qmake: use reserve to optimize memory allocation

Change-Id: I6ace338512c24fd9dc11c767a28f0a63454076fa
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@theqtcompany.com>
(cherry picked from qtbase/1d3503b8f3b49b0f684e1caa504deb0d05f2c60a)
Reviewed-by: Jake Petroules <jake.petroules@qt.io>
Reviewed-by: Anton Kudryavtsev <a.kudryavtsev@netris.ru>

2 files changed, 6 insertions, 1 deletions

diff --git a/src/shared/proparser/qmakebuiltins.cpp b/src/shared/proparser/qmakebuiltins.cpp
index 6a064a7ab6..035a18493a 100644
--- a/src/shared/proparser/qmakebuiltins.cpp
+++ b/src/shared/proparser/qmakebuiltins.cpp
@@ -146,6 +146,7 @@ void QMakeEvaluator::initFunctionStatics()
         { "shell_quote", E_SHELL_QUOTE },
         { "getenv", E_GETENV },
     };
+    statics.expands.reserve((int)(sizeof(expandInits)/sizeof(expandInits[0])));
     for (unsigned i = 0; i < sizeof(expandInits)/sizeof(expandInits[0]); ++i)
         statics.expands.insert(ProKey(expandInits[i].name), expandInits[i].func);
 
@@ -187,6 +188,7 @@ void QMakeEvaluator::initFunctionStatics()
         { "touch", T_TOUCH },
         { "cache", T_CACHE },
     };
+    statics.functions.reserve((int)(sizeof(testInits)/sizeof(testInits[0])));
     for (unsigned i = 0; i < sizeof(testInits)/sizeof(testInits[0]); ++i)
         statics.functions.insert(ProKey(testInits[i].name), testInits[i].func);
 }
diff --git a/src/shared/proparser/qmakeevaluator.cpp b/src/shared/proparser/qmakeevaluator.cpp
index 448139129b..2429e09912 100644
--- a/src/shared/proparser/qmakeevaluator.cpp
+++ b/src/shared/proparser/qmakeevaluator.cpp
@@ -183,6 +183,7 @@ void QMakeEvaluator::initStatics()
         { "IN_PWD", "PWD" },
         { "DEPLOYMENT", "INSTALLS" }
     };
+    statics.varMap.reserve((int)(sizeof(mapInits)/sizeof(mapInits[0])));
     for (unsigned i = 0; i < sizeof(mapInits)/sizeof(mapInits[0]); ++i)
         statics.varMap.insert(ProKey(mapInits[i].oldname), ProKey(mapInits[i].newname));
 }
@@ -760,12 +761,14 @@ QMakeEvaluator::VisitReturn QMakeEvaluator::visitProLoop(
                 if (ok) {
                     int end = itl.mid(dotdot+2).toInt(&ok);
                     if (ok) {
-                        if (m_cumulative && qAbs(end - start) > 100) {
+                        const int absDiff = qAbs(end - start);
+                        if (m_cumulative && absDiff > 100) {
                             // Such a loop is unlikely to contribute something useful to the
                             // file collection, and may cause considerable delay.
                             traceMsg("skipping excessive loop in cumulative mode");
                             return ReturnFalse;
                         }
+                        list.reserve(absDiff + 1);
                         if (start < end) {
                             for (int i = start; i <= end; i++)
                                 list << ProString(QString::number(i));