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Amiga MA Magazine 1998 #6
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amigamamagazinepolishissue1998.iso
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coders
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indent
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parse.c
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1999-06-09
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/* Copyright (c) 1985 Sun Microsystems, Inc. Copyright (c) 1980 The Regents
of the University of California. Copyright (c) 1976 Board of Trustees of
the University of Illinois. All rights reserved.
Redistribution and use in source and binary forms are permitted provided
that the above copyright notice and this paragraph are duplicated in all
such forms and that any documentation, advertising materials, and other
materials related to such distribution and use acknowledge that the
software was developed by the University of California, Berkeley, the
University of Illinois, Urbana, and Sun Microsystems, Inc. The name of
either University or Sun Microsystems may not be used to endorse or
promote products derived from this software without specific prior written
permission. THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES
OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE. */
#include "sys.h"
#include "indent.h"
struct parser_state *parser_state_tos;
#define INITIAL_BUFFER_SIZE 1000
#define INITIAL_STACK_SIZE 2
void
init_parser ()
{
parser_state_tos
= (struct parser_state *) xmalloc (sizeof (struct parser_state));
parser_state_tos->p_stack_size = INITIAL_STACK_SIZE;
parser_state_tos->p_stack
= (enum codes *) xmalloc (INITIAL_STACK_SIZE * sizeof (enum codes));
parser_state_tos->il
= (int *) xmalloc (INITIAL_STACK_SIZE * sizeof (int));
parser_state_tos->cstk
= (int *) xmalloc (INITIAL_STACK_SIZE * sizeof (int));
parser_state_tos->paren_indents = (short *) xmalloc (sizeof (short));
/* Although these are supposed to grow if we reach the end,
I can find no place in the code which does this. */
combuf = (char *) xmalloc (INITIAL_BUFFER_SIZE);
labbuf = (char *) xmalloc (INITIAL_BUFFER_SIZE);
codebuf = (char *) xmalloc (INITIAL_BUFFER_SIZE);
save_com.size = INITIAL_BUFFER_SIZE;
save_com.end = save_com.ptr = xmalloc (save_com.size);
di_stack_alloc = 2;
di_stack = (int *) xmalloc (di_stack_alloc * sizeof (*di_stack));
}
void
reset_parser ()
{
parser_state_tos->next = 0;
parser_state_tos->tos = 0;
parser_state_tos->paren_indents_size = 1;
parser_state_tos->p_stack[0] = stmt; /* this is the parser's stack */
parser_state_tos->last_nl = true; /* this is true if the last thing
scanned was a newline */
parser_state_tos->last_token = semicolon;
parser_state_tos->box_com = false;
parser_state_tos->comment_delta = 0;
parser_state_tos->n_comment_delta = 0;
parser_state_tos->cast_mask = 0;
parser_state_tos->noncast_mask = 0;
parser_state_tos->sizeof_mask = 0;
parser_state_tos->block_init = false;
parser_state_tos->block_init_level = 0;
parser_state_tos->col_1 = false;
parser_state_tos->com_col = 0;
parser_state_tos->dec_nest = 0;
parser_state_tos->i_l_follow = 0;
parser_state_tos->ind_level = 0;
parser_state_tos->last_u_d = false;
parser_state_tos->p_l_follow = 0;
parser_state_tos->paren_level = 0;
parser_state_tos->paren_depth = 0;
parser_state_tos->search_brace = false;
parser_state_tos->use_ff = false;
parser_state_tos->its_a_keyword = false;
parser_state_tos->sizeof_keyword = false;
parser_state_tos->dumped_decl_indent = false;
parser_state_tos->in_parameter_declaration = false;
parser_state_tos->just_saw_decl = false;
parser_state_tos->in_decl = false;
parser_state_tos->decl_on_line = false;
parser_state_tos->in_or_st = false;
parser_state_tos->bl_line = true;
parser_state_tos->want_blank = false;
parser_state_tos->in_stmt = false;
parser_state_tos->ind_stmt = false;
parser_state_tos->procname = "\0";
parser_state_tos->procname_end = "\0";
parser_state_tos->pcase = false;
parser_state_tos->dec_nest = 0;
di_stack[parser_state_tos->dec_nest] = 0;
l_com = combuf + INITIAL_BUFFER_SIZE - 5;
l_lab = labbuf + INITIAL_BUFFER_SIZE - 5;
l_code = codebuf + INITIAL_BUFFER_SIZE - 5;
combuf[0] = codebuf[0] = labbuf[0] = ' ';
combuf[1] = codebuf[1] = labbuf[1] = '\0';
else_if = 1;
else_or_endif = false;
s_lab = e_lab = labbuf + 1;
s_code = e_code = codebuf + 1;
s_com = e_com = combuf + 1;
line_no = 1;
had_eof = false;
break_comma = false;
bp_save = 0;
be_save = 0;
if (tabsize <= 0)
tabsize = 1;
}
/* like ++parser_state_tos->tos but checks for stack overflow and extends
stack if necessary. */
int
inc_pstack ()
{
if (++parser_state_tos->tos >= parser_state_tos->p_stack_size)
{
parser_state_tos->p_stack_size *= 2;
parser_state_tos->p_stack = (enum codes *)
xrealloc ((char *) parser_state_tos->p_stack,
parser_state_tos->p_stack_size * sizeof (enum codes));
parser_state_tos->il = (int *)
xrealloc ((char *) parser_state_tos->il,
parser_state_tos->p_stack_size * sizeof (int));
parser_state_tos->cstk = (int *)
xrealloc ((char *) parser_state_tos->cstk,
parser_state_tos->p_stack_size * sizeof (int));
}
return parser_state_tos->tos;
}
#ifdef DEBUG
static char **debug_symbol_strings;
void
debug_init ()
{
int size = ((int) period + 4) * sizeof (char *);
debug_symbol_strings = (char **) xmalloc (size);
debug_symbol_strings[code_eof] = "code_eof";
debug_symbol_strings[newline] = "newline";
debug_symbol_strings[lparen] = "lparen";
debug_symbol_strings[rparen] = "rparen";
debug_symbol_strings[unary_op] = "unary_op";
debug_symbol_strings[binary_op] = "binary_op";
debug_symbol_strings[postop] = "postop";
debug_symbol_strings[question] = "question";
debug_symbol_strings[casestmt] = "casestmt";
debug_symbol_strings[colon] = "colon";
debug_symbol_strings[semicolon] = "semicolon";
debug_symbol_strings[lbrace] = "lbrace";
debug_symbol_strings[rbrace] = "rbrace";
debug_symbol_strings[ident] = "ident";
debug_symbol_strings[comma] = "comma";
debug_symbol_strings[comment] = "comment";
debug_symbol_strings[swstmt] = "swstmt";
debug_symbol_strings[preesc] = "preesc";
debug_symbol_strings[form_feed] = "form_feed";
debug_symbol_strings[decl] = "decl";
debug_symbol_strings[sp_paren] = "sp_paren";
debug_symbol_strings[sp_nparen] = "sp_nparen";
debug_symbol_strings[ifstmt] = "ifstmt";
debug_symbol_strings[whilestmt] = "whilestmt";
debug_symbol_strings[forstmt] = "forstmt";
debug_symbol_strings[stmt] = "stmt";
debug_symbol_strings[stmtl] = "stmtl";
debug_symbol_strings[elselit] = "elselit";
debug_symbol_strings[dolit] = "dolit";
debug_symbol_strings[dohead] = "dohead";
debug_symbol_strings[dostmt] = "dostmt";
debug_symbol_strings[ifhead] = "ifhead";
debug_symbol_strings[elsehead] = "elsehead";
debug_symbol_strings[period] = "period";
}
#endif
void
parse (tk)
enum codes tk; /* the code for the construct scanned */
{
int i;
#ifdef DEBUG
if (debug)
{
if (tk >= code_eof && tk <= period)
printf ("Parse: %s\n", debug_symbol_strings[tk]);
else
printf ("Parse: Unknown code: %d for %s\n",
(int) tk, token ? token : "NULL");
}
#endif
while (parser_state_tos->p_stack[parser_state_tos->tos] == ifhead
&& tk != elselit)
{
/* true if we have an if without an else */
/* apply the if(..) stmt ::= stmt reduction */
parser_state_tos->p_stack[parser_state_tos->tos] = stmt;
reduce (); /* see if this allows any reduction */
}
switch (tk)
{ /* go on and figure out what to do with the
input */
case decl: /* scanned a declaration word */
parser_state_tos->search_brace = btype_2;
/* indicate that following brace should be on same line */
if (parser_state_tos->p_stack[parser_state_tos->tos] != decl)
{ /* only put one declaration onto stack */
break_comma = true; /* while in declaration, newline should be
forced after comma */
inc_pstack ();
parser_state_tos->p_stack[parser_state_tos->tos] = decl;
parser_state_tos->il[parser_state_tos->tos] = parser_state_tos->i_l_follow;
if (ljust_decl)
{ /* only do if we want left justified
declarations */
parser_state_tos->ind_level = 0;
for (i = parser_state_tos->tos - 1; i > 0; --i)
if (parser_state_tos->p_stack[i] == decl)
/* indentation is number of declaration levels deep we are
times spaces per level */
parser_state_tos->ind_level += ind_size;
parser_state_tos->i_l_follow = parser_state_tos->ind_level;
}
}
break;
case ifstmt: /* scanned if (...) */
if (parser_state_tos->p_stack[parser_state_tos->tos] == elsehead
&& else_if) /* "else if ..." */
parser_state_tos->i_l_follow
= parser_state_tos->il[parser_state_tos->tos];
case dolit: /* 'do' */
case forstmt: /* for (...) */
inc_pstack ();
parser_state_tos->p_stack[parser_state_tos->tos] = tk;
parser_state_tos->il[parser_state_tos->tos]
= parser_state_tos->ind_level = parser_state_tos->i_l_follow;
parser_state_tos->i_l_follow += ind_size; /* subsequent statements
should be indented 1 */
parser_state_tos->search_brace = btype_2;
break;
case lbrace: /* scanned { */
break_comma = false; /* don't break comma in an initial list */
if (parser_state_tos->p_stack[parser_state_tos->tos] == stmt
|| parser_state_tos->p_stack[parser_state_tos->tos] == stmtl)
/* it is a random, isolated stmt group or a declaration */
parser_state_tos->i_l_follow += ind_size;
else if (parser_state_tos->p_stack[parser_state_tos->tos] == decl)
{
parser_state_tos->i_l_follow += ind_size;
if (parser_state_tos->last_rw == rw_struct_like
&& parser_state_tos->block_init_level == 0)
#if 0
&& !btype_2 && !parser_state_tos->col_1)
#endif
{
parser_state_tos->ind_level += brace_indent;
parser_state_tos->i_l_follow += brace_indent;
}
}
else
{
if (s_code == e_code)
{
/* only do this if there is nothing on the line */
parser_state_tos->ind_level -= ind_size;
/* it is a group as part of a while, for, etc. */
/* For -bl formatting, indent by brace_indent additional spaces
e.g. if (foo == bar) { <--> brace_indent spaces (in this
example, 4) */
if (!btype_2)
{
parser_state_tos->ind_level += brace_indent;
parser_state_tos->i_l_follow += brace_indent;
if (parser_state_tos->p_stack[parser_state_tos->tos]
== swstmt)
case_ind += brace_indent;
}
if (parser_state_tos->p_stack[parser_state_tos->tos] == swstmt
&& case_indent
>= ind_size)
parser_state_tos->ind_level -= ind_size;
/* for a switch, brace should be two levels out from the code */
}
}
inc_pstack ();
parser_state_tos->p_stack[parser_state_tos->tos] = lbrace;
parser_state_tos->il[parser_state_tos->tos] = parser_state_tos->ind_level;
inc_pstack ();
parser_state_tos->p_stack[parser_state_tos->tos] = stmt;
/* allow null stmt between braces */
parser_state_tos->il[parser_state_tos->tos] = parser_state_tos->i_l_follow;
break;
case whilestmt: /* scanned while (...) */
if (parser_state_tos->p_stack[parser_state_tos->tos] == dohead)
{
/* it is matched with do stmt */
parser_state_tos->ind_level = parser_state_tos->i_l_follow
= parser_state_tos->il[parser_state_tos->tos];
inc_pstack ();
parser_state_tos->p_stack[parser_state_tos->tos] = whilestmt;
parser_state_tos->il[parser_state_tos->tos]
= parser_state_tos->ind_level = parser_state_tos->i_l_follow;
}
else
{ /* it is a while loop */
inc_pstack ();
parser_state_tos->p_stack[parser_state_tos->tos] = whilestmt;
parser_state_tos->il[parser_state_tos->tos] = parser_state_tos->i_l_follow;
parser_state_tos->i_l_follow += ind_size;
parser_state_tos->search_brace = btype_2;
}
break;
case elselit: /* scanned an else */
if (parser_state_tos->p_stack[parser_state_tos->tos] != ifhead)
diag (1, "Unmatched 'else'", 0, 0);
else
{
/* indentation for else should be same as for if */
parser_state_tos->ind_level
= parser_state_tos->il[parser_state_tos->tos];
/* everything following should be in 1 level */
parser_state_tos->i_l_follow = (parser_state_tos->ind_level
+ ind_size);
parser_state_tos->p_stack[parser_state_tos->tos] = elsehead;
/* remember if with else */
parser_state_tos->search_brace = btype_2 | else_if;
}
break;
case rbrace: /* scanned a } */
/* stack should have <lbrace> <stmt> or <lbrace> <stmtl> */
if (parser_state_tos->p_stack[parser_state_tos->tos - 1] == lbrace)
{
parser_state_tos->ind_level = parser_state_tos->i_l_follow
= parser_state_tos->il[--parser_state_tos->tos];
parser_state_tos->p_stack[parser_state_tos->tos] = stmt;
}
else
diag (1, "Stmt nesting error.", 0, 0);
break;
case swstmt: /* had switch (...) */
inc_pstack ();
parser_state_tos->p_stack[parser_state_tos->tos] = swstmt;
parser_state_tos->cstk[parser_state_tos->tos] = case_ind;
/* save current case indent level */
parser_state_tos->il[parser_state_tos->tos] = parser_state_tos->i_l_follow;
case_ind = parser_state_tos->i_l_follow + case_indent; /* cases should be one
level down from
switch */
/* statements should be two levels in */
parser_state_tos->i_l_follow += case_indent + ind_size;
parser_state_tos->search_brace = btype_2;
break;
case semicolon: /* this indicates a simple stmt */
break_comma = false; /* turn off flag to break after commas in a
declaration */
if (parser_state_tos->p_stack[parser_state_tos->tos] == dostmt)
{
parser_state_tos->p_stack[parser_state_tos->tos] = stmt;
}
else
{
inc_pstack ();
parser_state_tos->p_stack[parser_state_tos->tos] = stmt;
parser_state_tos->il[parser_state_tos->tos]
= parser_state_tos->ind_level;
}
break;
default: /* this is an error */
diag (1, "Unknown code to parser", 0, 0);
return;
} /* end of switch */
reduce (); /* see if any reduction can be done */
#ifdef DEBUG
if (debug)
{
printf ("\nParseStack [%d]:\n", (int) parser_state_tos->p_stack_size);
for (i = 1; i <= parser_state_tos->tos; ++i)
printf (" stack[%d] => stack: %d ind_level: %d\n",
(int) i, (int) parser_state_tos->p_stack[i],
(int) parser_state_tos->il[i]);
printf ("\n");
}
#endif
return;
}
/* NAME: reduce
FUNCTION: Implements the reduce part of the parsing algorithm
ALGORITHM: The following reductions are done. Reductions are repeated until
no more are possible.
Old TOS New TOS <stmt> <stmt> <stmtl> <stmtl> <stmt>
<stmtl> do <stmt> dohead <dohead> <whilestmt>
<dostmt> if <stmt> "ifstmt" switch <stmt> <stmt>
decl <stmt> <stmt> "ifelse" <stmt> <stmt> for
<stmt> <stmt> while <stmt> <stmt>
"dostmt" while <stmt>
On each reduction, parser_state_tos->i_l_follow (the indentation for the
following line) is set to the indentation level associated with the old
TOS.
PARAMETERS: None
RETURNS: Nothing
GLOBALS: parser_state_tos->cstk parser_state_tos->i_l_follow =
parser_state_tos->il parser_state_tos->p_stack = parser_state_tos->tos =
CALLS: None
CALLED BY: parse
HISTORY: initial coding November 1976 D A Willcox of CAC
*/
/*----------------------------------------------*\
| REDUCTION PHASE |
\*----------------------------------------------*/
reduce ()
{
register int i;
for (;;)
{ /* keep looping until there is nothing left
to reduce */
switch (parser_state_tos->p_stack[parser_state_tos->tos])
{
case stmt:
switch (parser_state_tos->p_stack[parser_state_tos->tos - 1])
{
case stmt:
case stmtl:
/* stmtl stmt or stmt stmt */
parser_state_tos->p_stack[--parser_state_tos->tos] = stmtl;
break;
case dolit: /* <do> <stmt> */
parser_state_tos->p_stack[--parser_state_tos->tos] = dohead;
parser_state_tos->i_l_follow
= parser_state_tos->il[parser_state_tos->tos];
break;
case ifstmt:
/* <if> <stmt> */
parser_state_tos->p_stack[--parser_state_tos->tos] = ifhead;
for (i = parser_state_tos->tos - 1;
(parser_state_tos->p_stack[i] != stmt
&& parser_state_tos->p_stack[i] != stmtl
&& parser_state_tos->p_stack[i] != lbrace);
--i);
parser_state_tos->i_l_follow = parser_state_tos->il[i];
/* for the time being, we will assume that there is no else on
this if, and set the indentation level accordingly. If an
else is scanned, it will be fixed up later */
break;
case swstmt:
/* <switch> <stmt> */
case_ind = parser_state_tos->cstk[parser_state_tos->tos - 1];
case decl: /* finish of a declaration */
case elsehead:
/* <<if> <stmt> else> <stmt> */
case forstmt:
/* <for> <stmt> */
case whilestmt:
/* <while> <stmt> */
parser_state_tos->p_stack[--parser_state_tos->tos] = stmt;
parser_state_tos->i_l_follow = parser_state_tos->il[parser_state_tos->tos];
break;
default: /* <anything else> <stmt> */
return;
} /* end of section for <stmt> on top of stack */
break;
case whilestmt: /* while (...) on top */
if (parser_state_tos->p_stack[parser_state_tos->tos - 1] == dohead)
{
/* it is termination of a do while */
#if 0
parser_state_tos->p_stack[--parser_state_tos->tos] = stmt;
#endif
parser_state_tos->p_stack[--parser_state_tos->tos] = dostmt;
break;
}
else
return;
default: /* anything else on top */
return;
}
}
}
/* This kludge is called from main. It is just like parse(semicolon) except
that it does not clear break_comma. Leaving break_comma alone is
necessary to make sure that "int foo(), bar()" gets formatted correctly
under -bc. */
INLINE void
parse_lparen_in_decl ()
{
inc_pstack ();
parser_state_tos->p_stack[parser_state_tos->tos] = stmt;
parser_state_tos->il[parser_state_tos->tos] = parser_state_tos->ind_level;
reduce ();
}