Handle __dead functions using lint comments.

5 files changed, 36 insertions, 8 deletions

diff --git a/usr.bin/xlint/lint1/externs1.h b/usr.bin/xlint/lint1/externs1.h
index 22e9e30a837..4bbabf1a30c 100644
--- a/usr.bin/xlint/lint1/externs1.h
+++ b/usr.bin/xlint/lint1/externs1.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: externs1.h,v 1.8 2005/12/12 23:35:59 cloder Exp $	*/
+/*	$OpenBSD: externs1.h,v 1.9 2005/12/17 21:08:27 cloder Exp $	*/
 /*	$NetBSD: externs1.h,v 1.7 1995/10/02 17:31:39 jpo Exp $	*/
 
 /*
@@ -251,6 +251,7 @@ extern	void	dobreak(void);
 extern	void	doreturn(tnode_t *);
 extern	void	glclup(int);
 extern	void	argsused(int);
+extern	void	noreturn(int);
 extern	void	constcond(int);
 extern	void	fallthru(int);
 extern	void	notreach(int);
diff --git a/usr.bin/xlint/lint1/func.c b/usr.bin/xlint/lint1/func.c
index c3ee8e6350b..5d73a4e896b 100644
--- a/usr.bin/xlint/lint1/func.c
+++ b/usr.bin/xlint/lint1/func.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: func.c,v 1.9 2005/12/17 20:19:46 cloder Exp $	*/
+/*	$OpenBSD: func.c,v 1.10 2005/12/17 21:08:27 cloder Exp $	*/
 /*	$NetBSD: func.c,v 1.7 1995/10/02 17:31:40 jpo Exp $	*/
 
 /*
@@ -33,7 +33,7 @@
  */
 
 #ifndef lint
-static char rcsid[] = "$OpenBSD: func.c,v 1.9 2005/12/17 20:19:46 cloder Exp $";
+static char rcsid[] = "$OpenBSD: func.c,v 1.10 2005/12/17 21:08:27 cloder Exp $";
 #endif
 
 #include <stdlib.h>
@@ -84,6 +84,12 @@ int	nargusg = -1;
 pos_t	aupos;
 
 /*
+ * If the following function has been declared NORETURN, noretflg is set
+ * to 1. Otherwise it is set to 0.
+ */
+int	noretflg = 0;
+
+/*
  * Number of arguments of the following function definition whose types
  * shall be checked by lint2. -1 stands for all arguments.
  *
@@ -387,6 +393,10 @@ funcend(void)
 	}
 	nargusg = -1;
 
+	if (noretflg)
+		funcsym->s_noreturn = 1;
+	noretflg = 0;
+
 	/*
 	 * write the information about the function definition to the
 	 * output file
@@ -1101,6 +1111,18 @@ argsused(int n)
 }
 
 /*
+ * NORETURN comment
+ *
+ * The following function will never return, which means any code
+ * following a call to this function is unreachable.
+ */
+void
+noreturn(int n)
+{
+	noretflg = 1;
+}
+
+/*
  * VARARGS comment
  *
  * Makes that lint2 checks only the first n arguments for compatibility
diff --git a/usr.bin/xlint/lint1/lint1.h b/usr.bin/xlint/lint1/lint1.h
index b4b4aed8d0c..758c25cc93a 100644
--- a/usr.bin/xlint/lint1/lint1.h
+++ b/usr.bin/xlint/lint1/lint1.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: lint1.h,v 1.10 2005/12/10 17:41:03 cloder Exp $	*/
+/*	$OpenBSD: lint1.h,v 1.11 2005/12/17 21:08:27 cloder Exp $	*/
 /*	$NetBSD: lint1.h,v 1.6 1995/10/02 17:31:41 jpo Exp $	*/
 
 /*
@@ -208,6 +208,7 @@ typedef	struct sym {
 	u_int	s_rimpl : 1;	/* return value of function implicit decl. */
 	u_int	s_osdef : 1;	/* symbol stems from old style function def. */
 	u_int	s_inline : 1;	/* true if this is a inline function */
+	u_int	s_noreturn : 1;	/* true if this is a NORETURN function */
 	struct	sym *s_xsym;	/* for local declared external symbols pointer
 				   to external symbol with same name */
 	def_t	s_def;		/* declared, tentative defined, defined */
diff --git a/usr.bin/xlint/lint1/scan.l b/usr.bin/xlint/lint1/scan.l
index 5b91da5edef..9784df6f167 100644
--- a/usr.bin/xlint/lint1/scan.l
+++ b/usr.bin/xlint/lint1/scan.l
@@ -1,5 +1,5 @@
 %{
-/*	$OpenBSD: scan.l,v 1.25 2005/12/11 20:02:09 deraadt Exp $	*/
+/*	$OpenBSD: scan.l,v 1.26 2005/12/17 21:08:27 cloder Exp $	*/
 /*	$NetBSD: scan.l,v 1.8 1995/10/23 13:38:51 jpo Exp $	*/
 
 /*
@@ -34,7 +34,7 @@
  */
 
 #ifndef lint
-static char rcsid[] = "$OpenBSD: scan.l,v 1.25 2005/12/11 20:02:09 deraadt Exp $";
+static char rcsid[] = "$OpenBSD: scan.l,v 1.26 2005/12/17 21:08:27 cloder Exp $";
 #endif
 
 #include <stdlib.h>
@@ -999,6 +999,7 @@ comment(void)
 		{ "CONSTCOND",		0,	constcond	},
 		{ "CONSTANTCOND",	0,	constcond	},
 		{ "CONSTANTCONDITION",	0,	constcond	},
+		{ "NORETURN",		1,	noreturn	},
 		{ "FALLTHRU",		0,	fallthru	},
 		{ "FALLTHROUGH",	0,	fallthru	},
 		{ "LINTLIBRARY",	0,	lintlib		},
diff --git a/usr.bin/xlint/lint1/tree.c b/usr.bin/xlint/lint1/tree.c
index e4d391615a9..e78ef4e3653 100644
--- a/usr.bin/xlint/lint1/tree.c
+++ b/usr.bin/xlint/lint1/tree.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: tree.c,v 1.29 2005/12/16 03:01:35 cloder Exp $	*/
+/*	$OpenBSD: tree.c,v 1.30 2005/12/17 21:08:27 cloder Exp $	*/
 /*	$NetBSD: tree.c,v 1.12 1995/10/02 17:37:57 jpo Exp $	*/
 
 /*
@@ -33,7 +33,7 @@
  */
 
 #ifndef lint
-static char rcsid[] = "$OpenBSD: tree.c,v 1.29 2005/12/16 03:01:35 cloder Exp $";
+static char rcsid[] = "$OpenBSD: tree.c,v 1.30 2005/12/17 21:08:27 cloder Exp $";
 #endif
 
 #include <stdlib.h>
@@ -3131,6 +3131,9 @@ funccall(tnode_t *func, tnode_t *args)
 		fcop = ICALL;
 	}
 
+	if (func->tn_sym->s_noreturn)
+		notreach(0);
+
 	/*
 	 * after cconv() func will always be a pointer to a function
 	 * if it is a valid function designator.