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IABSD.fr/src/usr.bin/mg/cmode.c
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- usr.bin/mg/cmode.c
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/* $OpenBSD: cmode.c,v 1.23 2024/05/21 05:00:48 jsg Exp $ */ /* * This file is in the public domain. * * Author: Kjell Wooding <kjell@openbsd.org> */ /* * Implement an non-irritating KNF-compliant mode for editing * C code. */ #include <sys/queue.h> #include <ctype.h> #include <signal.h> #include <stdio.h> #include "def.h" #include "funmap.h" #include "kbd.h" /* Pull in from modes.c */ extern int changemode(int, int, char *); static int cc_strip_trailp = TRUE; /* Delete Trailing space? */ static int cc_basic_indent = 8; /* Basic Indent multiple */ static int cc_cont_indent = 4; /* Continued line indent */ static int cc_colon_indent = -8; /* Label / case indent */ static int getmatch(int, int); static int getindent(const struct line *, int *); static int in_whitespace(struct line *, int); static int findcolpos(const struct buffer *, const struct line *, int); static struct line *findnonblank(struct line *); static int isnonblank(const struct line *, int); void cmode_init(void); /* Keymaps */ static PF cmode_brace[] = { cc_brace, /* } */ }; static PF cmode_cCP[] = { compile, /* C-c P */ }; static PF cmode_cc[] = { NULL, /* ^C */ rescan, /* ^D */ rescan, /* ^E */ rescan, /* ^F */ rescan, /* ^G */ rescan, /* ^H */ cc_tab, /* ^I */ rescan, /* ^J */ rescan, /* ^K */ rescan, /* ^L */ cc_lfindent, /* ^M */ }; static PF cmode_spec[] = { cc_char, /* : */ }; static struct KEYMAPE (1) cmode_cmap = { 1, 1, rescan, { { 'P', 'P', cmode_cCP, NULL } } }; static struct KEYMAPE (3) cmodemap = { 3, 3, rescan, { { CCHR('C'), CCHR('M'), cmode_cc, (KEYMAP *) &cmode_cmap }, { ':', ':', cmode_spec, NULL }, { '}', '}', cmode_brace, NULL } } }; /* Function, Mode hooks */ void cmode_init(void) { funmap_add(cmode, "c-mode", 0); funmap_add(cc_char, "c-handle-special-char", 0); funmap_add(cc_brace, "c-handle-special-brace", 0); funmap_add(cc_tab, "c-tab-or-indent", 0); funmap_add(cc_indent, "c-indent", 0); funmap_add(cc_lfindent, "c-indent-and-newline", 0); maps_add((KEYMAP *)&cmodemap, "c"); } /* * Enable/toggle c-mode */ int cmode(int f, int n) { return(changemode(f, n, "c")); } /* * Handle special C character - selfinsert then indent. */ int cc_char(int f, int n) { if (n < 0) return (FALSE); if (selfinsert(FFRAND, n) == FALSE) return (FALSE); return (cc_indent(FFRAND, n)); } /* * Handle special C character - selfinsert then indent. */ int cc_brace(int f, int n) { if (n < 0) return (FALSE); if (showmatch(FFRAND, 1) == FALSE) return (FALSE); return (cc_indent(FFRAND, n)); } /* * If we are in the whitespace at the beginning of the line, * simply act as a regular tab. If we are not, indent * current line according to whitespace rules. */ int cc_tab(int f, int n) { int inwhitep = FALSE; /* In leading whitespace? */ inwhitep = in_whitespace(curwp->w_dotp, llength(curwp->w_dotp)); /* If empty line, or in whitespace */ if (llength(curwp->w_dotp) == 0 || inwhitep) return (selfinsert(f, n)); return (cc_indent(FFRAND, 1)); } /* * Attempt to indent current line according to KNF rules. */ int cc_indent(int f, int n) { int pi, mi; /* Previous indents (mi is ignored) */ int ci; /* current indent */ struct line *lp; int ret; if (n < 0) return (FALSE); undo_boundary_enable(FFRAND, 0); if (cc_strip_trailp) deltrailwhite(FFRAND, 1); /* * Search backwards for a non-blank, non-preprocessor, * non-comment line */ lp = findnonblank(curwp->w_dotp); pi = getindent(lp, &mi); /* Strip leading space on current line */ delleadwhite(FFRAND, 1); /* current indent is computed only to current position */ (void)getindent(curwp->w_dotp, &ci); if (pi + ci < 0) ret = indent(FFOTHARG, 0); else ret = indent(FFOTHARG, pi + ci); undo_boundary_enable(FFRAND, 1); return (ret); } /* * Indent-and-newline (technically, newline then indent) */ int cc_lfindent(int f, int n) { if (n < 0) return (FALSE); if (cc_strip_trailp) (void)delwhite(FFRAND, 1); if (enewline(FFRAND, 1) == FALSE) return (FALSE); return (cc_indent(FFRAND, n)); } /* * Get the level of indentation after line lp is processed * Note getindent has two returns: * curi = value if indenting current line. * return value = value affecting subsequent lines. */ static int getindent(const struct line *lp, int *curi) { int lo, co; /* leading space, current offset*/ int nicol = 0; /* position count */ int c = '\0'; /* current char */ int newind = 0; /* new index value */ int stringp = FALSE; /* in string? */ int escp = FALSE; /* Escape char? */ int lastc = '\0'; /* Last matched string delimiter */ int nparen = 0; /* paren count */ int obrace = 0; /* open brace count */ int cbrace = 0; /* close brace count */ int firstnwsp = FALSE; /* First nonspace encountered? */ int colonp = FALSE; /* Did we see a colon? */ int questionp = FALSE; /* Did we see a question mark? */ int slashp = FALSE; /* Slash? */ int astp = FALSE; /* Asterisk? */ int cpos = -1; /* comment position */ int cppp = FALSE; /* Preprocessor command? */ *curi = 0; /* Compute leading space */ for (lo = 0; lo < llength(lp); lo++) { if (!isspace(c = lgetc(lp, lo))) break; if (c == '\t') nicol = ntabstop(nicol, curbp->b_tabw); else nicol++; } /* If last line was blank, choose 0 */ if (lo == llength(lp)) nicol = 0; newind = 0; /* Compute modifiers */ for (co = lo; co < llength(lp); co++) { c = lgetc(lp, co); /* We have a non-whitespace char */ if (!firstnwsp && !isspace(c)) { if (c == '#') cppp = TRUE; firstnwsp = TRUE; } if (c == '\\') escp = !escp; else if (stringp) { if (!escp && (c == '"' || c == '\'')) { /* unescaped string char */ if (getmatch(c, lastc)) stringp = FALSE; } } else if (c == '"' || c == '\'') { stringp = TRUE; lastc = c; } else if (c == '(') { nparen++; } else if (c == ')') { nparen--; } else if (c == '{') { obrace++; firstnwsp = FALSE; } else if (c == '}') { cbrace++; } else if (c == '?') { questionp = TRUE; } else if (c == ':') { /* ignore (foo ? bar : baz) construct */ if (!questionp) colonp = TRUE; } else if (c == '/') { /* first nonwhitespace? -> indent */ if (firstnwsp) { /* If previous char asterisk -> close */ if (astp) cpos = -1; else slashp = TRUE; } } else if (c == '*') { /* If previous char slash -> open */ if (slashp) cpos = co; else astp = TRUE; } else if (firstnwsp) { firstnwsp = FALSE; } /* Reset matches that apply to next character only */ if (c != '\\') escp = FALSE; if (c != '*') astp = FALSE; if (c != '/') slashp = FALSE; } /* * If not terminated with a semicolon, and brace or paren open. * we continue */ if (colonp) { *curi += cc_colon_indent; newind -= cc_colon_indent; } *curi -= (cbrace) * cc_basic_indent; newind += obrace * cc_basic_indent; if (nparen < 0) newind -= cc_cont_indent; else if (nparen > 0) newind += cc_cont_indent; *curi += nicol; /* Ignore preprocessor. Otherwise, add current column */ if (cppp) { newind = nicol; *curi = 0; } else { newind += nicol; } if (cpos != -1) newind = findcolpos(curbp, lp, cpos); return (newind); } /* * Given a delimiter and its purported mate, tell us if they * match. */ static int getmatch(int c, int mc) { int match = FALSE; switch (c) { case '"': match = (mc == '"'); break; case '\'': match = (mc == '\''); break; case '(': match = (mc == ')'); break; case '[': match = (mc == ']'); break; case '{': match = (mc == '}'); break; } return (match); } static int in_whitespace(struct line *lp, int len) { int lo; int inwhitep = FALSE; for (lo = 0; lo < len; lo++) { if (!isspace(lgetc(lp, lo))) break; if (lo == len - 1) inwhitep = TRUE; } return (inwhitep); } /* convert a line/offset pair to a column position (for indenting) */ static int findcolpos(const struct buffer *bp, const struct line *lp, int lo) { int col, i, c; char tmp[5]; /* determine column */ col = 0; for (i = 0; i < lo; ++i) { c = lgetc(lp, i); if (c == '\t') { col = ntabstop(col, curbp->b_tabw); } else if (ISCTRL(c) != FALSE) col += 2; else if (isprint(c)) { col++; } else { col += snprintf(tmp, sizeof(tmp), "\\%o", c); } } return (col); } /* * Find a non-blank line, searching backwards from the supplied line pointer. * For C, nonblank is non-preprocessor, non C++, and accounts * for complete C-style comments. */ static struct line * findnonblank(struct line *lp) { int lo; int nonblankp = FALSE; int commentp = FALSE; int slashp; int astp; int c; while (lback(lp) != curbp->b_headp && (commentp || !nonblankp)) { lp = lback(lp); slashp = FALSE; astp = FALSE; /* Potential nonblank? */ nonblankp = isnonblank(lp, llength(lp)); /* * Search from end, removing complete C-style * comments. If one is found, ignore it and * test for nonblankness from where it starts. */ for (lo = llength(lp) - 1; lo >= 0; lo--) { if (!isspace(c = lgetc(lp, lo))) { if (commentp) { /* find comment "open" */ if (c == '*') astp = TRUE; else if (astp && c == '/') { commentp = FALSE; /* whitespace to here? */ nonblankp = isnonblank(lp, lo); } } else { /* find comment "close" */ if (c == '/') slashp = TRUE; else if (slashp && c == '*') /* found a comment */ commentp = TRUE; } } } } /* Rewound to start of file? */ if (lback(lp) == curbp->b_headp && !nonblankp) return (curbp->b_headp); return (lp); } /* * Given a line, scan forward to 'omax' and determine if we * are all C whitespace. * Note that preprocessor directives and C++-style comments * count as whitespace. C-style comments do not, and must * be handled elsewhere. */ static int isnonblank(const struct line *lp, int omax) { int nonblankp = FALSE; /* Return value */ int slashp = FALSE; /* Encountered slash */ int lo; /* Loop index */ int c; /* char being read */ /* Scan from front for preprocessor, C++ comments */ for (lo = 0; lo < omax; lo++) { if (!isspace(c = lgetc(lp, lo))) { /* Possible nonblank line */ nonblankp = TRUE; /* skip // and # starts */ if (c == '#' || (slashp && c == '/')) { nonblankp = FALSE; break; } else if (!slashp && c == '/') { slashp = TRUE; continue; } } slashp = FALSE; } return (nonblankp); }