QMakeGlobals::expandEnvVars: Make sane

Use indexOf() to match individual characters, which is a lot faster than
QRegExp. As a side effect, don't try to expand what we just inserted.

Change-Id: I964fbd92055f2f2649e7d8ed5739cf1fc7cae927
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@digia.com>
Reviewed-by: Daniel Teske <daniel.teske@digia.com>
Reviewed-by: Joerg Bornemann <joerg.bornemann@theqtcompany.com>
(cherry picked from qtcreator/2cc17a61eb6d0fee80fd388fcc5be03a59e4f2b5)
Reviewed-by: hjk <hjk@theqtcompany.com>
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@theqtcompany.com>

1 files changed, 18 insertions, 24 deletions

diff --git a/src/linguist/shared/qmakeglobals.cpp b/src/linguist/shared/qmakeglobals.cpp
index dda9c1f13..853309cae 100644
--- a/src/linguist/shared/qmakeglobals.cpp
+++ b/src/linguist/shared/qmakeglobals.cpp
@@ -74,27 +74,8 @@ QT_BEGIN_NAMESPACE
 
 #define fL1S(s) QString::fromLatin1(s)
 
-namespace { // MSVC doesn't seem to know the semantics of "static" ...
-
-static struct {
-    QRegExp reg_variableName;
-} statics;
-
-}
-
-static void initStatics()
-{
-    if (!statics.reg_variableName.isEmpty())
-        return;
-
-    statics.reg_variableName.setPattern(QLatin1String("\\$\\(.*\\)"));
-    statics.reg_variableName.setMinimal(true);
-}
-
 QMakeGlobals::QMakeGlobals()
 {
-    initStatics();
-
     do_cache = true;
 
 #ifdef PROEVALUATOR_DEBUG
@@ -292,11 +273,24 @@ QStringList QMakeGlobals::getPathListEnv(const QString &var) const
 QString QMakeGlobals::expandEnvVars(const QString &str) const
 {
     QString string = str;
-    int rep;
-    QRegExp reg_variableName = statics.reg_variableName; // Copy for thread safety
-    while ((rep = reg_variableName.indexIn(string)) != -1)
-        string.replace(rep, reg_variableName.matchedLength(),
-                       getEnv(string.mid(rep + 2, reg_variableName.matchedLength() - 3)));
+    int startIndex = 0;
+    forever {
+        startIndex = string.indexOf(QLatin1Char('$'), startIndex);
+        if (startIndex < 0)
+            break;
+        if (string.length() < startIndex + 3)
+            break;
+        if (string.at(startIndex + 1) != QLatin1Char('(')) {
+            startIndex++;
+            continue;
+        }
+        int endIndex = string.indexOf(QLatin1Char(')'), startIndex + 2);
+        if (endIndex < 0)
+            break;
+        QString value = getEnv(string.mid(startIndex + 2, endIndex - startIndex - 2));
+        string.replace(startIndex, endIndex - startIndex + 1, value);
+        startIndex += value.length();
+    }
     return string;
 }