fixed @(#) stuff

[unix-history] / usr / src / old / dbx / c.c

/* Copyright (c) 1982 Regents of the University of California */

static char sccsid[] = "@(#)c.c 1.2 %G%";

/*
* C-dependent symbol routines.
*/

#include "defs.h"
#include "symbols.h"
#include "printsym.h"
#include "languages.h"
#include "c.h"
#include "tree.h"
#include "eval.h"
#include "operators.h"
#include "mappings.h"
#include "process.h"
#include "runtime.h"
#include "machine.h"

#define isdouble(range) ( \
   range->symvalue.rangev.upper == 0 and range->symvalue.rangev.lower > 0 \
)

#define isrange(t, name) (t->class == RANGE and istypename(t->type, name))

/*
* Initialize C language information.
*/

public c_init()
{
   Language lang;

   lang = language_define("c", ".c");
   language_setop(lang, L_PRINTDECL, c_printdecl);
   language_setop(lang, L_PRINTVAL, c_printval);
   language_setop(lang, L_TYPEMATCH, c_typematch);
}

/*
* Test if two types are compatible.
*
* Integers and reals are not compatible since they cannot always be mixed.
*/

public Boolean c_typematch(type1, type2)
Symbol type1, type2;
{
   Boolean b;
   register Symbol t1, t2, tmp;

   t1 = type1;
   t2 = type2;
   if (t1 == t2) {
       b = true;
   } else {
       t1 = rtype(t1);
       t2 = rtype(t2);
       if (t1->type == t_int or t1->type == t_char) {
           tmp = t1;
           t1 = t2;
           t2 = tmp;
       }
       b = (Boolean) (
           (
               isrange(t1, "int") and
               (t2->type == t_int or t2->type == t_char)
           ) or (
               isrange(t1, "char") and
               (t2->type == t_char or t2->type == t_int)
           ) or (
               t1->type == t2->type and (
                   (t1->class == t2->class) or
                   (t1->class == SCAL and t2->class == CONST) or
                   (t1->class == CONST and t2->class == SCAL)
               )
           )
       );
   }
   return b;
}

/*
* Decide if a field is a bit field.
*/

private Boolean isbitfield(s)
register Symbol s;
{
   Boolean b;
   register Integer off, len;
   register Symbol t;

   off = s->symvalue.field.offset;
   len = s->symvalue.field.length;
   if ((off mod BITSPERBYTE) != 0 or (len mod BITSPERBYTE) != 0) {
       b = true;
   } else {
       t = rtype(s->type);
       b = (Boolean)
           (t->class == SCAL and len != (sizeof(int)*BITSPERBYTE) or
           len != (size(t)*BITSPERBYTE)
       );
   }
   return b;
}

/*
* Print out the declaration of a C variable.
*/

public c_printdecl(s)
Symbol s;
{
   printdecl(s, 0);
}

private printdecl(s, indent)
register Symbol s;
Integer indent;
{
   register Symbol t;
   Boolean semicolon, newline;

   semicolon = true;
   newline = true;
   if (indent > 0) {
       printf("%*c", indent, ' ');
   }
   if (s->class == TYPE) {
       printf("typedef ");
   }
   switch (s->class) {
       case CONST:
           if (s->type->class == SCAL) {
               printf("(enumeration constant, ord %ld)",
                   s->symvalue.iconval);
           } else {
               printf("const %s = ", symname(s));
               printval(s);
           }
           break;

       case TYPE:
       case VAR:
           if (s->class != TYPE) {
               if (s->level == 2) {
                   printf("static ");
               } else if (s->level < 0) {
                   printf("register ");
               }
           }
           if (s->type->class == ARRAY) {
               printtype(s->type, s->type->type, indent);
               t = rtype(s->type->chain);
               assert(t->class == RANGE);
               printf(" %s[%d]", symname(s), t->symvalue.rangev.upper + 1);
           } else {
               printtype(s, s->type, indent);
               if (s->type->class != PTR) {
                   printf(" ");
               }
               printf("%s", symname(s));
           }
           break;

       case FIELD:
           if (s->type->class == ARRAY) {
               printtype(s->type, s->type->type, indent);
               t = rtype(s->type->chain);
               assert(t->class == RANGE);
               printf(" %s[%d]", symname(s), t->symvalue.rangev.upper + 1);
           } else {
               printtype(s, s->type, indent);
               if (s->type->class != PTR) {
                   printf(" ");
               }
               printf("%s", symname(s));
           }
           if (isbitfield(s)) {
               printf(" : %d", s->symvalue.field.length);
           }
           break;

       case TAG:
           if (s->type == nil) {
               findtype(s);
               if (s->type == nil) {
                   error("unexpected missing type information");
               }
           }
           printtype(s, s->type, indent);
           break;

       case RANGE:
       case ARRAY:
       case RECORD:
       case VARNT:
       case PTR:
           semicolon = false;
           printtype(s, s, indent);
           break;

       case PROC:
           semicolon = false;
           printf("%s", symname(s));
           c_listparams(s);
           newline = false;
           break;

       case FUNC:
           semicolon = false;
           if (not istypename(s->type, "void")) {
               printtype(s, s->type, indent);
               printf(" ");
           }
           printf("%s", symname(s));
           c_listparams(s);
           newline = false;
           break;

       case MODULE:
           semicolon = false;
           printf("source file \"%s.c\"", symname(s));
           break;

       case PROG:
           semicolon = false;
           printf("executable file \"%s\"", symname(s));
           break;

       default:
           error("class %s in c_printdecl", classname(s));
   }
   if (semicolon) {
       putchar(';');
   }
   if (newline) {
       putchar('\n');
   }
}

/*
* Recursive whiz-bang procedure to print the type portion
* of a declaration.
*
* The symbol associated with the type is passed to allow
* searching for type names without getting "type blah = blah".
*/

private printtype(s, t, indent)
Symbol s;
Symbol t;
Integer indent;
{
   register Symbol i;
   long r0, r1;
   register String p;

   checkref(s);
   checkref(t);
   switch (t->class) {
       case VAR:
       case CONST:
       case PROC:
           panic("printtype: class %s", classname(t));
           break;

       case ARRAY:
           printf("array[");
           i = t->chain;
           if (i != nil) {
               for (;;) {
                   printtype(i, i, indent);
                   i = i->chain;
                   if (i == nil) {
                       break;
                   }
                   printf(", ");
               }
           }
           printf("] of ");
           printtype(t, t->type, indent);
           break;

       case RECORD:
       case VARNT:
           printf("%s ", c_classname(t));
           if (s->name != nil and s->class == TAG) {
               p = symname(s);
               if (p[0] == '$' and p[1] == '$') {
                   printf("%s ", &p[2]);
               } else {
                   printf("%s ", p);
               }
           }
           printf("{\n", t->class == RECORD ? "struct" : "union");
           for (i = t->chain; i != nil; i = i->chain) {
               assert(i->class == FIELD);
               printdecl(i, indent+4);
           }
           if (indent > 0) {
               printf("%*c", indent, ' ');
           }
           printf("}");
           break;

       case RANGE:
           r0 = t->symvalue.rangev.lower;
           r1 = t->symvalue.rangev.upper;
           if (istypename(t->type, "char")) {
               if (r0 < 0x20 or r0 > 0x7e) {
                   printf("%ld..", r0);
               } else {
                   printf("'%c'..", (char) r0);
               }
               if (r1 < 0x20 or r1 > 0x7e) {
                   printf("\\%lo", r1);
               } else {
                   printf("'%c'", (char) r1);
               }
           } else if (r0 > 0 and r1 == 0) {
               printf("%ld byte real", r0);
           } else if (r0 >= 0) {
               printf("%lu..%lu", r0, r1);
           } else {
               printf("%ld..%ld", r0, r1);
           }
           break;

       case PTR:
           printtype(t, t->type, indent);
           if (t->type->class != PTR) {
               printf(" ");
           }
           printf("*");
           break;

       case FUNC:
           printtype(t, t->type, indent);
           printf("()");
           break;

       case TYPE:
           if (t->name != nil) {
               printname(stdout, t);
           } else {
               printtype(t, t->type, indent);
           }
           break;

       case TYPEREF:
           printf("@%s", symname(t));
           break;

       case SCAL:
           printf("enum ");
           if (s->name != nil and s->class == TAG) {
               printf("%s ", symname(s));
           }
           printf("{ ");
           i = t->chain;
           if (i != nil) {
               for (;;) {
                   printf("%s", symname(i));
                   i = i->chain;
               if (i == nil) break;
                   printf(", ");
               }
           }
           printf(" }");
           break;

       case TAG:
           if (t->type == nil) {
               printf("unresolved tag %s", symname(t));
           } else {
               i = rtype(t->type);
               printf("%s %s", c_classname(i), symname(t));
           }
           break;

       default:
           printf("(class %d)", t->class);
           break;
   }
}

/*
* List the parameters of a procedure or function.
* No attempt is made to combine like types.
*/

public c_listparams(s)
Symbol s;
{
   register Symbol t;

   putchar('(');
   for (t = s->chain; t != nil; t = t->chain) {
       printf("%s", symname(t));
       if (t->chain != nil) {
           printf(", ");
       }
   }
   putchar(')');
   if (s->chain != nil) {
       printf("\n");
       for (t = s->chain; t != nil; t = t->chain) {
           if (t->class != VAR) {
               panic("unexpected class %d for parameter", t->class);
           }
           printdecl(t, 0);
       }
   } else {
       putchar('\n');
   }
}

/*
* Print out the value on the top of the expression stack
* in the format for the type of the given symbol.
*/

public c_printval(s)
Symbol s;
{
   register Symbol t;
   register Address a;
   register int i, len;

   switch (s->class) {
       case CONST:
       case TYPE:
       case VAR:
       case REF:
       case FVAR:
       case TAG:
           c_printval(s->type);
           break;

       case FIELD:
           if (isbitfield(s)) {
               len = s->symvalue.field.length;
               if (len <= BITSPERBYTE) {
                   i = pop(char);
               } else if (len <= sizeof(short)*BITSPERBYTE) {
                   i = pop(short);
               } else {
                   i = pop(long);
               }
               i >>= (s->symvalue.field.offset mod BITSPERBYTE);
               i &= ((1 << len) - 1);
               t = rtype(s->type);
               if (t->class == SCAL) {
                   printenum(i, t);
               } else {
                   printrange(i, t);
               }
           } else {
               c_printval(s->type);
           }
           break;

       case ARRAY:
           t = rtype(s->type);
           if (t->class == RANGE and istypename(t->type, "char")) {
               len = size(s);
               sp -= len;
               printf("\"%.*s\"", len, sp);
           } else {
               printarray(s);
           }
           break;

       case RECORD:
       case VARNT:
           c_printstruct(s);
           break;

       case RANGE:
           if (istypename(s->type, "boolean")) {
               printrange(popsmall(s), s);
           } else if (istypename(s->type, "char")) {
               printrange(pop(char), s);
           } else if (isdouble(s)) {
               switch (s->symvalue.rangev.lower) {
                   case sizeof(float):
                       prtreal(pop(float));
                       break;

                   case sizeof(double):
                       prtreal(pop(double));
                       break;

                   default:
                       panic("bad real size %d", t->symvalue.rangev.lower);
                       break;
               }
           } else {
               printrange(popsmall(s), s);
           }
           break;

       case PTR:
           t = rtype(s->type);
           a = pop(Address);
           if (a == 0) {
               printf("(nil)");
           } else if (t->class == RANGE and istypename(t->type, "char")) {
               printstring(a);
           } else {
               printf("0x%x", a);
           }
           break;

       case SCAL:
           i = pop(Integer);
           printenum(i, s);
           break;

       default:
           if (ord(s->class) > ord(TYPEREF)) {
               panic("printval: bad class %d", ord(s->class));
           }
           error("don't know how to print a %s", c_classname(s));
           /* NOTREACHED */
   }
}

/*
* Print out a C structure.
*/

private c_printstruct(s)
Symbol s;
{
   register Symbol f;
   register Stack *savesp;
   register Integer n, off, len;

   sp -= size(s);
   savesp = sp;
   printf("(");
   f = s->chain;
   for (;;) {
       off = f->symvalue.field.offset;
       len = f->symvalue.field.length;
       n = (off + len + 7) div BITSPERBYTE;
       sp += n;
       printf("%s = ", symname(f));
       c_printval(f);
       sp = savesp;
       f = f->chain;
   if (f == nil) break;
       printf(", ");
   }
   printf(")");
}

/*
* Print out a range type (integer, char, or boolean).
*/

private printrange(i, t)
Integer i;
register Symbol t;
{
   if (istypename(t->type, "boolean")) {
       printf(((Boolean) i) == true ? "true" : "false");
   } else if (istypename(t->type, "char")) {
       putchar('\'');
       printchar(i);
       putchar('\'');
   } else if (t->symvalue.rangev.lower >= 0) {
       printf("%lu", i);
   } else {
       printf("%ld", i);
   }
}

/*
* Print out a null-terminated string (pointer to char)
* starting at the given address.
*/

private printstring(addr)
Address addr;
{
   register Address a;
   register Integer i, len;
   register Boolean endofstring;
   union {
       char ch[sizeof(Word)];
       int word;
   } u;

   putchar('"');
   a = addr;
   endofstring = false;
   while (not endofstring) {
       dread(&u, a, sizeof(u));
       i = 0;
       do {
           if (u.ch[i] == '\0') {
               endofstring = true;
           } else {
               printchar(u.ch[i]);
           }
           ++i;
       } while (i < sizeof(Word) and not endofstring);
       a += sizeof(Word);
   }
   putchar('"');
}

/*
* Print out an enumerated value by finding the corresponding
* name in the enumeration list.
*/

private printenum(i, t)
Integer i;
Symbol t;
{
   register Symbol e;

   e = t->chain;
   while (e != nil and e->symvalue.iconval != i) {
       e = e->chain;
   }
   if (e != nil) {
       printf("%s", symname(e));
   } else {
       printf("%d", i);
   }
}

/*
* Return the C name for the particular class of a symbol.
*/

public String c_classname(s)
Symbol s;
{
   String str;

   switch (s->class) {
       case RECORD:
           str = "struct";
           break;

       case VARNT:
           str = "union";
           break;

       case SCAL:
           str = "enum";
           break;

       default:
           str = classname(s);
   }
   return str;
}