Remove null checks from COMPONENT_REF node. But add check in different parent nodes.

8 files changed, 195 insertions, 10 deletions

diff --git a/src/analysis/analysis.cpp b/src/analysis/analysis.cpp
index 32c0170..50f9211 100644
--- a/src/analysis/analysis.cpp
+++ b/src/analysis/analysis.cpp
@@ -53,6 +53,7 @@
 #include "nodes/expr/truthor_expr.h"
 #include "nodes/expr/truthorif_expr.h"
 
+#include "nodes/ref/array_ref.h"
 #include "nodes/ref/component_ref.h"
 
 #include "nodes/stmt/break_stmt.h"
@@ -291,6 +292,9 @@ void analyseNode(Node *node, const WalkItem &wi, WalkItem &wo)
         case CONTINUE_STMT:
             analyseContinueStmt(static_cast<ContinueStmtNode*>(node), wi2, wo);
             break;
+        case ARRAY_REF:
+            analyseArrayRef(static_cast<ArrayRefNode*>(node), wi2, wo);
+            break;
         case COMPONENT_REF:
             analyseComponentRef(static_cast<ComponentRefNode*>(node), wi2, wo);
             break;
diff --git a/src/analysis/expression.cpp b/src/analysis/expression.cpp
index 3877d68..7370a57 100644
--- a/src/analysis/expression.cpp
+++ b/src/analysis/expression.cpp
@@ -60,6 +60,7 @@
 #include "nodes/ref/indirect_ref.h"
 #include "nodes/ref/objtype_ref.h"
 
+#include "nodes/type/array_type.h"
 #include "nodes/type/method_type.h"
 
 #include <set>
@@ -141,6 +142,78 @@ std::string getComponentRefVariable(Node *node)
     return str;
 }
 
+std::vector<std::string> getComponentRefParts(Node *node)
+{
+    std::vector<std::string> str;
+    ComponentRefNode *const comp = static_cast<ComponentRefNode*>(skipNop(node));
+    if (comp &&
+        comp->object &&
+        comp->field)
+    {
+        Node *object = skipNop(comp->object);
+        Node *field = skipNop(comp->field);
+        if (object == INDIRECT_REF &&
+            field == FIELD_DECL)
+        {
+            FieldDeclNode *fieldDecl = static_cast<FieldDeclNode*>(field);
+            IndirectRefNode *indirect = static_cast<IndirectRefNode*>(object);
+            Node *ref = skipNop(indirect->ref);
+            if (ref == PARM_DECL)
+            {
+                ParmDeclNode *parmDecl = static_cast<ParmDeclNode*>(ref);
+                if (parmDecl->declType == POINTER_TYPE)
+                    str.push_back(ref->label);
+            }
+            if (ref == VAR_DECL)
+            {
+                VarDeclNode *varDecl = static_cast<VarDeclNode*>(ref);
+                if (varDecl->varType == POINTER_TYPE)
+                    str.push_back(ref->label);
+            }
+            if (ref == PARM_DECL || ref == VAR_DECL)
+            {
+                if (skipNop(fieldDecl->fieldType) != POINTER_TYPE)
+                {
+                    if (skipNop(fieldDecl->fieldType) != ARRAY_TYPE)
+                        return str;
+                    ArrayTypeNode *arr = static_cast<ArrayTypeNode*>(skipNop(fieldDecl->fieldType));
+                    if (arr->elementType != POINTER_TYPE)
+                        return str;
+                }
+                str.push_back(std::string(ref->label).append("->").append(field->label));
+            }
+        }
+    }
+    return str;
+}
+
+std::vector<std::string> getComponentRefLeftParts(Node *node)
+{
+    std::vector<std::string> str;
+    ComponentRefNode *const comp = static_cast<ComponentRefNode*>(skipNop(node));
+    if (comp &&
+        comp->object &&
+        comp->field)
+    {
+        Node *object = skipNop(comp->object);
+        Node *field = skipNop(comp->field);
+        if (object == INDIRECT_REF &&
+            field == FIELD_DECL)
+        {
+//            FieldDeclNode *fieldDecl = static_cast<FieldDeclNode*>(field);
+//            if (fieldDecl->fieldType != POINTER_TYPE)
+//                return str;
+            IndirectRefNode *indirect = static_cast<IndirectRefNode*>(object);
+            Node *ref = skipNop(indirect->ref);
+            if (ref == PARM_DECL || ref == VAR_DECL)
+            {
+                str.push_back(ref->label);
+            }
+        }
+    }
+    return str;
+}
+
 void analyseModifyExpr(ModifyExprNode *node, const WalkItem &wi, WalkItem &wo)
 {
     // need atleast one arg for check
@@ -159,15 +232,24 @@ void analyseModifyExpr(ModifyExprNode *node, const WalkItem &wi, WalkItem &wo)
             ComponentRefNode *comp = static_cast<ComponentRefNode*>(arg);
             if (skipNop(comp->object) == INDIRECT_REF)
                 arg0 = skipNop(comp->object);
+
+            if (arg0 == INDIRECT_REF)
+            {
+                // var2 not found in known checking pointer
+                reportParmDeclNullPointer(node,
+                    static_cast<IndirectRefNode*>(arg0)->ref,
+                    wi);
+            }
         }
-        if (arg0 == INDIRECT_REF)
+        if (arg == INDIRECT_REF)
         {
             // var2 not found in known checking pointer
             reportParmDeclNullPointer(node,
-                static_cast<IndirectRefNode*>(arg0)->ref,
+                static_cast<IndirectRefNode*>(arg)->ref,
                 wi);
 
-            if (isNotIn(var2, wi.needCheckNullVars) &&
+            if (!var1.empty() &&
+                isNotIn(var2, wi.needCheckNullVars) &&
                 isNotIn(var2, wi.knownVars))
             {
                 removeVar(wo, var1);
@@ -263,6 +345,9 @@ void analyseNeExpr(NeExprNode *node, const WalkItem &wi, WalkItem &wo)
     // INTEGER_CST?
     Node *node2 = skipNop(node->args[1]);
 
+    reportParmDeclLeftNullPointer(node, node1, wi);
+    reportParmDeclLeftNullPointer(node, node2, wi);
+
     std::string var = getVariableName(node1);
     // if (var != 0)
     if (!var.empty() &&
@@ -375,6 +460,10 @@ void analyseEqExpr(EqExprNode *node, const WalkItem &wi, WalkItem &wo)
     Node *node1 = skipNop(node->args[0]);
     // INTEGER_CST?
     Node *node2 = skipNop(node->args[1]);
+
+    reportParmDeclLeftNullPointer(node, node1, wi);
+    reportParmDeclLeftNullPointer(node, node2, wi);
+
     std::string var = getVariableName(node1);
     // if (var == 0)
     if (!var.empty() &&
diff --git a/src/analysis/expression.h b/src/analysis/expression.h
index 9c42bd2..602a9ae 100644
--- a/src/analysis/expression.h
+++ b/src/analysis/expression.h
@@ -44,6 +44,8 @@ struct TruthOrExprNode;
 struct TruthOrIfExprNode;
 struct WalkItem;
 
+#include <vector>
+
 namespace Analysis
 {
     void analyseModifyExpr(ModifyExprNode *node, const WalkItem &wi, WalkItem &wo);
@@ -95,6 +97,10 @@ namespace Analysis
 
     std::string getComponentRefVariable(Node *node);
 
+    std::vector<std::string> getComponentRefParts(Node *node);
+
+    std::vector<std::string> getComponentRefLeftParts(Node *node);
+
     bool handleSetVarToFunction(const std::string &var,
                                 Node *node1,
                                 Node *node2,
diff --git a/src/analysis/ref.cpp b/src/analysis/ref.cpp
index 4c8a4be..2391fa3 100644
--- a/src/analysis/ref.cpp
+++ b/src/analysis/ref.cpp
@@ -30,6 +30,7 @@
 #include "nodes/expr/modify_expr.h"
 #include "nodes/expr/pointerplus_expr.h"
 
+#include "nodes/ref/array_ref.h"
 #include "nodes/ref/component_ref.h"
 #include "nodes/ref/indirect_ref.h"
 
@@ -59,4 +60,18 @@ void analyseComponentRef(ComponentRefNode *node,
 */
 }
 
+void analyseArrayRef(ArrayRefNode *node,
+                     const WalkItem &wi,
+                     WalkItem &wo A_UNUSED)
+{
+    // need atleast one arg for check
+    if (node->args.empty() || checkCommand(FindArgs))
+        return;
+
+    FOR_EACH(it, node->args)
+    {
+        reportParmDeclNullPointer(node, it, wi);
+    }
+}
+
 }
diff --git a/src/analysis/ref.h b/src/analysis/ref.h
index ff245cc..608d033 100644
--- a/src/analysis/ref.h
+++ b/src/analysis/ref.h
@@ -22,12 +22,14 @@
 
 #include "includes.h"
 
+struct ArrayRefNode;
 struct ComponentRefNode;
 struct WalkItem;
 
 namespace Analysis
 {
     void analyseComponentRef(ComponentRefNode *node, const WalkItem &wi, WalkItem &wo);
+    void analyseArrayRef(ArrayRefNode *node, const WalkItem &wi, WalkItem &wo);
 }
 
 #endif // ANALYSIS_REF_H
diff --git a/src/analysis/reports.cpp b/src/analysis/reports.cpp
index af5806b..733171a 100644
--- a/src/analysis/reports.cpp
+++ b/src/analysis/reports.cpp
@@ -28,6 +28,9 @@
 
 #include "nodes/base/node.h"
 
+#include "nodes/decl/parm_decl.h"
+#include "nodes/decl/var_decl.h"
+
 #include "localconsts.h"
 
 namespace Analysis
@@ -66,7 +69,9 @@ void reportParmDeclNullPointer(Node *mainNode,
         {
             if (node == PARM_DECL)
             {
-                if (isIn(node->label, wi.needCheckNullVars))
+                ParmDeclNode *parmDecl = static_cast<ParmDeclNode*>(node);
+                if (parmDecl->declType == POINTER_TYPE &&
+                    isIn(node->label, wi.needCheckNullVars))
                 {
                     Log::warn(findBackLocation(mainNode),
                         "Using parameter '%s' without checking for null pointer",
@@ -75,7 +80,9 @@ void reportParmDeclNullPointer(Node *mainNode,
             }
             else if (node == VAR_DECL)
             {
-                if (isIn(node->label, wi.needCheckNullVars))
+                VarDeclNode *varDecl = static_cast<VarDeclNode*>(node);
+                if (varDecl->varType == POINTER_TYPE &&
+                    isIn(node->label, wi.needCheckNullVars))
                 {
                     Log::warn(findBackLocation(mainNode),
                         "Using variable '%s' without checking for null pointer",
@@ -85,12 +92,64 @@ void reportParmDeclNullPointer(Node *mainNode,
         }
         else if (node == COMPONENT_REF)
         {
-            std::string var = getComponentRefVariable(node);
-            if (isIn(var, wi.needCheckNullVars))
+            auto vars = getComponentRefParts(node);
+            FOR_EACH (var, vars)
             {
-                Log::warn(findBackLocation(mainNode),
-                    "Using field '%s' without checking for null pointer",
-                    var);
+                if (isIn(var, wi.needCheckNullVars) ||
+                    isNotIn(var, wi.knownVars))
+                {
+                    Log::warn(findBackLocation(mainNode),
+                        "Using variable '%s' without checking for null pointer",
+                        var);
+                }
+            }
+        }
+    }
+}
+
+// report about null pointer if need for node
+void reportParmDeclLeftNullPointer(Node *mainNode,
+                                   Node *node,
+                                   const WalkItem &wi)
+{
+    node = skipNop(node);
+    if (node)
+    {
+        if (node == COMPONENT_REF)
+        {
+            auto vars = getComponentRefLeftParts(node);
+            FOR_EACH (var, vars)
+            {
+                if (isIn(var, wi.needCheckNullVars))
+                {
+                    Log::warn(findBackLocation(mainNode),
+                        "Using field '%s' without checking for null pointer",
+                        var);
+                }
+            }
+        }
+    }
+}
+
+// report about null pointer if need for node
+void reportComponentRefNullPointer(Node *mainNode,
+                                   Node *node,
+                                   const WalkItem &wi)
+{
+    node = skipNop(node);
+    if (node)
+    {
+        if (node == COMPONENT_REF)
+        {
+            auto vars = getComponentRefParts(node);
+            FOR_EACH (var, vars)
+            {
+                if (isIn(var, wi.needCheckNullVars))
+                {
+                    Log::warn(findBackLocation(mainNode),
+                        "Using field '%s' without checking for null pointer",
+                        var);
+                }
             }
         }
     }
diff --git a/src/analysis/reports.h b/src/analysis/reports.h
index 4278ee4..7f65fb8 100644
--- a/src/analysis/reports.h
+++ b/src/analysis/reports.h
@@ -34,6 +34,14 @@ namespace Analysis
                                    Node *node,
                                    const WalkItem &wi);
 
+    void reportParmDeclLeftNullPointer(Node *mainNode,
+                                       Node *node,
+                                       const WalkItem &wi);
+
+    void reportComponentRefNullPointer(Node *mainNode,
+                                       Node *node,
+                                       const WalkItem &wi);
+
     void reportParmDeclAttrNullPointer(Node *mainNode,
                                        Node *node,
                                        const WalkItem &wi);
diff --git a/src/analysis/statement.cpp b/src/analysis/statement.cpp
index 5e6ea7a..a5aba2d 100644
--- a/src/analysis/statement.cpp
+++ b/src/analysis/statement.cpp
@@ -79,6 +79,7 @@ void analyseCondition(Node *node,
     reportParmDeclNullPointer(node,
         thenNode,
         wi2);
+    reportParmDeclLeftNullPointer(node, thenNode, wi2);
     walkTree(thenNode, wi2, wo2);
     Log::dumpWI(node, "wo2 then ", wo2);
 
@@ -98,6 +99,7 @@ void analyseCondition(Node *node,
     reportParmDeclNullPointer(node,
         elseNode,
         wi3);
+    reportParmDeclLeftNullPointer(node, elseNode, wi3);
     walkTree(elseNode, wi3, wo3);
     Log::dumpWI(node, "wo3 else ", wo3);