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>

5 files changed, 29 insertions, 26 deletions

diff --git a/qmake/library/qmakebuiltins.cpp b/qmake/library/qmakebuiltins.cpp
index 9d35a31ffc..c5ea26977e 100644
--- a/qmake/library/qmakebuiltins.cpp
+++ b/qmake/library/qmakebuiltins.cpp
@@ -1210,7 +1210,8 @@ 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);
@@ -1226,7 +1227,7 @@ QMakeEvaluator::VisitReturn QMakeEvaluator::evaluateBuiltinConditional(
             evalError(fL1S("if(condition) requires one argument."));
             return ReturnFalse;
         }
-        return returnBool(evaluateConditional(args.at(0).toQString(),
+        return returnBool(evaluateConditional(args.at(0).toQStringRef(),
                                               m_current.pro->fileName(), m_current.line));
     }
     case T_CONFIG: {
diff --git a/qmake/library/qmakeevaluator.cpp b/qmake/library/qmakeevaluator.cpp
index 4ce7b0c4b8..6182e4bf3e 100644
--- a/qmake/library/qmakeevaluator.cpp
+++ b/qmake/library/qmakeevaluator.cpp
@@ -1277,7 +1277,7 @@ 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());
@@ -1760,7 +1760,7 @@ ProStringList QMakeEvaluator::evaluateExpandFunction(
     return ProStringList();
 }
 
-bool QMakeEvaluator::evaluateConditional(const QString &cond, const QString &where, int line)
+bool QMakeEvaluator::evaluateConditional(const QStringRef &cond, const QString &where, int line)
 {
     bool ret = false;
     ProFile *pro = m_parser->parsedProBlock(cond, where, line, QMakeParser::TestGrammar);
@@ -1778,7 +1778,7 @@ void QMakeEvaluator::checkRequirements(const ProStringList &deps)
 {
     ProStringList &failed = valuesRef(ProKey("QMAKE_FAILED_REQUIREMENTS"));
     for (const ProString &dep : deps)
-        if (!evaluateConditional(dep.toQString(), m_current.pro->fileName(), m_current.line))
+        if (!evaluateConditional(dep.toQStringRef(), m_current.pro->fileName(), m_current.line))
             failed << dep;
 }
 #endif
diff --git a/qmake/library/qmakeevaluator.h b/qmake/library/qmakeevaluator.h
index 8a87108c91..48dd631b19 100644
--- a/qmake/library/qmakeevaluator.h
+++ b/qmake/library/qmakeevaluator.h
@@ -216,7 +216,7 @@ public:
     ProStringList evaluateBuiltinExpand(int func_t, const ProKey &function, const ProStringList &args);
     VisitReturn evaluateBuiltinConditional(int func_t, const ProKey &function, const ProStringList &args);
 
-    bool evaluateConditional(const QString &cond, const QString &where, int line = -1);
+    bool evaluateConditional(const QStringRef &cond, const QString &where, int line = -1);
 #ifdef PROEVALUATOR_FULL
     void checkRequirements(const ProStringList &deps);
 #endif
diff --git a/qmake/library/qmakeparser.cpp b/qmake/library/qmakeparser.cpp
index 2a48103147..90bc64bd2b 100644
--- a/qmake/library/qmakeparser.cpp
+++ b/qmake/library/qmakeparser.cpp
@@ -224,7 +224,7 @@ 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);
@@ -247,7 +247,7 @@ 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;
 }
 
@@ -289,7 +289,7 @@ 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/qmake/library/qmakeparser.h b/qmake/library/qmakeparser.h
index f78b3215bb..f8ff2fc3cc 100644
--- a/qmake/library/qmakeparser.h
+++ b/qmake/library/qmakeparser.h
@@ -87,7 +87,7 @@ 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);
@@ -130,7 +130,7 @@ 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);
@@ -141,7 +141,7 @@ 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);