Added a simple syntax checker.

1 files changed, 79 insertions, 0 deletions

diff --git a/qv4syntaxchecker.cpp b/qv4syntaxchecker.cpp
new file mode 100644
index 0000000000..64247d6954
--- /dev/null
+++ b/qv4syntaxchecker.cpp
@@ -0,0 +1,79 @@
+
+#include "qv4syntaxchecker_p.h"
+
+using namespace QQmlJS;
+
+SyntaxChecker::SyntaxChecker()
+    : Lexer(&m_engine)
+    , m_stateStack(128)
+{
+}
+
+void QQmlJS::SyntaxChecker::clearText()
+{
+    m_code.clear();
+    m_tokens.clear();
+}
+
+void SyntaxChecker::appendText(const QString &text)
+{
+    m_code += text;
+}
+
+QString SyntaxChecker::text() const
+{
+    return m_code;
+}
+
+bool SyntaxChecker::canEvaluate()
+{
+    int yyaction = 0;
+    int yytoken = -1;
+    int yytos = -1;
+
+    setCode(m_code, 1);
+
+    m_tokens.clear();
+    m_tokens.append(T_FEED_JS_PROGRAM);
+
+    do {
+        if (++yytos == m_stateStack.size())
+            m_stateStack.resize(m_stateStack.size() * 2);
+
+        m_stateStack[yytos] = yyaction;
+
+again:
+        if (yytoken == -1 && action_index[yyaction] != -TERMINAL_COUNT) {
+            if (m_tokens.isEmpty())
+                yytoken = lex();
+            else
+                yytoken = m_tokens.takeFirst();
+        }
+
+        yyaction = t_action(yyaction, yytoken);
+        if (yyaction > 0) {
+            if (yyaction == ACCEPT_STATE) {
+                --yytos;
+                return true;
+            }
+            yytoken = -1;
+        } else if (yyaction < 0) {
+            const int ruleno = -yyaction - 1;
+            yytos -= rhs[ruleno];
+            yyaction = nt_action(m_stateStack[yytos], lhs[ruleno] - TERMINAL_COUNT);
+        }
+    } while (yyaction);
+
+    const int errorState = m_stateStack[yytos];
+    if (t_action(errorState, T_AUTOMATIC_SEMICOLON) && canInsertAutomaticSemicolon(yytoken)) {
+        yyaction = errorState;
+        m_tokens.prepend(yytoken);
+        yytoken = T_SEMICOLON;
+        goto again;
+    }
+
+    if (yytoken != EOF_SYMBOL)
+        return true;
+
+    return false;
+}