Mark functions as __dead2 in order to help the LLVM static checker

understand which code paths aren't possible.

This commit eliminates 117 false positive bug reports of the form
"allocate memory; error out if pointer is NULL; use pointer".

4 files changed, 28 insertions, 27 deletions

diff --git a/usr.bin/cpio/cpio.h b/usr.bin/cpio/cpio.h
index 4dce00f..1db7ec1 100644
--- a/usr.bin/cpio/cpio.h
+++ b/usr.bin/cpio/cpio.h
@@ -85,7 +85,7 @@ struct cpio {
 /* Name of this program; used in error reporting, initialized in main(). */
 const char *cpio_progname;
 
-void	cpio_errc(int _eval, int _code, const char *fmt, ...);
+void	cpio_errc(int _eval, int _code, const char *fmt, ...) __dead2;
 void	cpio_warnc(int _code, const char *fmt, ...);
 
 int	owner_parse(const char *, int *, int *);
diff --git a/usr.bin/lex/flex.skl b/usr.bin/lex/flex.skl
index d741652..460b2fa 100644
--- a/usr.bin/lex/flex.skl
+++ b/usr.bin/lex/flex.skl
@@ -9,6 +9,7 @@
 #include <sys/cdefs.h>
 #else
 #define __unused
+#define __dead2
 #endif
 
 #define FLEX_SCANNER
@@ -290,7 +291,7 @@ static void yy_flex_free YY_PROTO(( void * ));
 static yy_state_type yy_get_previous_state YY_PROTO(( void ));
 static yy_state_type yy_try_NUL_trans YY_PROTO(( yy_state_type current_state ));
 static int yy_get_next_buffer YY_PROTO(( void ));
-static void yy_fatal_error YY_PROTO(( yyconst char msg[] ));
+static void yy_fatal_error YY_PROTO(( yyconst char msg[] )) __dead2;
 %*
 
 /* Done after the current pattern has been matched and before the
diff --git a/usr.bin/tar/bsdtar.h b/usr.bin/tar/bsdtar.h
index dbbdbdc..eee53a9 100644
--- a/usr.bin/tar/bsdtar.h
+++ b/usr.bin/tar/bsdtar.h
@@ -103,7 +103,7 @@ struct bsdtar {
 };
 
 void	bsdtar_errc(struct bsdtar *, int _eval, int _code,
-	    const char *fmt, ...);
+	    const char *fmt, ...) __dead2;
 void	bsdtar_warnc(struct bsdtar *, int _code, const char *fmt, ...);
 void	cleanup_exclusions(struct bsdtar *);
 void	do_chdir(struct bsdtar *);
diff --git a/usr.bin/yacc/defs.h b/usr.bin/yacc/defs.h
index cb8b083..5219e1b 100644
--- a/usr.bin/yacc/defs.h
+++ b/usr.bin/yacc/defs.h
@@ -309,26 +309,26 @@ char *allocate(unsigned);
 void closure(short *, int);
 void create_symbol_table(void);
 void default_action_warning(void);
-void dollar_error(int, char *, char *);
+void dollar_error(int, char *, char *) __dead2;
 void dollar_warning(int, int);
-void done(int);
-void fatal(const char *msg);
+void done(int) __dead2;
+void fatal(const char *msg) __dead2;
 void finalize_closure(void);
 void free_parser(void);
 void free_symbols(void);
 void free_symbol_table(void);
-void illegal_character(char *);
-void illegal_tag(int, char *, char *);
+void illegal_character(char *) __dead2;
+void illegal_tag(int, char *, char *) __dead2;
 void lalr(void);
 bucket *lookup(char *);
 void lr0(void);
 bucket *make_bucket(const char *);
 void make_parser(void);
-void no_grammar(void);
-void no_space(void);
-void open_error(const char *);
+void no_grammar(void) __dead2;
+void no_space(void) __dead2;
+void open_error(const char *) __dead2;
 void output(void);
-void over_unionized(char *);
+void over_unionized(char *) __dead2;
 void prec_redeclared(void);
 void reader(void);
 void reflexive_transitive_closure(unsigned *, int);
@@ -337,21 +337,21 @@ void restarted_warning(void);
 void retyped_warning(char *);
 void revalued_warning(char *);
 void set_first_derives(void);
-void syntax_error(int, char *, char *);
-void terminal_lhs(int);
-void terminal_start(char *);
-void tokenized_start(char *);
-void undefined_goal(char *);
+void syntax_error(int, char *, char *) __dead2;
+void terminal_lhs(int) __dead2;
+void terminal_start(char *) __dead2;
+void tokenized_start(char *) __dead2;
+void undefined_goal(char *) __dead2;
 void undefined_symbol_warning(char *);
-void unexpected_EOF(void);
-void unknown_rhs(int);
-void unterminated_action(int, char *, char *);
-void unterminated_comment(int, char *, char *);
-void unterminated_string(int, char *, char *);
-void unterminated_text(int, char *, char *);
-void unterminated_union(int, char *, char *);
-void untyped_lhs(void);
-void untyped_rhs(int, char *);
-void used_reserved(char *);
+void unexpected_EOF(void) __dead2;
+void unknown_rhs(int) __dead2;
+void unterminated_action(int, char *, char *) __dead2;
+void unterminated_comment(int, char *, char *) __dead2;
+void unterminated_string(int, char *, char *) __dead2;
+void unterminated_text(int, char *, char *) __dead2;
+void unterminated_union(int, char *, char *) __dead2;
+void untyped_lhs(void) __dead2;
+void untyped_rhs(int, char *) __dead2;
+void used_reserved(char *) __dead2;
 void verbose(void);
 void write_section(const char **);