Add support for related checks for "linked" variables.

Example:
    void func(int *ptr1)
    {
        int *ptr2 = ptr1;
        if (!ptr1)
            return;
        *ptr2 = 10;
    }

here will be no warning.

5 files changed, 72 insertions, 49 deletions

diff --git a/src/analysis/analysis.cpp b/src/analysis/analysis.cpp
index d22646a..5a47151 100644
--- a/src/analysis/analysis.cpp
+++ b/src/analysis/analysis.cpp
@@ -57,18 +57,7 @@ namespace Analysis
 // remove check null vars.
 void removeCheckNullVars(WalkItem &wi)
 {
-    FOR_EACH (std::set<std::string>::const_iterator, it, wi.removeNullVars)
-    {
-        // found var for deletion
-        if (wi.checkNullVars.find(*it) != wi.checkNullVars.end())
-        {
-            wi.checkNullVars.erase(*it);
-        }
-        if (wi.addNullVars.find(*it) != wi.addNullVars.end())
-        {
-            wi.addNullVars.erase(*it);
-        }
-    }
+    removeCheckNullVarsSet(wi, wi.removeNullVars);
 }
 
 void addCheckNullVars(WalkItem &wi, WalkItem &wo)
@@ -88,9 +77,35 @@ void removeCheckNullVarsSet(WalkItem &wi, std::set<std::string> &vars)
         {
             wi.checkNullVars.erase(*it);
         }
+        if (wi.addNullVars.find(*it) != wi.addNullVars.end())
+        {
+            wi.addNullVars.erase(*it);
+        }
+        StringMapSet::const_iterator it2 = wi.linkedVars.find(*it);
+        if (it2 != wi.linkedVars.end())
+        {
+            const StringSet &linked = (*it2).second;
+            FOR_EACH (StringSet::const_iterator, it3, linked)
+            {
+                if (wi.checkNullVars.find(*it3) != wi.checkNullVars.end())
+                {
+                    wi.checkNullVars.erase(*it3);
+                }
+            }
+            wi.linkedVars.erase(*it);
+        }
     }
 }
 
+void addLinkedVar(WalkItem &wi,
+                  const std::string &parent,
+                  const std::string &var)
+{
+    if (wi.linkedVars.find(parent) == wi.linkedVars.end())
+        wi.linkedVars[parent] = std::set<std::string>();
+    wi.linkedVars[parent].insert(var);
+}
+
 void startWalkTree(Node *node)
 {
     WalkItem wi;
@@ -108,6 +123,7 @@ void walkTree(Node *node, const WalkItem &wi, WalkItem &wo)
     removeCheckNullVars(wi2);
     addCheckNullVars(wo, wi2);
     addCheckNullVars(wi2, wi2);
+    wi2.linkedVars = wo.linkedVars;
 //    Log::dumpAttr(node, 1, wo.isReturned);
 
     const bool isReturned = wo.isReturned;
diff --git a/src/analysis/analysis.h b/src/analysis/analysis.h
index fe4bf67..fe3d295 100644
--- a/src/analysis/analysis.h
+++ b/src/analysis/analysis.h
@@ -45,6 +45,10 @@ namespace Analysis
     bool checkForReport(Node *node,
                         const WalkItem &wi);
 
+    void addLinkedVar(WalkItem &wi,
+                      const std::string &parent,
+                      const std::string &var);
+
     void removeCheckNullVars(WalkItem &wi);
 
     void removeCheckNullVarsSet(WalkItem &wi,
diff --git a/src/analysis/expression.cpp b/src/analysis/expression.cpp
index e460438..34f4998 100644
--- a/src/analysis/expression.cpp
+++ b/src/analysis/expression.cpp
@@ -362,6 +362,7 @@ void analyseBindExpr(BindExprNode *node, const WalkItem &wi, WalkItem &wo)
         if (checkForReport(initial, wi))
         {
             wo.addNullVars.insert(varDecl->label);
+            addLinkedVar(wo, initial->label, varDecl->label);
         }
     }
     Log::dumpWI(node, "wo out ", wo);
diff --git a/src/analysis/walkitem.h b/src/analysis/walkitem.h
index 046ece0..3db62f8 100644
--- a/src/analysis/walkitem.h
+++ b/src/analysis/walkitem.h
@@ -20,9 +20,13 @@
 #ifndef ANALYSIS_WALKITEM_H
 #define ANALYSIS_WALKITEM_H
 
+#include <map>
 #include <set>
 #include <string>
 
+typedef std::set<std::string> StringSet;
+typedef std::map<std::string, StringSet> StringMapSet;
+
 struct WalkItem
 {
     WalkItem() :
@@ -31,6 +35,7 @@ struct WalkItem
         addNullVars(),
         checkedNullVars(),
         checkedNonNullVars(),
+        linkedVars(),
         stopWalking(false),
         isReturned(false),
         cleanExpr(false),
@@ -44,6 +49,7 @@ struct WalkItem
         addNullVars(item.addNullVars),
         checkedNullVars(item.checkedNullVars),
         checkedNonNullVars(item.checkedNonNullVars),
+        linkedVars(item.linkedVars),
         stopWalking(item.stopWalking),
         isReturned(item.isReturned),
         cleanExpr(item.cleanExpr),
@@ -51,11 +57,12 @@ struct WalkItem
     {
     }
 
-    std::set<std::string> checkNullVars;        // need check for usage without null pointer check
-    std::set<std::string> removeNullVars;       // need remove vars from parent checkNullVars
-    std::set<std::string> addNullVars;          // need add vars to parent checkNullVars
-    std::set<std::string> checkedNullVars;      // vars checked for null in expressions
-    std::set<std::string> checkedNonNullVars;   // vars checked for nonnull in expressions
+    StringSet checkNullVars;       // need check for usage without null pointer check
+    StringSet removeNullVars;      // need remove vars from parent checkNullVars
+    StringSet addNullVars;         // need add vars to parent checkNullVars
+    StringSet checkedNullVars;     // vars checked for null in expressions
+    StringSet checkedNonNullVars;  // vars checked for nonnull in expressions
+    StringMapSet linkedVars;       // linked vars. map <parent, set(vars)>
     bool stopWalking;   // stop walking on tree after this node
     bool isReturned;    // set if return present in child nodes
     bool cleanExpr;     // set if expression is only variable check without compound conditions
diff --git a/src/logger.cpp b/src/logger.cpp
index 1a1428d..af52e26 100644
--- a/src/logger.cpp
+++ b/src/logger.cpp
@@ -192,6 +192,15 @@ void dumpAttr(const Node *const node, int num, bool isReturned)
     fprintf(stderr, " walkTree%d: %d\n", num, isReturned ? 1 : 0);
 }
 
+#define dumpWIProps(comment, name) \
+    Log::log(comment); \
+    FOR_EACH (StringSet::const_iterator, \
+              it, \
+              name) \
+    { \
+        Log::log("%s, ", (*it).c_str()); \
+    }
+
 void dumpWI(Node *const node,
             const std::string &name,
             const WalkItem &wi)
@@ -207,40 +216,26 @@ void dumpWI(Node *const node,
         Log::log(" useless");
     if (wi.isReturned)
         Log::log(" returned");
-    Log::log(" checkedNullVars:");
-    FOR_EACH (std::set<std::string>::const_iterator,
-              it,
-              wi.checkedNullVars)
-    {
-        Log::log("%s, ", (*it).c_str());
-    }
-    Log::log(" checkedNonNullVars:");
-    FOR_EACH (std::set<std::string>::const_iterator,
-              it,
-              wi.checkedNonNullVars)
-    {
-        Log::log("%s, ", (*it).c_str());
-    }
-    Log::log(" checkNullVars:");
-    FOR_EACH (std::set<std::string>::const_iterator,
-              it,
-              wi.checkNullVars)
-    {
-        Log::log("%s, ", (*it).c_str());
-    }
-    Log::log(" removeNullVars:");
-    FOR_EACH (std::set<std::string>::const_iterator,
-              it,
-              wi.removeNullVars)
-    {
-        Log::log("%s, ", (*it).c_str());
-    }
-    Log::log(" addNullVars:");
-    FOR_EACH (std::set<std::string>::const_iterator,
+    dumpWIProps(" checkedNullVars:", wi.checkedNullVars)
+    dumpWIProps(" checkedNonNullVars:", wi.checkedNonNullVars)
+    dumpWIProps(" checkNullVars:", wi.checkNullVars)
+    dumpWIProps(" removeNullVars:", wi.removeNullVars)
+    dumpWIProps(" addNullVars:", wi.addNullVars)
+
+    Log::log(" linkedVars:");
+    FOR_EACH (StringMapSet::const_iterator,
               it,
-              wi.addNullVars)
+              wi.linkedVars)
     {
-        Log::log("%s, ", (*it).c_str());
+        Log::log("%s -> (", ((*it).first).c_str());
+        const StringSet &vars = (*it).second;
+        FOR_EACH (StringSet::const_iterator,
+                  it2,
+                  vars)
+        {
+            Log::log("%s, ", (*it2).c_str());
+        }
+        Log::log("), ");
     }
     Log::log("\n");
 }