Attached is a patch fixing the ICE caused by a prior change of mine:
https://gcc.gnu.org/viewcvs/gcc?view=revision&revision=230081 Tested on x86_64, committing to trunk as per Jason via IRC. Martin gcc/ChangeLog: 2015-11-17 Martin Sebor <mse...@redhat.com> PR c++/68308 * cp/init.c (build_new_1): Check for expression constness the right way. testsuite/ChangeLog: 2015-11-17 Martin Sebor <mse...@redhat.com> PR c++/68308 * g++.dg/init/new46.C: New test.
Index: gcc/cp/init.c =================================================================== --- gcc/cp/init.c (revision 230463) +++ gcc/cp/init.c (working copy) @@ -2715,7 +2715,7 @@ size = size_binop (MULT_EXPR, size, fold_convert (sizetype, nelts)); - if (TREE_CONSTANT (outer_nelts)) + if (INTEGER_CST == TREE_CODE (outer_nelts)) { if (tree_int_cst_lt (max_outer_nelts_tree, outer_nelts)) { @@ -3330,7 +3330,8 @@ non-class type and its value before converting to std::size_t is less than zero. ... If the expression is a constant expression, the program is ill-fomed. */ - if (TREE_CONSTANT (cst_nelts) && tree_int_cst_sgn (cst_nelts) == -1) + if (INTEGER_CST == TREE_CODE (cst_nelts) + && tree_int_cst_sgn (cst_nelts) == -1) { if (complain & tf_error) error ("size of array is negative"); Index: gcc/testsuite/g++.dg/init/new46.C =================================================================== --- gcc/testsuite/g++.dg/init/new46.C (revision 0) +++ gcc/testsuite/g++.dg/init/new46.C (working copy) @@ -0,0 +1,65 @@ +// { dg-do compile } +// { dg-options "-Wall" } + +// Test for c++/68308 - [6 Regression] ICE: tree check: expected integer_cst, +// have var_decl in decompose, at tree.h:5105 + +typedef __typeof__ (sizeof 0) size_t; + +// Not defined, only referenced in templates that aren't expected +// to be instantiated to make sure they really aren't to verify +// verify c++/68308. +template <class T> void inst_check (); + +// Not instantiated (must not be diagnosed). +template <class T> +char* fn1_x () { + const size_t a = sizeof (T); + return inst_check<T>() ? new char [a] : 0; +} + +// Not instantiated (must not be diagnosed). +template <size_t N> +char* fn2_1_x () { + return inst_check<char [N]>() ? new char [N] : 0; +} + +template <size_t N> +char* fn2_1 () { + return new char [N]; +} + +// Not instantiated (must not be diagnosed). +template <size_t M, size_t N> +char* fn2_2_x () { + return inst_check<char [M][N]>() ? new char [M][N] : 0; +} + +template <size_t M, size_t N> +char* fn2_2 () { + return new char [M][N]; // { dg-error "size of array is too large" } +} + +// Not instantiated (must not be diagnosed). +template <class T> +T* fn3_x () { + const size_t a = sizeof (T); + return inst_check<T>() ? new T [a] : 0; +} + +template <class T> +T* fn3 () { + const size_t a = sizeof (T); + return new T [a]; // { dg-error "size of array is too large" } +} + + +struct S { char a [__SIZE_MAX__ / 8]; }; + +void foo () +{ + fn2_1<1>(); + fn2_1<__SIZE_MAX__ / 4>(); + fn2_2<__SIZE_MAX__ / 4, 4>(); + fn3<S>(); +}