xref: /src/usr.bin/indent/indent.h

/*	$NetBSD: indent.h,v 1.146 2023/05/16 13:26:26 rillig Exp $	*/

/*-
 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
 *
 * Copyright (c) 2001 Jens Schweikhardt
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */
/*-
 * SPDX-License-Identifier: BSD-4-Clause
 *
 * Copyright (c) 1985 Sun Microsystems, Inc.
 * Copyright (c) 1980, 1993
 *	The Regents of the University of California.  All rights reserved.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by the University of
 *	California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include <ctype.h>
#include <stdbool.h>
#include <stdio.h>

typedef enum lexer_symbol {
    lsym_eof,
    lsym_preprocessing,		/* '#' */
    lsym_newline,
    lsym_comment,		/* the initial '/ *' or '//' of a comment */
    lsym_lparen_or_lbracket,
    lsym_rparen_or_rbracket,
    lsym_lbrace,
    lsym_rbrace,
    lsym_period,
    lsym_unary_op,		/* e.g. '*', '&', '-' or leading '++' */
    lsym_binary_op,		/* e.g. '*', '&', '<<', '&&' or '/=' */
    lsym_postfix_op,		/* trailing '++' or '--' */
    lsym_question,		/* the '?' from a '?:' expression */
    lsym_colon,
    lsym_comma,
    lsym_semicolon,
    lsym_typedef,
    lsym_storage_class,
    lsym_type_outside_parentheses,
    lsym_type_in_parentheses,
    lsym_tag,			/* 'struct', 'union' or 'enum' */
    lsym_case_label,		/* 'case' or 'default' */
    lsym_sizeof,
    lsym_offsetof,
    lsym_word,			/* identifier, constant or string */
    lsym_funcname,
    lsym_do,
    lsym_else,
    lsym_for,
    lsym_if,
    lsym_switch,
    lsym_while,
    lsym_return
} lexer_symbol;

typedef enum parser_symbol {
    psym_0,			/* a placeholder */
    psym_lbrace,
    psym_rbrace,
    psym_decl,
    psym_stmt,
    psym_stmt_list,
    psym_for_exprs,		/* 'for' '(' ... ')' */
    psym_if_expr,		/* 'if' '(' expr ')' */
    psym_if_expr_stmt,		/* 'if' '(' expr ')' stmt */
    psym_if_expr_stmt_else,	/* 'if' '(' expr ')' stmt 'else' */
    psym_else,			/* 'else'; not stored on the stack */
    psym_switch_expr,		/* 'switch' '(' expr ')' */
    psym_do,			/* 'do' */
    psym_do_stmt,		/* 'do' stmt */
    psym_while_expr,		/* 'while' '(' expr ')' */
} parser_symbol;

/* A range of characters, not null-terminated. */
struct buffer {
    const char *st;		/* start of the usable text */
    char *mem;
    size_t len;			/* length of the usable text, from 'mem' */
    size_t cap;
};

extern FILE *input;
extern FILE *output;

/*
 * The current line from the input file, used by the lexer to generate tokens.
 * To read from the line, start at inp.st and continue up to and including the
 * next '\n'. To read beyond the '\n', call inp_skip or inp_next, which will
 * make the next line available, invalidating any pointers into the previous
 * line.
 */
extern struct buffer inp;

extern struct buffer token;	/* the current token to be processed, is
				 * typically copied to the buffer 'code', or
				 * in some cases to 'lab'. */

extern struct buffer lab;	/* the label or preprocessor directive */
extern struct buffer code;	/* the main part of the current line of code,
				 * containing declarations or statements */
extern struct buffer com;	/* the trailing comment of the line, or the
				 * start or end of a multi-line comment, or
				 * while in process_comment, a single line of
				 * a multi-line comment */

extern struct options {
    bool blanklines_around_conditional_compilation;
    bool blank_line_after_decl_at_top;	/* this is vaguely similar to
					 * blank_line_after_decl except that
					 * it only applies to the first set of
					 * declarations in a procedure (just
					 * after the first '{') and it causes
					 * a blank line to be generated even
					 * if there are no declarations */
    bool blank_line_after_decl;
    bool blanklines_after_procs;
    bool blanklines_before_block_comments;
    bool break_after_comma;	/* whether to add a line break after each
				 * declarator */
    bool brace_same_line;	/* whether brace should be on same line as if,
				 * while, etc */
    bool blank_after_sizeof;	/* whether a blank should always be inserted
				 * after sizeof */
    bool comment_delimiter_on_blankline;
    int decl_comment_column;	/* the column in which comments after
				 * declarations should be put */
    bool cuddle_else;		/* whether 'else' should cuddle up to '}' */
    int continuation_indent;	/* the indentation between the edge of code
				 * and continuation lines */
    float case_indent;		/* The distance (measured in indentation
				 * levels) to indent case labels from the
				 * switch statement */
    int comment_column;		/* the column in which comments to the right
				 * of code should start */
    int decl_indent;		/* indentation of identifier in declaration */
    bool ljust_decl;		/* true if declarations should be left
				 * justified */
    int unindent_displace;	/* comments not to the right of code will be
				 * placed this many indentation levels to the
				 * left of code */
    bool extra_expr_indent;	/* whether continuation lines from the
				 * expression part of "if (e)", "while (e)",
				 * "for (e; e; e)" should be indented an extra
				 * tab stop so that they don't conflict with
				 * the code that follows */
    bool else_if;		/* whether else-if pairs use the same line */
    bool function_brace_split;	/* split function declaration and brace onto
				 * separate lines */
    bool format_col1_comments;	/* If comments which start in column 1 are to
				 * be reformatted (just like comments that
				 * begin in later columns) */
    bool format_block_comments;	/* whether comments beginning with '/ * \n'
				 * are to be reformatted */
    bool indent_parameters;
    int indent_size;		/* the size of one indentation level */
    int block_comment_max_line_length;
    int local_decl_indent;	/* like decl_indent but for locals */
    bool lineup_to_parens_always;	/* whether to not(?) attempt to keep
					 * lined-up code within the margin */
    bool lineup_to_parens;	/* whether continued code within parens will
				 * be lined up to the open paren */
    bool proc_calls_space;	/* whether function calls look like: foo (bar)
				 * rather than foo(bar) */
    bool procnames_start_line;	/* whether the names of procedures being
				 * defined get placed in column 1 (i.e. a
				 * newline is placed between the type of the
				 * procedure and its name) */
    bool space_after_cast;	/* "b = (int) a" vs "b = (int)a" */
    bool star_comment_cont;	/* whether comment continuation lines should
				 * have stars at the beginning of each line */
    bool swallow_optional_blanklines;
    bool auto_typedefs;		/* whether to recognize identifiers ending in
				 * "_t" like typedefs */
    int tabsize;		/* the size of a tab */
    int max_line_length;
    bool use_tabs;		/* set true to use tabs for spacing, false
				 * uses all spaces */
    bool verbose;		/* whether non-essential error messages are
				 * printed */
} opt;

extern bool found_err;
extern bool break_comma;	/* when true and not in parentheses, break
				 * after a comma */
extern float case_ind;		/* indentation level to be used for a "case
				 * n:" */
extern bool had_eof;		/* whether input is exhausted */
extern int line_no;		/* the current line number. */
extern enum indent_enabled {
    indent_on,
    indent_off,
    indent_last_off_line,
} indent_enabled;

#define	STACKSIZE 256

/* Properties of each level of parentheses or brackets. */
typedef struct paren_level_props {
    short indent;		/* indentation of the operand/argument,
				 * relative to the enclosing statement; if
				 * negative, reflected at -1 */
    enum paren_level_cast {
	cast_unknown,
	cast_maybe,
	cast_no,
    } cast;			/* whether the parentheses form a type cast */
} paren_level_props;

/*
 * The parser state determines the layout of the formatted text.
 *
 * In a function body, the number of block braces determines the indentation
 * of statements and declarations.
 *
 * In a statement, the number of parentheses or brackets determines the
 * indentation of follow-up lines.
 *
 * In an expression, the token type determine whether to put spaces around.
 *
 * In a source file, the types of line determine the vertical spacing, such as
 * around preprocessing directives or function bodies, or above block
 * comments.
 */
extern struct parser_state {
    lexer_symbol prev_token;	/* the previous token, but never comment,
				 * newline or preprocessing line */

    /* Token classification */

    int quest_level;		/* when this is positive, we have seen a '?'
				 * without the matching ':' in a '?:'
				 * expression */
    bool is_function_definition;
    bool block_init;		/* whether inside a block initialization */
    int block_init_level;	/* the level of brace nesting in an
				 * initialization */
    bool init_or_struct;	/* whether there has been a type name and no
				 * left parenthesis since the last semicolon.
				 * When true, a '{' starts a structure
				 * definition or an initialization list */
    bool decl_on_line;		/* whether this line of code has part of a
				 * declaration on it */
    bool in_stmt_or_decl;	/* whether in a statement or a struct
				 * declaration or a plain declaration */
    bool in_decl;		/* whether we are in a declaration. The
				 * processing of braces is then slightly
				 * different */
    bool in_func_def_params;
    bool seen_case;		/* set to true when we see a 'case', so we
				 * know what to do with the following colon */
    bool is_case_label;		/* 'case' and 'default' labels are indented
				 * differently from regular labels */
    parser_symbol spaced_expr_psym;	/* the parser symbol to be shifted
					 * after the parenthesized expression
					 * from a 'for', 'if', 'switch' or
					 * 'while'; or psym_0 */

    /* Indentation of statements and declarations */

    int ind_level;		/* the indentation level for the line that is
				 * currently prepared for output */
    int ind_level_follow;	/* the level to which ind_level should be set
				 * after the current line is printed */
    bool in_stmt_cont;		/* whether the current line should have an
				 * extra indentation level because we are in
				 * the middle of a statement */
    int decl_level;		/* current nesting level for a structure
				 * declaration or an initializer */
    bool decl_indent_done;	/* whether the indentation for a declaration
				 * has been added to the code buffer. */
    int decl_ind;		/* current indentation for declarations */
    int di_stack[20];		/* a stack of structure indentation levels */
    bool tabs_to_var;		/* true if using tabs to indent to var name */

    enum {
	eei_no,
	eei_yes,
	eei_last
    } extra_expr_indent;

    enum {
	in_enum_no,		/* outside any 'enum { ... }' */
	in_enum_enum,		/* after keyword 'enum' */
	in_enum_type,		/* after 'enum' or 'enum tag' */
	in_enum_brace		/* between '{' and '}' */
    } in_enum;			/* enum { . } */

    int tos;			/* pointer to top of stack */
    parser_symbol s_sym[STACKSIZE];
    int s_ind_level[STACKSIZE];
    float s_case_ind_level[STACKSIZE];

    /* Spacing inside a statement or declaration */

    bool next_unary;		/* whether the following operator should be
				 * unary; is used in declarations for '*', as
				 * well as in expressions */
    bool want_blank;		/* whether the following token should be
				 * prefixed by a blank. (Said prefixing is
				 * ignored in some cases.) */
    int line_start_nparen;	/* the number of parentheses or brackets that
				 * were open at the beginning of the current
				 * line; used to indent within statements,
				 * initializers and declarations */
    int nparen;			/* the number of parentheses or brackets that
				 * are currently open; used to indent the
				 * remaining lines of the statement,
				 * initializer or declaration */
    paren_level_props paren[20];

    /* Horizontal spacing for comments */

    int comment_delta;		/* used to set up indentation for all lines of
				 * a boxed comment after the first one */
    int n_comment_delta;	/* remembers how many columns there were
				 * before the start of a box comment so that
				 * forthcoming lines of the comment are
				 * indented properly */
    int com_ind;		/* indentation of the current comment */

    /* Vertical spacing */

    bool force_nl;		/* whether the next token is forced to go to a
				 * new line; used after 'if (expr)' and in
				 * similar situations; tokens like '{' may
				 * ignore this */

    enum declaration {
	decl_no,		/* no declaration anywhere nearby */
	decl_begin,		/* collecting tokens of a declaration */
	decl_end,		/* finished a declaration */
    } declaration;
    bool blank_line_after_decl;

    /* Comments */

    bool curr_col_1;		/* whether the current token started in column
				 * 1 of the original input */
    bool next_col_1;
} ps;


#define array_length(array) (sizeof(array) / sizeof((array)[0]))

#ifdef debug
void debug_printf(const char *, ...) __printflike(1, 2);
void debug_println(const char *, ...) __printflike(1, 2);
void debug_vis_range(const char *, const char *, size_t, const char *);
void debug_parser_state(lexer_symbol);
void debug_parse_stack(const char *);
void debug_buffers(void);
extern const char *const lsym_name[];
extern const char *const psym_name[];
extern const char *const paren_level_cast_name[];
#else
#define debug_noop() do { } while (false)
#define	debug_printf(fmt, ...) debug_noop()
#define	debug_println(fmt, ...) debug_noop()
#define	debug_vis_range(prefix, s, e, suffix) debug_noop()
#define	debug_parser_state(lsym) debug_noop()
#define	debug_parse_stack(situation) debug_noop()
#define	debug_buffers() debug_noop()
#endif

void register_typename(const char *);
int compute_code_indent(void);
int compute_label_indent(void);
int ind_add(int, const char *, size_t);

void inp_skip(void);
char inp_next(void);
void clear_indent_off_text(void);

lexer_symbol lexi(void);
void diag(int, const char *, ...) __printflike(2, 3);
void output_line(void);
void output_line_ff(void);
void inp_read_line(void);
void parse(parser_symbol);
void process_comment(void);
void set_option(const char *, const char *);
void load_profiles(const char *);

void *nonnull(void *);

void buf_add_char(struct buffer *, char);
void buf_add_chars(struct buffer *, const char *, size_t);

static inline bool
ch_isalnum(char ch)
{
    return isalnum((unsigned char)ch) != 0;
}

static inline bool
ch_isalpha(char ch)
{
    return isalpha((unsigned char)ch) != 0;
}

static inline bool
ch_isblank(char ch)
{
    return ch == ' ' || ch == '\t';
}

static inline bool
ch_isdigit(char ch)
{
    return '0' <= ch && ch <= '9';
}

static inline bool
ch_isspace(char ch)
{
    return isspace((unsigned char)ch) != 0;
}

static inline int
next_tab(int ind)
{
    return ind - ind % opt.tabsize + opt.tabsize;
}