------- Comment #62 from rguenth at gcc dot gnu dot org 2007-05-14 16:20 ------- We ICE with
template <class T, class T2, int D> class Vector { public: Vector() { for (int i = 0; i < D; ++i) new (&x_m[i]) T2(); } T2& operator[](int i) { return *reinterpret_cast<T2*>(&x_m[i]); } private: T x_m[D]; }; void foo(Vector<double, long, 3> *m) { Vector<double, long, 3> v; v[0] = 1; v[1] = 2; v[2] = 3; *m = v; } (adjust the storage type to be of same size for double/long): Program received signal SIGSEGV, Segmentation fault. 0x0000000000b11a5e in unmodifiable_var_p (var=0x0) at /space/rguenther/src/svn/trunk/gcc/tree-flow-inline.h:1598 1598 if (TREE_CODE (var) == SSA_NAME) #0 0x0000000000b11a5e in unmodifiable_var_p (var=0x0) at /space/rguenther/src/svn/trunk/gcc/tree-flow-inline.h:1598 #1 0x0000000000b194c3 in may_alias_p (ptr=0x2b537d358210, mem_alias_set=2, var=0x2b537d359e00, var_alias_set=3, alias_set_only=0 '\0') at /space/rguenther/src/svn/trunk/gcc/tree-ssa-alias.c:2685 #2 0x0000000000b17f2b in add_flow_insensitive_var_aliases (ai=0x14d7890, pvar=0x2b537d358210, set=2, tag=0x2b537d356ba0) at /space/rguenther/src/svn/trunk/gcc/tree-ssa-alias.c:2190 #3 0x0000000000b184d3 in compute_change_dynamic_type_aliasing ( vcdt=0x2b537d357a00, vai=0x14d7890) at /space/rguenther/src/svn/trunk/gcc/tree-ssa-alias.c:2242 #4 0x000000000098a387 in pointer_set_traverse (pset=0x14e4e10, fn=0xb17f84 <compute_change_dynamic_type_aliasing>, data=0x14d7890) at /space/rguenther/src/svn/trunk/gcc/pointer-set.c:181 #5 0x0000000000b18719 in compute_flow_insensitive_aliasing (ai=0x14d7890) at /space/rguenther/src/svn/trunk/gcc/tree-ssa-alias.c:2295 #6 0x0000000000b15b17 in compute_may_aliases () where in may_alias_p the ptr we passed does not have a symbol memory tag associated. (but var is SFT.3) -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=29286