Added error when exhausting zeropage space for variables. Closes #233

src/main/java/dk/camelot64/kickc/Compiler.java

@@ -521,7 +521,7 @@ public class Compiler {
          new Pass4ZeroPageCoalesce(program).coalesce();
       }
       new Pass4RegistersFinalize(program).allocate(true);
-
+      new Pass4AssertZeropageAllocation(program).check();
    }
 
    private void pass5GenerateAndOptimizeAsm() {

src/main/java/dk/camelot64/kickc/passes/Pass4AssertZeropageAllocation.java

@@ -0,0 +1,35 @@
+package dk.camelot64.kickc.passes;
+
+import dk.camelot64.kickc.model.CompileError;
+import dk.camelot64.kickc.model.Program;
+import dk.camelot64.kickc.model.Registers;
+import dk.camelot64.kickc.model.symbols.Variable;
+
+import java.util.Collection;
+
+/*** Ensures that the variables fit on zeropage.  */
+public class Pass4AssertZeropageAllocation extends Pass2Base {
+
+   public Pass4AssertZeropageAllocation(Program program) {
+      super(program);
+   }
+
+   /**
+    * Check that all variables fit onto zeropage
+    */
+   public void check() {
+      Collection<Variable> allVariables = getSymbols().getAllVariables(true);
+      for(Variable variable : allVariables) {
+         Registers.Register allocation = variable.getAllocation();
+         if(allocation!=null && allocation.isZp()) {
+            int zp = ((Registers.RegisterZp) allocation).getZp();
+            int sizeBytes = variable.getType().getSizeBytes();
+            if(zp+sizeBytes>0x100) {
+               // Allocation is outside ZP!
+               throw new CompileError("Error! Variables used in program do not fit on zeropage. Maybe try compiling with -Ocoalesce to optimize ZP usage.");
+            }
+         }
+      }
+   }
+
+}

src/test/java/dk/camelot64/kickc/test/TestPrograms.java

@@ -35,12 +35,16 @@ public class TestPrograms {
    public TestPrograms() {
    }
 
+   @Test
+   public void testZeropageExhausted() throws IOException, URISyntaxException {
+      assertError("zeropage-exhausted", "Variables used in program do not fit on zeropage", false);
+   }
+
    @Test
    public void testPlatformAsm6502() throws IOException, URISyntaxException {
       compileAndCompare("platform-asm6502");
    }
 
-
    @Test
    public void testEuclid2() throws IOException, URISyntaxException {
       compileAndCompare("euclid-3");

src/test/kc/zeropage-exhausted.kc

@@ -0,0 +1,11 @@
+// Tests warning when running out of zeropage-addresses for variables
+
+// Start by reserving most of zeropage (254 bytes)
+#reserve(1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50,51,52,53,54,55,56,57,58,59,60,61,62,63,64,65,66,67,68,69,70,71,72,73,74,75,76,77,78,79,80,81,82,83,84,85,86,87,88,89,90,91,92,93,94,95,96,97,98,99,100,101,102,103,104,105,106,107,108,109,110,111,112,113,114,115,116,117,118,119,120,121,122,123,124,125,126,127,128,129,130,131,132,133,134,135,136,137,138,139,140,141,142,143,144,145,146,147,148,149,150,151,152,153,154,155,156,157,158,159,160,161,162,163,164,165,166,167,168,169,170,171,172,173,174,175,176,177,178,179,180,181,182,183,184,185,186,187,188,189,190,191,192,193,194,195,196,197,198,199,200,201,202,203,204,205,206,207,208,209,210,211,212,213,214,215,216,217,218,219,220,221,222,223,224,225,226,227,228,229,230,231,232,233,234,235,236,237,238,239,240,241,242,243,244,245,246,247,248,249,250,251,252,253,254)
+
+// And then allocate a 2-byte-variable
+void main() {
+    const int* SCREEN = 0x0400;
+    for(int i=0;i<10;i++)
+        SCREEN[(char)i] = i;
+}

src/test/ref/euclid-3.asm

@@ -1,5 +1,5 @@
 /*
- * Find least common denominator using subtraction-based Euclidian algorithm
+ * Find greatest common denominator using subtraction-based Euclidian algorithm
  * See https://en.wikipedia.org/wiki/Euclidean_algorithm
  * Based on facebook post from
  */

src/test/ref/euclid-3.log

@@ -1230,7 +1230,7 @@ INITIAL ASM
 Target platform is c64basic
   // File Comments
 /*
- * Find least common denominator using subtraction-based Euclidian algorithm
+ * Find greatest common denominator using subtraction-based Euclidian algorithm
  * See https://en.wikipedia.org/wiki/Euclidean_algorithm
  * Based on facebook post from
  */
@@ -1782,7 +1782,7 @@ Allocated (was zp ZP_WORD:12) zp ZP_WORD:8 [ memset::dst#2 memset::dst#1 ]
 ASSEMBLER BEFORE OPTIMIZATION
   // File Comments
 /*
- * Find least common denominator using subtraction-based Euclidian algorithm
+ * Find greatest common denominator using subtraction-based Euclidian algorithm
  * See https://en.wikipedia.org/wiki/Euclidean_algorithm
  * Based on facebook post from
  */
@@ -2443,7 +2443,7 @@ Score: 1577
 
   // File Comments
 /*
- * Find least common denominator using subtraction-based Euclidian algorithm
+ * Find greatest common denominator using subtraction-based Euclidian algorithm
  * See https://en.wikipedia.org/wiki/Euclidean_algorithm
  * Based on facebook post from
  */