'signgam', 'daylight', 'timezone', 'getdate_err',
+                            'h_errno', 'in6addr_any', 'in6addr_loopback'})
+EXTRA_SYMS['POSIX2008'] = (EXTRA_SYMS['POSIX']
+                           | {'in6addr_any', 'in6addr_loopback'})
+EXTRA_SYMS['XOPEN2K8'] = (EXTRA_SYMS['POSIX2008']
+                          | {'signgam', 'daylight', 'timezone', 'getdate_err'})
+
+
+def main():
+    """The main entry point."""
+    parser = argparse.ArgumentParser(description='List exported symbols.')
+    parser.add_argument('--headers', metavar='HEADERS',
+                        help='list of headers')
+    parser.add_argument('--standard', metavar='STD',
+                        help='standard to use when processing headers')
+    parser.add_argument('--cc', metavar='CC',
+                        help='C compiler to use')
+    parser.add_argument('--flags', metavar='CFLAGS',
+                        help='Compiler flags to use with CC')
+    args = parser.parse_args()
+    fns = set()
+    compiler = '%s %s' % (args.cc, args.flags)
+    for header in args.headers.split():
+        fns |= glibcconform.list_exported_functions(compiler, args.standard,
+                                                    header)
+    fns |= EXTRA_SYMS[args.standard]
+    print('\n'.join(sorted(fn for fn in fns if not fn.startswith('_'))))
+
+
+if __name__ == '__main__':
+    main()