RISC-V V C Intrinsic API v1.0 release meeting reminder (September 05th, 2023)

[Eop Chen via Gcc]

Hi all,

Since 09/04 is Labor Day in the States and people may not be able to attend, 
the meeting is postponed one day later, to 09/05,  of the same time slot.

A reminder that the next open meeting to discuss on the RISC-V V C Intrinsic 
API v1.0 is going to
be held tomorrow on 2023/09/05 7AM (GMT -7) / 10PM (GMT +8).

The agenda can be found in the second page of the meeting slides (link 
).
Please join the calendar to be constantly notified - Google calender link 
,
 ICal 

We also have a mailing list now hosted by RISC-V International (link 
).

Regards,

eop Chen

Relocations to odd addresses in .eh_frame section

[Vincent Rivière]

Hi,

By looking at the sections generated by m68k-elf-g++, I noticed there 
was relocations to odd addresses in the .eh_frame section. Is this 
expected? Is there a way to avoid that, maybe by adding some padding?


Actually, I would like to upgrade the experimental m68k-atari-mintelf 
toolchain from SJ/LJ exceptions to DWARF2. But the operating system 
can't handle relocations to odd addresses. So I wonder if there is a 
solution.


Cheers,

--
Vincent Rivière

Re: Relocations to odd addresses in .eh_frame section

[Andreas Schwab via Gcc]

On Sep 04 2023, Vincent Rivière wrote:

> By looking at the sections generated by m68k-elf-g++, I noticed there was
> relocations to odd addresses in the .eh_frame section. Is this expected?
> Is there a way to avoid that, maybe by adding some padding?

I think you need to change ASM_PREFERRED_EH_DATA_FORMAT to use
DW_EH_PE_aligned instead of DW_EH_PE_absptr.

-- 
Andreas Schwab, SUSE Labs, sch...@suse.de
GPG Key fingerprint = 0196 BAD8 1CE9 1970 F4BE  1748 E4D4 88E3 0EEA B9D7
"And now for something completely different."

[PATCH] analyzer: implement symbolic value support for CPython plugin's refcnt checker [PR107646]

[Eric Feng via Gcc]

Hi Dave,

Recently I've been working on symbolic value support for the reference
count checker. I've attached a patch for it below; let me know it looks
OK for trunk. Thanks!

Best,
Eric

---

This patch enhances the reference count checker in the CPython plugin by
adding support for symbolic values. Whereas previously we were only able
to check the reference count of PyObject* objects created in the scope
of the function; we are now able to emit diagnostics on reference count
mismatch of objects that were, for example, passed in as a function
parameter.

rc6.c:6:10: warning: expected ‘obj’ to have reference count: N + ‘1’ but 
ob_refcnt field is N + ‘2’
6 |   return obj;
  |  ^~~
  ‘create_py_object2’: event 1
|
|6 |   return obj;
|  |  ^~~
|  |  |
|  |  (1) here
|


gcc/testsuite/ChangeLog:
PR analyzer/107646
* gcc.dg/plugin/analyzer_cpython_plugin.c: Support reference count 
checking
of symbolic values.
* gcc.dg/plugin/cpython-plugin-test-PyList_Append.c: New test.
* gcc.dg/plugin/plugin.exp: New test.
* gcc.dg/plugin/cpython-plugin-test-refcnt.c: New test.

Signed-off-by: Eric Feng 

---
 .../gcc.dg/plugin/analyzer_cpython_plugin.c   | 133 +++---
 .../cpython-plugin-test-PyList_Append.c   |  21 ++-
 .../plugin/cpython-plugin-test-refcnt.c   |  18 +++
 gcc/testsuite/gcc.dg/plugin/plugin.exp|   1 +
 4 files changed, 118 insertions(+), 55 deletions(-)
 create mode 100644 gcc/testsuite/gcc.dg/plugin/cpython-plugin-test-refcnt.c

diff --git a/gcc/testsuite/gcc.dg/plugin/analyzer_cpython_plugin.c 
b/gcc/testsuite/gcc.dg/plugin/analyzer_cpython_plugin.c
index bf1982e79c3..d7ecd7fce09 100644
--- a/gcc/testsuite/gcc.dg/plugin/analyzer_cpython_plugin.c
+++ b/gcc/testsuite/gcc.dg/plugin/analyzer_cpython_plugin.c
@@ -314,17 +314,20 @@ public:
   {
 diagnostic_metadata m;
 bool warned;
-// just assuming constants for now
-auto actual_refcnt
-   = m_actual_refcnt->dyn_cast_constant_svalue ()->get_constant ();
-auto ob_refcnt = m_ob_refcnt->dyn_cast_constant_svalue ()->get_constant ();
-warned = warning_meta (rich_loc, m, get_controlling_option (),
-  "expected %qE to have "
-  "reference count: %qE but ob_refcnt field is: %qE",
-  m_reg_tree, actual_refcnt, ob_refcnt);
-
-// location_t loc = rich_loc->get_loc ();
-// foo (loc);
+
+const auto *actual_refcnt_constant
+   = m_actual_refcnt->dyn_cast_constant_svalue ();
+const auto *ob_refcnt_constant = m_ob_refcnt->dyn_cast_constant_svalue ();
+if (!actual_refcnt_constant || !ob_refcnt_constant)
+  return false;
+
+auto actual_refcnt = actual_refcnt_constant->get_constant ();
+auto ob_refcnt = ob_refcnt_constant->get_constant ();
+warned = warning_meta (
+   rich_loc, m, get_controlling_option (),
+   "expected %qE to have "
+   "reference count: N + %qE but ob_refcnt field is N + %qE",
+   m_reg_tree, actual_refcnt, ob_refcnt);
 return warned;
   }
 
@@ -336,10 +339,6 @@ public:
 
 private:
 
-  void foo(location_t loc) const 
-  {
-inform(loc, "something is up right here");
-  }
   const region *m_base_region;
   const svalue *m_ob_refcnt;
   const svalue *m_actual_refcnt;
@@ -369,6 +368,19 @@ increment_region_refcnt (hash_map 
&map, const region *key)
   refcnt = existed ? refcnt + 1 : 1;
 }
 
+static const region *
+get_region_from_svalue (const svalue *sval, region_model_manager *mgr)
+{
+  const auto *region_sval = sval->dyn_cast_region_svalue ();
+  if (region_sval)
+return region_sval->get_pointee ();
+
+  const auto *initial_sval = sval->dyn_cast_initial_svalue ();
+  if (initial_sval)
+return mgr->get_symbolic_region (initial_sval);
+
+  return nullptr;
+}
 
 /* Recursively fills in region_to_refcnt with the references owned by
pyobj_ptr_sval.  */
@@ -381,20 +393,9 @@ count_pyobj_references (const region_model *model,
   if (!pyobj_ptr_sval)
 return;
 
-  const auto *pyobj_region_sval = pyobj_ptr_sval->dyn_cast_region_svalue ();
-  const auto *pyobj_initial_sval = pyobj_ptr_sval->dyn_cast_initial_svalue ();
-  if (!pyobj_region_sval && !pyobj_initial_sval)
-return;
-
-  // todo: support initial sval (e.g passed in as parameter)
-  if (pyobj_initial_sval)
-{
-  // increment_region_refcnt (region_to_refcnt,
-  //  pyobj_initial_sval->get_region ());
-  return;
-}
+  region_model_manager *mgr = model->get_manager ();
 
-  const region *pyobj_region = pyobj_region_sval->get_pointee ();
+  const region *pyobj_region = get_region_from_svalue (pyobj_ptr_sval, mgr);
   if (!pyobj_region || seen.contains (pyobj_region))
 return;
 
@@ -409,49 +410,75 @@ count_pyobj_references (const region_model *model,
 return;
 
   const auto &retval_binding_map = retval_cluster->get_map ();
-
   fo