4.1cBSD/usr/src/ucb/dbx/c.c
/* Copyright (c) 1982 Regents of the University of California */
static char sccsid[] = "@(#)c.c 1.2 12/15/82";
/*
* 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;
}