Fwd: [PATCH] pedantic warning behavior when casting void* to ptr-to-func, 4.8 and 4.9
Hi,
could you please consider this patch for the upcoming LTS? I've just
started a thread in the gcc-patches list.
Thanks,
Daniel.
---------- Forwarded message ----------
From: Daniel Gutson <daniel.gutson@tallertechnologies.com>
Date: Tue, Apr 1, 2014 at 10:43 AM
Subject: [PATCH] pedantic warning behavior when casting void* to
ptr-to-func, 4.8 and 4.9
To: gcc Mailing List <gcc@gcc.gnu.org>
Hi,
I observed two different behaviors in gcc 4.8.2 and 4.9 regarding
the same issue, IMO both erroneous.
Regarding 4.8.2, #pragma GCC diagnostic ignored "-pedantic" doesn't
work in cases such as:
void* p = 0;
#pragma GCC diagnostic ignored "-pedantic"
F* f2 = reinterpret_cast<F*>(p);
(see testcase in the patch).
The attached patch attempts to fix this issue. Since I no longer have
write access, please
apply this for me if correct (is the 4.8 branch still alive for adding fixes?).
Regarding 4.9, gcc fails to complain at all when -pedantic is passed,
even specifying -std=c++03.
Please let me know if this is truly a bug, in which case I could also
fix it for the latest version as well
(if so, please let me know if I should look into trunk or any other branch).
Thanks,
Daniel.
2014-03-31 Daniel Gutson <daniel.gutson@tallertechnologies.com>
gcc/cp/
* typeck.c (build_reinterpret_cast_1): Pass proper argument to
warn() in pedantic.
gcc/testsuite/g++.dg/
* diagnostic/pedantic.C: New test case.
--
Daniel F. Gutson
Chief Engineering Officer, SPD
San Lorenzo 47, 3rd Floor, Office 5
Córdoba, Argentina
Phone: +54 351 4217888 / +54 351 4218211
Skype: dgutson
--- gcc-4.8.2-orig/gcc/cp/typeck.c 2014-03-31 22:29:42.736367936 -0300
+++ gcc-4.8.2/gcc/cp/typeck.c 2014-03-31 14:26:43.536747050 -0300
@@ -6639,7 +6639,7 @@
where possible, and it is necessary in some cases. DR 195
addresses this issue, but as of 2004/10/26 is still in
drafting. */
- warning (0, "ISO C++ forbids casting between pointer-to-function and pointer-to-object");
+ warning (OPT_Wpedantic, "ISO C++ forbids casting between pointer-to-function and pointer-to-object");
return fold_if_not_in_template (build_nop (type, expr));
}
else if (TREE_CODE (type) == VECTOR_TYPE)
--- gcc-4.8.2-orig/gcc/testsuite/g++.dg/diagnostic/pedantic.C 1969-12-31 21:00:00.000000000 -0300
+++ gcc-4.8.2/gcc/testsuite/g++.dg/diagnostic/pedantic.C 2014-03-31 17:24:42.532607344 -0300
@@ -0,0 +1,12 @@
+// { dg-do compile }
+// { dg-options "-pedantic" }
+typedef void F(void);
+
+void foo()
+{
+ void* p = 0;
+ F* f1 = reinterpret_cast<F*>(p); // { dg-warning "ISO" }
+#pragma GCC diagnostic ignored "-pedantic"
+ F* f2 = reinterpret_cast<F*>(p);
+}
+
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