| Submitter | Kamil Dudka |
|---|---|
| Date | 2009-07-18 21:34:10 |
| Message ID | <200907182334.10900.kdudka@redhat.com> |
| Download | mbox | patch |
| Permalink | /patch/36215/ |
| State | New |
| Headers | show |
Comments
On Sat, Jul 18, 2009 at 2:34 PM, Kamil Dudka<kdudka@redhat.com> wrote: > Hello, > > I've probably encountered a bug within compile-i386.c. It generates > an infinite loop for 'while' statement. My testing example and proposed > patch are enclosed. Adding Jeff to the CC list. The compile-i386.c is Jeff's pet project. The change looks good to me. I would like to give Jeff some time to comment it before I apply the patch. BTW, have you take a look at Linus's example.c? It is based on the linearized byte code and It does more advance stuff like simple register allocation. In my opinion example.c is a better place to start hacking compiler back end than compile.c Chris -- To unsubscribe from this list: send the line "unsubscribe linux-sparse" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Wed July 22 2009 10:38:43 Christopher Li wrote: > Adding Jeff to the CC list. The compile-i386.c is Jeff's pet project. > The change looks good to me. I would like to give Jeff some time > to comment it before I apply the patch. Thanks! > BTW, have you take a look at Linus's example.c? It is based on the > linearized byte code and It does more advance stuff like simple > register allocation. In my opinion example.c is a better place to start > hacking compiler back end than compile.c Linus's example.c works fine with the same test-case. I decided to take compile.c as template just because it doesn't use the linearized code. The tree structure better accomplishes my requirements for now. Maybe I'll turn to byte code in future. I've just started to play with it. Anyway SPARSE seems to be quite helpful. It's easy to read and can save a lot of development time while processing C sources. Kamil -- To unsubscribe from this list: send the line "unsubscribe linux-sparse" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Christopher Li wrote: > On Sat, Jul 18, 2009 at 2:34 PM, Kamil Dudka<kdudka@redhat.com> wrote: >> Hello, >> >> I've probably encountered a bug within compile-i386.c. It generates >> an infinite loop for 'while' statement. My testing example and proposed >> patch are enclosed. > > Adding Jeff to the CC list. The compile-i386.c is Jeff's pet project. > The change looks good to me. I would like to give Jeff some time > to comment it before I apply the patch. Acked-by: Jeff Garzik <jgarzik@redhat.com> -- To unsubscribe from this list: send the line "unsubscribe linux-sparse" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Wed, Jul 22, 2009 at 2:24 AM, Kamil Dudka<kdudka@redhat.com> wrote: > Anyway SPARSE seems to be quite helpful. It's easy to read and can save > a lot of development time while processing C sources. Just curious, what are you trying to build with sparse? A Linus filter would be pretty cool. BTW, I want to start some hacking guide for sparse. I am particular interested in what is the common pain when a new hacker try to work on sparse. Do you find sparse pretty easy to learn on? Chris -- To unsubscribe from this list: send the line "unsubscribe linux-sparse" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Oh one last thing. I need a signed-off line from you. Chris On Sat, Jul 18, 2009 at 2:34 PM, Kamil Dudka<kdudka@redhat.com> wrote: > Hello, > > I've probably encountered a bug within compile-i386.c. It generates > an infinite loop for 'while' statement. My testing example and proposed > patch are enclosed. > > Kamil > -- To unsubscribe from this list: send the line "unsubscribe linux-sparse" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Christopher Li wrote:
> Oh one last thing. I need a signed-off line from you.
I think sparse needs some text document, describing what Signed-off-by
means. I did this in one of my own projects by copying the relevant
"DCO" from kernel tree's Documentation/SubmittingPatches.
Jeff
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On Wednesday 22 of July 2009 18:34:13 Christopher Li wrote: > Just curious, what are you trying to build with sparse? A Linus filter > would be pretty cool. Sorry for my ignorance, I've never heard about the Linus filter. Could you please point me to some relevant info? For now we only want to play with separation logic and use it for static analysis of code as part of our research at FIT BUT. > BTW, I want to start some hacking guide for sparse. I am particular > interested in what is the common pain when a new hacker try to work on > sparse. Do you find sparse pretty easy to learn on? I've just written my first "hello world" SPARSE client (nothing useful yet) and I am going to write the same as gcc-4.5 plug-in and compare it with each other - what is similar, what is different etc. I haven't encountered any problem while learning SPARSE yet. The code is easy to read and the examples sufficient. Maybe worth to write some brief description of the particular examples within README? I'll come with some ideas later if any. Kamil -- To unsubscribe from this list: send the line "unsubscribe linux-sparse" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Wed, Jul 22, 2009 at 9:51 AM, Jeff Garzik<jeff@garzik.org> wrote: > Christopher Li wrote: > > I think sparse needs some text document, describing what Signed-off-by > means. I did this in one of my own projects by copying the relevant "DCO" > from kernel tree's Documentation/SubmittingPatches. Good idea. Chris -- To unsubscribe from this list: send the line "unsubscribe linux-sparse" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Wed, Jul 22, 2009 at 10:21 AM, Kamil Dudka<kdudka@redhat.com> wrote: > Sorry for my ignorance, I've never heard about the Linus filter. Could you > please point me to some relevant info? For now we only want to play with > separation logic and use it for static analysis of code as part of our > research at FIT BUT. Of course you haven't heard of it. I just make it up myself. A Linus filter is a program that take bad C code as input and output good C code as if it is written by Linus himself. We just need to hook it to LKML. Chris -- To unsubscribe from this list: send the line "unsubscribe linux-sparse" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Patch
From 60c47d120b577092f0d8fe9001ca6753706dcdbc Mon Sep 17 00:00:00 2001 From: Kamil Dudka <kdudka@redhat.com> Date: Sat, 18 Jul 2009 23:24:38 +0200 Subject: [PATCH] compile-i386: do not generate an infinite loop --- compile-i386.c | 8 ++++---- 1 files changed, 4 insertions(+), 4 deletions(-) diff --git a/compile-i386.c b/compile-i386.c index 37ea52e..abe9313 100644 --- a/compile-i386.c +++ b/compile-i386.c @@ -1913,6 +1913,10 @@ static void emit_loop(struct statement *stmt) x86_symbol_decl(stmt->iterator_syms); x86_statement(pre_statement); + if (!post_condition || post_condition->type != EXPR_VALUE || post_condition->value) { + loop_top = new_label(); + emit_label(loop_top, "loop top"); + } if (pre_condition) { if (pre_condition->type == EXPR_VALUE) { if (!pre_condition->value) { @@ -1936,10 +1940,6 @@ static void emit_loop(struct statement *stmt) insn("jz", lbv, NULL, NULL); } } - if (!post_condition || post_condition->type != EXPR_VALUE || post_condition->value) { - loop_top = new_label(); - emit_label(loop_top, "loop top"); - } x86_statement(statement); if (stmt->iterator_continue->used) emit_label(loop_continue, "'continue' iterator"); -- 1.6.3.3