[shellprocess] Allow gs[key] variables in commands

src/libcalamares/utils/CommandList.cpp

@@ -55,6 +55,41 @@ get_variant_stringlist( const QVariantList& l )
     return retl;
 }
 
+/** @brief Inserts the keys from @p map into @p expander as "gs"-keys
+ *
+ * For each key k in @p map, a key with literal `gs[` + prefix + '.' + key +
+ * literal `]` is inserted into the exapander.
+ */
+static void
+expand_tree( Calamares::String::DictionaryExpander& expander, const QString& prefix, const QVariantMap& map )
+{
+    // With the current prefix, turn a key into gs[prefix.key]
+    auto gs_key = [ &prefix ]( const QString& k ) -> QString
+    { return QStringLiteral( "gs[" ) + ( prefix.isEmpty() ? QString() : prefix + '.' ) + k + ']'; };
+
+    for ( QVariantMap::const_iterator valueiter = map.cbegin(); valueiter != map.cend(); ++valueiter )
+    {
+        const QString key = valueiter.key();
+        const QVariant value = valueiter.value();
+
+        switch ( Calamares::typeOf( value ) )
+        {
+        case Calamares::MapVariantType:
+            expand_tree( expander, prefix.isEmpty() ? key : ( prefix + '.' + key ), value.toMap() );
+            break;
+        case Calamares::StringVariantType:
+            expander.add( gs_key( key ), value.toString() );
+            break;
+        case Calamares::IntVariantType:
+            expander.add( gs_key( key ), QString::number( value.toInt() ) );
+            break;
+        default:
+            // Silently ignore
+            break;
+        }
+    }
+}
+
 static Calamares::String::DictionaryExpander
 get_gs_expander( System::RunLocation location )
 {
@@ -88,6 +123,11 @@ get_gs_expander( System::RunLocation location )
         }
     }
 
+    if ( gs )
+    {
+        expand_tree( expander, QString(), gs->data() );
+    }
+
     return expander;
 }
 

src/libcalamares/utils/Tests.cpp

@@ -282,9 +282,17 @@ LibCalamaresTests::testCommandExpansion_data()
     QTest::addColumn< QString >( "command" );
     QTest::addColumn< QString >( "expected" );
 
-    QTest::newRow( "empty" ) << QString() << QString();
+    QTest::newRow( "empty  " ) << QString() << QString();
-    QTest::newRow( "ls   " ) << QStringLiteral( "ls" ) << QStringLiteral( "ls" );
+    QTest::newRow( "ls     " ) << QStringLiteral( "ls" ) << QStringLiteral( "ls" );
-    QTest::newRow( "user " ) << QStringLiteral( "chmod $USER" ) << QStringLiteral( "chmod alice" );
+    QTest::newRow( "$USER  " ) << QStringLiteral( "chmod $USER" ) << QStringLiteral( "chmod alice" );
+    QTest::newRow( "${USER}" ) << QStringLiteral( "chmod ${USER}" ) << QStringLiteral( "chmod alice" );
+    QTest::newRow( "gs-user" ) << QStringLiteral( "chmod ${gs[username]}" ) << QStringLiteral( "chmod alice" );
+    QTest::newRow( "gs-*   " ) << QStringLiteral(
+        "${gs[username]} has ${gs[branding.bootloader]} ${gs[branding.ducks]} ducks" )
+                               << QStringLiteral( "alice has found 3 ducks" );
+    // QStringList does not expand
+    QTest::newRow( "gs-list" ) << QStringLiteral( "colors ${gs[branding.color]}" )
+                               << QStringLiteral( "colors ${gs[branding.color]}" );
 }
 
 void
@@ -295,6 +303,12 @@ LibCalamaresTests::testCommandExpansion()
     QVERIFY( gs );
     gs->insert( QStringLiteral( "username" ), QStringLiteral( "alice" ) );
 
+    QVariantMap m;
+    m.insert( QStringLiteral( "bootloader" ), QStringLiteral( "found" ) );
+    m.insert( QStringLiteral( "ducks" ), 3 );
+    m.insert( QStringLiteral( "color" ), QStringList { "green", "red" } );
+    gs->insert( QStringLiteral( "branding" ), m );
+
     QFETCH( QString, command );
     QFETCH( QString, expected );
     Calamares::CommandLine c( command, std::chrono::seconds( 0 ) );

src/modules/shellprocess/shellprocess.conf

@@ -16,6 +16,17 @@
 #    of Calamares, set on the welcome page. This may not reflect the
 #    chosen system language from the locale page.
 #
+# As a special case, variables of the form `gs[key]` where `key` is
+# a dotted-keys string and `gs` is literally the letters `g` and `s`,
+# use **any** value from Global Storage. For example,
+#
+#    gs[branding.bootloader]
+#
+# This variable refers to the GS value stored in `bootloader` in the
+# `branding` map. Examine the Debug window for information about the
+# keys stored in GS. Only strings and integers are exposed this way,
+# lists and other data types do not set any variable this way.
+#
 # Variables are written as `${var}`, e.g. `${ROOT}`.
 # Write `$$` to get a shell-escaped `\$` in the shell command.
 # It is not possible to get an un-escaped `$` in the shell command