[src/trunk]: src/usr.bin/xlint/lint1 lint: fix reachability for if-then-else ...

[rillig <rillig%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/073d2a18b6a3
branches:  trunk
changeset: 953824:073d2a18b6a3
user:      rillig <rillig%NetBSD.org@localhost>
date:      Sun Mar 21 15:24:55 2021 +0000

description:
lint: fix reachability for if-then-else statements

diffstat:

 tests/usr.bin/xlint/lint1/msg_130.c   |   4 ++--
 tests/usr.bin/xlint/lint1/msg_130.exp |   1 +
 tests/usr.bin/xlint/lint1/msg_193.c   |   4 ++--
 tests/usr.bin/xlint/lint1/msg_193.exp |   1 +
 tests/usr.bin/xlint/lint1/msg_217.c   |   4 ++--
 tests/usr.bin/xlint/lint1/msg_217.exp |   1 -
 usr.bin/xlint/lint1/func.c            |  15 ++++++++-------
 7 files changed, 16 insertions(+), 14 deletions(-)

diffs (119 lines):

diff -r 993f26f14e71 -r 073d2a18b6a3 tests/usr.bin/xlint/lint1/msg_130.c
--- a/tests/usr.bin/xlint/lint1/msg_130.c       Sun Mar 21 14:49:21 2021 +0000
+++ b/tests/usr.bin/xlint/lint1/msg_130.c       Sun Mar 21 15:24:55 2021 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: msg_130.c,v 1.11 2021/03/10 00:02:00 rillig Exp $      */
+/*     $NetBSD: msg_130.c,v 1.12 2021/03/21 15:24:56 rillig Exp $      */
 # 3 "msg_130.c"
 
 // Test for message: enum type mismatch: '%s' '%s' '%s' [130]
@@ -89,7 +89,7 @@
        if (sizeof_int == sizeof_uint)  /* expect: 130 *//* FIXME */
                return 6;
 
-       return 0;
+       return 0;               /* expect: statement not reached */
 }
 
 /*
diff -r 993f26f14e71 -r 073d2a18b6a3 tests/usr.bin/xlint/lint1/msg_130.exp
--- a/tests/usr.bin/xlint/lint1/msg_130.exp     Sun Mar 21 14:49:21 2021 +0000
+++ b/tests/usr.bin/xlint/lint1/msg_130.exp     Sun Mar 21 15:24:55 2021 +0000
@@ -2,4 +2,5 @@
 msg_130.c(31): warning: enum type mismatch: 'enum color' '!=' 'enum size' [130]
 msg_130.c(32): warning: enum type mismatch: 'enum color' '==' 'enum size' [130]
 msg_130.c(89): warning: enum type mismatch: 'enum <unnamed>' '==' 'enum <unnamed>' [130]
+msg_130.c(92): warning: statement not reached [193]
 msg_130.c(127): warning: enum type mismatch: 'enum <unnamed>' '==' 'enum <unnamed>' [130]
diff -r 993f26f14e71 -r 073d2a18b6a3 tests/usr.bin/xlint/lint1/msg_193.c
--- a/tests/usr.bin/xlint/lint1/msg_193.c       Sun Mar 21 14:49:21 2021 +0000
+++ b/tests/usr.bin/xlint/lint1/msg_193.c       Sun Mar 21 15:24:55 2021 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: msg_193.c,v 1.4 2021/03/21 14:36:59 rillig Exp $       */
+/*     $NetBSD: msg_193.c,v 1.5 2021/03/21 15:24:56 rillig Exp $       */
 # 3 "msg_193.c"
 
 // Test for message: statement not reached [193]
@@ -140,7 +140,7 @@
 {
        if (1)
                return;
-       unreachable();                  /* TODO: expect: 193 */
+       unreachable();                  /* expect: 193 */
 }
 
 void
diff -r 993f26f14e71 -r 073d2a18b6a3 tests/usr.bin/xlint/lint1/msg_193.exp
--- a/tests/usr.bin/xlint/lint1/msg_193.exp     Sun Mar 21 14:49:21 2021 +0000
+++ b/tests/usr.bin/xlint/lint1/msg_193.exp     Sun Mar 21 15:24:55 2021 +0000
@@ -10,6 +10,7 @@
 msg_193.c(128): warning: statement not reached [193]
 msg_193.c(131): warning: statement not reached [193]
 msg_193.c(133): warning: statement not reached [193]
+msg_193.c(143): warning: statement not reached [193]
 msg_193.c(152): warning: statement not reached [193]
 msg_193.c(161): warning: statement not reached [193]
 msg_193.c(169): warning: statement not reached [193]
diff -r 993f26f14e71 -r 073d2a18b6a3 tests/usr.bin/xlint/lint1/msg_217.c
--- a/tests/usr.bin/xlint/lint1/msg_217.c       Sun Mar 21 14:49:21 2021 +0000
+++ b/tests/usr.bin/xlint/lint1/msg_217.c       Sun Mar 21 15:24:55 2021 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: msg_217.c,v 1.8 2021/03/21 14:36:59 rillig Exp $       */
+/*     $NetBSD: msg_217.c,v 1.9 2021/03/21 15:24:56 rillig Exp $       */
 # 3 "msg_217.c"
 
 // Test for message: function %s falls off bottom without returning value [217]
@@ -55,7 +55,7 @@
                        continue;
                break;
        }
-}                              /* FIXME *//* expect: 217 */
+}
 
 int
 unreachable_continue_falls_through(void)
diff -r 993f26f14e71 -r 073d2a18b6a3 tests/usr.bin/xlint/lint1/msg_217.exp
--- a/tests/usr.bin/xlint/lint1/msg_217.exp     Sun Mar 21 14:49:21 2021 +0000
+++ b/tests/usr.bin/xlint/lint1/msg_217.exp     Sun Mar 21 15:24:55 2021 +0000
@@ -1,4 +1,3 @@
 msg_217.c(11): warning: function random falls off bottom without returning value [217]
-msg_217.c(58): warning: function reachable_continue_leads_to_endless_loop falls off bottom without returning value [217]
 msg_217.c(65): warning: statement not reached [193]
 msg_217.c(68): warning: function unreachable_continue_falls_through falls off bottom without returning value [217]
diff -r 993f26f14e71 -r 073d2a18b6a3 usr.bin/xlint/lint1/func.c
--- a/usr.bin/xlint/lint1/func.c        Sun Mar 21 14:49:21 2021 +0000
+++ b/usr.bin/xlint/lint1/func.c        Sun Mar 21 15:24:55 2021 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: func.c,v 1.89 2021/03/21 14:49:21 rillig Exp $ */
+/*     $NetBSD: func.c,v 1.90 2021/03/21 15:24:55 rillig Exp $ */
 
 /*
  * Copyright (c) 1994, 1995 Jochen Pohl
@@ -37,7 +37,7 @@
 
 #include <sys/cdefs.h>
 #if defined(__RCSID) && !defined(lint)
-__RCSID("$NetBSD: func.c,v 1.89 2021/03/21 14:49:21 rillig Exp $");
+__RCSID("$NetBSD: func.c,v 1.90 2021/03/21 15:24:55 rillig Exp $");
 #endif
 
 #include <stdlib.h>
@@ -631,12 +631,13 @@
 void
 if3(bool els)
 {
+       if (cstmt->c_reached_end_of_then)
+               reached = true;
+       else if (cstmt->c_always_then)
+               reached = false;
+       else if (!els)
+               reached = true;
 
-       if (els) {
-               reached |= cstmt->c_reached_end_of_then;
-       } else {
-               reached = true;
-       }
        popctrl(T_IF);
 }