make macro substitutions reusable

MacroTable::parseSubstitutionStatement now returns an Substitution
object that can be applied on multiple values.

Change-Id: I48329701666020f3d8d551b56696d8aa9038cbd2
Reviewed-by: Joerg Bornemann <joerg.bornemann@digia.com>

3 files changed, 28 insertions, 9 deletions

diff --git a/src/jomlib/macrotable.cpp b/src/jomlib/macrotable.cpp
index e4fe900..6c1c8ed 100644
--- a/src/jomlib/macrotable.cpp
+++ b/src/jomlib/macrotable.cpp
@@ -237,8 +237,10 @@ QString MacroTable::expandMacros(const QString& str, bool inDependentsLine, QSet
                     {
                         QString macroValue = cycleCheckedMacroValue(macroName, usedMacros);
                         macroValue = expandMacros(macroValue, inDependentsLine, usedMacros);
-                        if (macroNameEnd != macroInvokationEnd)
-                            parseSubstitutionStatement(str, macroNameEnd + 1, macroValue, macroInvokationEnd);
+                        if (macroNameEnd != macroInvokationEnd) {
+                            const Substitution s = parseSubstitutionStatement(str, macroNameEnd + 1, macroInvokationEnd);
+                            applySubstitution(s, macroValue);
+                        }
                         usedMacros.remove(macroName);
                         ret.append(macroValue);
                     }
@@ -334,7 +336,9 @@ void MacroTable::dump() const
  * equalsSignIdx:                       ^
  * macroInvokationEndIdx:                   ^
  */
-void MacroTable::parseSubstitutionStatement(const QString &str, int substitutionStartIdx, QString &value, int &macroInvokationEndIdx)
+MacroTable::Substitution MacroTable::parseSubstitutionStatement(const QString &str,
+                                                                int substitutionStartIdx,
+                                                                int &macroInvokationEndIdx)
 {
     macroInvokationEndIdx = -1;
     int equalsSignIdx = -1;
@@ -360,11 +364,17 @@ void MacroTable::parseSubstitutionStatement(const QString &str, int substitution
     if (equalsSignIdx < 0 || macroInvokationEndIdx < 0)
         throw Exception(QLatin1String("Cannot find = after : in macro substitution."));
 
-    QString before = str.mid(substitutionStartIdx, equalsSignIdx - substitutionStartIdx);
-    QString after = str.mid(equalsSignIdx + 1, macroInvokationEndIdx - equalsSignIdx - 1);
+    Substitution result;
+    result.before = str.mid(substitutionStartIdx, equalsSignIdx - substitutionStartIdx);
+    result.after = str.mid(equalsSignIdx + 1, macroInvokationEndIdx - equalsSignIdx - 1);
     for (int i=quotePositions.count() - 1; i >= 0; --i)
-        after.remove(quotePositions.at(i) - equalsSignIdx - 1, 1);
-    value.replace(before, after);
+        result.after.remove(quotePositions.at(i) - equalsSignIdx - 1, 1);
+    return result;
+}
+
+void MacroTable::applySubstitution(const MacroTable::Substitution &substitution, QString &value)
+{
+    value.replace(substitution.before, substitution.after);
 }
 
 } // namespace NMakeFile
diff --git a/src/jomlib/macrotable.h b/src/jomlib/macrotable.h
index 1906ed9..443884f 100644
--- a/src/jomlib/macrotable.h
+++ b/src/jomlib/macrotable.h
@@ -48,7 +48,14 @@ public:
     QString expandMacros(const QString& str, bool inDependentsLine = false) const;
     void dump() const;
 
-    static void parseSubstitutionStatement(const QString &str, int substitutionStartIdx, QString &value, int &macroInvokationEndIdx);
+    struct Substitution
+    {
+        QString before;
+        QString after;
+    };
+
+    static Substitution parseSubstitutionStatement(const QString &str, int substitutionStartIdx, int &macroInvokationEndIdx);
+    static void applySubstitution(const Substitution &substitution, QString &value);
 
 private:
     struct MacroData
diff --git a/src/jomlib/makefile.cpp b/src/jomlib/makefile.cpp
index 286246d..15f65a8 100644
--- a/src/jomlib/makefile.cpp
+++ b/src/jomlib/makefile.cpp
@@ -239,7 +239,9 @@ void DescriptionBlock::expandFileNameMacros(QString& str, int depIdx, bool depen
 
                 if (substitutionIdx > 0) {
                     int macroInvokationEnd;
-                    MacroTable::parseSubstitutionStatement(str, substitutionIdx, macroValue, macroInvokationEnd);
+                    const MacroTable::Substitution substitution =
+                            MacroTable::parseSubstitutionStatement(str, substitutionIdx, macroInvokationEnd);
+                    MacroTable::applySubstitution(substitution, macroValue);
                     replacementLength = macroInvokationEnd - idx - 2;  // because we're later adding 4
                 }