make QMakeParser take a QStringRef as input

the only place where this actually saves a deep copy is the evaluation
of if(), but as a side effect the parser is now able to deal with not
null-terminated strings, which is kinda nice as well.

Change-Id: Ib6d08617aa79d2f9eaecd4906d4d548f34bf377d
Reviewed-by: Joerg Bornemann <joerg.bornemann@qt.io>
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@theqtcompany.com>
(cherry picked from qtbase/ad17a35853fe21a93fc34f7b2d9262c5ac992b29)
Reviewed-by: Jake Petroules <jake.petroules@qt.io>

7 files changed, 33 insertions, 29 deletions

diff --git a/src/plugins/qmakeprojectmanager/qmakenodes.cpp b/src/plugins/qmakeprojectmanager/qmakenodes.cpp
index 2766209e9c..30cd934c72 100644
--- a/src/plugins/qmakeprojectmanager/qmakenodes.cpp
+++ b/src/plugins/qmakeprojectmanager/qmakenodes.cpp
@@ -1229,7 +1229,7 @@ QPair<ProFile *, QStringList> QmakePriFileNode::readProFile(const QString &file)
         QMakeVfs vfs;
         QtSupport::ProMessageHandler handler;
         QMakeParser parser(0, &vfs, &handler);
-        includeFile = parser.parsedProBlock(contents, file, 1);
+        includeFile = parser.parsedProBlock(QStringRef(&contents), file, 1);
     }
     return qMakePair(includeFile, lines);
 }
@@ -1264,7 +1264,8 @@ bool QmakePriFileNode::renameFile(const QString &oldName,
 
     // We need to re-parse here: The file has changed.
     QMakeParser parser(0, 0, 0);
-    includeFile = parser.parsedProBlock(lines.join(QLatin1Char('\n')),
+    QString contents = lines.join(QLatin1Char('\n'));
+    includeFile = parser.parsedProBlock(QStringRef(&contents),
                                         m_projectFilePath.toString(), 1, QMakeParser::FullGrammar);
     QTC_ASSERT(includeFile, return false); // The file should still be valid after what we did.
 
diff --git a/src/shared/proparser/prowriter.cpp b/src/shared/proparser/prowriter.cpp
index 700e134c1b..d49c3aa864 100644
--- a/src/shared/proparser/prowriter.cpp
+++ b/src/shared/proparser/prowriter.cpp
@@ -175,7 +175,7 @@ QString ProWriter::compileScope(const QString &scope)
     if (scope.isEmpty())
         return QString();
     QMakeParser parser(0, 0, 0);
-    ProFile *includeFile = parser.parsedProBlock(scope, QLatin1String("no-file"), 1);
+    ProFile *includeFile = parser.parsedProBlock(QStringRef(&scope), QLatin1String("no-file"), 1);
     if (!includeFile)
         return QString();
     QString result = includeFile->items();
diff --git a/src/shared/proparser/qmakebuiltins.cpp b/src/shared/proparser/qmakebuiltins.cpp
index ed920ea8ac..ca0f717519 100644
--- a/src/shared/proparser/qmakebuiltins.cpp
+++ b/src/shared/proparser/qmakebuiltins.cpp
@@ -1221,7 +1221,8 @@ QMakeEvaluator::VisitReturn QMakeEvaluator::evaluateBuiltinConditional(
         return ReturnFalse; // Another qmake breakage
     case T_EVAL: {
             VisitReturn ret = ReturnFalse;
-            ProFile *pro = m_parser->parsedProBlock(args.join(statics.field_sep),
+            QString contents = args.join(statics.field_sep);
+            ProFile *pro = m_parser->parsedProBlock(QStringRef(&contents),
                                                     m_current.pro->fileName(), m_current.line);
             if (m_cumulative || pro->isOk()) {
                 m_locationStack.push(m_current);
@@ -1237,7 +1238,7 @@ QMakeEvaluator::VisitReturn QMakeEvaluator::evaluateBuiltinConditional(
             evalError(fL1S("if(condition) requires one argument."));
             return ReturnFalse;
         }
-        return evaluateConditional(args.at(0).toQString(),
+        return evaluateConditional(args.at(0).toQStringRef(),
                                    m_current.pro->fileName(), m_current.line);
     }
     case T_CONFIG: {
diff --git a/src/shared/proparser/qmakeevaluator.cpp b/src/shared/proparser/qmakeevaluator.cpp
index 2429e09912..f2a71e9252 100644
--- a/src/shared/proparser/qmakeevaluator.cpp
+++ b/src/shared/proparser/qmakeevaluator.cpp
@@ -1288,7 +1288,7 @@ void QMakeEvaluator::setupProject()
 void QMakeEvaluator::evaluateCommand(const QString &cmds, const QString &where)
 {
     if (!cmds.isEmpty()) {
-        ProFile *pro = m_parser->parsedProBlock(cmds, where, -1);
+        ProFile *pro = m_parser->parsedProBlock(QStringRef(&cmds), where, -1);
         if (pro->isOk()) {
             m_locationStack.push(m_current);
             visitProBlock(pro, pro->tokPtr());
@@ -1780,7 +1780,7 @@ QMakeEvaluator::VisitReturn QMakeEvaluator::evaluateExpandFunction(
 }
 
 QMakeEvaluator::VisitReturn QMakeEvaluator::evaluateConditional(
-        const QString &cond, const QString &where, int line)
+        const QStringRef &cond, const QString &where, int line)
 {
     VisitReturn ret = ReturnFalse;
     ProFile *pro = m_parser->parsedProBlock(cond, where, line, QMakeParser::TestGrammar);
@@ -1798,7 +1798,7 @@ QMakeEvaluator::VisitReturn QMakeEvaluator::checkRequirements(const ProStringLis
 {
     ProStringList &failed = valuesRef(ProKey("QMAKE_FAILED_REQUIREMENTS"));
     for (const ProString &dep : deps) {
-        VisitReturn vr = evaluateConditional(dep.toQString(), m_current.pro->fileName(), m_current.line);
+        VisitReturn vr = evaluateConditional(dep.toQStringRef(), m_current.pro->fileName(), m_current.line);
         if (vr == ReturnError)
             return ReturnError;
         if (vr != ReturnTrue)
diff --git a/src/shared/proparser/qmakeevaluator.h b/src/shared/proparser/qmakeevaluator.h
index 672a36b7b7..9426445810 100644
--- a/src/shared/proparser/qmakeevaluator.h
+++ b/src/shared/proparser/qmakeevaluator.h
@@ -211,7 +211,7 @@ public:
     ProStringList evaluateBuiltinExpand(int func_t, const ProKey &function, const ProStringList &args);
     VisitReturn evaluateBuiltinConditional(int func_t, const ProKey &function, const ProStringList &args);
 
-    VisitReturn evaluateConditional(const QString &cond, const QString &where, int line = -1);
+    VisitReturn evaluateConditional(const QStringRef &cond, const QString &where, int line = -1);
 #ifdef PROEVALUATOR_FULL
     VisitReturn checkRequirements(const ProStringList &deps);
 #endif
diff --git a/src/shared/proparser/qmakeparser.cpp b/src/shared/proparser/qmakeparser.cpp
index 777402068f..7751265e91 100644
--- a/src/shared/proparser/qmakeparser.cpp
+++ b/src/shared/proparser/qmakeparser.cpp
@@ -221,7 +221,7 @@ ProFile *QMakeParser::parsedProFile(const QString &fileName, ParseFlags flags)
 }
 
 ProFile *QMakeParser::parsedProBlock(
-        const QString &contents, const QString &name, int line, SubGrammar grammar)
+        const QStringRef &contents, const QString &name, int line, SubGrammar grammar)
 {
     ProFile *pro = new ProFile(name);
     read(pro, contents, line, grammar);
@@ -244,7 +244,7 @@ bool QMakeParser::read(ProFile *pro, ParseFlags flags)
                                fL1S("Cannot read %1: %2").arg(pro->fileName(), errStr));
         return false;
     }
-    read(pro, content, 1, FullGrammar);
+    read(pro, QStringRef(&content), 1, FullGrammar);
     return true;
 }
 
@@ -286,7 +286,7 @@ void QMakeParser::finalizeHashStr(ushort *buf, uint len)
     buf[-2] = (ushort)(hash >> 16);
 }
 
-void QMakeParser::read(ProFile *pro, const QString &in, int line, SubGrammar grammar)
+void QMakeParser::read(ProFile *pro, const QStringRef &in, int line, SubGrammar grammar)
 {
     m_proFile = pro;
     m_lineNo = line;
@@ -334,8 +334,8 @@ void QMakeParser::read(ProFile *pro, const QString &in, int line, SubGrammar gra
     QStack<ParseCtx> xprStack;
     xprStack.reserve(10);
 
-    // We rely on QStrings being null-terminated, so don't maintain a global end pointer.
     const ushort *cur = (const ushort *)in.unicode();
+    const ushort *inend = cur + in.length();
     m_canElse = false;
   freshLine:
     m_state = StNew;
@@ -418,7 +418,7 @@ void QMakeParser::read(ProFile *pro, const QString &in, int line, SubGrammar gra
     int indent;
 
     if (context == CtxPureValue) {
-        end = (const ushort *)in.unicode() + in.length();
+        end = inend;
         cptr = 0;
         lineCont = false;
         indent = 0; // just gcc being stupid
@@ -430,24 +430,30 @@ void QMakeParser::read(ProFile *pro, const QString &in, int line, SubGrammar gra
 
         // First, skip leading whitespace
         for (indent = 0; ; ++cur, ++indent) {
+            if (cur == inend) {
+                cur = 0;
+                goto flushLine;
+            }
             c = *cur;
             if (c == '\n') {
                 ++cur;
                 goto flushLine;
-            } else if (!c) {
-                cur = 0;
-                goto flushLine;
-            } else if (c != ' ' && c != '\t' && c != '\r') {
-                break;
             }
+            if (c != ' ' && c != '\t' && c != '\r')
+                break;
         }
 
         // Then strip comments. Yep - no escaping is possible.
         for (cptr = cur;; ++cptr) {
+            if (cptr == inend) {
+                end = cptr;
+                break;
+            }
             c = *cptr;
             if (c == '#') {
-                for (end = cptr; (c = *++cptr);) {
-                    if (c == '\n') {
+                end = cptr;
+                while (++cptr < inend) {
+                    if (*cptr == '\n') {
                         ++cptr;
                         break;
                     }
@@ -460,10 +466,6 @@ void QMakeParser::read(ProFile *pro, const QString &in, int line, SubGrammar gra
                 }
                 break;
             }
-            if (!c) {
-                end = cptr;
-                break;
-            }
             if (c == '\n') {
                 end = cptr++;
                 break;
@@ -1215,7 +1217,7 @@ void QMakeParser::finalizeCall(ushort *&tokPtr, ushort *uc, ushort *ptr, int arg
 bool QMakeParser::resolveVariable(ushort *xprPtr, int tlen, int needSep, ushort **ptr,
                                   ushort **buf, QString *xprBuff,
                                   ushort **tokPtr, QString *tokBuff,
-                                  const ushort *cur, const QString &in)
+                                  const ushort *cur, const QStringRef &in)
 {
     QString out;
     m_tmp.setRawData((const QChar *)xprPtr, tlen);
diff --git a/src/shared/proparser/qmakeparser.h b/src/shared/proparser/qmakeparser.h
index d44523d024..d370d17cbb 100644
--- a/src/shared/proparser/qmakeparser.h
+++ b/src/shared/proparser/qmakeparser.h
@@ -83,7 +83,7 @@ public:
     enum SubGrammar { FullGrammar, TestGrammar, ValueGrammar };
     // fileName is expected to be absolute and cleanPath()ed.
     ProFile *parsedProFile(const QString &fileName, ParseFlags flags = ParseDefault);
-    ProFile *parsedProBlock(const QString &contents, const QString &name, int line = 0,
+    ProFile *parsedProBlock(const QStringRef &contents, const QString &name, int line = 0,
                             SubGrammar grammar = FullGrammar);
 
     void discardFileFromCache(const QString &fileName);
@@ -126,7 +126,7 @@ private:
     };
 
     bool read(ProFile *pro, ParseFlags flags);
-    void read(ProFile *pro, const QString &content, int line, SubGrammar grammar);
+    void read(ProFile *pro, const QStringRef &content, int line, SubGrammar grammar);
 
     ALWAYS_INLINE void putTok(ushort *&tokPtr, ushort tok);
     ALWAYS_INLINE void putBlockLen(ushort *&tokPtr, uint len);
@@ -137,7 +137,7 @@ private:
     ALWAYS_INLINE bool resolveVariable(ushort *xprPtr, int tlen, int needSep, ushort **ptr,
                                        ushort **buf, QString *xprBuff,
                                        ushort **tokPtr, QString *tokBuff,
-                                       const ushort *cur, const QString &in);
+                                       const ushort *cur, const QStringRef &in);
     void finalizeCond(ushort *&tokPtr, ushort *uc, ushort *ptr, int wordCount);
     void finalizeCall(ushort *&tokPtr, ushort *uc, ushort *ptr, int argc);
     void warnOperator(const char *msg);