Add resolve_depends(var, prefix) function to qmake

This function calculates the topological order of variables.
We will use it to determine which and in what order to link
module libraries.

The function is not tied to libraries/modules only, but requires
the variables to be ordered to have their dependencies in the
[prefix]<var>.depends subvariable.

Due to the recursive nature of the algorithm it was just much easier
to implement it directly in C++ rather than in a qmake-language
function.

2 files changed, 46 insertions, 1 deletions

diff --git a/qmake/project.cpp b/qmake/project.cpp
index d4fa786ac5..993c16185e 100644
--- a/qmake/project.cpp
+++ b/qmake/project.cpp
@@ -81,7 +81,7 @@ enum ExpandFunc { E_MEMBER=1, E_FIRST, E_LAST, E_CAT, E_FROMFILE, E_EVAL, E_LIST
                   E_SPRINTF, E_JOIN, E_SPLIT, E_BASENAME, E_DIRNAME, E_SECTION,
                   E_FIND, E_SYSTEM, E_UNIQUE, E_QUOTE, E_ESCAPE_EXPAND,
                   E_UPPER, E_LOWER, E_FILES, E_PROMPT, E_RE_ESCAPE, E_REPLACE,
-                  E_SIZE, E_GENERATE_UID };
+                  E_SIZE, E_GENERATE_UID, E_RESOLVE_DEPENDS };
 QMap<QString, ExpandFunc> qmake_expandFunctions()
 {
     static QMap<QString, ExpandFunc> *qmake_expand_functions = 0;
@@ -114,6 +114,7 @@ QMap<QString, ExpandFunc> qmake_expandFunctions()
         qmake_expand_functions->insert("replace", E_REPLACE);
         qmake_expand_functions->insert("size", E_SIZE);
         qmake_expand_functions->insert("generate_uid", E_GENERATE_UID);
+        qmake_expand_functions->insert("resolve_depends", E_RESOLVE_DEPENDS);
     }
     return *qmake_expand_functions;
 }
@@ -1800,6 +1801,39 @@ QMakeProject::doProjectExpand(QString func, QStringList args,
 // defined in symbian generator
 extern QString generate_test_uid(const QString& target);
 
+
+void calculateDeps(QStringList &sortedList, const QString &item, const QString &prefix,
+                   QStringList &org, QMap<QString, QStringList> &place)
+{
+    if (sortedList.contains(item))
+        return;
+
+    foreach(QString dep, place.value(prefix + item + ".depends")) {
+        calculateDeps(sortedList, dep, prefix, org, place);
+        if (org.isEmpty())
+            break;
+    }
+
+    if (org.contains(item)) {
+        sortedList += item;
+        org.removeAll(item);
+    }
+}
+
+QStringList
+QMakeProject::resolveDepends(const QStringList &deps, const QString &prefix,
+                             QMap<QString, QStringList> &place)
+{
+    QStringList sortedList;
+    QStringList org = deps;
+    foreach(QString item, deps) {
+        calculateDeps(sortedList, item, prefix, org, place);
+        if (org.isEmpty())
+            break;
+    }
+    return sortedList;
+}
+
 QStringList
 QMakeProject::doProjectExpand(QString func, QList<QStringList> args_list,
                               QMap<QString, QStringList> &place)
@@ -2246,6 +2280,16 @@ QMakeProject::doProjectExpand(QString func, QList<QStringList> args_list,
             ret += generate_test_uid(args.first());
         }
         break;
+    case E_RESOLVE_DEPENDS: {
+        if(args.count() < 1 || args.count() > 2) {
+            fprintf(stderr, "%s:%d: resolve_depends(var, prefix) requires one or two arguments.\n",
+                    parser.file.toLatin1().constData(), parser.line_no);
+        } else {
+            ret += resolveDepends(args[0].split(QString(Option::field_sep)),
+                                  (args.count() != 2 ? QString() : args[1]),
+                                  place);
+        }
+        break; }
     default: {
         fprintf(stderr, "%s:%d: Unknown replace function: %s\n",
                 parser.file.toLatin1().constData(), parser.line_no,
diff --git a/qmake/project.h b/qmake/project.h
index 0e6131d3a2..aea18afd52 100644
--- a/qmake/project.h
+++ b/qmake/project.h
@@ -107,6 +107,7 @@ class QMakeProject
     QStringList doVariableReplaceExpand(const QString &str, QMap<QString, QStringList> &place, bool *ok=0);
     void init(QMakeProperty *, const QMap<QString, QStringList> *);
     QStringList &values(const QString &v, QMap<QString, QStringList> &place);
+    QStringList resolveDepends(const QStringList &deps, const QString &prefix, QMap<QString, QStringList> &place);
     void validateModes();
 
 public: