Cpp{Tools,Editor}: Respect multi-QChar code points when handling identifiers

* Consolidate code dealing with C++ identifiers into cpptoolsreuse.h
* Handle code points that are represented with two QChars

Change-Id: I4fb4435aa539f65d88598cac0b50629f33f32440
Reviewed-by: Erik Verbruggen <erik.verbruggen@digia.com>

src/plugins/cpptools/cppcompletionassist.cpp

@@ -35,6 +35,7 @@
 #include "cppsnapshotupdater.h"
 #include "cpptoolsconstants.h"
 #include "cpptoolseditorsupport.h"
+#include "cpptoolsreuse.h"
 
 #include <coreplugin/icore.h>
 #include <cppeditor/cppeditorconstants.h>
@@ -314,8 +315,7 @@ void CppAssistProposalItem::applyContextualContent(TextEditor::BaseTextEditor *e
         while (preserveLength > 0) {
             if (inEditor.startsWith(toInsert.right(preserveLength))
                     && (inEditorLength == preserveLength
-                        || (!inEditor.at(preserveLength).isLetterOrNumber()
-                            && inEditor.at(preserveLength) != QLatin1Char('_')))) {
+                        || !CppTools::isValidIdentifierChar(inEditor.at(preserveLength)))) {
                 break;
             }
             --preserveLength;
@@ -671,11 +671,12 @@ bool CppCompletionAssistProcessor::accepts() const
     } else {
         // Trigger completion after three characters of a name have been typed, when not editing an existing name
         QChar characterUnderCursor = m_interface->characterAt(pos);
-        if (!characterUnderCursor.isLetterOrNumber() && characterUnderCursor != QLatin1Char('_')) {
+
+        if (!isValidIdentifierChar(characterUnderCursor)) {
             const int startOfName = findStartOfName(pos);
             if (pos - startOfName >= 3) {
                 const QChar firstCharacter = m_interface->characterAt(startOfName);
-                if (firstCharacter.isLetter() || firstCharacter == QLatin1Char('_')) {
+                if (isValidFirstIdentifierChar(firstCharacter)) {
                     // Finally check that we're not inside a comment or string (code copied from startOfOperator)
                     QTextCursor tc(m_interface->textDocument());
                     tc.setPosition(pos);
@@ -875,7 +876,7 @@ int CppCompletionAssistProcessor::findStartOfName(int pos) const
     // Skip to the start of a name
     do {
         chr = m_interface->characterAt(--pos);
-    } while (chr.isLetterOrNumber() || chr == QLatin1Char('_'));
+    } while (CppTools::isValidIdentifierChar(chr));
 
     return pos + 1;
 }

src/plugins/cpptools/cppcompletionassistprovider.cpp

@@ -29,6 +29,8 @@
 
 #include "cppcompletionassistprovider.h"
 
+#include "cpptoolsreuse.h"
+
 #include <cppeditor/cppeditorconstants.h>
 
 #include <cplusplus/Token.h>
@@ -59,6 +61,11 @@ bool CppCompletionAssistProvider::isActivationCharSequence(const QString &sequen
     return false;
 }
 
+bool CppCompletionAssistProvider::isContinuationChar(const QChar &c) const
+{
+    return isValidIdentifierChar(c);
+}
+
 int CppCompletionAssistProvider::activationSequenceChar(const QChar &ch,
                                                         const QChar &ch2,
                                                         const QChar &ch3,

src/plugins/cpptools/cppcompletionassistprovider.h

@@ -58,6 +58,7 @@ public:
     bool supportsEditor(const Core::Id &editorId) const QTC_OVERRIDE;
     int activationCharSequenceLength() const QTC_OVERRIDE;
     bool isActivationCharSequence(const QString &sequence) const QTC_OVERRIDE;
+    bool isContinuationChar(const QChar &c) const QTC_OVERRIDE;
 
     virtual TextEditor::IAssistInterface *createAssistInterface(
             ProjectExplorer::Project *project, TextEditor::BaseTextEditor *editor,

src/plugins/cpptools/cpptoolsreuse.cpp

@@ -50,7 +50,7 @@ static void moveCursorToStartOrEndOfIdentifier(QTextCursor *tc,
         return;
 
     QChar ch = doc->characterAt(tc->position() - posDiff);
-    while (ch.isLetterOrNumber() || ch == QLatin1Char('_')) {
+    while (isValidIdentifierChar(ch)) {
         tc->movePosition(op);
         ch = doc->characterAt(tc->position() - posDiff);
     }
@@ -111,16 +111,31 @@ bool isOwnershipRAIIType(CPlusPlus::Symbol *symbol, const LookupContext &context
     return false;
 }
 
+bool isValidAsciiIdentifierChar(const QChar &ch)
+{
+    return ch.isLetterOrNumber() || ch == QLatin1Char(' ');
+}
+
+bool isValidFirstIdentifierChar(const QChar &ch)
+{
+    return ch.isLetter() || ch == QLatin1Char('_') || ch.isHighSurrogate() || ch.isLowSurrogate();
+}
+
+bool isValidIdentifierChar(const QChar &ch)
+{
+    return isValidFirstIdentifierChar(ch) || ch.isNumber();
+}
+
 bool isValidIdentifier(const QString &s)
 {
     const int length = s.length();
     for (int i = 0; i < length; ++i) {
         const QChar &c = s.at(i);
         if (i == 0) {
-            if (!c.isLetter() && c != QLatin1Char('_'))
+            if (!isValidFirstIdentifierChar(c))
                 return false;
         } else {
-            if (!c.isLetterOrNumber() && c != QLatin1Char('_'))
+            if (!isValidIdentifierChar(c))
                 return false;
         }
     }

src/plugins/cpptools/cpptoolsreuse.h

@@ -32,6 +32,7 @@
 
 #include "cpptools_global.h"
 
+QT_FORWARD_DECLARE_CLASS(QChar)
 QT_FORWARD_DECLARE_CLASS(QTextCursor)
 QT_FORWARD_DECLARE_CLASS(QStringRef)
 
@@ -48,6 +49,9 @@ void CPPTOOLS_EXPORT moveCursorToStartOfIdentifier(QTextCursor *tc);
 bool CPPTOOLS_EXPORT isOwnershipRAIIType(CPlusPlus::Symbol *symbol,
                                          const CPlusPlus::LookupContext &context);
 
+bool CPPTOOLS_EXPORT isValidAsciiIdentifierChar(const QChar &ch);
+bool CPPTOOLS_EXPORT isValidFirstIdentifierChar(const QChar &ch);
+bool CPPTOOLS_EXPORT isValidIdentifierChar(const QChar &ch);
 bool CPPTOOLS_EXPORT isValidIdentifier(const QString &s);
 
 bool CPPTOOLS_EXPORT isQtKeyword(const QStringRef &text);