From b71085aacf405e824dfbbb10dddb092b3bd9d332 Mon Sep 17 00:00:00 2001
From: Stefan Farfeleder <stefanf@FreeBSD.org>
Date: Thu, 15 May 2008 19:55:27 +0000
Subject: [PATCH] Expand $LINENO to the current line number.  This is required
 by SUSv3's "User Portability Utilities" option.

Often configure scripts generated by the autotools test if $LINENO works and
refuse to use /bin/sh if not.

Package test run by:	pav
---
 bin/sh/expand.c |  9 ++++++++-
 bin/sh/parser.c | 25 ++++++++++++++++++++++---
 bin/sh/parser.h |  8 +++++---
 3 files changed, 35 insertions(+), 7 deletions(-)

diff --git a/bin/sh/expand.c b/bin/sh/expand.c
index 1bd707936a32..2f0b9fda54fa 100644
--- a/bin/sh/expand.c
+++ b/bin/sh/expand.c
@@ -638,7 +638,13 @@ evalvar(char *p, int flag)
 		special = 1;
 	p = strchr(p, '=') + 1;
 again: /* jump here after setting a variable with ${var=text} */
-	if (special) {
+	if (varflags & VSLINENO) {
+		set = 1;
+		special = 0;
+		val = var;
+		p[-1] = '\0';	/* temporarily overwrite '=' to have \0
+				   terminated string */
+	} else if (special) {
 		set = varisset(var, varflags & VSNUL);
 		val = NULL;
 	} else {
@@ -768,6 +774,7 @@ record:
 	default:
 		abort();
 	}
+	p[-1] = '=';	/* recover overwritten '=' */
 
 	if (subtype != VSNORMAL) {	/* skip to end of alternative */
 		int nesting = 1;
diff --git a/bin/sh/parser.c b/bin/sh/parser.c
index fb9abc9ff4c7..75b4cac74ba4 100644
--- a/bin/sh/parser.c
+++ b/bin/sh/parser.c
@@ -94,6 +94,7 @@ STATIC union node *redirnode;
 STATIC struct heredoc *heredoc;
 STATIC int quoteflag;		/* set if (part of) last token was quoted */
 STATIC int startlinno;		/* line # where last token started */
+STATIC int funclinno;		/* line # where the current function started */
 
 /* XXX When 'noaliases' is set to one, no alias expansion takes place. */
 static int noaliases = 0;
@@ -567,12 +568,14 @@ simplecmd(union node **rpp, union node *redir)
 			/* We have a function */
 			if (readtoken() != TRP)
 				synexpect(TRP);
+			funclinno = plinno;
 #ifdef notdef
 			if (! goodname(n->narg.text))
 				synerror("Bad function name");
 #endif
 			n->type = NDEFUN;
 			n->narg.next = command();
+			funclinno = 0;
 			goto checkneg;
 		} else {
 			tokpushback++;
@@ -1176,12 +1179,15 @@ parseredir: {
  */
 
 parsesub: {
+	char buf[10];
 	int subtype;
 	int typeloc;
 	int flags;
 	char *p;
 	static const char types[] = "}-+?=";
-       int bracketed_name = 0; /* used to handle ${[0-9]*} variables */
+	int bracketed_name = 0; /* used to handle ${[0-9]*} variables */
+	int i;
+	int linno;
 
 	c = pgetc();
 	if (c != '(' && c != '{' && (is_eof(c) || !is_name(c)) &&
@@ -1200,6 +1206,7 @@ parsesub: {
 		typeloc = out - stackblock();
 		USTPUTC(VSNORMAL, out);
 		subtype = VSNORMAL;
+		flags = 0;
 		if (c == '{') {
 			bracketed_name = 1;
 			c = pgetc();
@@ -1213,10 +1220,23 @@ parsesub: {
 				subtype = 0;
 		}
 		if (!is_eof(c) && is_name(c)) {
+			p = out;
 			do {
 				STPUTC(c, out);
 				c = pgetc();
 			} while (!is_eof(c) && is_in_name(c));
+			if (out - p == 6 && strncmp(p, "LINENO", 6) == 0) {
+				/* Replace the variable name with the
+				 * current line number. */
+				linno = plinno;
+				if (funclinno != 0)
+					linno -= funclinno - 1;
+				snprintf(buf, sizeof(buf), "%d", linno);
+				STADJUST(-6, out);
+				for (i = 0; buf[i] != '\0'; i++)
+					STPUTC(buf[i], out);
+				flags |= VSLINENO;
+			}
 		} else if (is_digit(c)) {
 			if (bracketed_name) {
 				do {
@@ -1239,11 +1259,10 @@ parsesub: {
 				c = pgetc();
 			}
 		}
-		flags = 0;
 		if (subtype == 0) {
 			switch (c) {
 			case ':':
-				flags = VSNUL;
+				flags |= VSNUL;
 				c = pgetc();
 				/*FALLTHROUGH*/
 			default:
diff --git a/bin/sh/parser.h b/bin/sh/parser.h
index 6b5687d9d71c..40dd8bda2405 100644
--- a/bin/sh/parser.h
+++ b/bin/sh/parser.h
@@ -45,9 +45,11 @@
 #define	CTLQUOTEMARK '\210'
 
 /* variable substitution byte (follows CTLVAR) */
-#define VSTYPE	0x0f		/* type of variable substitution */
-#define VSNUL	0x10		/* colon--treat the empty string as unset */
-#define VSQUOTE 0x80		/* inside double quotes--suppress splitting */
+#define VSTYPE		0x0f	/* type of variable substitution */
+#define VSNUL		0x10	/* colon--treat the empty string as unset */
+#define VSLINENO	0x20	/* expansion of $LINENO, the line number \
+				   follows immediately */
+#define VSQUOTE		0x80	/* inside double quotes--suppress splitting */
 
 /* values of VSTYPE field */
 #define VSNORMAL	0x1		/* normal variable:  $var or ${var} */