tree-wide: drop gcrypt dependency from all binaries except for unit tests

With this change, gcrypt dependency is not mandatory. Hence, allow to build
systemd even when -D gcrypt=enabled but gcrypt devel package is not installed.

README

@@ -230,7 +230,6 @@ REQUIREMENTS:
         libarchive >= 3.0 (optional)
         libxkbcommon >= 0.3.0 (optional)
         libpcre2 (optional)
-        libgcrypt (optional)
         libqrencode >= 3 (optional)
         libmicrohttpd >= 0.9.33 (optional)
         libcurl >= 7.32.0 (optional)

meson.build

@@ -1206,8 +1206,9 @@ libqrencode = dependency('libqrencode',
 libqrencode_cflags = libqrencode.partial_dependency(includes: true, compile_args: true)
 conf.set10('HAVE_QRENCODE', libqrencode.found())
 
+feature = get_option('gcrypt')
 libgcrypt = dependency('libgcrypt',
-                       required : get_option('gcrypt'))
+                       required : feature.disabled() ? feature : false)
 conf.set10('HAVE_GCRYPT', libgcrypt.found())
 if libgcrypt.found()
         libgcrypt_cflags = libgcrypt.partial_dependency(includes: true, compile_args: true)

src/basic/build.c

@@ -64,12 +64,6 @@ const char* const systemd_features =
 
         /* cryptographic libraries */
 
-#if HAVE_GCRYPT
-        " +GCRYPT"
-#else
-        " -GCRYPT"
-#endif
-
 #if HAVE_GNUTLS
         " +GNUTLS"
 #else

src/shared/meson.build

@@ -87,10 +87,8 @@ shared_sources = files(
         'firewall-util.c',
         'fork-notify.c',
         'format-table.c',
-        'fsprg.c',
         'fsprg-openssl.c',
         'fstab-util.c',
-        'gcrypt-util.c',
         'generator.c',
         'geneve-util.c',
         'gnutls-util.c',
@@ -409,7 +407,6 @@ libshared_deps = [libacl_cflags,
                   libelf_cflags,
                   libfdisk_cflags,
                   libfido2_cflags,
-                  libgcrypt_cflags,
                   libgnutls_cflags,
                   libidn2_cflags,
                   libkmod_cflags,

src/test/meson.build

@@ -300,10 +300,14 @@ executables += [
                 'type' : 'manual',
         },
         test_template + {
-                'sources' : files('test-dlopen-so.c'),
+                'sources' : files(
+                        'test-dlopen-so.c',
+                        'gcrypt-util.c',
+                ),
                 'dependencies' : [
                         libblkid_cflags,
                         libfdisk_cflags,
+                        libgcrypt_cflags,
                         libgnutls_cflags,
                         libkmod_cflags,
                         libmicrohttpd_cflags,
@@ -339,6 +343,8 @@ executables += [
         test_template + {
                 'sources' : files(
                         'test-fsprg.c',
+                        'fsprg.c',
+                        'gcrypt-util.c',
                 ),
                 'dependencies' : [
                         libgcrypt_cflags,