Project/platform syms for address table formatting

The address table formatter tries to map the calculated addresses
to offsets within the file.  When that fails, it currently just
gives up.

We now try to resolve external addresses to project/platform symbols.

(issue #160)

SourceGen/SymbolTable.cs

@@ -520,7 +520,7 @@ private void RegenerateAddressTable() {
 
         /// <summary>
         /// Searches the table for symbols with matching address values.  Ignores constants and
-        /// variables.
+        /// variables.  This does take the width of project/platform symbols into account.
         /// </summary>
         /// <param name="addr">Address to find.</param>
         /// <param name="effect">Memory effect type to match against.</param>

SourceGen/WpfGui/FormatAddressTable.xaml.cs

@@ -376,6 +376,7 @@ private void GenerateFormats(int div, int highConst, int bankConst) {
             bool isBigEndian;
 
             // Identify the offset where each set of data starts.
+            Debug.Assert(mSelection.Count % div == 0);
             int span = mSelection.Count / div;
             int lowOff, highOff, bankOff;
             int stride;
@@ -461,10 +462,7 @@ private void GenerateFormats(int div, int highConst, int bankConst) {
                 offsets[index++] = tup.Value;
             }
 
-            int adj = 0;
-            if (IsAdjustedForReturn) {
-                adj = 1;
-            }
+            int adj = IsAdjustedForReturn ? 1 : 0;      // RTS/RTL adjustment
 
             // Walk through the file data, generating addresses as we go.
             byte[] fileData = mProject.FileData;
@@ -483,20 +481,28 @@ private void GenerateFormats(int div, int highConst, int bankConst) {
                     bank = (byte) bankConst;
                 }
 
+                // This is the target address.
                 int addr = ((bank << 16) | (high << 8) | low) + adj;
 
+                // Map it to a target label.  Start by looking for an offset inside file bounds.
                 int targetOffset = mProject.AddrMap.AddressToOffset(offsets[0], addr);
+                string targetLabel = null;
                 if (targetOffset < 0) {
-                    // Address not within file bounds.
-                    // TODO(maybe): look for matching platform/project symbols
-                    AddPreviewItem(addr, -1, Res.Strings.INVALID_ADDRESS);
+                    // Address not within file bounds; check for a matching project/platform symbol.
+                    // The method we're calling will potentially return globals and locals, but
+                    // those should have been found by AddressToOffset.
+                    Symbol ppsym = mProject.SymbolTable.FindNonVariableByAddress(addr,
+                        OpDef.MemoryEffect.ReadModifyWrite);
+                    if (ppsym != null) {
+                        targetLabel = ppsym.Label;
+                        AddPreviewItem(addr, -1, targetLabel);
+                    }
                 } else {
                     // Note the same target offset may appear more than once.
                     targetOffsets.Add(targetOffset);
 
                     // If there's a user-defined label there already, use it.  Otherwise, we'll
                     // need to generate one.
-                    string targetLabel;
                     if (mProject.UserLabels.TryGetValue(targetOffset, out Symbol sym)) {
                         targetLabel = sym.Label;
                         AddPreviewItem(addr, targetOffset, targetLabel);
@@ -509,14 +515,16 @@ private void GenerateFormats(int div, int highConst, int bankConst) {
                         Symbol tmpSym = AutoLabel.GenerateUniqueForAddress(addr,
                             mProject.SymbolTable, "T");
                         // tmpSym was returned as an auto-label, make it a user label instead
-                        // (with global scope)
+                        // (with global scope).
                         tmpSym = new Symbol(tmpSym.Label, tmpSym.Value, Symbol.Source.User,
                             Symbol.Type.GlobalAddr, Symbol.LabelAnnotation.Generated);
                         newLabels[targetOffset] = tmpSym;       // overwrites previous
                         targetLabel = tmpSym.Label;
                         AddPreviewItem(addr, targetOffset, "(+) " + targetLabel);
                     }
+                }
 
+                if (targetLabel != null) {
                     if (IsSplitTable) {
                         // Now we need to create format descriptors for the addresses where we
                         // extracted the low, high, and bank values.
@@ -542,16 +550,18 @@ private void GenerateFormats(int div, int highConst, int bankConst) {
                         newDfds.Add(offsets[0 + i * stride], FormatDescriptor.Create(stride,
                             new WeakSymbolRef(targetLabel, WeakSymbolRef.Part.Low), isBigEndian));
                     }
+                } else {
+                    AddPreviewItem(addr, -1, Res.Strings.INVALID_ADDRESS);
                 }
             }
 
             NewFormatDescriptors = newDfds;
             NewUserLabels = newLabels;
             AllTargetOffsets = targetOffsets;
 
-            // Don't show ready if all addresses are invalid.  It's okay if some work and
+            // Don't show ready if all entries are invalid.  It's okay if some work and
             // some don't.
-            mOutputReady = (AllTargetOffsets.Count > 0);
+            mOutputReady = (NewFormatDescriptors.Count > 0);
         }
 
         private void AddPreviewItem(int addr, int offset, string label) {