[gcc/devel/c++-modules] PR middle-end/93437 - bogus -Warray-bounds on protobuf generated code

[gcc/devel/c++-modules] PR middle-end/93437 - bogus -Warray-bounds on protobuf generated code

[Nathan Sidwell]

https://gcc.gnu.org/g:4dd27b527c503aa50909fe1eb7d308266b1e103a

commit 4dd27b527c503aa50909fe1eb7d308266b1e103a
Author: Martin Sebor <msebor@redhat.com>
Date:   Tue Jan 28 14:48:52 2020 -0700

    PR middle-end/93437 - bogus -Warray-bounds on protobuf generated code
    
    gcc/testsuite/ChangeLog:
    
    	PR middle-end/93437
    	* g++.dg/warn/Wstringop-overflow-5.C: New test.

Diff:
---
 gcc/testsuite/ChangeLog                          |  5 ++++
 gcc/testsuite/g++.dg/warn/Wstringop-overflow-5.C | 37 ++++++++++++++++++++++++
 2 files changed, 42 insertions(+)

diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 8610164..279ab64 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2020-01-28  Martin Sebor  <msebor@redhat.com>
+
+	PR middle-end/93437
+	* g++.dg/warn/Wstringop-overflow-5.C: New test.a
+
 2020-01-28  Jan Hubicka  <hubicka@ucw.cz>
 
 	* g++.dg/tree-prof/indir-call-prof.C: Update template.
diff --git a/gcc/testsuite/g++.dg/warn/Wstringop-overflow-5.C b/gcc/testsuite/g++.dg/warn/Wstringop-overflow-5.C
new file mode 100644
index 0000000..3e905fc
--- /dev/null
+++ b/gcc/testsuite/g++.dg/warn/Wstringop-overflow-5.C
@@ -0,0 +1,37 @@
+/* PR middle-end/93437 - bogus -Warray-bounds on protobuf generated code
+   { dg-do compile }
+   { dg-options "-O3 -Wall" } */
+
+typedef __SIZE_TYPE__ size_t;
+typedef __UINT32_TYPE__ uint32_t;
+
+inline void* operator new (size_t, void* p)
+{
+  return p;
+}
+
+extern "C" void* memset(void*, int, size_t);
+
+struct Bucket {
+  Bucket ();
+  uint32_t _has_bits_;
+  uint32_t cumulative_count_;
+  uint32_t upper_bound_;
+};
+
+extern Bucket _Bucket_default_instance_;
+
+Bucket::Bucket ()
+{
+  memset (&_has_bits_, 0, sizeof _has_bits_);
+  memset (&cumulative_count_, 0,    // { dg-bogus "\\\[-Warray-bounds|-wstringop-overflow" }
+	 static_cast<size_t>(reinterpret_cast<char*>(&upper_bound_)
+			     - reinterpret_cast<char*>(&cumulative_count_))
+	 + sizeof upper_bound_);
+}
+
+void* InitDefaultsBucket ()
+{
+  void* ptr = &::_Bucket_default_instance_;
+  return new (ptr)::Bucket();
+}