qstring: first cut at full quoted string support in the preprocessor

First attempt at properly handle quoted strings in the preprocessor.
This also adds range support in %substr.

No support in the assembler yet.

1 files changed, 473 insertions, 0 deletions

diff --git a/quote.c b/quote.c
new file mode 100644
index 0000000..0d8ee2b
--- /dev/null
+++ b/quote.c
@@ -0,0 +1,473 @@
+/* quote.c	library routines for the Netwide Assembler
+ *
+ * The Netwide Assembler is copyright (C) 1996 Simon Tatham and
+ * Julian Hall. All rights reserved. The software is
+ * redistributable under the license given in the file "LICENSE"
+ * distributed in the NASM archive.
+ */
+
+#include "compiler.h"
+
+#include <assert.h>
+#include <stdlib.h>
+
+#include "nasmlib.h"
+#include "quote.h"
+
+#define numvalue(c)  ((c)>='a' ? (c)-'a'+10 : (c)>='A' ? (c)-'A'+10 : (c)-'0')
+
+char *nasm_quote(char *str, size_t len)
+{
+    char c, c1, *p, *q, *nstr, *ep;
+    bool sq_ok, dq_ok;
+    size_t qlen;
+
+    sq_ok = dq_ok = true;
+    ep = str+len;
+    qlen = 0;			/* Length if we need `...` quotes */
+    for (p = str; p < ep; p++) {
+	c = *p;
+	switch (c) {
+	case '\'':
+	    sq_ok = false;
+	    qlen++;
+	    break;
+	case '\"':
+	    dq_ok = false;
+	    qlen++;
+	    break;
+	case '`':
+	case '\\':
+	    qlen += 2;
+	    break;
+	default:
+	    if (c < ' ' || c > '~') {
+		sq_ok = dq_ok = false;
+		switch (c) {
+		case '\a':
+		case '\b':
+		case '\t':
+		case '\n':
+		case '\v':
+		case '\f':
+		case '\r':
+		case 27:
+		    qlen += 2;
+		    break;
+		default:
+		    c1 = (p+1 < ep) ? p[1] : 0;
+		    if (c > 077 || (c1 >= '0' && c1 <= '7'))
+			qlen += 4; /* Must use the full form */
+		    else if (c > 07)
+			qlen += 3;
+		    else
+			qlen += 2;
+		    break;
+		}
+	    } else {
+		qlen++;
+	    }
+	    break;
+	}
+    }
+
+    if (sq_ok || dq_ok) {
+	/* Use '...' or "..." */
+	nstr = nasm_malloc(len+3);
+	nstr[0] = nstr[len+1] = sq_ok ? '\'' : '\"';
+	nstr[len+2] = '\0';
+	memcpy(nstr+1, str, len);
+    } else {
+	/* Need to use `...` quoted syntax */
+	nstr = nasm_malloc(qlen+3);
+	q = nstr;
+	*q++ = '`';
+	for (p = str; p < ep; p++) {
+	    c = *p;
+	    switch (c) {
+	    case '`':
+	    case '\\':
+		*q++ = '\\';
+		*q++ = c;
+		break;
+	    case '\a':
+		*q++ = '\\';
+		*q++ = 'a';
+		break;
+	    case '\b':
+		*q++ = '\\';
+		*q++ = 'b';
+		break;
+	    case '\t':
+		*q++ = '\\';
+		*q++ = 't';
+		break;
+	    case '\n':
+		*q++ = '\\';
+		*q++ = 'n';
+		break;
+	    case '\v':
+		*q++ = '\\';
+		*q++ = 'v';
+		break;
+	    case '\f':
+		*q++ = '\\';
+		*q++ = 'f';
+		break;
+	    case '\r':
+		*q++ = '\\';
+		*q++ = 'r';
+		break;
+	    case 27:
+		*q++ = '\\';
+		*q++ = 'e';
+		break;
+	    default:
+		if (c < ' ' || c > '~') {
+		    c1 = (p+1 < ep) ? p[1] : 0;
+		    if (c1 >= '0' && c1 <= '7')
+			q += sprintf(q, "\\%03o", (unsigned char)c);
+		    else
+			q += sprintf(q, "\\%o", (unsigned char)c);
+		} else {
+		    *q++ = c;
+		}
+		break;
+	    }
+	}
+	*q++ = '`';
+	*q++ = '\0';
+	assert((size_t)(q-nstr) == qlen+3);
+    }
+    return nstr;
+}
+
+static char *emit_utf8(char *q, int32_t v)
+{
+    if (v < 0) {
+	/* Impossible - do nothing */
+    } else if (v <= 0x7f) {
+	*q++ = v;
+    } else if (v <= 0x000007ff) {
+	*q++ = 0xc0 | (v >> 6);
+	*q++ = 0x80 | (v & 63);
+    } else if (v <= 0x0000ffff) {
+	*q++ = 0xe0 | (v >> 12);
+	*q++ = 0x80 | ((v >> 6) & 63);
+	*q++ = 0x80 | (v & 63);
+    } else if (v <= 0x001fffff) {
+	*q++ = 0xf0 | (v >> 18);
+	*q++ = 0x80 | ((v >> 12) & 63);
+	*q++ = 0x80 | ((v >> 6) & 63);
+	*q++ = 0x80 | (v & 63);
+    } else if (v <= 0x03ffffff) {
+	*q++ = 0xf8 | (v >> 24);
+	*q++ = 0x80 | ((v >> 18) & 63);
+	*q++ = 0x80 | ((v >> 12) & 63);
+	*q++ = 0x80 | ((v >> 6) & 63);
+	*q++ = 0x80 | (v & 63);
+    } else {
+	*q++ = 0xfc | (v >> 30);
+	*q++ = 0x80 | ((v >> 24) & 63);
+	*q++ = 0x80 | ((v >> 18) & 63);
+	*q++ = 0x80 | ((v >> 12) & 63);
+	*q++ = 0x80 | ((v >> 6) & 63);
+	*q++ = 0x80 | (v & 63);
+    }
+    return q;
+}
+
+/*
+ * Do an *in-place* dequoting of the specified string, returning the
+ * resulting length (which may be containing embedded nulls.)
+ *
+ * In-place replacement is possible since the unquoted length is always
+ * shorter than or equal to the quoted length.
+ */
+size_t nasm_unquote(char *str)
+{
+    size_t ln;
+    char bq, eq;
+    char *p, *q, *ep;
+    char *escp = NULL;
+    char c;
+    enum unq_state {
+	st_start,
+	st_backslash,
+	st_hex,
+	st_oct,
+	st_ucs,
+    } state;
+    int ndig = 0;
+    int32_t nval = 0;
+
+    bq = str[0];
+    if (!bq)
+	return 0;
+    ln = strlen(str);
+    eq = str[ln-1];
+
+    if ((bq == '\'' || bq == '\"') && bq == eq) {
+	/* '...' or "..." string */
+	memmove(str, str+1, ln-2);
+	str[ln-2] = '\0';
+	return ln-2;
+    }
+    if (bq == '`' || eq == '`') {
+	/* `...` string */
+	q = str;
+	p = str+1;
+	ep = str+ln-1;
+	state = st_start;
+
+	while (p < ep) {
+	    c = *p++;
+	    switch (state) {
+	    case st_start:
+		if (c == '\\')
+		    state = st_backslash;
+		else
+		    *q++ = c;
+		break;
+
+	    case st_backslash:
+		state = st_start;
+		escp = p-1;
+		switch (c) {
+		case 'a':
+		    *q++ = 7;
+		    break;
+		case 'b':
+		    *q++ = 8;
+		    break;
+		case 'e':
+		    *q++ = 27;
+		    break;
+		case 'f':
+		    *q++ = 12;
+		    break;
+		case 'n':
+		    *q++ = 10;
+		    break;
+		case 'r':
+		    *q++ = 13;
+		    break;
+		case 't':
+		    *q++ = 9;
+		    break;
+		case 'u':
+		    state = st_ucs;
+		    ndig = 4;
+		    nval = 0;
+		    break;
+		case 'U':
+		    state = st_ucs;
+		    ndig = 8;
+		    nval = 0;
+		    break;
+		case 'v':
+		    *q++ = 11;
+		case 'x':
+		case 'X':
+		    state = st_hex;
+		    ndig = nval = 0;
+		    break;
+		case '0':
+		case '1':
+		case '2':
+		case '3':
+		case '4':
+		case '5':
+		case '6':
+		case '7':
+		    state = st_oct;
+		    ndig = 1;
+		    nval = c - '0';
+		    break;
+		default:
+		    *q++ = c;
+		    break;
+		}
+		break;
+
+	    case st_oct:
+		if (c >= '0' && c <= '7') {
+		    nval = (nval << 3) + (c - '0');
+		    if (++ndig >= 3) {
+			*q++ = nval;
+			state = st_start;
+		    }
+		} else {
+		    p--;	/* Process this character again */
+		    *q++ = nval;
+		    state = st_start;
+		}
+		break;
+
+	    case st_hex:
+		if ((c >= '0' && c <= '9') ||
+		    (c >= 'A' && c <= 'F') ||
+		    (c >= 'a' && c <= 'f')) {
+		    nval = (nval << 4) + numvalue(c);
+		    if (++ndig >= 2) {
+			*q++ = nval;
+			state = st_start;
+		    }
+		} else {
+		    p--;	/* Process this character again */
+		    *q++ = ndig ? nval : *escp;
+		    state = st_start;
+		}
+		break;
+
+	    case st_ucs:
+		if ((c >= '0' && c <= '9') ||
+		    (c >= 'A' && c <= 'F') ||
+		    (c >= 'a' && c <= 'f')) {
+		    nval = (nval << 4) + numvalue(c);
+		    if (!--ndig) {
+			q = emit_utf8(q, nval);
+			state = st_start;
+		    }
+		} else {
+		    p--;	/* Process this character again */
+		    if (p > escp+1)
+			q = emit_utf8(q, nval);
+		    else
+			*q++ = *escp;
+		    state = st_start;
+		}
+		break;
+	    }
+	}
+	*q = '\0';
+	return q-str;
+    }
+
+    /* Otherwise, just return the input... */
+    return ln;
+}
+
+/*
+ * Find the end of a quoted string; returns the pointer to the terminating
+ * character (either the ending quote or the null character, if unterminated.)
+ */
+char *nasm_skip_string(char *str)
+{
+    char bq;
+    char *p;
+    char c;
+    enum unq_state {
+	st_start,
+	st_backslash,
+	st_hex,
+	st_oct,
+	st_ucs,
+    } state;
+    int ndig = 0;
+
+    bq = str[0];
+    if (bq == '\'' || bq == '\"') {
+	/* '...' or "..." string */
+	for (p = str+1; *p && *p != bq; p++)
+	    ;
+	return p;
+    } else if (bq == '`') {
+	/* `...` string */
+	p = str+1;
+	state = st_start;
+
+	while ((c = *p++)) {
+	    switch (state) {
+	    case st_start:
+		switch (c) {
+		case '\\':
+		    state = st_backslash;
+		    break;
+		case '`':
+		    return p-1;	/* Found the end */
+		default:
+		    break;
+		}
+		break;
+
+	    case st_backslash:
+		switch (c) {
+		case 'a':
+		case 'b':
+		case 'e':
+		case 'f':
+		case 'n':
+		case 'r':
+		case 't':
+		case 'v':
+		default:
+		    state = st_start;
+		    break;
+		case 'u':
+		    state = st_ucs;
+		    ndig = 4;
+		    break;
+		case 'U':
+		    state = st_ucs;
+		    ndig = 8;
+		    break;
+		case 'x':
+		case 'X':
+		    state = st_hex;
+		    ndig = 0;
+		    break;
+		case '0':
+		case '1':
+		case '2':
+		case '3':
+		case '4':
+		case '5':
+		case '6':
+		case '7':
+		    state = st_oct;
+		    ndig = 1;
+		    break;
+		}
+		break;
+
+	    case st_oct:
+		if (c >= '0' && c <= '7') {
+		    if (++ndig >= 3)
+			state = st_start;
+		} else {
+		    p--;	/* Process this character again */
+		    state = st_start;
+		}
+		break;
+
+	    case st_hex:
+		if ((c >= '0' && c <= '9') ||
+		    (c >= 'A' && c <= 'F') ||
+		    (c >= 'a' && c <= 'f')) {
+		    if (++ndig >= 2)
+			state = st_start;
+		} else {
+		    p--;	/* Process this character again */
+		    state = st_start;
+		}
+		break;
+
+	    case st_ucs:
+		if ((c >= '0' && c <= '9') ||
+		    (c >= 'A' && c <= 'F') ||
+		    (c >= 'a' && c <= 'f')) {
+		    if (!--ndig)
+			state = st_start;
+		} else {
+		    p--;	/* Process this character again */
+		    state = st_start;
+		}
+		break;
+	    }
+	}
+	return p;		/* Unterminated string... */
+    } else {
+	return str;		/* Not a string... */
+    }
+}