scripts/singleuse: script to use to track single-use functions

That is functions that are declared global but are not used from outside
of the file in which it is declared. Such functions should be made
static or even at times be removed.

It also verifies that all used curl_ prefixed functions are "blessed"

Closes #3538

1 files changed, 223 insertions, 0 deletions

diff --git a/scripts/singleuse.pl b/scripts/singleuse.pl
new file mode 100755
index 000000000..f26abff87
--- /dev/null
+++ b/scripts/singleuse.pl
@@ -0,0 +1,223 @@
+#!/usr/bin/perl
+#***************************************************************************
+#                                  _   _ ____  _
+#  Project                     ___| | | |  _ \| |
+#                             / __| | | | |_) | |
+#                            | (__| |_| |  _ <| |___
+#                             \___|\___/|_| \_\_____|
+#
+# Copyright (C) 2019, Daniel Stenberg, <daniel@haxx.se>, et al.
+#
+# This software is licensed as described in the file COPYING, which
+# you should have received as part of this distribution. The terms
+# are also available at https://curl.haxx.se/docs/copyright.html.
+#
+# You may opt to use, copy, modify, merge, publish, distribute and/or sell
+# copies of the Software, and permit persons to whom the Software is
+# furnished to do so, under the terms of the COPYING file.
+#
+# This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+# KIND, either express or implied.
+#
+###########################################################################
+#
+# This script is aimed to help scan for and detect globally declared functions
+# that are not used from other source files.
+#
+# Use it like this:
+#
+# $ ./scripts/singleuse.pl lib/.libs/libcurl.a
+#
+# Be aware that it might cause false positives due to various build options.
+#
+
+my $file = $ARGV[0];
+
+my %wl = (
+    'Curl_none_cert_status_request' => 'multiple TLS backends',
+    'Curl_none_check_cxn' => 'multiple TLS backends',
+    'Curl_none_cleanup' => 'multiple TLS backends',
+    'Curl_none_close_all' => 'multiple TLS backends',
+    'Curl_none_data_pending' => 'multiple TLS backends',
+    'Curl_none_engines_list' => 'multiple TLS backends',
+    'Curl_none_init' => 'multiple TLS backends',
+    'Curl_none_md5sum' => 'multiple TLS backends',
+    'Curl_none_random' => 'multiple TLS backends',
+    'Curl_none_session_free' => 'multiple TLS backends',
+    'Curl_none_set_engine' => 'multiple TLS backends',
+    'Curl_none_set_engine_default' => 'multiple TLS backends',
+    'Curl_none_shutdown' => 'multiple TLS backends',
+    'Curl_multi_dump' => 'debug build only',
+    'Curl_parse_port' => 'UNITTEST',
+    'Curl_shuffle_addr' => 'UNITTEST',
+    'de_cleanup' => 'UNITTEST',
+    'doh_decode' => 'UNITTEST',
+    'doh_encode' => 'UNITTEST',
+    'Curl_auth_digest_get_pair' => 'by digest_sspi',
+    'curlx_uztoso' => 'cmdline tool use',
+    'curlx_uztoul' => 'by krb5_sspi',
+    'curlx_uitous' => 'by schannel',
+    'Curl_islower' => 'by curl_fnmatch',
+    'getaddressinfo' => 'UNITTEST',
+    );
+
+my %api = (
+    'curl_easy_cleanup' => 'API',
+    'curl_easy_duphandle' => 'API',
+    'curl_easy_escape' => 'API',
+    'curl_easy_getinfo' => 'API',
+    'curl_easy_init' => 'API',
+    'curl_easy_pause' => 'API',
+    'curl_easy_perform' => 'API',
+    'curl_easy_recv' => 'API',
+    'curl_easy_reset' => 'API',
+    'curl_easy_send' => 'API',
+    'curl_easy_setopt' => 'API',
+    'curl_easy_strerror' => 'API',
+    'curl_easy_unescape' => 'API',
+    'curl_easy_upkeep' => 'API',
+    'curl_escape' => 'API',
+    'curl_formadd' => 'API',
+    'curl_formfree' => 'API',
+    'curl_formget' => 'API',
+    'curl_free' => 'API',
+    'curl_getdate' => 'API',
+    'curl_getenv' => 'API',
+    'curl_global_cleanup' => 'API',
+    'curl_global_init' => 'API',
+    'curl_global_init_mem' => 'API',
+    'curl_global_sslset' => 'API',
+    'curl_maprintf' => 'API',
+    'curl_mfprintf' => 'API',
+    'curl_mime_addpart' => 'API',
+    'curl_mime_data' => 'API',
+    'curl_mime_data_cb' => 'API',
+    'curl_mime_encoder' => 'API',
+    'curl_mime_filedata' => 'API',
+    'curl_mime_filename' => 'API',
+    'curl_mime_free' => 'API',
+    'curl_mime_headers' => 'API',
+    'curl_mime_init' => 'API',
+    'curl_mime_name' => 'API',
+    'curl_mime_subparts' => 'API',
+    'curl_mime_type' => 'API',
+    'curl_mprintf' => 'API',
+    'curl_msnprintf' => 'API',
+    'curl_msprintf' => 'API',
+    'curl_multi_add_handle' => 'API',
+    'curl_multi_assign' => 'API',
+    'curl_multi_cleanup' => 'API',
+    'curl_multi_fdset' => 'API',
+    'curl_multi_info_read' => 'API',
+    'curl_multi_init' => 'API',
+    'curl_multi_perform' => 'API',
+    'curl_multi_remove_handle' => 'API',
+    'curl_multi_setopt' => 'API',
+    'curl_multi_socket' => 'API',
+    'curl_multi_socket_action' => 'API',
+    'curl_multi_socket_all' => 'API',
+    'curl_multi_strerror' => 'API',
+    'curl_multi_timeout' => 'API',
+    'curl_multi_wait' => 'API',
+    'curl_mvaprintf' => 'API',
+    'curl_mvfprintf' => 'API',
+    'curl_mvprintf' => 'API',
+    'curl_mvsnprintf' => 'API',
+    'curl_mvsprintf' => 'API',
+    'curl_pushheader_byname' => 'API',
+    'curl_pushheader_bynum' => 'API',
+    'curl_share_cleanup' => 'API',
+    'curl_share_init' => 'API',
+    'curl_share_setopt' => 'API',
+    'curl_share_strerror' => 'API',
+    'curl_slist_append' => 'API',
+    'curl_slist_free_all' => 'API',
+    'curl_strequal' => 'API',
+    'curl_strnequal' => 'API',
+    'curl_unescape' => 'API',
+    'curl_url' => 'API',
+    'curl_url_cleanup' => 'API',
+    'curl_url_dup' => 'API',
+    'curl_url_get' => 'API',
+    'curl_url_set' => 'API',
+    'curl_version' => 'API',
+    'curl_version_info' => 'API',
+
+    # the following funcions are provided globally in debug builds
+    'curl_easy_perform_ev' => 'debug-build',
+    'curl_memdebug' => 'debug-build',
+    'curl_memlimit' => 'debug-build',
+    'curl_memlog' => 'debug-build',
+    'curl_accept' => 'debug-build',
+    'curl_docalloc' => 'debug-build',
+    'curl_dofree' => 'debug-build',
+    'curl_domalloc' => 'debug-build',
+    'curl_dorealloc' => 'debug-build',
+    'curl_dorecv' => 'debug-build',
+    'curl_dosend' => 'debug-build',
+    'curl_dostrdup' => 'debug-build',
+    'curl_fclose' => 'debug-build',
+    'curl_fopen' => 'debug-build',
+    'curl_sclose' => 'debug-build',
+    'curl_socket' => 'debug-build',
+    'curl_socketpair' => 'debug-build',
+    );
+
+open(N, "nm $file|") ||
+    die;
+
+my %exist;
+my %uses;
+my $file;
+while (<N>) {
+    my $l = $_;
+    chomp $l;
+
+    if($l =~ /^([0-9a-z_-]+)\.o:/) {
+        $file = $1;
+    }
+    if($l =~ /^([0-9a-f]+) T (.*)/) {
+        my ($name)=($2);
+        #print "Define $name in $file\n";
+        $file =~ s/^libcurl_la-//;
+        $exist{$name} = $file;
+    }
+    elsif($l =~ /^                 U (.*)/) {
+        my ($name)=($1);
+        #print "Uses $name in $file\n";
+        $uses{$name} .= "$file, ";
+    }
+}
+close(N);
+
+my $err;
+for(sort keys %exist) {
+    #printf "%s is defined in %s, used by: %s\n", $_, $exist{$_}, $uses{$_};
+    if(!$uses{$_}) {
+        # this is a symbol with no "global" user
+        if($_ =~ /^curl_/) {
+            if(!$api{$_}) {
+                # not present in the API, or for debug-builds
+                print STDERR "Bad curl-prefix: $_\n";
+                $err++;
+            }
+        }
+        elsif($wl{$_}) {
+            #print "$_ is WL\n";
+        }
+        else {
+            printf "%s is defined in %s, but not used outside\n", $_, $exist{$_};
+            $err++;
+        }
+    }
+    elsif($_ =~ /^curl_/) {
+        # global prefix, make sure it is "blessed"
+        if(!$api{$_}) {
+            # not present in the API, or for debug-builds
+            print STDERR "Bad curl-prefix $_\n";
+            $err++;
+        }
+    }
+}
+
+exit $err;