-- test b0t
package b0t is 
body
x: integer;
y,z: boolean;
begin
z := true;
writeln("z = ",z);
%%dmp
end;


in     simple.c

Token  : Package

Token  : Id
grammar: packname -> Id # PutPackName
After  : PutPackName Semstack is:
                EMPTY

Token  : Is

Token  : Body

Token  : Id
grammar:  idlist  -> Id #PushId#CreateIdList
After  : PushId Semstack is:
         IdEntry (x)    <+ SemTop
After  : CreateIdList Semstack is:
         IdListEntry    <+ SemTop

Token  : Colonsym

Token  : Id
grammar: type     -> Id #PushId#MakeTypeEntry
After  : PushId Semstack is:
         IdEntry (integer)      <+ SemTop
         IdListEntry 
After  : MakeTypeEntry Semstack is:
         TypeEntry      <+ SemTop
         IdListEntry 

Token  : Termsym
grammar: decl     -> idlist Colonsym type ; #EnterIdList
After  : EnterIdlist Semstack is:
                EMPTY
grammar: decl     -> decl

Token  : Id
grammar:  idlist  -> Id #PushId#CreateIdList
After  : PushId Semstack is:
         IdEntry (y)    <+ SemTop
After  : CreateIdList Semstack is:
         IdListEntry    <+ SemTop

Token  : Commasym

Token  : Id
grammar: idlist   -> idlist Commasym Id #PushId#MergeIdList
After  : PushId Semstack is:
         IdEntry (z)    <+ SemTop
         IdListEntry 
After  : MergeIdList Semstack is:
         IdListEntry    <+ SemTop

Token  : Colonsym

Token  : Id
grammar: type     -> Id #PushId#MakeTypeEntry
After  : PushId Semstack is:
         IdEntry (boolean)      <+ SemTop
         IdListEntry 
After  : MakeTypeEntry Semstack is:
         TypeEntry      <+ SemTop
         IdListEntry 

Token  : Termsym
grammar: decl     -> idlist Colonsym type ; #EnterIdList
After  : EnterIdlist Semstack is:
                EMPTY
grammar: decl     -> decllist decl

Token  : Begin
grammar: stmtlist -> lambda #NullList
After  : NullList Semstack is:
         StLstEntry     <+ SemTop

Token  : Id
grammar: identifier->Id #PushId
After  : PushId Semstack is:
         IdEntry (z)    <+ SemTop
         StLstEntry
grammar: memref   -> identifier #IdToAddr
After  : IdToAddr Semstack is:
         AddrEntry (type boolean)       <+ SemTop
         StLstEntry

Token  : Assignop

Token  : True
grammar: boolean_const-> True #PushBool
After  : PushBool Semstack is:
         ConstEntry (type boolean)      <+ SemTop
         AddrEntry (type boolean)
         StLstEntry
grammar: primary  -> boolean_const #ConstReduce
After  : ConstReduce Semstack is:
         ExprEntry (type boolean)       <+ SemTop
         AddrEntry (type boolean)
         StLstEntry
grammar: fact     -> primary
grammar: u_expr   -> fact
grammar: term     -> u_expr

Token  : Termsym
grammar: s_expr   -> term
grammar: relation -> s_expr
grammar: expr     -> relation
grammar: assignstmt->memeref Assignop expr #Assign
After  : Assign Semstack is:
         StmtEntry      <+ SemTop
         StLstEntry
grammar: stmt     -> assignstmt Termsym
grammar: stmtlist -> stmtlist stmt #MergeStmts
After  : MergeStmts Semstack is:
         StLstEntry     <+ SemTop

Token  : Writeln

Token  : Lparen

Token  : Strconst
grammar: actparam   -> Strconst #PushString#CreateaActParam
After  : PushString Semstack is:
         StrConstEntry (z = )   <+ SemTop
         StLstEntry
After  : CreateActParam Semstack is:
         ParmEntry      <+ SemTop
         StLstEntry
grammar: actparamlist->actparam

Token  : Commasym

Token  : Id
grammar: identifier->Id #PushId
After  : PushId Semstack is:
         IdEntry (z)    <+ SemTop
         ParmEntry 
         StLstEntry
grammar: memref   -> identifier #IdToAddr
After  : IdToAddr Semstack is:
         AddrEntry (type boolean)       <+ SemTop
         ParmEntry 
         StLstEntry
grammar: primary  -> memref #AddrToPrimary
After  : AddrToPrimary Semstack is:
         ExprEntry (type boolean)       <+ SemTop
         ParmEntry 
         StLstEntry
grammar: fact     -> primary
grammar: u_expr   -> fact
grammar: term     -> u_expr

Token  : Rparen
grammar: s_expr   -> term
grammar: relation -> s_expr
grammar: expr     -> relation
grammar: actparam   -> expr #CreateActParam
After  : CreateActParam Semstack is:
         ParmEntry      <+ SemTop
         ParmEntry 
         StLstEntry
grammar: actparamlist->actparamlist Commasym actparam #MergeActParam
After  : MergeActParam Semstack is:
         ParmEntry      <+ SemTop
         StLstEntry
grammar: writestmt-> Writeln Lparen actparamlist Rparen #Call
After  : Call Semstack is:
         StmtEntry      <+ SemTop
         StLstEntry

Token  : Termsym
grammar: stmt     -> writestmt Termsym
grammar: stmtlist -> stmtlist stmt #MergeStmts
After  : MergeStmts Semstack is:
         StLstEntry     <+ SemTop
 
Symbol table dump:
  boolean  Type: boolean
  integer  Type: integer
  x  Type: integer
  y  Type: boolean
  z  Type: boolean

Token  : End
grammar: body     -> Body decllst Begin stmtlst

Token  : Termsym
grammar: pgm -> Package packname Is body End ;# Done
Warning          - integer 'x' is not used 
Warning          - boolean 'y' is not used 
After  : Done Semstack is:
                EMPTY
 
Intermediate Representation - the Abstract Syntax Tree
   Statements
      Assign
         z
            gets
         Immediate Value 1
      Writeln
         parameters
            String: z = 
            z


>From codegen.c - DisplayRegs() marks used registers

Register: 0 1 2 3 4 5 6 7 8 9 
          - - - - - - - - - - 
Used = x:                 x x

COMPILATION COMPLETE
out    simple.c

listing file

  1  -- test b0t
  2  package b0t is 
  3  body
  4  x: integer;
  5  y,z: boolean;
  6  begin
  7  z := true;
  8  writeln("z = ",z);
  9  %%dmp
 10  end;
Warning          - integer 'x' is not used 

Warning          - boolean 'y' is not used 

 11  

 spim code generated by compiler

# Register Usage:
#     $s0 for global variables
#
        .text 
        .globl main 
 main:
        la      $s0, VARS
#
# Start Code
# Generate Assignment Statement 
# 
        li      $t0,1
        sw      $t0,8($s0)
# 
# Generate Writeln statement 
        la      $a0, S1
        li      $v0, 4
        syscall
        li      $v0, 1
        lw      $a0,8($s0)
        syscall
        la      $a0, S0
        li      $v0, 4
        syscall

#
# Halt execution
        li      $v0 10
        syscall

#
# Finish up by writing out constants 
        .word 0
CONST:          #Constant storage area
        .data
S0:     .asciiz "\n"
        .data
S1:     .asciiz "z = "
#
# Reserve space for global variables
        .word 0
VARS:           # space for Global Variables
        .data
_x:     .word 0 # Offset at 0
        .data
_y:     .word 0 # Offset at 4
        .data
_z:     .word 0 # Offset at 8