Debugger: Use the code model to detect unitialized variables.

This should save debugger round trips and crashes in the debugging
helpers.
Add respective option to debugging helper option page, defaulting to
true.On this occasion, make CDB detect shadowed variables correctly
and display them as "<shadowed n>" as does the Gdb engine by
reversing the direction in which
CdbSymbolGroupContext::populateINameIndexMap works.
Rubber-stamped-by: hjk <[email protected]>

1 files changed, 203 insertions, 0 deletions

diff --git a/src/plugins/debugger/watchutils.cpp b/src/plugins/debugger/watchutils.cpp
index 6fe9256b744..e7d52147aa9 100644
--- a/src/plugins/debugger/watchutils.cpp
+++ b/src/plugins/debugger/watchutils.cpp
@@ -43,6 +43,9 @@
 #include <cpptools/cpptoolsconstants.h>
 
 #include <cplusplus/ExpressionUnderCursor.h>
+#include <cplusplus/Overview.h>
+#include <Symbols.h>
+#include <Scope.h>
 
 #include <extensionsystem/pluginmanager.h>
 
@@ -51,6 +54,7 @@
 #include <QtCore/QStringList>
 #include <QtCore/QCoreApplication>
 #include <QtCore/QTextStream>
+#include <QtCore/QHash>
 
 #include <QtGui/QTextCursor>
 #include <QtGui/QPlainTextEdit>
@@ -59,6 +63,78 @@
 #include <ctype.h>
 
 enum { debug = 0 };
+
+// Debug helpers for code model. @todo: Move to some CppTools library?
+namespace CPlusPlus {
+
+static void debugCppSymbolRecursion(QTextStream &str, const Overview &o,
+                                    const Symbol &s, bool doRecurse = true,
+                                    int recursion = 0)
+{
+    for (int i = 0; i < recursion; i++)
+        str << "  ";
+    str << "Symbol: " << o.prettyName(s.name()) << " at line " << s.line();
+    if (s.isFunction())
+        str << " function";
+    if (s.isClass())
+        str << " class";
+    if (s.isDeclaration())
+        str << " declaration";
+    if (s.isBlock())
+        str << " block";
+    if (doRecurse && s.isScopedSymbol()) {
+        const ScopedSymbol *scoped = s.asScopedSymbol();
+        const int size =  scoped->memberCount();
+        str << " scoped symbol of " << size << '\n';
+        for (int m = 0; m < size; m++)
+            debugCppSymbolRecursion(str, o, *scoped->memberAt(m), true, recursion + 1);
+    } else {
+        str << '\n';
+    }
+}
+
+QDebug operator<<(QDebug d, const Symbol &s)
+{
+    QString output;
+    CPlusPlus::Overview o;
+    QTextStream str(&output);
+    debugCppSymbolRecursion(str, o, s, true, 0);
+    d.nospace() << output;
+    return d;
+}
+
+QDebug operator<<(QDebug d, const Scope &scope)
+{
+    QString output;
+    Overview o;
+    QTextStream str(&output);
+    const int size =  scope.symbolCount();
+    str << "Scope of " << size;
+    if (scope.isNamespaceScope())
+        str << " namespace";
+    if (scope.isClassScope())
+        str << " class";
+    if (scope.isEnumScope())
+        str << " enum";
+    if (scope.isBlockScope())
+        str << " block";
+    if (scope.isFunctionScope())
+        str << " function";
+    if (scope.isPrototypeScope())
+        str << " prototype";
+    if (const Symbol *owner = scope.owner()) {
+        str << " owner: ";
+        debugCppSymbolRecursion(str, o, *owner, false, 0);
+    } else {
+        str << " 0-owner\n";
+    }
+    for (int s = 0; s < size; s++)
+        debugCppSymbolRecursion(str, o, *scope.symbolAt(s), true, 2);
+    d.nospace() << output;
+    return d;
+}
+} // namespace CPlusPlus
+
 namespace Debugger {
 namespace Internal {
 
@@ -217,6 +293,133 @@ QString stripPointerType(QString type)
     return type;
 }
 
+/* getUninitializedVariables(): Get variables that are not initialized
+ * at a certain line of a function from the code model to be able to
+ * indicate them as not in scope in the locals view.
+ * Find document + function in the code model, do a double check and
+ * collect declarative symbols that are in the function past or on
+ * the current line. blockRecursion() recurses up the scopes
+ * and collect symbols declared past or on the current line.
+ * Recursion goes up from the innermost scope, keeping a map
+ * of occurrences seen, to be able to derive the names of
+ * shadowed variables as the debugger sees them:
+\code
+int x;             // Occurrence (1), should be reported as "x <shadowed 1>"
+if (true) {
+   int x = 5; (2)  // Occurrence (2), should be reported as "x"
+}
+\endcode
+ */
+
+typedef QHash<QString, int> SeenHash;
+
+static void blockRecursion(const CPlusPlus::Overview &overview,
+                           const CPlusPlus::Scope *scope,
+                           unsigned line,
+                           QStringList *uninitializedVariables,
+                           SeenHash *seenHash,
+                           int level = 0)
+{
+    const int size = scope->symbolCount();
+    for (int s = 0; s < size; s++){
+        const CPlusPlus::Symbol *symbol = scope->symbolAt(s);
+        if (symbol->isDeclaration()) {
+            // Find out about shadowed symbols by bookkeeping
+            // the already seen occurrences in a hash.
+            const QString name = overview.prettyName(symbol->name());
+            SeenHash::iterator it = seenHash->find(name);
+            if (it == seenHash->end()) {
+                it = seenHash->insert(name, 0);
+            } else {
+                ++(it.value());
+            }            
+            // Is the declaration on or past the current line, that is,
+            // the variable not initialized.
+            if (symbol->line() >= line)
+                uninitializedVariables->push_back(WatchData::shadowedName(name, it.value()));
+        }
+    }
+    // Next block scope.
+    if (const CPlusPlus::Scope *enclosingScope = scope->enclosingBlockScope())
+        blockRecursion(overview, enclosingScope, line, uninitializedVariables, seenHash, level + 1);
+}
+
+// Inline helper with integer error return codes.
+static inline
+int getUninitializedVariablesI(const CPlusPlus::Snapshot &snapshot,
+                               const QString &functionName,
+                               const QString &file,
+                               int line,
+                               QStringList *uninitializedVariables)
+{
+    uninitializedVariables->clear();
+    // Find document
+    if (snapshot.empty() || functionName.isEmpty() || file.isEmpty() || line < 1)
+        return 1;
+    const CPlusPlus::Snapshot::ConstIterator docIt = snapshot.constFind(file);
+    if (docIt == snapshot.constEnd())
+        return 2;
+    const CPlusPlus::Document::Ptr doc = docIt.value();
+    // Look at symbol at line and find its function. Either it is the
+    // function itself or some expression/variable.
+    const CPlusPlus::Symbol *symbolAtLine = doc->findSymbolAt(line, 0);
+    if (!symbolAtLine)
+        return 4;
+    // First figure out the function to do a safety name check.
+    const CPlusPlus::Function *function = 0;
+    const bool hitFunction = symbolAtLine->isFunction();
+    if (hitFunction) {
+        function = symbolAtLine->asFunction();
+    } else {
+        if (CPlusPlus::Scope *functionScope = symbolAtLine->enclosingFunctionScope())
+            function = functionScope->owner()->asFunction();
+    }
+    if (!function)
+        return 7;
+    // Compare function names with a bit off fuzz,
+    // skipping modules from a CDB symbol "lib!foo" or namespaces
+    // that the code model does not show at this point
+    CPlusPlus::Overview overview;
+    const QString name = overview.prettyName(function->name());
+    if (!functionName.endsWith(name))
+        return 11;
+    if (functionName.size() > name.size()) {
+        const char previousChar = functionName.at(functionName.size() - name.size() - 1).toLatin1();
+        if (previousChar != ':' && previousChar != '!' )
+            return 11;
+    }
+    // Starting from the innermost block scope, collect
+    // declarations.
+    const CPlusPlus::Scope *innerMostScope = hitFunction ?
+                                             symbolAtLine->asFunction()->members() :
+                                             symbolAtLine->enclosingBlockScope();
+    if (!innerMostScope)
+        return 15;
+    SeenHash seenHash;
+    blockRecursion(overview, innerMostScope, line, uninitializedVariables, &seenHash);
+    return 0;
+}
+
+bool getUninitializedVariables(const CPlusPlus::Snapshot &snapshot,
+                               const QString &function,
+                               const QString &file,
+                               int line,
+                               QStringList *uninitializedVariables)
+{
+    const int rc = getUninitializedVariablesI(snapshot, function, file, line, uninitializedVariables);
+    if (debug) {
+        QString msg;
+        QTextStream str(&msg);
+        str << "getUninitializedVariables() " << function << ' ' << file << ':' << line
+                << " returns (int) " << rc << " '"
+                << uninitializedVariables->join(QString(QLatin1Char(','))) << '\'';
+        if (rc)
+            str << " of " << snapshot.keys().size() << " documents";
+        qDebug() << msg;
+    }
+    return rc == 0;
+}
+
 QString gdbQuoteTypes(const QString &type)
 {
     // gdb does not understand sizeof(Core::IFile*).