Emit warnings for wasted bytes when aligning

doc/ca65.sgml

@@ -2372,7 +2372,8 @@ Here's a list of all control commands and a description, what they do:
   calculated in advance by the assembler. You are therefore required to
   specify a matching alignment for the segment in the linker config. The
   linker will output a warning if the alignment of the segment is less than
-  what is necessary to have a correct alignment in the object file.
+  what is necessary to have a correct alignment in the object file. It will
+  also emit a warning to inform about the number of bytes wasted for alignment.
 
   Example:
 

src/ca65/segment.c

@@ -313,7 +313,9 @@ void SegAlign (unsigned long Alignment, int FillVal)
 
         /* Calculate the number of fill bytes */
         Count = AlignCount (ActiveSeg->PC, Alignment);
-
+        if (Count != 0) {
+            Warning(0, "Wasting %lu bytes for alignment", Count);
+        }
     }
 
 

src/ld65/config.c

@@ -2035,8 +2035,8 @@ unsigned CfgProcess (void)
                     if (M->FillLevel == 0 && NewAddr > Addr) {
                         PWarning (GetSourcePos (S->LI),
                                   "The first segment in memory area `%s' "
-                                  "needs fill bytes for alignment.",
-                                  GetString (M->Name));
+                                  "needs %lu fill bytes for alignment.",
+                                  GetString (M->Name), NewAddr - Addr);
                     }
 
                     /* Use the aligned address */

src/ld65/segments.c

@@ -236,6 +236,9 @@ Section* ReadSection (FILE* F, ObjData* O)
                      GetString (Name), Alignment, GetObjFileName (O));
         }
         S->Alignment = Alignment;
+        if (Sec->Fill != 0) {
+            Warning("Wasting %lu bytes for alignment from %s", Sec->Fill, GetObjFileName (O));
+        }
     }
 
     /* Start reading fragments from the file and insert them into the section . */