From a60d98890bba58649c26c2fc0c6f28cd6073aaaf Mon Sep 17 00:00:00 2001 From: David Malcolm Date: Tue, 11 Feb 2020 10:52:40 -0500 Subject: [PATCH] analyzer: fix ICE due to missing state_change purging (PR 93374) PR analyzer/93374 reports an ICE within state_change::validate due to an m_new_sid in a recorded state-change being out of range of the svalues of the region_model of the new state. During get_or_create_node we attempt to merge the new state with the state of each of the existing enodes at the program point (in the absence of sm-state differences), simplifying the state at each attempt, and potentially reusing a node if we get a match. This state-merging invalidates any svalue_ids within any state_change object. The root cause is that, although the code was purging any such svalue_ids for the case where no match was found during merging, it was failing to purge them for the case where a matching enode *was* found for the merged state, leading to an invalid state_change along the exploded_edge to the reused enode. This patch moves the invalidation code to cover both cases, fixing the ICE. It also extends state_change validation so that states are also checked. gcc/analyzer/ChangeLog: PR analyzer/93374 * engine.cc (exploded_edge::exploded_edge): Add ext_state param and pass it to change.validate. (exploded_graph::get_or_create_node): Move purging of change svalues to also cover the case of reusing an existing enode. (exploded_graph::add_edge): Pass m_ext_state to exploded_edge's ctor. * exploded-graph.h (exploded_edge::exploded_edge): Add ext_state param. * program-state.cc (state_change::sm_change::validate): Likewise. Assert that m_sm_idx is sane. Use ext_state to validate m_old_state and m_new_state. (state_change::validate): Add ext_state param and pass it to the sm_change validate calls. * program-state.h (state_change::sm_change::validate): Add ext_state param. (state_change::validate): Likewise. gcc/testsuite/ChangeLog: PR analyzer/93374 * gcc.dg/analyzer/torture/pr93374.c: New test. --- gcc/analyzer/ChangeLog | 20 ++++++++++++++++++++ gcc/analyzer/engine.cc | 21 +++++++++++---------- gcc/analyzer/exploded-graph.h | 1 + gcc/analyzer/program-state.cc | 12 +++++++++--- gcc/analyzer/program-state.h | 6 ++++-- gcc/testsuite/ChangeLog | 5 +++++ gcc/testsuite/gcc.dg/analyzer/torture/pr93374.c | 2 ++ 7 files changed, 52 insertions(+), 15 deletions(-) create mode 100644 gcc/testsuite/gcc.dg/analyzer/torture/pr93374.c diff --git a/gcc/analyzer/ChangeLog b/gcc/analyzer/ChangeLog index 0734716..0313e43 100644 --- a/gcc/analyzer/ChangeLog +++ b/gcc/analyzer/ChangeLog @@ -1,5 +1,25 @@ 2020-02-11 David Malcolm + PR analyzer/93374 + * engine.cc (exploded_edge::exploded_edge): Add ext_state param + and pass it to change.validate. + (exploded_graph::get_or_create_node): Move purging of change + svalues to also cover the case of reusing an existing enode. + (exploded_graph::add_edge): Pass m_ext_state to exploded_edge's + ctor. + * exploded-graph.h (exploded_edge::exploded_edge): Add ext_state + param. + * program-state.cc (state_change::sm_change::validate): Likewise. + Assert that m_sm_idx is sane. Use ext_state to validate + m_old_state and m_new_state. + (state_change::validate): Add ext_state param and pass it to + the sm_change validate calls. + * program-state.h (state_change::sm_change::validate): Add + ext_state param. + (state_change::validate): Likewise. + +2020-02-11 David Malcolm + PR analyzer/93669 * engine.cc (exploded_graph::dump_exploded_nodes): Handle missing case of STATUS_WORKLIST in implementation of diff --git a/gcc/analyzer/engine.cc b/gcc/analyzer/engine.cc index 8d5f9c6..4d329e2 100644 --- a/gcc/analyzer/engine.cc +++ b/gcc/analyzer/engine.cc @@ -1398,13 +1398,14 @@ rewind_info_t::add_events_to_path (checker_path *emission_path, /* exploded_edge's ctor. */ exploded_edge::exploded_edge (exploded_node *src, exploded_node *dest, + const extrinsic_state &ext_state, const superedge *sedge, const state_change &change, custom_info_t *custom_info) : dedge (src, dest), m_sedge (sedge), m_change (change), m_custom_info (custom_info) { - change.validate (dest->get_state ()); + change.validate (dest->get_state (), ext_state); } /* exploded_edge's dtor. */ @@ -1898,8 +1899,14 @@ exploded_graph::get_or_create_node (const program_point &point, logger->log ("merging new state with that of EN: %i", existing_enode->m_index); - /* Try again for a cache hit. */ + /* Try again for a cache hit. + Whether we get one or not, merged_state's value_ids have no + relationship to those of the input state, and thus to those + of CHANGE, so we must purge any svalue_ids from *CHANGE. */ ps.set_state (merged_state); + if (change) + change->on_svalue_purge (svalue_id::from_int (0)); + if (exploded_node **slot = m_point_and_state_to_node.get (&ps)) { /* An exploded_node for PS already exists. */ @@ -1910,13 +1917,6 @@ exploded_graph::get_or_create_node (const program_point &point, per_cs_stats->m_node_reuse_after_merge_count++; return *slot; } - - /* Otherwise, continue, using the merged state in "ps". - Given that merged_state's svalue_ids have no relationship - to those of the input state, and thus to those of CHANGE, - purge any svalue_ids from *CHANGE. */ - if (change) - change->on_svalue_purge (svalue_id::from_int (0)); } else if (logger) @@ -1986,7 +1986,8 @@ exploded_graph::add_edge (exploded_node *src, exploded_node *dest, const state_change &change, exploded_edge::custom_info_t *custom_info) { - exploded_edge *e = new exploded_edge (src, dest, sedge, change, custom_info); + exploded_edge *e = new exploded_edge (src, dest, m_ext_state, + sedge, change, custom_info); digraph::add_edge (e); return e; } diff --git a/gcc/analyzer/exploded-graph.h b/gcc/analyzer/exploded-graph.h index e47816a..5d69bff 100644 --- a/gcc/analyzer/exploded-graph.h +++ b/gcc/analyzer/exploded-graph.h @@ -306,6 +306,7 @@ class exploded_edge : public dedge }; exploded_edge (exploded_node *src, exploded_node *dest, + const extrinsic_state &ext_state, const superedge *sedge, const state_change &change, custom_info_t *custom_info); diff --git a/gcc/analyzer/program-state.cc b/gcc/analyzer/program-state.cc index 4c0b9a8..82b921e 100644 --- a/gcc/analyzer/program-state.cc +++ b/gcc/analyzer/program-state.cc @@ -1083,8 +1083,13 @@ state_change::sm_change::on_svalue_purge (svalue_id first_unused_sid) /* Assert that this object is sane. */ void -state_change::sm_change::validate (const program_state &new_state) const +state_change::sm_change::validate (const program_state &new_state, + const extrinsic_state &ext_state) const { + gcc_assert ((unsigned)m_sm_idx < ext_state.get_num_checkers ()); + const state_machine &sm = ext_state.get_sm (m_sm_idx); + sm.validate (m_old_state); + sm.validate (m_new_state); m_new_sid.validate (*new_state.m_region_model); } @@ -1191,7 +1196,8 @@ state_change::on_svalue_purge (svalue_id first_unused_sid) /* Assert that this object is sane. */ void -state_change::validate (const program_state &new_state) const +state_change::validate (const program_state &new_state, + const extrinsic_state &ext_state) const { /* Skip this in a release build. */ #if !CHECKING_P @@ -1200,7 +1206,7 @@ state_change::validate (const program_state &new_state) const unsigned i; sm_change *change; FOR_EACH_VEC_ELT (m_sm_changes, i, change) - change->validate (new_state); + change->validate (new_state, ext_state); } #if CHECKING_P diff --git a/gcc/analyzer/program-state.h b/gcc/analyzer/program-state.h index d2badb1..a4608c7 100644 --- a/gcc/analyzer/program-state.h +++ b/gcc/analyzer/program-state.h @@ -343,7 +343,8 @@ class state_change void remap_svalue_ids (const svalue_id_map &map); int on_svalue_purge (svalue_id first_unused_sid); - void validate (const program_state &new_state) const; + void validate (const program_state &new_state, + const extrinsic_state &ext_state) const; int m_sm_idx; svalue_id m_new_sid; @@ -367,7 +368,8 @@ class state_change void remap_svalue_ids (const svalue_id_map &map); int on_svalue_purge (svalue_id first_unused_sid); - void validate (const program_state &new_state) const; + void validate (const program_state &new_state, + const extrinsic_state &ext_state) const; private: auto_vec m_sm_changes; diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index f75a678..4f59153 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,5 +1,10 @@ 2020-02-11 David Malcolm + PR analyzer/93374 + * gcc.dg/analyzer/torture/pr93374.c: New test. + +2020-02-11 David Malcolm + PR analyzer/93669 * gcc.dg/analyzer/pr93669.c: New test. diff --git a/gcc/testsuite/gcc.dg/analyzer/torture/pr93374.c b/gcc/testsuite/gcc.dg/analyzer/torture/pr93374.c new file mode 100644 index 0000000..a7adecd --- /dev/null +++ b/gcc/testsuite/gcc.dg/analyzer/torture/pr93374.c @@ -0,0 +1,2 @@ +#include +#include "../../../gcc.c-torture/execute/pr27073.c" -- 2.7.4