GP-2859 Clearing symbols from HighVariable must set symboldirty

Ghidra/Features/Decompiler/src/decompile/cpp/funcdata.hh

@@ -408,7 +408,6 @@ public:
   void clearDeadVarnodes(void);					///< Delete any dead Varnodes
   void calcNZMask(void);					///< Calculate \e non-zero masks for all Varnodes
   void clearDeadOps(void) { obank.destroyDead(); }		///< Delete any dead PcodeOps
-  void clearSymbolLinks(HighVariable *high);			///< Clear Symbols attached to Varnodes in the given HighVariable
   void remapVarnode(Varnode *vn,Symbol *sym,const Address &usepoint);
   void remapDynamicVarnode(Varnode *vn,Symbol *sym,const Address &usepoint,uint8 hash);
   Symbol *linkSymbol(Varnode *vn);				///< Find or create Symbol associated with given Varnode

Ghidra/Features/Decompiler/src/decompile/cpp/funcdata_varnode.cc

@@ -1002,18 +1002,6 @@ bool Funcdata::syncVarnodesWithSymbol(VarnodeLocSet::const_iterator &iter,uint4
   return updateoccurred;
 }
 
-/// For each instance Varnode, remove any SymbolEntry reference and associated properties.
-/// \param high is the given HighVariable to clear
-void Funcdata::clearSymbolLinks(HighVariable *high)
-
-{
-  for(int4 i=0;i<high->numInstances();++i) {
-    Varnode *vn = high->getInstance(i);
-    vn->mapentry = (SymbolEntry *)0;
-    vn->clearFlags(Varnode::namelock | Varnode::typelock | Varnode::mapped);
-  }
-}
-
 /// \brief Remap a Symbol to a given Varnode using a static mapping
 ///
 /// Any previous links between the Symbol, the Varnode, and the associate HighVariable are
@@ -1024,7 +1012,7 @@ void Funcdata::clearSymbolLinks(HighVariable *high)
 void Funcdata::remapVarnode(Varnode *vn,Symbol *sym,const Address &usepoint)
 
 {
-  clearSymbolLinks(vn->getHigh());
+  vn->clearSymbolLinks();
   SymbolEntry *entry = localmap->remapSymbol(sym, vn->getAddr(), usepoint);
   vn->setSymbolEntry(entry);
 }
@@ -1040,7 +1028,7 @@ void Funcdata::remapVarnode(Varnode *vn,Symbol *sym,const Address &usepoint)
 void Funcdata::remapDynamicVarnode(Varnode *vn,Symbol *sym,const Address &usepoint,uint8 hash)
 
 {
-  clearSymbolLinks(vn->getHigh());
+  vn->clearSymbolLinks();
   SymbolEntry *entry = localmap->remapSymbolDynamic(sym, hash, usepoint);
   vn->setSymbolEntry(entry);
 }

Ghidra/Features/Decompiler/src/decompile/cpp/variable.cc

@@ -175,15 +175,14 @@ void HighVariable::updateSymbol(void) const
   highflags &= ~((uint4)symboldirty);
   vector<Varnode *>::const_iterator iter;
   symbol = (Symbol *)0;
-  Varnode *vn = (Varnode *)0;
 
   for(iter=inst.begin();iter!=inst.end();++iter) {
-    Varnode *tmpvn = *iter;
+    Varnode *vn = *iter;
-    if (tmpvn->getSymbolEntry() != (SymbolEntry *)0)
+    if (vn->getSymbolEntry() != (SymbolEntry *)0) {
-      vn = tmpvn;
-  }
-  if (vn != (Varnode *)0)
       setSymbol(vn);
+      return;
+    }
+  }
 }
 
 /// Compare two Varnode objects based just on their storage address

Ghidra/Features/Decompiler/src/decompile/cpp/variable.hh

@@ -88,6 +88,7 @@ private:
   void flagsDirty(void) const { highflags |= flagsdirty | namerepdirty; }	///< Mark the boolean properties as \e dirty
   void coverDirty(void) const { highflags |= coverdirty; }	///< Mark the cover as \e dirty
   void typeDirty(void) const { highflags |= typedirty; }	///< Mark the data-type as \e dirty
+  void symbolDirty(void) const { highflags |= symboldirty; }	///< Mark the symbol as \e dirty
   void setUnmerged(void) const { highflags |= unmerged; }	///< Mark \b this as having merge problems
 public:
   HighVariable(Varnode *vn);		///< Construct a HighVariable with a single member Varnode

Ghidra/Features/Decompiler/src/decompile/cpp/varnode.cc

@@ -352,6 +352,22 @@ void Varnode::clearFlags(uint4 fl) const
   }
 }
 
+/// For \b this Varnode and any others attached to the same HighVariable,
+/// remove any SymbolEntry reference and associated properties.
+void Varnode::clearSymbolLinks(void)
+
+{
+  bool foundEntry = false;
+  for(int4 i=0;i<high->numInstances();++i) {
+    Varnode *vn = high->getInstance(i);
+    foundEntry = foundEntry || (vn->mapentry != (SymbolEntry *)0);
+    vn->mapentry = (SymbolEntry *)0;
+    vn->clearFlags(Varnode::namelock | Varnode::typelock | Varnode::mapped);
+  }
+  if (foundEntry)
+    high->symbolDirty();
+}
+
 /// Directly change the defining PcodeOp and set appropriate dirty bits
 /// \param op is the pointer to the new PcodeOp, which can be \b null
 void Varnode::setDef(PcodeOp *op)

Ghidra/Features/Decompiler/src/decompile/cpp/varnode.hh

@@ -159,6 +159,7 @@ private:
   void clearCover(void) const; ///< Turn off any coverage information
   void setFlags(uint4 fl) const; ///< Internal method for setting boolean attributes
   void clearFlags(uint4 fl) const; ///< Internal method for clearing boolean attributes
+  void clearSymbolLinks(void);	///< Clear any Symbol attached to \b this Varnode
   void setUnaffected(void) { setFlags(Varnode::unaffected); } ///< Mark Varnode as \e unaffected
   // These functions should be only private things used by VarnodeBank
   void setInput(void) { setFlags(Varnode::input|Varnode::coverdirty); }	///< Mark Varnode as \e input