Clean-up

[cc65] / src / cc65 / symtab.c

diff --git a/src/cc65/symtab.c b/src/cc65/symtab.c
index 51b43b4c91a7c04df2f3e52f560522353ca82873..f7fb07f61dae2e9f542fa4015c63c2dad915d80c 100644 (file)
--- a/src/cc65/symtab.c
+++ b/src/cc65/symtab.c
@@ -670,6 +670,9 @@ DefOrRef* AddDefOrRef(SymEntry* E, unsigned Flags)
     DOR->Line = GetCurrentLine ();
     DOR->LocalsBlockNum = (long)CollLast (&CurrentFunc->LocalsBlockStack);
     DOR->Flags = Flags;
+    DOR->StackPtr = StackPtr;
+    DOR->Depth = CollCount (&CurrentFunc->LocalsBlockStack);
+    DOR->LateSP_Label = GetLocalLabel ();
 
     return DOR;
 }
@@ -679,7 +682,8 @@ SymEntry* AddLabelSym (const char* Name, unsigned Flags)
 /* Add a goto label to the label table */
 {
     unsigned i;
-    DefOrRef *DOR;
+    DefOrRef *DOR, *NewDOR;
+
     /* Do we have an entry with this name already? */
     SymEntry* Entry = FindSymInTable (LabelTab, Name, HashStr (Name));
     if (Entry) {
@@ -689,22 +693,45 @@ SymEntry* AddLabelSym (const char* Name, unsigned Flags)
             Error ("Label `%s' is defined more than once", Name);
         }
 
-        /* Walk through all occurrences of the label so far and check
-           if any of them is in a region that would be risky to jump from/to
-           from the place where we are right now. */
+        NewDOR = AddDefOrRef (Entry, Flags);
+
+        /* Walk through all occurrences of the label so far and evaluate
+           their relationship with the one passed to the function. */
         for (i = 0; i < CollCount (Entry->V.L.DefsOrRefs); i++) {
             DOR = CollAt (Entry->V.L.DefsOrRefs, i);
-            /* We are only interested in label occurences of type opposite to
-             the one currently being added, i.e.  if we are processing the
-             definition, we will only check the gotos; if we are processing
-             a goto statement, we will only look for the label definition. */
-            if (((DOR->Flags & SC_DEF) != (Flags & SC_DEF)) &&
-                (DOR->LocalsBlockNum != (long)CollLast (&CurrentFunc->LocalsBlockStack)))
-                Warning ("Goto from line %d to label \'%s\' can result in a "
-                    "trashed stack", Flags & SC_DEF ? DOR->Line : GetCurrentLine (), Name);
-        }
 
-        AddDefOrRef (Entry, Flags);
+            if((DOR->Flags & SC_DEF) && (Flags & SC_REF)) {
+                /* We're processing a goto and here is its destination label.
+                   This means the difference between SP values is already known,
+                   so we simply emit the SP adjustment code. */
+                if(StackPtr != DOR->StackPtr)
+                    g_space (StackPtr - DOR->StackPtr);
+
+                /* Are we jumping into same or deeper nesting region? That's risky,
+                   so let's emit a warning. */
+                if (CollCount (&CurrentFunc->LocalsBlockStack) <= DOR->Depth &&
+                    DOR->LocalsBlockNum != (long)CollLast (&CurrentFunc->LocalsBlockStack)) {
+                    Warning ("Goto from line %d to label \'%s\' can result in a "
+                        "trashed stack", DOR->Line, Name);
+                }
+            }
+
+            if((DOR->Flags & SC_REF) && (Flags & SC_DEF)) {
+                /* We're processing a label, let's update all gotos encountered
+                   so far */
+                g_defdatalabel (DOR->LateSP_Label);
+                g_defdata (CF_CONST | CF_INT, StackPtr - DOR->StackPtr, 0);
+
+                /* Are we jumping into same or deeper nesting region? That's risky,
+                   so let's emit a warning. */
+                if (CollCount (&CurrentFunc->LocalsBlockStack) >= DOR->Depth &&
+                    DOR->LocalsBlockNum != (long)CollLast (&CurrentFunc->LocalsBlockStack)) {
+                    Warning ("Goto from line %d to label \'%s\' can result in a "
+                        "trashed stack", DOR->Line, Name);
+                }
+             }
+
+        }
 
         Entry->Flags |= Flags;
 
@@ -718,7 +745,7 @@ SymEntry* AddLabelSym (const char* Name, unsigned Flags)
 
         /* Create Collection for label definition and references */
         Entry->V.L.DefsOrRefs = NewCollection ();
-        AddDefOrRef (Entry, Flags);
+        NewDOR = AddDefOrRef (Entry, Flags);
 
         /* Generate the assembler name of the label */
         Entry->AsmName = xstrdup (LocalLabelName (Entry->V.L.Label));
@@ -728,6 +755,11 @@ SymEntry* AddLabelSym (const char* Name, unsigned Flags)
 
     }
 
+    /* We are processing a goto, but the label has not yet been defined */
+    if (!SymIsDef (Entry) && (Flags & SC_REF)) {
+        g_lateadjustSP (NewDOR->LateSP_Label);
+    }
+
     /* Return the entry */
     return Entry;
 }