[src/trunk]: src/usr.bin/xlint/lint1 lint: fix crash in malformed initialization

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

details:   https://anonhg.NetBSD.org/src/rev/49b4f2d42072
branches:  trunk
changeset: 379786:49b4f2d42072
user:      rillig <rillig%NetBSD.org@localhost>
date:      Sat Jun 19 15:51:11 2021 +0000

description:
lint: fix crash in malformed initialization

diffstat:

 distrib/sets/lists/tests/mi                              |   3 ++-
 tests/usr.bin/xlint/lint1/Makefile                       |   3 ++-
 tests/usr.bin/xlint/lint1/d_gcc_compound_statements1.c   |  12 +++++++++++-
 tests/usr.bin/xlint/lint1/d_gcc_compound_statements1.exp |   2 ++
 usr.bin/xlint/lint1/decl.c                               |   9 ++++++---
 usr.bin/xlint/lint1/func.c                               |  13 ++++++++++---
 6 files changed, 33 insertions(+), 9 deletions(-)

diffs (127 lines):

diff -r 941e161f5ce2 -r 49b4f2d42072 distrib/sets/lists/tests/mi
--- a/distrib/sets/lists/tests/mi       Sat Jun 19 15:23:57 2021 +0000
+++ b/distrib/sets/lists/tests/mi       Sat Jun 19 15:51:11 2021 +0000
@@ -1,4 +1,4 @@
-# $NetBSD: mi,v 1.1058 2021/06/19 08:30:08 rillig Exp $
+# $NetBSD: mi,v 1.1059 2021/06/19 15:51:11 rillig Exp $
 #
 # Note: don't delete entries from here - mark them as "obsolete" instead.
 #
@@ -6159,6 +6159,7 @@
 ./usr/tests/usr.bin/xlint/lint1/d_fold_test.c                  tests-usr.bin-tests     compattestfile,atf
 ./usr/tests/usr.bin/xlint/lint1/d_fold_test.exp                        tests-usr.bin-tests     compattestfile,atf
 ./usr/tests/usr.bin/xlint/lint1/d_gcc_compound_statements1.c   tests-usr.bin-tests     compattestfile,atf
+./usr/tests/usr.bin/xlint/lint1/d_gcc_compound_statements1.exp tests-usr.bin-tests     compattestfile,atf
 ./usr/tests/usr.bin/xlint/lint1/d_gcc_compound_statements2.c   tests-usr.bin-tests     compattestfile,atf
 ./usr/tests/usr.bin/xlint/lint1/d_gcc_compound_statements3.c   tests-usr.bin-tests     compattestfile,atf
 ./usr/tests/usr.bin/xlint/lint1/d_gcc_extension.c              tests-usr.bin-tests     compattestfile,atf
diff -r 941e161f5ce2 -r 49b4f2d42072 tests/usr.bin/xlint/lint1/Makefile
--- a/tests/usr.bin/xlint/lint1/Makefile        Sat Jun 19 15:23:57 2021 +0000
+++ b/tests/usr.bin/xlint/lint1/Makefile        Sat Jun 19 15:51:11 2021 +0000
@@ -1,4 +1,4 @@
-# $NetBSD: Makefile,v 1.60 2021/06/19 08:30:08 rillig Exp $
+# $NetBSD: Makefile,v 1.61 2021/06/19 15:51:11 rillig Exp $
 
 NOMAN=         # defined
 MAX_MESSAGE=   344             # see lint1/err.c
@@ -64,6 +64,7 @@ FILES+=               d_ellipsis_in_switch.c
 FILES+=                d_fold_test.c
 FILES+=                d_fold_test.exp
 FILES+=                d_gcc_compound_statements1.c
+FILES+=                d_gcc_compound_statements1.exp
 FILES+=                d_gcc_compound_statements2.c
 FILES+=                d_gcc_compound_statements3.c
 FILES+=                d_gcc_extension.c
diff -r 941e161f5ce2 -r 49b4f2d42072 tests/usr.bin/xlint/lint1/d_gcc_compound_statements1.c
--- a/tests/usr.bin/xlint/lint1/d_gcc_compound_statements1.c    Sat Jun 19 15:23:57 2021 +0000
+++ b/tests/usr.bin/xlint/lint1/d_gcc_compound_statements1.c    Sat Jun 19 15:51:11 2021 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: d_gcc_compound_statements1.c,v 1.4 2021/03/27 13:59:18 rillig Exp $    */
+/*     $NetBSD: d_gcc_compound_statements1.c,v 1.5 2021/06/19 15:51:11 rillig Exp $    */
 # 3 "d_gcc_compound_statements1.c"
 
 /* GCC compound statement with expression */
@@ -12,3 +12,13 @@ foo(unsigned long z)
        });
        foo(z);
 }
+
+/*
+ * Compound statements are only allowed in functions, not at file scope.
+ *
+ * Before decl.c 1.186 from 2021-06-19, lint crashed with a segmentation
+ * fault.
+ */
+int c = ({
+    return 3;          /* expect: return outside function */
+});                    /* expect: cannot initialize 'int' from 'void' */
diff -r 941e161f5ce2 -r 49b4f2d42072 tests/usr.bin/xlint/lint1/d_gcc_compound_statements1.exp
--- /dev/null   Thu Jan 01 00:00:00 1970 +0000
+++ b/tests/usr.bin/xlint/lint1/d_gcc_compound_statements1.exp  Sat Jun 19 15:51:11 2021 +0000
@@ -0,0 +1,2 @@
+d_gcc_compound_statements1.c(23): error: syntax error 'return outside function' [249]
+d_gcc_compound_statements1.c(24): error: cannot initialize 'int' from 'void' [185]
diff -r 941e161f5ce2 -r 49b4f2d42072 usr.bin/xlint/lint1/decl.c
--- a/usr.bin/xlint/lint1/decl.c        Sat Jun 19 15:23:57 2021 +0000
+++ b/usr.bin/xlint/lint1/decl.c        Sat Jun 19 15:51:11 2021 +0000
@@ -1,4 +1,4 @@
-/* $NetBSD: decl.c,v 1.185 2021/06/19 14:28:04 rillig Exp $ */
+/* $NetBSD: decl.c,v 1.186 2021/06/19 15:51:11 rillig Exp $ */
 
 /*
  * Copyright (c) 1996 Christopher G. Demetriou.  All Rights Reserved.
@@ -38,7 +38,7 @@
 
 #include <sys/cdefs.h>
 #if defined(__RCSID) && !defined(lint)
-__RCSID("$NetBSD: decl.c,v 1.185 2021/06/19 14:28:04 rillig Exp $");
+__RCSID("$NetBSD: decl.c,v 1.186 2021/06/19 15:51:11 rillig Exp $");
 #endif
 
 #include <sys/param.h>
@@ -3052,7 +3052,10 @@ check_variable_usage(bool novar, sym_t *
        sym_t   *xsym;
 
        lint_assert(block_level != 0);
-       lint_assert(sym->s_block_level != 0);
+
+       /* example at file scope: int c = ({ return 3; }); */
+       if (sym->s_block_level == 0 && ch_isdigit(sym->s_name[0]))
+               return;
 
        /* errors in expressions easily cause lots of these warnings */
        if (nerr != 0)
diff -r 941e161f5ce2 -r 49b4f2d42072 usr.bin/xlint/lint1/func.c
--- a/usr.bin/xlint/lint1/func.c        Sat Jun 19 15:23:57 2021 +0000
+++ b/usr.bin/xlint/lint1/func.c        Sat Jun 19 15:51:11 2021 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: func.c,v 1.108 2021/05/15 19:12:14 rillig Exp $        */
+/*     $NetBSD: func.c,v 1.109 2021/06/19 15:51:11 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 1.108 2021/05/15 19:12:14 rillig Exp $");
+__RCSID("$NetBSD: func.c,v 1.109 2021/06/19 15:51:11 rillig Exp $");
 #endif
 
 #include <stdlib.h>
@@ -1049,7 +1049,14 @@ do_return(tnode_t *tn)
        cstk_t  *ci;
        op_t    op;
 
-       for (ci = cstmt; ci->c_surrounding != NULL; ci = ci->c_surrounding)
+       ci = cstmt;
+       if (ci == NULL) {
+               /* syntax error '%s' */
+               error(249, "return outside function");
+               return;
+       }
+
+       for (; ci->c_surrounding != NULL; ci = ci->c_surrounding)
                continue;
 
        if (tn != NULL)