GHA: add workflow to compare configure vs cmake outputs

Uses scripts/cmp-config.pl two compare two curl_config.h files,
presumbly generated with configure and cmake. It displays the
differences and filters out a lot of known lines we ignore.

The script also shows the matches that were *not* used. Possibly
subjects for removal.

Closes curl#11964

.github/workflows/configure-vs-cmake.yml

@@ -0,0 +1,45 @@
+# Copyright (C) Daniel Stenberg, <[email protected]>, et al.
+#
+# SPDX-License-Identifier: curl
+
+name: configure-vs-cmake
+on:
+  push:
+    branches:
+    - master
+    paths:
+    - '*.ac'
+    - '**/*.m4'
+    - '**/CMakeLists.txt'
+    - 'lib/curl_config.h.cmake'
+    - 'scripts/cmp-config.pl'
+
+  pull_request:
+    branches:
+    - master
+    paths:
+    - '*.ac'
+    - '**/*.m4'
+    - '**/CMakeLists.txt'
+    - 'lib/curl_config.h.cmake'
+    - 'scripts/cmp-config.pl'
+
+permissions: {}
+
+jobs:
+  check:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v3
+
+    - name: run configure --with-openssl
+      run: |
+         autoreconf -fi
+         ./configure --with-openssl
+
+    - name: run cmake
+      run: |
+         mkdir build && cd build && cmake ..
+
+    - name: compare generated curl_config.h files
+      run: ./scripts/cmp-config.pl lib/curl_config.h build/lib/curl_config.h

scripts/cmp-config.pl

@@ -0,0 +1,123 @@
+#!/usr/bin/env perl
+#***************************************************************************
+#                                  _   _ ____  _
+#  Project                     ___| | | |  _ \| |
+#                             / __| | | | |_) | |
+#                            | (__| |_| |  _ <| |___
+#                             \___|\___/|_| \_\_____|
+#
+# Copyright (C) Daniel Stenberg, <[email protected]>, 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.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.
+#
+# SPDX-License-Identifier: curl
+#
+###########################################################################
+
+my $autotools = $ARGV[0];
+my $cmake = $ARGV[1];
+
+if(!$cmake) {
+    print "Usage: cmp-config <config1> <config2.h>\n";
+    exit;
+}
+
+# this lists complete lines that will be removed from the the output if
+# matching
+my %remove = (
+    '#define _FILE_OFFSET_BITS 64' => 1,
+    '#define CURL_EXTERN_SYMBOL' => 1,
+    '#define CURL_SA_FAMILY_T sa_family_t' => 1,
+    '#define GETHOSTNAME_TYPE_ARG2 size_t' => 1,
+    '#define HAVE_BROTLI 1' => 1,
+    '#define HAVE_BROTLI_DECODE_H 1' => 1,
+    '#define HAVE_DECL_GETPWUID_R 1' => 1,
+    '#define HAVE_DLFCN_H 1' => 1,
+    '#define HAVE_GETHOSTBYNAME 1' => 1,
+    '#define HAVE_IOCTL 1' => 1,
+    '#define HAVE_LDAP_SSL 1' => 1,
+    '#define HAVE_LIBBROTLIDEC 1' => 1,
+    '#define HAVE_LIBSSL 1' => 1,
+    '#define HAVE_LIBZSTD 1' => 1,
+    '#define HAVE_OPENSSL3 1' => 1,
+    '#define HAVE_OPENSSL_CRYPTO_H 1' => 1,
+    '#define HAVE_OPENSSL_ERR_H 1' => 1,
+    '#define HAVE_OPENSSL_PEM_H 1' => 1,
+    '#define HAVE_OPENSSL_RSA_H 1' => 1,
+    '#define HAVE_OPENSSL_SSL_H 1' => 1,
+    '#define HAVE_OPENSSL_X509_H 1' => 1,
+    '#define HAVE_SA_FAMILY_T 1' => 1,
+    '#define HAVE_SETJMP_H 1' => 1,
+    '#define HAVE_STDIO_H 1' => 1,
+    '#define HAVE_STDLIB_H 1' => 1,
+    '#define HAVE_STRING_H 1' => 1,
+    '#define HAVE_SYS_XATTR_H 1' => 1,
+    '#define HAVE_ZSTD 1' => 1,
+    '#define HAVE_ZSTD_H 1' => 1,
+    '#define LT_OBJDIR ".libs/"' => 1,
+    '#define OS "Linux"' => 1,
+    '#define OS "x86_64-pc-linux-gnu"' => 1,
+    '#define PACKAGE "curl"' => 1,
+    '#define PACKAGE_BUGREPORT "a suitable curl mailing list: https://curl.se/mail/"' => 1,
+    '#define PACKAGE_NAME "curl"' => 1,
+    '#define PACKAGE_STRING "curl -"' => 1,
+    '#define PACKAGE_TARNAME "curl"' => 1,
+    '#define PACKAGE_URL ""' => 1,
+    '#define PACKAGE_VERSION "-"' => 1,
+    '#define SIZEOF_LONG_LONG 8' => 1,
+    '#define USE_MANUAL 1' => 1,
+    '#define VERSION "-"' => 1,
+    );
+
+sub filter {
+    my ($line) = @_;
+    if(!$remove{$line}) {
+        return "$line\n";
+    }
+    $remove{$line}++;
+    return "";
+}
+
+sub grepit {
+    my ($input, $output) = @_;
+    my @defines;
+    # first get all the #define lines
+    open(F, "<$input");
+    while(<F>) {
+        if($_ =~ /^#def/) {
+            chomp;
+            push @defines, $_;
+        }
+    }
+    close(F);
+
+    open(O, ">$output");
+
+    # output the sorted list through the filter
+    foreach my $d(sort @defines) {
+        print O filter($d);
+    }
+    close(O);
+}
+
+grepit($autotools, "/tmp/autotools");
+grepit($cmake, "/tmp/cmake");
+
+foreach my $v (keys %remove) {
+    if($remove{$v} == 1) {
+        print "Ignored, never matched line: $v\n";
+    }
+}
+
+
+# return the exit code from diff
+exit system("diff -u /tmp/autotools /tmp/cmake") >> 8;