[src/trunk]: src/usr.bin/xlint/lint1 lint: fix initialization for arrays with...

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

details:   https://anonhg.NetBSD.org/src/rev/633cf3d2971c
branches:  trunk
changeset: 953956:633cf3d2971c
user:      rillig <rillig%NetBSD.org@localhost>
date:      Thu Mar 25 22:53:05 2021 +0000

description:
lint: fix initialization for arrays with designators

>From the previous commit, there was an off-by-one error left, which was
due to the interaction between designation_add_subscript and
extend_if_array_of_unknown_size.

The other crucial point was to call initstack_pop_nobrace before
accessing the "current initialization stack element".  Without this
call, in msg_168.c the "current element" would point to the initializer
level for 'const char *' instead of the one for 'array of const char *'.

One more step towards supporting C99.

diffstat:

 tests/usr.bin/xlint/lint1/msg_168.c   |   4 ++--
 tests/usr.bin/xlint/lint1/msg_168.exp |   3 +--
 usr.bin/xlint/lint1/init.c            |  22 ++++++++++++++--------
 3 files changed, 17 insertions(+), 12 deletions(-)

diffs (91 lines):

diff -r 99d73fb69e43 -r 633cf3d2971c tests/usr.bin/xlint/lint1/msg_168.c
--- a/tests/usr.bin/xlint/lint1/msg_168.c       Thu Mar 25 22:15:38 2021 +0000
+++ b/tests/usr.bin/xlint/lint1/msg_168.c       Thu Mar 25 22:53:05 2021 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: msg_168.c,v 1.4 2021/03/25 22:15:38 rillig Exp $       */
+/*     $NetBSD: msg_168.c,v 1.5 2021/03/25 22:53:05 rillig Exp $       */
 # 3 "msg_168.c"
 
 // Test for message: array subscript cannot be > %d: %ld [168]
@@ -37,6 +37,6 @@
            ['9'] = "IX"
        };
 
-       print_string(to_roman['9']);    /*FIXME*//* expect: 168 */
+       print_string(to_roman['9']);
        print_string(to_roman[':']);    /* expect: 168 */
 }
diff -r 99d73fb69e43 -r 633cf3d2971c tests/usr.bin/xlint/lint1/msg_168.exp
--- a/tests/usr.bin/xlint/lint1/msg_168.exp     Thu Mar 25 22:15:38 2021 +0000
+++ b/tests/usr.bin/xlint/lint1/msg_168.exp     Thu Mar 25 22:53:05 2021 +0000
@@ -1,3 +1,2 @@
 msg_168.c(28): warning: array subscript cannot be > 19: 20 [168]
-msg_168.c(40): warning: array subscript cannot be > 51: 57 [168]
-msg_168.c(41): warning: array subscript cannot be > 51: 58 [168]
+msg_168.c(41): warning: array subscript cannot be > 57: 58 [168]
diff -r 99d73fb69e43 -r 633cf3d2971c usr.bin/xlint/lint1/init.c
--- a/usr.bin/xlint/lint1/init.c        Thu Mar 25 22:15:38 2021 +0000
+++ b/usr.bin/xlint/lint1/init.c        Thu Mar 25 22:53:05 2021 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: init.c,v 1.132 2021/03/25 22:15:38 rillig Exp $        */
+/*     $NetBSD: init.c,v 1.133 2021/03/25 22:53:05 rillig Exp $        */
 
 /*
  * Copyright (c) 1994, 1995 Jochen Pohl
@@ -37,7 +37,7 @@
 
 #include <sys/cdefs.h>
 #if defined(__RCSID) && !defined(lint)
-__RCSID("$NetBSD: init.c,v 1.132 2021/03/25 22:15:38 rillig Exp $");
+__RCSID("$NetBSD: init.c,v 1.133 2021/03/25 22:53:05 rillig Exp $");
 #endif
 
 #include <stdlib.h>
@@ -497,6 +497,9 @@
        debug_designation();
 }
 
+/* TODO: Move the function body up here, to avoid the forward declaration. */
+static void initstack_pop_nobrace(void);
+
 /*
  * A sub-object of an array is initialized using a designator.  This does not
  * have to be an array element directly, it can also be used to initialize
@@ -523,9 +526,12 @@
        debug_step("subscript range is %zu ... %zu", range.lo, range.hi);
        debug_initstack();
 
+       initstack_pop_nobrace();
+
        istk = initstk_lvalue;
        if (istk->i_array_of_unknown_size) {
-               int auto_dim = (int)(range.hi + 1);
+               /* No +1 here, extend_if_array_of_unknown_size will add it. */
+               int auto_dim = (int)range.hi;
                if (auto_dim > istk->i_type->t_dim) {
                        debug_step("setting the array size to %d", auto_dim);
                        istk->i_type->t_dim = auto_dim;
@@ -734,6 +740,11 @@
 
        if (istk->i_remaining != 0)
                return;
+       /*
+        * XXX: According to the function name, there should be a 'return' if
+        * i_array_of_unknown_size is false.  There's probably a test missing
+        * for that case.
+        */
 
        /*
         * The only place where an incomplete array may appear is at the
@@ -1292,11 +1303,6 @@
        len = strg->st_len;
 
        if (istk->i_array_of_unknown_size) {
-               /*
-                * FIXME: C99 6.7.8p22 explicitly says that only "at the end
-                * of its initializer list, the array no longer has incomplete
-                * type".
-                */
                istk->i_array_of_unknown_size = false;
                istk->i_type->t_dim = len + 1;
                setcomplete(istk->i_type, true);