Simplify buffer allocation in parser.

src/alloc.asm

@@ -64,7 +64,7 @@
         .export         alloc_prog, alloc_laddr
         .export         parser_alloc_init, alloc_area_8
 
-        .importzp       prog_ptr, laddr_ptr, mem_end, var_buf, tmp1
+        .importzp       prog_ptr, laddr_ptr, mem_end, var_buf, tmp1, end_ptr
         .import         move_dwn, err_nomem
         .importzp       move_dwn_src, move_dwn_dst
 
@@ -83,6 +83,16 @@ alloc_size=     tmp1
 ; Following routines are part of the parser/editor
         .code
 
+        ; Increase program memory area by "opos" (size in bytes)
+.proc alloc_prog
+        .importzp       opos
+        lda     opos
+        ldx     #prog_ptr - mem_start
+        .assert prog_ptr = mem_start, error, "Prog Ptr should be at mem start"
+        stx     opos
+        .byte   $2C   ; Skip 2 bytes over next "LDX"
+.endproc        ; Fall through
+
 .proc   alloc_laddr
         ldx     #laddr_ptr - mem_start
 .endproc        ; Fall through
@@ -152,30 +162,19 @@ skip:
 ;----------------------------------------------------------
 ; Parser initialization here:
 .proc   parser_alloc_init
-        ; Init all pointers to AY
-        ldx     #(mem_end-mem_start)
+        ; Init all pointers to AY, starting from "end_ptr"
+        ldx     #(mem_end-end_ptr)
         ; Adds 256 bytes as program buffer
         iny
 loop:
-        sta     mem_start, x
-        sty     mem_start+1, x
+        sta     end_ptr, x
+        sty     end_ptr+1, x
         dex
         dex
         bpl     loop
-        ; Remove 256 bytes at program start
+        ; Restore correct value of program start and end of source
         dec     prog_ptr+1
-        rts
-.endproc
-
-        ; Increase program memory area by "opos" (size in bytes)
-.proc alloc_prog
-        .importzp       opos
-        ; Move from "prog_ptr", up by "alloc_size"
-        ldx     #prog_ptr - mem_start
-        .assert prog_ptr = mem_start, error, "Prog Ptr should be at mem start"
-        lda     opos
-        stx     opos
-        bne     alloc_area_8
+        dec     end_ptr+1
         rts
 .endproc
 

src/cmdline.bas

@@ -122,7 +122,8 @@ PROC CompileFile
   poke MemEnd, $9B
   ? "Compiling..."
   dpoke @@RELOC_OFFSET, @BYTECODE_ADDR - MemEnd
-  if USR( @compile_buffer, Adr(MemStart), MemEnd)
+  dpoke @@BUF_PTR, Adr(MemStart)
+  if USR( @compile_buffer, MemEnd)
     ' Parse error, show
     ? " at line "; dpeek(@@linenum); " column "; peek( @@bmax )
   else

src/cmdmenu.asm

@@ -42,25 +42,19 @@
         ; Exported to CMDLINE.BAS
 BMAX=bmax
 LINENUM=linenum
-        .exportzp RELOC_OFFSET
+        .exportzp RELOC_OFFSET, BUF_PTR
 RELOC_OFFSET = reloc_addr
+BUF_PTR = buf_ptr
 
         .code
         ; Called from editor
 COMPILE_BUFFER:
 
         ; Buffer end pointer
         pla
-        sta     end_ptr+1
         tay
         pla
-        sta     end_ptr
         jsr     parser_alloc_init
-        ; Buffer address
-        pla
-        sta     buf_ptr+1
-        pla
-        sta     buf_ptr
 
         ; Save our CPU return stack
         lda     saved_cpu_stack

src/compile.asm

@@ -47,9 +47,9 @@
         ; Exported to EDITOR.BAS
 BMAX=bmax
 LINENUM=linenum
-        .exportzp RELOC_OFFSET
+        .exportzp RELOC_OFFSET, BUF_PTR
 RELOC_OFFSET = reloc_addr
-
+BUF_PTR = buf_ptr
 
         ; Our BREAK key handler, placed in DATA segment, as it is modified
         ; during runtime.
@@ -71,16 +71,9 @@ COMPILE_BUFFER:
 
         ; Buffer end pointer
         pla
-        sta     end_ptr+1
         tay
         pla
-        sta     end_ptr
         jsr     parser_alloc_init
-        ; Buffer address
-        pla
-        sta     buf_ptr+1
-        pla
-        sta     buf_ptr
 
         ; Save our CPU return stack
         lda     saved_cpu_stack

src/editor.bas

@@ -160,7 +160,8 @@ ENDPROC
 PROC CompileFile
   ' Compile main file
   ? "Parsing: ";
-  if USR( @compile_buffer, Adr(MemStart), MemEnd)
+  dpoke @@BUF_PTR, Adr(MemStart)
+  if USR( @compile_buffer, MemEnd)
     ' Parse error, go to error line
     topLine = dpeek(@@linenum) - 11
     column = peek( @@bmax )

src/memptr.asm

@@ -24,39 +24,33 @@
 ; linked into a combine executable.)
 
 
-; Memory functions
-; ----------------
+; Parser Memory Areas
+; -------------------
 
         .exportzp       prog_ptr, array_ptr, var_buf, var_ptr, mem_end
-        .exportzp       label_buf, label_ptr, laddr_buf, laddr_ptr
+        .exportzp       label_buf, label_ptr, laddr_buf, laddr_ptr, end_ptr
 
         .zeropage
 
-        ; Note that the memory pointers are shared between parser and runtime,
-        ; so that less zeropage memory is used.
-        ;
-        ;           During Parsing           During Execution
-        ;           ---------------------------------------------
-        ; Pointer to program buffer        / UNUSED
-mem_start:
+        ; End of program to parse
+end_ptr:        .res    2
+        ; Pointer to end of program buffer
 prog_ptr:       .res    2
-        ; Pointer to variable name table   / variable value table
+        ; Pointers to start / end of variable name table
 var_buf:        .res    2
-var_ptr=        array_buf
-        ; Pointer to labels name table     / strings/arrays table
-array_buf:      .res    2
-label_buf=      array_buf
-array_ptr=      laddr_buf
+var_ptr=        label_buf
+        ; Pointers to start / end of labels name table
+label_buf:      .res    2
 label_ptr=      laddr_buf
-        ; Pointer to labels address table  / end of string/arrays table,
-        ;                                    top of used memory
+        ; Pointers to start / end of labels address table
 laddr_buf:      .res    2
 laddr_ptr=      mem_end
-        ; End of used memory
+        ; End of parser memory
 mem_end:        .res    2
 
-        ; Used from BASIC code
+        ; Share this to BASIC runtime, to use less ZP memory
         .exportzp       BASIC_TOP
+array_ptr=      laddr_buf
 BASIC_TOP= array_ptr
 
 ; vi:syntax=asm_ca65

src/parse.asm

@@ -21,7 +21,7 @@
 
         .export         parser_start, parser_error, parser_skipws, parser_emit_byte, parser_inc_opos
         ; Parser state
-        .exportzp       bptr, bpos, bmax, linenum, buf_ptr, end_ptr
+        .exportzp       bptr, bpos, bmax, linenum, buf_ptr
         .exportzp       loop_sp, var_sp
         ; Output state
         .exportzp       opos
@@ -32,7 +32,7 @@
         .importzp       LT_WHILE_2, LT_FOR_1,LT_FOR_2, LT_EXIT, LT_IF, LT_ELSE, LT_ELIF
         ; From alloc.asm
         .import         alloc_prog
-        .importzp       prog_ptr, BASIC_TOP
+        .importzp       prog_ptr, end_ptr, BASIC_TOP
         ; From vars.asm
         .exportzp       var_count, label_count
         ; From runtime.asm
@@ -49,7 +49,6 @@
 
         .zeropage
 buf_ptr:.res 2
-end_ptr:.res 2
 bmax:   .res 1
 pptr:   .res 2