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apl.h
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apl.h
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#include<string.h>
#include<stdlib.h>
#define TRUE 1
#define FALSE 0
extern int linecount;
unsigned long main_pos=-1; //lseek of jump to main
unsigned long temp_pos; //temporary lseek
int out_linecount=0; //no of lines of code generated
int flag_decl=0;
int flag_break=0;
int m=-1, m2=-1, m3=-1; //m-variable type, m2-argtype, m3-returntype of function
struct tree *funcid=NULL;
int memcount=1536, regcount=0;
FILE *fp;
struct ArgStruct{
char* name;
int type;//0-integer, 1-boolean, 3-string
int passtype;//0-by value, 1-by reference
struct ArgStruct* next;
};
struct Lsymbol
{
char *name;
int type; //integer-0, 3-string
int bind;
struct Lsymbol *next;
};
struct Gsymbol
{
char *name;
int type; //integer-0, 3-string
int size;
int bind;
struct ArgStruct *arglist;
struct Gsymbol *next;
};
struct Gsymbol *root=NULL;
struct Lsymbol *Lroot=NULL;
struct tree
{
int type; //0-integer , 1-boolean , 2-void, 3-string
char nodetype; /* +, -, *, /, %, =, <, >, !
?-if statement
c-number, i-identifier, r-read, p-print,
n-nonterminal, e-double equals, l-lessthan or equals
g-greaterthan or equals w-while s-string
f-function, u-return
a-AND o-OR x-NOT
C-Create O-Open W-Write
S-Seek R-Read L-Close
D-Delete F-Fork X-Exec E-Exit
G-Getpid P-Getppid Y-Wait Z-Signal
b-break t-continue
B-breakpoint*/
char *name;
int value;
struct Gsymbol *Gentry;
struct Lsymbol *Lentry;
struct tree *argument;
struct tree *ptr1, *ptr2, *ptr3;
};
int labelcount=0;
struct jmp_point
{
unsigned long pos;
char instr[32];
struct jmp_point *next;
};
struct label
{
int i;
unsigned long pos1,pos2;
char instr1[32],instr2[32];
struct label *next;
struct jmp_point *points;
};
struct label *top=NULL, *top_while=NULL;
void push()
{
struct label *temp;
temp=malloc(sizeof(struct label));
temp->i=labelcount;
temp->pos1=0;
temp->pos2=0;
bzero(temp->instr1,32);
bzero(temp->instr2,32);
temp->next=top;
temp->points=NULL;
top=temp;
labelcount++;
}
int pop()
{
int i;
struct label *temp;
temp=top;
top=top->next;
i=temp->i;
free(temp);
return i;
}
void push_while(int n)
{
struct label *temp;
temp=malloc(sizeof(struct label));
temp->i=n;
temp->pos1=0;
temp->pos2=0;
bzero(temp->instr1,32);
bzero(temp->instr2,32);
temp->next=top_while;
temp->points=NULL;
top_while=temp;
}
void pop_while()
{
struct label *temp;
temp=top_while;
top_while=top_while->next;
free(temp);
}
void add_jmp_point(char instr[32])
{
struct jmp_point *temp;
temp=malloc(sizeof(struct jmp_point));
fflush(fp);
temp->pos = ftell(fp);
strcpy(temp->instr,instr);
temp->next = top_while->points;
top_while->points = temp;
}
void use_jmp_points(struct jmp_point *root)
{
if(root == NULL)
return;
else
{
fflush(fp);
temp_pos = ftell(fp);
fseek(fp,root->pos,SEEK_SET);
fprintf(fp,"%s %05d",root->instr,out_linecount*2);
fseek(fp,temp_pos,SEEK_SET);
use_jmp_points(root->next);
free(root);
}
}
void pushargs(struct tree *);
void popargs(struct tree *, struct ArgStruct *, int);
void endfn();
void codegen(struct tree * root)
{
int n;
if(root==NULL)
return;
switch(root->nodetype)
{
case '<':
codegen(root->ptr1);
codegen(root->ptr2);
out_linecount++; fprintf(fp, "LT R%d, R%d\n", regcount-2, regcount-1);
regcount--;
break;
case '>':
codegen(root->ptr1);
codegen(root->ptr2);
out_linecount++; fprintf(fp, "GT R%d, R%d\n", regcount-2, regcount-1);
regcount--;
break;
case 'e':
codegen(root->ptr1);
codegen(root->ptr2);
out_linecount++; fprintf(fp, "EQ R%d, R%d\n", regcount-2, regcount-1);
regcount--;
break;
case 'l':
codegen(root->ptr1);
codegen(root->ptr2);
out_linecount++; fprintf(fp, "LE R%d, R%d\n", regcount-2, regcount-1);
regcount--;
break;
case 'g':
codegen(root->ptr1);
codegen(root->ptr2);
out_linecount++; fprintf(fp, "GE R%d, R%d\n", regcount-2, regcount-1);
regcount--;
break;
case '!':
codegen(root->ptr1);
codegen(root->ptr2);
out_linecount++; fprintf(fp, "NE R%d, R%d\n", regcount-2, regcount-1);
regcount--;
break;
case 'a': //AND operator
codegen(root->ptr1);
codegen(root->ptr2);
out_linecount++; fprintf(fp, "MUL R%d, R%d\n", regcount-2, regcount-1);
regcount--;
break;
case 'o': //OR operator
codegen(root->ptr1);
codegen(root->ptr2);
out_linecount++; fprintf(fp, "ADD R%d, R%d\n", regcount-2, regcount-1);
regcount--;
break;
case 'x': //NOT operator
codegen(root->ptr1);
out_linecount++; fprintf(fp, "MOV R%d, 1\n", regcount);
regcount++;
out_linecount++; fprintf(fp, "SUB R%d, R%d\n", regcount-1, regcount-2);
out_linecount++; fprintf(fp, "MOV R%d, R%d\n", regcount-2, regcount-1);
regcount--;
break;
case 'n': //statement list
codegen(root->ptr1);
codegen(root->ptr2);
break;
case '+':
codegen(root->ptr1);
codegen(root->ptr2);
out_linecount++; fprintf(fp, "ADD R%d, R%d\n", regcount-2, regcount-1);
regcount--;
break;
case '-':
codegen(root->ptr1);
codegen(root->ptr2);
out_linecount++; fprintf(fp, "SUB R%d, R%d\n", regcount-2, regcount-1);
regcount--;
break;
case '*':
codegen(root->ptr1);
codegen(root->ptr2);
out_linecount++; fprintf(fp, "MUL R%d, R%d\n", regcount-2, regcount-1);
regcount--;
break;
case '/':
codegen(root->ptr1);
codegen(root->ptr2);
out_linecount++; fprintf(fp, "DIV R%d, R%d\n", regcount-2, regcount-1);
regcount--;
break;
case '%':
codegen(root->ptr1);
codegen(root->ptr2);
out_linecount++; fprintf(fp, "MOD R%d, R%d\n", regcount-2, regcount-1);
regcount--;
break;
case '=':
if(root->ptr1->Gentry!=NULL)
{
out_linecount++;
fprintf(fp, "MOV R%d, %d\n", regcount, root->ptr1->Gentry->bind);
}
else
{
out_linecount++; fprintf(fp, "MOV R%d, %d\n", regcount, root->ptr1->Lentry->bind);
out_linecount++; fprintf(fp, "MOV R%d, BP\n", regcount+1);
out_linecount++; fprintf(fp, "ADD R%d, R%d\n", regcount, regcount+1);
}
regcount++;
if(root->ptr1->ptr1!=NULL)
{
codegen(root->ptr1->ptr1);
out_linecount++; fprintf(fp, "ADD R%d, R%d\n", regcount-2, regcount-1);
regcount--;
}
codegen(root->ptr2);
out_linecount++; fprintf(fp, "MOV [R%d], R%d\n", regcount-2, regcount-1);
regcount=regcount-2;
break;
case 'r': //READ
if(root->ptr1->Gentry!=NULL)
{
out_linecount++;
fprintf(fp, "MOV R%d, %d\n", regcount, root->ptr1->Gentry->bind);
}
else
{
out_linecount++; fprintf(fp, "MOV R%d, %d\n", regcount, root->ptr1->Lentry->bind);
out_linecount++; fprintf(fp, "MOV R%d, BP\n", regcount+1);
out_linecount++; fprintf(fp, "ADD R%d, R%d\n", regcount, regcount+1);
}
regcount++;
if(root->ptr1->ptr1!=NULL)
{
codegen(root->ptr1->ptr1);
out_linecount++; fprintf(fp, "ADD R%d, R%d\n", regcount-2, regcount-1);
regcount--;
}
out_linecount++; fprintf(fp, "IN R%d\n", regcount);
regcount++;
out_linecount++; fprintf(fp, "MOV [R%d], R%d\n", regcount-2, regcount-1);
regcount=regcount-2;
break;
case 'p': //PRINT
codegen(root->ptr1);
out_linecount++; fprintf(fp, "OUT R%d\n", regcount-1);
regcount--;
break;
case 'c': //constants
out_linecount++; fprintf(fp, "MOV R%d, %d\n", regcount, root->value);
regcount++;
break;
case 's': //string constants
out_linecount++; fprintf(fp, "MOV R%d, %s\n", regcount, root->name);
regcount++;
break;
case 'i': //variables and array variables
if(root->Gentry!=NULL)
{
out_linecount++;
fprintf(fp, "MOV R%d, %d\n", regcount, root->Gentry->bind);
}
else
{
out_linecount++; fprintf(fp, "MOV R%d, %d\n", regcount, root->Lentry->bind);
out_linecount++; fprintf(fp, "MOV R%d, BP\n", regcount+1);
out_linecount++; fprintf(fp, "ADD R%d, R%d\n", regcount, regcount+1);
}
regcount++;
if(root->ptr1!=NULL)
{
codegen(root->ptr1);
out_linecount++; fprintf(fp, "ADD R%d, R%d\n", regcount-2, regcount-1);
regcount--;
}
out_linecount++; fprintf(fp, "MOV R%d, [R%d]\n", regcount-1, regcount-1);
break;
case '?': //IF statement , IF-ELSE statements
push();
codegen(root->ptr1);
fflush(fp);
top->pos1 = ftell(fp);
out_linecount++;
fprintf(fp, "JZ R%d, 00000\n", regcount-1);
sprintf(top->instr1, "JZ R%d,", regcount-1);
regcount--;
codegen(root->ptr2);
fflush(fp);
top->pos2 = ftell(fp);
out_linecount++;
fprintf(fp, "JMP 00000\n");
sprintf(top->instr2, "JMP");
fflush(fp);
temp_pos = ftell(fp);
fseek(fp,top->pos1,SEEK_SET);
fprintf(fp,"%s %05d",top->instr1,out_linecount*2);
fseek(fp,temp_pos,SEEK_SET);
codegen(root->ptr3);
fflush(fp);
temp_pos = ftell(fp);
fseek(fp,top->pos2,SEEK_SET);
fprintf(fp,"%s %05d",top->instr2,out_linecount*2);
fseek(fp,temp_pos,SEEK_SET);
pop();
break;
case 'w': //WHILE loop
push();
push_while(top->i);
top->pos1=out_linecount*2;
top_while->pos1=out_linecount*2;
codegen(root->ptr1);
fflush(fp);
top->pos2 = ftell(fp);
out_linecount++;
fprintf(fp, "JZ R%d, 00000\n", regcount-1);
sprintf(top->instr2, "JZ R%d,", regcount-1);
regcount--;
codegen(root->ptr2);
out_linecount++;
fprintf(fp, "JMP %ld\n", top->pos1);
fflush(fp);
temp_pos = ftell(fp);
fseek(fp,top->pos2,SEEK_SET);
fprintf(fp,"%s %05d",top->instr2,out_linecount*2);
fseek(fp,temp_pos,SEEK_SET);
use_jmp_points(top_while->points);
pop_while();
pop();
break;
case 'b': //BREAK loop
add_jmp_point("JMP");
out_linecount++;
fprintf(fp, "JMP 00000\n");
break;
case 't': //CONTINUE loop
out_linecount++;
fprintf(fp, "JMP %ld\n", top_while->pos1);
break;
case 'B': //Breakpoint
out_linecount++;
fprintf(fp, "BRKP\n");
break;
case 'f':
n=regcount;
while(regcount>0)
{
out_linecount++; fprintf(fp, "PUSH R%d\n", regcount-1);
regcount--;
}
pushargs(root->ptr1);
out_linecount+=2; fprintf(fp, "PUSH R0\nCALL %d\n", root->Gentry->bind * 2);
out_linecount++; fprintf(fp, "POP R%d\n", n);
popargs(root->ptr1, root->Gentry->arglist, n);
while(regcount<n)
{
out_linecount++; fprintf(fp, "POP R%d\n", regcount);
regcount++;
}
regcount++;
break;
case 'u':
if(funcid!=NULL) //NOT MAIN
{
codegen(root->ptr1);
out_linecount+=3; fprintf(fp, "MOV R%d, -2\nMOV R%d, BP\nADD R%d, R%d\n", regcount, regcount+1, regcount, regcount+1);
regcount++;
out_linecount++;
fprintf(fp, "MOV [R%d], R%d\n", regcount-1, regcount-2);
regcount=regcount-2;
endfn();
}
break;
case 'C': //Create syscall
case 'O': //Open syscall
case 'L': //Close syscall
case 'D': //Delete syscall
case 'Y': //Wait syscall
codegen(root->ptr1);
out_linecount+=2; fprintf(fp, "PUSH R%d\nPUSH R0\n", regcount-1);
regcount--;
out_linecount+=2; fprintf(fp, "MOV R%d, %d\nPUSH R%d\n",regcount, root->value,regcount);
out_linecount++;
if( root->nodetype == 'C' || root->nodetype=='D')
fprintf(fp, "INT 1\n");
else if( root->nodetype == 'Y')
fprintf(fp, "INT 7\n");
else
fprintf(fp, "INT 2\n");
//Interrupt
out_linecount++; fprintf(fp, "POP R%d\n",regcount+1);
out_linecount++; fprintf(fp, "POP R%d\n",regcount);
out_linecount++; fprintf(fp, "POP R%d\n",regcount+1);
regcount++;
break;
case 'W': //Write syscall
case 'R': //Read syscall
codegen(root->ptr1);
out_linecount++; fprintf(fp, "PUSH R%d\n", regcount-1);
regcount--;
codegen(root->ptr1->ptr3);
out_linecount+=2; fprintf(fp, "PUSH R%d\nPUSH R0\n", regcount-1);
regcount--;
out_linecount+=2; fprintf(fp, "MOV R%d, %d\nPUSH R%d\n", regcount, root->value, regcount);
if(root->nodetype == 'W')
{
out_linecount++;
fprintf(fp, "INT 4\n");
}
else
{
out_linecount++;
fprintf(fp, "INT 3\n");
}
//Interrupt
out_linecount++; fprintf(fp, "POP R%d\n",regcount+1);
if(root->nodetype == 'R')
{
if(root->ptr1->ptr3->Gentry!=NULL)
{
out_linecount++;
fprintf(fp, "MOV R%d, %d\n", regcount, root->ptr1->ptr3->Gentry->bind);
}
else
{
out_linecount++; fprintf(fp, "MOV R%d, %d\n", regcount, root->ptr1->ptr3->Lentry->bind);
out_linecount++; fprintf(fp, "MOV R%d, BP\n", regcount+1);
out_linecount++; fprintf(fp, "ADD R%d, R%d\n", regcount, regcount+1);
}
regcount++;
if(root->ptr1->ptr3->ptr1!=NULL)
{
codegen(root->ptr1->ptr3->ptr1);
out_linecount++; fprintf(fp, "ADD R%d, R%d\n", regcount-2, regcount-1);
regcount--;
}
}
out_linecount++; fprintf(fp, "POP R%d\n",regcount);
out_linecount++; fprintf(fp, "POP R%d\n",regcount+1);
if(root->nodetype == 'R')
{
out_linecount++;
fprintf(fp, "MOV [R%d], R%d\n", regcount-1, regcount+1);
out_linecount++;
fprintf(fp, "MOV R%d, R%d\n", regcount-1, regcount);
regcount--;
}
out_linecount++; fprintf(fp, "POP R%d\n",regcount+1);
regcount++;
break;
case 'S': //Seek syscall
codegen(root->ptr1);
out_linecount++; fprintf(fp, "PUSH R%d\n", regcount-1);
regcount--;
codegen(root->ptr1->ptr3);
out_linecount+=2; fprintf(fp, "PUSH R%d\nPUSH R0\n", regcount-1);
regcount--;
out_linecount+=2; fprintf(fp, "MOV R%d, %d\nPUSH R%d\n", regcount, root->value, regcount);
out_linecount++; fprintf(fp, "INT 3\n");
//Interrupt
out_linecount++; fprintf(fp, "POP R%d\n", regcount+1);
out_linecount++; fprintf(fp, "POP R%d\n", regcount);
out_linecount++; fprintf(fp, "POP R%d\n", regcount+1);
out_linecount++; fprintf(fp, "POP R%d\n", regcount+1);
regcount++;
break;
case 'F': //Fork syscall
case 'G': //Getpid syscall
case 'P': //Getppid syscall
case 'Z': //Signal syscall
out_linecount++; fprintf(fp, "PUSH R0\n");
out_linecount+=2; fprintf(fp, "MOV R%d, %d\nPUSH R%d\n", regcount, root->value, regcount);
out_linecount++;
if( root->nodetype == 'F')
fprintf(fp, "INT 5\n");
else if( root->nodetype == 'G' || root->nodetype=='P')
fprintf(fp, "INT 6\n");
else
fprintf(fp, "INT 7\n");
//Interrupt
out_linecount++; fprintf(fp, "POP R%d\n", regcount+1);
out_linecount++; fprintf(fp, "POP R%d\n", regcount);
regcount++;
break;
case 'X': //Exec syscall
codegen(root->ptr1);
out_linecount+=2; fprintf(fp, "PUSH R%d\nPUSH R0\n", regcount-1);
regcount--;
out_linecount+=2; fprintf(fp, "MOV R%d, %d\nPUSH R%d\n", regcount, root->value, regcount);
out_linecount++; fprintf(fp, "INT 6\n");
//Interrupt
out_linecount++; fprintf(fp, "POP R%d\n", regcount+1);
out_linecount++; fprintf(fp, "POP R%d\n", regcount);
out_linecount++; fprintf(fp, "POP R%d\n", regcount+1);
regcount++;
break;
case 'E': //Exit syscall
out_linecount+=2; fprintf(fp, "MOV R%d, %d\nPUSH R%d\n", regcount, root->value, regcount);
out_linecount++; fprintf(fp, "INT 7\n");
//Interrupt
out_linecount++; fprintf(fp, "POP R%d\n", regcount);
break;
default:
return;
}
}
void pushargs(struct tree *a)
{
if(a==NULL)
return;
if(a->ptr3!=NULL)
pushargs(a->ptr3);
codegen(a);
out_linecount++; fprintf(fp, "PUSH R%d\n", regcount-1);
regcount--;
}
void popargs(struct tree *a, struct ArgStruct *arg, int n)
{
int regcount=n+1;
if(a==NULL)
return;
out_linecount++; fprintf(fp, "POP R%d\n", regcount);
//printf(" %s %s-%d\n", a->name, arg->name, arg->passtype);
if(arg->passtype==1) //call by reference
{
regcount++;
if(a->Gentry!=NULL)
{
out_linecount++;
fprintf(fp, "MOV R%d, %d\n", regcount, a->Gentry->bind);
}
else
{
out_linecount++; fprintf(fp, "MOV R%d, %d\n", regcount, a->Lentry->bind);
out_linecount++; fprintf(fp, "MOV R%d, BP\n", regcount+1);
out_linecount++; fprintf(fp, "ADD R%d, R%d\n", regcount, regcount+1);
}
regcount++;
if(a->ptr1!=NULL)
{
codegen(a->ptr1);
out_linecount++; fprintf(fp, "ADD R%d, R%d\n", regcount-2, regcount-1);
regcount--;
}
out_linecount++; fprintf(fp, "MOV [R%d], R%d\n", regcount-1, regcount-2);
regcount=regcount-2;
}
popargs(a->ptr3, arg->next, n);
}
void endfn()
{
struct Lsymbol *temp;
temp=Lroot;
while(temp!=NULL)
{
//printf("%s-%d\n", temp->name, temp->bind);
if(temp->bind>0)
{
out_linecount++;
fprintf(fp, "POP R%d\n", regcount);
}
temp=temp->next;
}
out_linecount+=2; fprintf(fp, "POP BP\nRET\n");
}
struct Gsymbol * lookup(char * name)
{
struct Gsymbol *temp=root;
while(temp!=NULL)
{
if(strcmp(name, temp->name)==0)
return temp;
temp=temp->next;
}
return NULL;
}
struct Lsymbol * Llookup(char * name)
{
struct Lsymbol *temp=Lroot;
while(temp!=NULL)
{
if(strcmp(name, temp->name)==0)
return temp;
temp=temp->next;
}
return NULL;
}
struct tree * nontermcreate(char *name, struct tree *a, struct tree *b)
{
struct tree *temp=malloc(sizeof(struct tree));
temp->type=2;
temp->nodetype='n';
temp->name=name;
temp->Gentry=NULL;
temp->Lentry=NULL;
temp->ptr1=a;
temp->ptr2=b;
temp->ptr3=NULL;
return temp;
}
struct tree* maketree(struct tree *a, struct tree *b, struct tree *c, struct tree *d)
{
//printf("%c\n", a->nodetype);
if(a->nodetype=='i') //checks in symbol table for variable and assigns pointer to it.
{
if(a->Gentry==NULL && a->Lentry==NULL)
{
if(a->ptr1==NULL)
a->Lentry=Llookup(a->name);
if(a->Lentry==NULL)
a->Gentry=lookup(a->name);
if(a->Gentry==NULL && a->Lentry==NULL)
{
printf("\n%d: Undeclared variable %s!!\n", linecount, a->name);
exit(0);
}
if(a->Gentry!=NULL)
a->type=a->Gentry->type;
else
a->type=a->Lentry->type;
}
if(b!=NULL) //array operations
{
if(b->type==0)
a->ptr1=b;
else
{
printf("\n%d: Array error !!\n", linecount);
exit(0);
}
}
return a;
}
if(a->type==2) //for void type nodes (READ, PRINT, IF, WHILE, ASG, RETURN)
{
if(c==NULL && d==NULL) //for READ and PRINT - assigns the variable to ptr1. Also Return
{
a->ptr1=b;
if(a->nodetype=='u') //RETURN
{
if(a->ptr1->type!=m3)
{
printf("\n%d: Wrong type of return value in function %s !!\n",
linecount, funcid==NULL?"main":funcid->name);
exit(0);
}
}
if(b->type==1)
{
printf("\n%d: Unexpected type of expression !!\n", linecount);
exit(0);
}
return a;
}
else
{
if(b->nodetype=='i') //for assignment statements
{
if(b->type==c->type)
{
a->ptr1=b;
a->ptr2=c;
a->ptr3=d;
return a;
}
else
{
printf("\n%d: Type Error!!\n", linecount);
exit(0);
}
}
if(b->type==1) //for IF statement and IF-ELSE statements and WHILE.
{
a->ptr1=b;
a->ptr2=c;
a->ptr3=d;
return a;
}
else
{
printf("\n%d: IF/WHILE condition must have logical expression!!\n", linecount);
exit(0);
}
}
}
else
if(b!=NULL && c!=NULL && a->type==b->type && b->type==c->type) //type checking of arith and logic(and, or) expressions
{
a->ptr1=b;
a->ptr2=c;
a->ptr3=NULL;
return a;
}
else if(c==NULL && a->type==b->type) //for unary plus minus and NOT operator
{
struct tree* temp=malloc(sizeof(struct tree));
temp->type=0;
temp->nodetype='c';
if(temp->type==0)
temp->value=0;
else
temp->value=1;
temp->ptr1=NULL;
temp->ptr2=NULL;
temp->ptr3=NULL;
a->ptr1=temp;
a->ptr2=b;
a->ptr3=NULL;
return a;
}
else if(a->type==1 && b->type==c->type) //type checking of relational expression
{
a->ptr1=b;
a->ptr2=c;
a->ptr3=NULL;
return a;
}
else
{
printf("\n%d: Type Error !!\n ", linecount);
exit(0);
}
}
void finstall(struct tree *node, int type, struct ArgStruct *arg)
{
struct Gsymbol * temp;
temp=lookup(node->name);
if(temp==NULL)
{
temp=malloc(sizeof(struct Gsymbol));
temp->name=node->name;
temp->type=type;
node->type=type;
temp->arglist=arg;
temp->size=0; //flag for checking whether fuction defined
temp->next=root;
root=temp;
}
else
{
printf("\n%d: Multiple declaration of identifier %s !!\n", linecount, temp->name);
exit(0);
}
}
void install(struct tree *node, int type, int size)
{
int i=0;
struct Gsymbol * temp;
temp=lookup(node->name);
if(temp==NULL)
{
temp=malloc(sizeof(struct Gsymbol));
temp->name=node->name;
temp->type=type;
node->type=type;
temp->size=size;
temp->bind=memcount;
if(size==1)
{
out_linecount++;
fprintf(fp, "PUSH R0\n");
}
else
{
out_linecount+=2; fprintf(fp, "MOV R%d, SP\nMOV R%d, %d\n", regcount, regcount+1, size);
out_linecount+=2; fprintf(fp, "ADD R%d, R%d\nMOV SP, R%d\n", regcount, regcount+1, regcount);
}
memcount=memcount+size;
temp->next=root;
root=temp;
}
else
{
printf("\n%d: Multiple declaration of variable %s !!\n", linecount, temp->name);
exit(0);
}
}
void Linstall(struct tree *node, int type, int size)
{
struct Lsymbol * temp;
temp=Llookup(node->name);
if(flag_decl!=0)
{
printf("\n%d: Declaration of variable cannot be made inside if or while !!\n", linecount);
exit(0);
}
if(temp==NULL)
{
temp=malloc(sizeof(struct Lsymbol));
temp->name=node->name;
temp->type=type;
node->type=type;
out_linecount++; fprintf(fp, "PUSH R0\n");
temp->bind=memcount;
memcount=memcount+size;
temp->next=Lroot;
Lroot=temp;
}
else
{
printf("\n%d Multiple declaration of variable %s !!\n", linecount, temp->name);
exit(0);
}
}
struct ArgStruct * makearg(char *name, int type, int p)
{
struct ArgStruct *temp;
temp=malloc(sizeof(struct ArgStruct));
temp->name=name;
temp->type=type;
temp->passtype=p;
temp->next=NULL;
return temp;
}
struct ArgStruct * makeargtree(struct ArgStruct *a, struct ArgStruct *b)
{
struct ArgStruct *temp=a;
while(a->next!=NULL)
{
if(strcmp(a->name, b->name)==0)
{
printf("\n%d: Argument declared more than once in function!!\n", linecount);
exit(0);
}
a=a->next;
}
a->next=b;
return(temp);
}
void fdefcheck(struct tree *a, struct ArgStruct *b, int type)
{
struct ArgStruct *temp;
a->Gentry=lookup(a->name);
if(a->Gentry==NULL)
{
printf("\n%d: Undeclared function %s defined!!\n", linecount, a->name);
exit(0);
}
if(a->Gentry->type!=type)
{
printf("\n%d: Wrong return type of function %s !!\n", linecount, a->name);
exit(0);
}
temp=a->Gentry->arglist;
while(temp!=NULL&&b!=NULL)
{ //printf(" %s-%d %s-%d\n", temp->name, temp->type, b->name, b->type);
if(temp->type!=b->type)
{
printf("\n%d: Argument type mismatch in function %s !!\n", linecount, a->name);
exit(0);
}
if(strcmp(temp->name, b->name)!=0)
{
printf("\n%d Arguments mismatch in function %s !!\n", linecount, a->name);
exit(0);
}
temp=temp->next;
b=b->next;
}
if(temp!=NULL||b!=NULL)
{
printf("\n%d: Arguments mismatch in function %s !!\n", linecount, a->name);
exit(0);
}
a->Gentry->size=1; //flag set to one. ie fuction defined
a->Gentry->bind=out_linecount;
out_linecount++; fprintf(fp, "PUSH BP\n");
out_linecount++; fprintf(fp, "MOV BP, SP\n");
}
void arglistinstall(struct tree *a)
{
struct ArgStruct *temp;
struct Lsymbol * temp2;
int i=-3;
temp=a->Gentry->arglist;
while(temp!=NULL)
{
temp2=Llookup(temp->name);
if(temp2==NULL)
{
temp2=malloc(sizeof(struct Lsymbol));
temp2->name=temp->name;
temp2->type=temp->type;
temp2->bind=i;
i--;
temp2->next=Lroot;
Lroot=temp2;
}
else
{
printf("\n%d: Multiple declaration of variable %s !!\n", linecount, temp2->name);
exit(0);
}
temp=temp->next;
}
}
struct tree * makeparam(struct tree *a, struct tree *b)
{
struct tree *temp;
if(b->nodetype=='i')
{
if(b->Gentry==NULL && b->Lentry==NULL)
{
if(b->ptr1==NULL)
b->Lentry=Llookup(b->name);
if(b->Lentry==NULL)
b->Gentry=lookup(b->name);
if(b->Gentry==NULL && b->Lentry==NULL)
{
printf("\n%d: Undeclared variable %s as function parameter!!\n", linecount, b->name);
exit(0);
}
if(a->Gentry!=NULL)
b->type=b->Gentry->type;
else
b->type=b->Lentry->type;
}
}
temp=a;
while(temp->ptr3!=NULL)
temp=temp->ptr3;
temp->ptr3=b;
return a;
}
struct tree * functioncall(struct tree * a, struct tree * b)
{
struct ArgStruct *temp1;
struct tree *temp2;
a->Gentry=lookup(a->name);
if(a->Gentry==NULL)
{
printf("\n%d: Undeclared function %s!!\n", linecount, a->name);
exit(0);
}
if(a->Gentry->size==0)
{
printf("\n%d: UnDefined function %s!!\n", linecount, a->name);
exit(0);
}
a->type=a->Gentry->type;
temp1=a->Gentry->arglist;
temp2=b;
while(temp1!=NULL && temp2!=NULL)