On Mon, Jan 18, 2016 at 10:28 AM, Prathamesh Kulkarni <prathamesh.kulka...@linaro.org> wrote: > On 17 January 2016 at 14:56, Prathamesh Kulkarni > <prathamesh.kulka...@linaro.org> wrote: >> Hi, >> I was having a look at PR69133. >> It appears that with -flto-partition=none, >> cgraph_node::get_untransformed_body () >> is called twice for node with asm_name _ZThn4_N11xercesc_3_11C5m_fn6ERKi. >> c++filt says it is: non-virtual thunk to xercesc_3_1::C::m_fn6(int const&) >> >> get_untransformed_body() calls >> lto_free_function_in_decl_state_for_node() which sets >> node->lto_file_data to NULL. >> Now 2nd time get_untransformed_body is called for the same node, >> node->lto_file_data is NULL and lto_get_decl_name_mapping() dereferences >> lto_file_data which results in segfault. >> >> I was wondering if gating on lto_file_data could be a reasonable solution ? >> if (!lto_file_data) >> return false; >> I am not sure what value to return for this case (I chose false >> because of early exit). >> It prevents the ICE, and the patch passes bootstrap+test on >> x86_64-unknown-linux-gnu. >> With partitoning enabled, for the above test-case, >> get_untransformed_body () is called only once per node. However I >> don't understand why it gets called twice with -flto-partition=none. > Kugan pointed out to me the test-case doesn't ICE by passing -fno-ipa-icf.
It looks to me we are not supposed to call this twice on the same node but nothing guards against that (and we don't release the untransformed body either). -flto-partition=none is special here becaue it combines WPA and late stage. IPA ICF is the only IPA pass needing untransformed bodies during WPA. Richard. > Thanks, > Prathamesh >> >> Thank you, >> Prathamesh
