From 0993ad65cc4e462223e9337d9b2d3b82a887c6c8 Mon Sep 17 00:00:00 2001 From: David Malcolm Date: Wed, 12 Feb 2020 10:56:28 -0500 Subject: [PATCH] analyzer: fix wording for assignment from NULL MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit This patch improves the wording of the state-transition event (1) in the -Wanalyzer-null-dereference diagnostic for: void test (void) { int *p = NULL; *p = 1; } taking the path description from: ‘test’: events 1-2 | | 5 | int *p = NULL; | | ^ | | | | | (1) assuming ‘p’ is NULL | 6 | *p = 1; | | ~~~~~~ | | | | | (2) dereference of NULL ‘p’ | to: ‘test’: events 1-2 | | 5 | int *p = NULL; | | ^ | | | | | (1) ‘p’ is NULL | 6 | *p = 1; | | ~~~~~~ | | | | | (2) dereference of NULL ‘p’ | since the "assuming" at (1) only makes sense for state transitions due to comparisons, not for assignments. gcc/analyzer/ChangeLog: * sm-malloc.cc (malloc_diagnostic::describe_state_change): For transition to the "null" state, only say "assuming" when transitioning from the "unchecked" state. gcc/testsuite/ChangeLog: * gcc.dg/analyzer/malloc-1.c (test_48): New. --- gcc/analyzer/ChangeLog | 6 ++++++ gcc/analyzer/sm-malloc.cc | 11 +++++++++-- gcc/testsuite/ChangeLog | 4 ++++ gcc/testsuite/gcc.dg/analyzer/malloc-1.c | 6 ++++++ 4 files changed, 25 insertions(+), 2 deletions(-) diff --git a/gcc/analyzer/ChangeLog b/gcc/analyzer/ChangeLog index 9f1e25d..5945abc 100644 --- a/gcc/analyzer/ChangeLog +++ b/gcc/analyzer/ChangeLog @@ -1,5 +1,11 @@ 2020-02-17 David Malcolm + * sm-malloc.cc (malloc_diagnostic::describe_state_change): For + transition to the "null" state, only say "assuming" when + transitioning from the "unchecked" state. + +2020-02-17 David Malcolm + * diagnostic-manager.h (diagnostic_manager::get_saved_diagnostic): Add const overload. * engine.cc (exploded_node::dump_dot): Dump saved_diagnostics. diff --git a/gcc/analyzer/sm-malloc.cc b/gcc/analyzer/sm-malloc.cc index bdd0731..46225b6 100644 --- a/gcc/analyzer/sm-malloc.cc +++ b/gcc/analyzer/sm-malloc.cc @@ -130,8 +130,15 @@ public: return change.formatted_print ("assuming %qE is non-NULL", change.m_expr); if (change.m_new_state == m_sm.m_null) - return change.formatted_print ("assuming %qE is NULL", - change.m_expr); + { + if (change.m_old_state == m_sm.m_unchecked) + return change.formatted_print ("assuming %qE is NULL", + change.m_expr); + else + return change.formatted_print ("%qE is NULL", + change.m_expr); + } + return label_text (); } diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index 83c581c..a08ad2e 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,3 +1,7 @@ +2020-02-17 David Malcolm + + * gcc.dg/analyzer/malloc-1.c (test_48): New. + 2020-02-17 Jiufu Guo PR target/93047 diff --git a/gcc/testsuite/gcc.dg/analyzer/malloc-1.c b/gcc/testsuite/gcc.dg/analyzer/malloc-1.c index c131705..3024e546 100644 --- a/gcc/testsuite/gcc.dg/analyzer/malloc-1.c +++ b/gcc/testsuite/gcc.dg/analyzer/malloc-1.c @@ -583,3 +583,9 @@ int test_47 (void) } return p_size; } + +void test_48 (void) +{ + int *p = NULL; /* { dg-message "'p' is NULL" } */ + *p = 1; /* { dg-warning "dereference of NULL 'p'" } */ +} -- 2.7.4