Patchwork C++ PATCH for c++/55893 (segfault running destructor on rodata)

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Submitter Jason Merrill
Date Jan. 9, 2013, 6:04 p.m.
Message ID <50EDB115.10507@redhat.com>
Download mbox | patch
Permalink /patch/210810/
State New
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Comments

Jason Merrill - Jan. 9, 2013, 6:04 p.m.
My fix for PR 49673 made it so that objects with constant initialization 
semantics through constexpr can go into rodata now.  But objects with 
non-trivial destruction semantics still need to go into writable data so 
that the destructor can modify the object.

Tested x86_64-pc-linux-gnu, applying to trunk and 4.7.

Patch

commit f7142c9ff05259adbda2cb5797088b6a2c281ad9
Author: Jason Merrill <jason@redhat.com>
Date:   Wed Jan 9 11:44:13 2013 -0500

    	PR c++/55893
    	* decl.c (cp_finish_decl): Clear TREE_READONLY if the variable
    	needs destruction.

diff --git a/gcc/cp/decl.c b/gcc/cp/decl.c
index 9640824..c3622ec 100644
--- a/gcc/cp/decl.c
+++ b/gcc/cp/decl.c
@@ -6417,6 +6417,10 @@  cp_finish_decl (tree decl, tree init, bool init_const_expr_p,
 	    }
 	  else if (was_readonly)
 	    TREE_READONLY (decl) = 1;
+
+	  /* Likewise if it needs destruction.  */
+	  if (TYPE_HAS_NONTRIVIAL_DESTRUCTOR (type))
+	    TREE_READONLY (decl) = 0;
 	}
 
       make_rtl_for_nonlocal_decl (decl, init, asmspec);
diff --git a/gcc/testsuite/g++.dg/init/const9.C b/gcc/testsuite/g++.dg/init/const9.C
new file mode 100644
index 0000000..ba1dfd4
--- /dev/null
+++ b/gcc/testsuite/g++.dg/init/const9.C
@@ -0,0 +1,12 @@ 
+// PR c++/55893
+// { dg-final { scan-assembler-not "rodata" } }
+
+struct foo
+{
+  virtual ~foo ();
+};
+
+int main ()
+{
+  static const foo tmp;
+}