* [PATCH] Print an error if typeof() lacks an argument
@ 2009-04-25 11:03 Martin Nagy
2009-04-25 11:11 ` Martin Nagy
2009-04-27 6:38 ` Christopher Li
0 siblings, 2 replies; 4+ messages in thread
From: Martin Nagy @ 2009-04-25 11:03 UTC (permalink / raw)
To: linux-sparse
We weren't checking if the initializer isn't NULL, which caused sparse
to segfault later on when performing lazy evaluation in classify_type().
Signed-off-by: Martin Nagy <nagy.martin@gmail.com>
---
parse.c | 17 +++++++++++------
1 files changed, 11 insertions(+), 6 deletions(-)
diff --git a/parse.c b/parse.c
index 9662122..18cfaef 100644
--- a/parse.c
+++ b/parse.c
@@ -924,12 +924,17 @@ static struct token *typeof_specifier(struct token *token, struct decl_state *ct
ctx->ctype.base_type = sym->ctype.base_type;
apply_ctype(token->pos, &sym->ctype, &ctx->ctype);
} else {
- struct symbol *typeof_sym = alloc_symbol(token->pos, SYM_TYPEOF);
- token = parse_expression(token->next, &typeof_sym->initializer);
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH] Print an error if typeof() lacks an argument
2009-04-25 11:03 [PATCH] Print an error if typeof() lacks an argument Martin Nagy
@ 2009-04-25 11:11 ` Martin Nagy
2009-04-27 6:38 ` Christopher Li
1 sibling, 0 replies; 4+ messages in thread
From: Martin Nagy @ 2009-04-25 11:11 UTC (permalink / raw)
To: linux-sparse
[-- Attachment #1: Type: text/plain, Size: 425 bytes --]
Martin Nagy wrote:
>
> We weren't checking if the initializer isn't NULL, which caused sparse
> to segfault later on when performing lazy evaluation in classify_type().
>
> Signed-off-by: Martin Nagy <nagy.martin@gmail.com>
I accidentally sent this from my work email address, which is
different than the sign-off address, sorry. I'm not sure if that's
an issue, but just to make sure, I'm sending the patch again.
Martin
[-- Attachment #2: 0001-Print-an-error-if-typeof-lacks-an-argument.patch --]
[-- Type: text/x-patch, Size: 941 bytes --]
From 962e4b1ad3b3cb13c7427d07dfa44cd15af11693 Mon Sep 17 00:00:00 2001
From: Martin Nagy <nagy.martin@gmail.com>
Date: Sat, 25 Apr 2009 12:56:33 +0200
Subject: [PATCH] Print an error if typeof() lacks an argument
We weren't checking if the initializer isn't NULL, which caused sparse
to segfault later on when performing lazy evaluation in classify_type().
Signed-off-by: Martin Nagy <nagy.martin@gmail.com>
---
parse.c | 17 +++++++++++------
1 files changed, 11 insertions(+), 6 deletions(-)
diff --git a/parse.c b/parse.c
index 9662122..18cfaef 100644
--- a/parse.c
+++ b/parse.c
@@ -924,12 +924,17 @@ static struct token *typeof_specifier(struct token *token, struct decl_state *ct
ctx->ctype.base_type = sym->ctype.base_type;
apply_ctype(token->pos, &sym->ctype, &ctx->ctype);
} else {
- struct symbol *typeof_sym = alloc_symbol(token->pos, SYM_TYPEOF);
- token = parse_expression(token->next, &typeof_sym->initializer);
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH] Print an error if typeof() lacks an argument
2009-04-25 11:03 [PATCH] Print an error if typeof() lacks an argument Martin Nagy
2009-04-25 11:11 ` Martin Nagy
@ 2009-04-27 6:38 ` Christopher Li
2009-04-27 9:15 ` Martin Nagy
1 sibling, 1 reply; 4+ messages in thread
From: Christopher Li @ 2009-04-27 6:38 UTC (permalink / raw)
To: Martin Nagy; +Cc: linux-sparse
On Sat, Apr 25, 2009 at 4:03 AM, Martin Nagy <mnagy@redhat.com> wrote:
>
> We weren't checking if the initializer isn't NULL, which caused sparse
> to segfault later on when performing lazy evaluation in classify_type().
>
> Signed-off-by: Martin Nagy <nagy.martin@gmail.com>
> ---
> parse.c | 17 +++++++++++------
> 1 files changed, 11 insertions(+), 6 deletions(-)
>
> diff --git a/parse.c b/parse.c
> index 9662122..18cfaef 100644
> --- a/parse.c
> +++ b/parse.c
> @@ -924,12 +924,17 @@ static struct token *typeof_specifier(struct token *token, struct decl_state *ct
> ctx->ctype.base_type = sym->ctype.base_type;
> apply_ctype(token->pos, &sym->ctype, &ctx->ctype);
> } else {
> - struct symbol *typeof_sym = alloc_symbol(token->pos, SYM_TYPEOF);
> - token = parse_expression(token->next, &typeof_sym->initializer);
> -
> - typeof_sym->endpos = token->pos;
> - ctx->ctype.base_type = typeof_sym;
> - }
> + struct expression *expr;
I think you want expr = NULL here. Otherwise if(expr) will pick up crap.
I would just add two lines after "token =
parse_expression(token->next, &typeof_sym->initializer);"
if (!type->initializer)
sparse_error(token->pos, "expected expression after the '(' token");
If there is compile error, the sparse should not continue the later
stage any way.
BTW, can you add a validation test case which will trigger the bug?
Thanks
Chris
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^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] Print an error if typeof() lacks an argument
2009-04-27 6:38 ` Christopher Li
@ 2009-04-27 9:15 ` Martin Nagy
0 siblings, 0 replies; 4+ messages in thread
From: Martin Nagy @ 2009-04-27 9:15 UTC (permalink / raw)
To: Christopher Li; +Cc: linux-sparse
[-- Attachment #1: Type: text/plain, Size: 1532 bytes --]
Christopher Li wrote:
> On Sat, Apr 25, 2009 at 4:03 AM, Martin Nagy <mnagy@redhat.com> wrote:
> > + struct expression *expr;
>
> I think you want expr = NULL here. Otherwise if(expr) will pick up crap.
Right. I somehow assumed that parse_expression() will set it to NULL in
case there is not any expression. I attached a new patch which fixes
this.
> I would just add two lines after "token =
> parse_expression(token->next, &typeof_sym->initializer);"
>
> if (!type->initializer)
> sparse_error(token->pos, "expected expression after the '(' token");
>
> If there is compile error, the sparse should not continue the later
> stage any way.
That won't work. sparse_error() will not exit, and sparse will still
segfault later, so we have to return from the function. You could
instead do something like this:
if (!typeof_sym->initializer) {
sparse_error(token->pos, "expected ...");
return expect(token, ')', "after typeof");
}
Or use a goto to jump to the return statement. In any case, I didn't
want to repeat the code and cause a memory leak. And I didn't want to
use a goto. I guess that it's ultimately a matter of style. If you
think the memory leak would be acceptable I can rework the patch again.
The leak would only occur in this specific case, so I guess maybe it
would be acceptable, but I wasn't sure so I rather went with this
approach.
> BTW, can you add a validation test case which will trigger the bug?
Yup, it's in the new patch.
Martin
[-- Attachment #2: 0001-Print-an-error-if-typeof-lacks-an-argument.patch --]
[-- Type: text/x-patch, Size: 2018 bytes --]
From bbd2e88cdd9d36d47ce50204d18547e08f2e2bea Mon Sep 17 00:00:00 2001
From: Martin Nagy <nagy.martin@gmail.com>
Date: Mon, 27 Apr 2009 10:48:50 +0200
Subject: [PATCH] Print an error if typeof() lacks an argument
We weren't checking if the initializer isn't NULL, which caused sparse
to segfault later on when performing lazy evaluation in classify_type().
Signed-off-by: Martin Nagy <nagy.martin@gmail.com>
---
parse.c | 17 +++++++++++------
validation/bad-typeof.c | 15 +++++++++++++++
2 files changed, 26 insertions(+), 6 deletions(-)
create mode 100644 validation/bad-typeof.c
diff --git a/parse.c b/parse.c
index 9662122..604e528 100644
--- a/parse.c
+++ b/parse.c
@@ -924,12 +924,17 @@ static struct token *typeof_specifier(struct token *token, struct decl_state *ct
ctx->ctype.base_type = sym->ctype.base_type;
apply_ctype(token->pos, &sym->ctype, &ctx->ctype);
} else {
- struct symbol *typeof_sym = alloc_symbol(token->pos, SYM_TYPEOF);
- token = parse_expression(token->next, &typeof_sym->initializer);
-
- typeof_sym->endpos = token->pos;
- ctx->ctype.base_type = typeof_sym;
- }
+ struct expression *expr = NULL;
+ token = parse_expression(token->next, &expr);
+ if (expr) {
+ struct symbol *typeof_sym = alloc_symbol(token->pos, SYM_TYPEOF);
+ typeof_sym->endpos = token->pos;
+ typeof_sym->initializer = expr;
+ ctx->ctype.base_type = typeof_sym;
+ } else {
+ sparse_error(token->pos, "expected expression after the '(' token");
+ }
+ }
return expect(token, ')', "after typeof");
}
diff --git a/validation/bad-typeof.c b/validation/bad-typeof.c
new file mode 100644
index 0000000..5c27de4
--- /dev/null
+++ b/validation/bad-typeof.c
@@ -0,0 +1,15 @@
+static int fun(void)
+{
+ typeof() a;
+ int b;
+
+ a = b;
+}
+/*
+ * check-name: Bad typeof syntax segfault
+ *
+ * check-error-start
+bad-typeof.c:3:16: error: expected expression after the '(' token
+bad-typeof.c:6:9: error: identifier 'a' has no type
+ * check-error-end
+ */
--
1.6.0.6
^ permalink raw reply related [flat|nested] 4+ messages in thread
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2009-04-25 11:03 [PATCH] Print an error if typeof() lacks an argument Martin Nagy
2009-04-25 11:11 ` Martin Nagy
2009-04-27 6:38 ` Christopher Li
2009-04-27 9:15 ` Martin Nagy
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