From: David Malcolm <dmalcolm@redhat.com>
To: jit@gcc.gnu.org, gcc-patches@gcc.gnu.org
Cc: David Malcolm <dmalcolm@redhat.com>
Subject: [PATCH, committed] jit: Add checking for dereference of void *
Date: Thu, 08 Jan 2015 01:11:00 -0000 [thread overview]
Message-ID: <1420680029-46138-1-git-send-email-dmalcolm@redhat.com> (raw)
Reject attempts to dereference a void *, otherwise we get an ICE
deep inside gimplification.
Committed to trunk as r219333.
FWIW, I ran into this as part of experiments at writing a libgccjit
backend for PyPy; see
https://bitbucket.org/pypy/pypy/branch/libgccjit-backend
In particular, the testcase is a simplified version of a buggy
version of what became:
https://bitbucket.org/pypy/pypy/commits/72cda48c154f1bcefec8b5db7c7a84d542c52938
gcc/jit/ChangeLog:
* jit-recording.h (gcc::jit::recording::type::is_void): New
virtual function.
(gcc::jit::recording::memento_of_get_type::is_void): New
function, overriding default implementation.
* libgccjit.c (gcc_jit_rvalue_dereference): Verify that
the underlying type is not "void".
gcc/testsuite/ChangeLog:
* jit.dg/test-error-dereferencing-void-ptr.c: New test case.
---
gcc/jit/jit-recording.h | 2 +
gcc/jit/libgccjit.c | 7 ++
.../jit.dg/test-error-dereferencing-void-ptr.c | 96 ++++++++++++++++++++++
3 files changed, 105 insertions(+)
create mode 100644 gcc/testsuite/jit.dg/test-error-dereferencing-void-ptr.c
diff --git a/gcc/jit/jit-recording.h b/gcc/jit/jit-recording.h
index 3734e9a..9034e11 100644
--- a/gcc/jit/jit-recording.h
+++ b/gcc/jit/jit-recording.h
@@ -443,6 +443,7 @@ public:
virtual bool is_bool () const = 0;
virtual type *is_pointer () = 0;
virtual type *is_array () = 0;
+ virtual bool is_void () const { return false; }
bool is_numeric () const
{
@@ -494,6 +495,7 @@ public:
bool is_bool () const;
type *is_pointer () { return dereference (); }
type *is_array () { return NULL; }
+ bool is_void () const { return m_kind == GCC_JIT_TYPE_VOID; }
public:
void replay_into (replayer *r);
diff --git a/gcc/jit/libgccjit.c b/gcc/jit/libgccjit.c
index 6853bb0..99b2d56 100644
--- a/gcc/jit/libgccjit.c
+++ b/gcc/jit/libgccjit.c
@@ -1664,6 +1664,13 @@ gcc_jit_rvalue_dereference (gcc_jit_rvalue *rvalue,
rvalue->get_debug_string (),
rvalue->get_type ()->get_debug_string ());
+ RETURN_NULL_IF_FAIL_PRINTF2 (
+ !underlying_type->is_void (),
+ rvalue->m_ctxt, loc,
+ "dereference of void pointer %s (type: %s)",
+ rvalue->get_debug_string (),
+ rvalue->get_type ()->get_debug_string ());
+
return (gcc_jit_lvalue *)rvalue->dereference (loc);
}
diff --git a/gcc/testsuite/jit.dg/test-error-dereferencing-void-ptr.c b/gcc/testsuite/jit.dg/test-error-dereferencing-void-ptr.c
new file mode 100644
index 0000000..a813f67
--- /dev/null
+++ b/gcc/testsuite/jit.dg/test-error-dereferencing-void-ptr.c
@@ -0,0 +1,96 @@
+#include <libgccjit.h>
+#include "harness.h"
+
+void
+create_code (gcc_jit_context *ctxt, void *user_data)
+{
+ /* Replay of API calls for ctxt. */
+ gcc_jit_type *type_long_long =
+ gcc_jit_context_get_type (ctxt, GCC_JIT_TYPE_LONG_LONG);
+ gcc_jit_type *type_void =
+ gcc_jit_context_get_type (ctxt, GCC_JIT_TYPE_VOID);
+ gcc_jit_type *type_void_ptr =
+ gcc_jit_context_get_type (ctxt, GCC_JIT_TYPE_VOID_PTR);
+ gcc_jit_field *field_u_signed =
+ gcc_jit_context_new_field (ctxt,
+ NULL, /* gcc_jit_location *loc */
+ type_long_long, /* gcc_jit_type *type, */
+ "u_signed"); /* const char *name */
+ gcc_jit_field *field_u_ptr =
+ gcc_jit_context_new_field (ctxt,
+ NULL, /* gcc_jit_location *loc */
+ type_void_ptr, /* gcc_jit_type *type, */
+ "u_ptr"); /* const char *name */
+ gcc_jit_field *fields_for_union_any[2] = {
+ field_u_signed,
+ field_u_ptr,
+ };
+ gcc_jit_type *union_any =
+ gcc_jit_context_new_union_type (ctxt,
+ NULL, /* gcc_jit_location *loc */
+ "any", /* const char *name */
+ 2, /* int num_fields */
+ fields_for_union_any);
+ gcc_jit_function *func =
+ gcc_jit_context_new_function (ctxt, /* gcc_jit_context *ctxt */
+ NULL, /* gcc_jit_location *loc */
+ GCC_JIT_FUNCTION_EXPORTED,
+ type_void, /* gcc_jit_type *return_type */
+ "anonloop_0", /* const char *name */
+ 0, /* int num_params */
+ NULL, /* gcc_jit_param **params */
+ 0); /* int is_variadic */
+ gcc_jit_block *block_initial =
+ gcc_jit_function_new_block (func, "initial");
+
+ gcc_jit_lvalue *local_tmp =
+ gcc_jit_function_new_local (func, /* gcc_jit_function *func */
+ NULL, /* gcc_jit_location *loc */
+ union_any, /* gcc_jit_type *type */
+ "tmp"); /* const char *name */
+
+ /* "tmp.u_signed = 0x213d640;" */
+ gcc_jit_block_add_assignment (
+ block_initial, /*gcc_jit_block *block */
+ NULL, /* gcc_jit_location *loc */
+ gcc_jit_lvalue_access_field (local_tmp, /*gcc_jit_lvalue *struct_or_union */
+ NULL, /*gcc_jit_location *loc */
+ field_u_signed),
+ gcc_jit_context_new_rvalue_from_long (
+ ctxt, /* gcc_jit_context *ctxt */
+ type_long_long, /* gcc_jit_type *numeric_type */
+ 0x213d640)); /* long value */
+
+ /* "(*tmp.u_ptr) += 1;" which can't be done since u_ptr is a (void *). */
+ gcc_jit_block_add_assignment_op (
+ block_initial, /*gcc_jit_block *block */
+ NULL, /* gcc_jit_location *loc */
+ /* "(*tmp.u_ptr)". */
+ gcc_jit_rvalue_dereference (
+ gcc_jit_lvalue_as_rvalue (
+ gcc_jit_lvalue_access_field (
+ local_tmp, /*gcc_jit_lvalue *struct_or_union */
+ NULL, /*gcc_jit_location *loc */
+ field_u_ptr)),
+ NULL), /* gcc_jit_location *loc */
+ GCC_JIT_BINARY_OP_PLUS, /* enum gcc_jit_binary_op op */
+ gcc_jit_context_new_rvalue_from_int (
+ ctxt, /* gcc_jit_context *ctxt */
+ type_long_long, /* gcc_jit_type *numeric_type */
+ 1)); /* int value */
+
+ gcc_jit_block_end_with_void_return (block_initial, /*gcc_jit_block *block */
+ NULL);
+}
+
+void
+verify_code (gcc_jit_context *ctxt, gcc_jit_result *result)
+{
+ CHECK_VALUE (result, NULL);
+
+ /* Verify that the correct error message was emitted. */
+ CHECK_STRING_VALUE (gcc_jit_context_get_first_error (ctxt),
+ "gcc_jit_rvalue_dereference:"
+ " dereference of void pointer tmp.u_ptr"
+ " (type: void *)");
+}
--
1.8.5.3
reply other threads:[~2015-01-08 1:11 UTC|newest]
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