From 623730d954a051941ae6a098f851bef308916ca0 Mon Sep 17 00:00:00 2001 From: Marek Polacek Date: Thu, 26 Jan 2023 09:34:28 -0500 Subject: [PATCH] c++: fix ICE with -Wduplicated-cond [PR107593] Here we crash because a CAST_EXPR, representing T(), doesn't have its operand, and operand_equal_p's STRIP_ANY_LOCATION_WRAPPER doesn't expect that. (o_e_p is called from warn_duplicated_cond_add_or_warn.) In the past we've adjusted o_e_p to better cope with template codes, but in this case I think we just want to avoid attempting to warn about inst-dependent expressions; I don't think I've ever envisioned -Wduplicated-cond to warn about them. Also destroy the chain when an inst-dependent expression is encountered to not warn in Wduplicated-cond4.C. The ICE started with r12-6022, two-stage name lookup for overloaded operators, which gave dependent operators a TREE_TYPE (in particular, DEPENDENT_OPERATOR_TYPE), so we no longer bail out here in o_e_p: /* Similar, if either does not have a type (like a template id), they aren't equal. */ if (!TREE_TYPE (arg0) || !TREE_TYPE (arg1)) return false; PR c++/107593 PR c++/108597 gcc/c-family/ChangeLog: * c-common.h (instantiation_dependent_expression_p): Declare. * c-warn.cc (warn_duplicated_cond_add_or_warn): If the condition is dependent, invalidate the chain. gcc/c/ChangeLog: * c-objc-common.cc (instantiation_dependent_expression_p): New. gcc/cp/ChangeLog: * cp-tree.h (instantiation_dependent_expression_p): Don't declare here. gcc/testsuite/ChangeLog: * g++.dg/warn/Wduplicated-cond3.C: New test. * g++.dg/warn/Wduplicated-cond4.C: New test. * g++.dg/warn/Wduplicated-cond5.C: New test. --- gcc/c-family/c-common.h | 1 + gcc/c-family/c-warn.cc | 2 +- gcc/c/c-objc-common.cc | 8 ++++++ gcc/cp/cp-tree.h | 1 - gcc/testsuite/g++.dg/warn/Wduplicated-cond3.C | 38 +++++++++++++++++++++++++++ gcc/testsuite/g++.dg/warn/Wduplicated-cond4.C | 17 ++++++++++++ gcc/testsuite/g++.dg/warn/Wduplicated-cond5.C | 16 +++++++++++ 7 files changed, 81 insertions(+), 2 deletions(-) create mode 100644 gcc/testsuite/g++.dg/warn/Wduplicated-cond3.C create mode 100644 gcc/testsuite/g++.dg/warn/Wduplicated-cond4.C create mode 100644 gcc/testsuite/g++.dg/warn/Wduplicated-cond5.C diff --git a/gcc/c-family/c-common.h b/gcc/c-family/c-common.h index bb6271d..2dadb33 100644 --- a/gcc/c-family/c-common.h +++ b/gcc/c-family/c-common.h @@ -1101,6 +1101,7 @@ extern tree lookup_label (tree); extern tree lookup_name (tree); extern bool lvalue_p (const_tree); extern int maybe_adjust_arg_pos_for_attribute (const_tree); +extern bool instantiation_dependent_expression_p (tree); extern bool vector_targets_convertible_p (const_tree t1, const_tree t2); extern bool vector_types_convertible_p (const_tree t1, const_tree t2, bool emit_lax_note); diff --git a/gcc/c-family/c-warn.cc b/gcc/c-family/c-warn.cc index 5ed7bca..29efce3 100644 --- a/gcc/c-family/c-warn.cc +++ b/gcc/c-family/c-warn.cc @@ -2535,7 +2535,7 @@ warn_duplicated_cond_add_or_warn (location_t loc, tree cond, vec **chain) if (*chain == NULL) return; - if (TREE_SIDE_EFFECTS (cond)) + if (TREE_SIDE_EFFECTS (cond) || instantiation_dependent_expression_p (cond)) { /* Uh-oh! This condition has a side-effect, thus invalidates the whole chain. */ diff --git a/gcc/c/c-objc-common.cc b/gcc/c/c-objc-common.cc index d4f0b26..0350733 100644 --- a/gcc/c/c-objc-common.cc +++ b/gcc/c/c-objc-common.cc @@ -400,3 +400,11 @@ maybe_adjust_arg_pos_for_attribute (const_tree) { return 0; } + +/* In C, no expression is dependent. */ + +bool +instantiation_dependent_expression_p (tree) +{ + return false; +} diff --git a/gcc/cp/cp-tree.h b/gcc/cp/cp-tree.h index 9f18872..31fd8af 100644 --- a/gcc/cp/cp-tree.h +++ b/gcc/cp/cp-tree.h @@ -7428,7 +7428,6 @@ extern bool any_type_dependent_arguments_p (const vec *); extern bool any_type_dependent_elements_p (const_tree); extern bool type_dependent_expression_p_push (tree); extern bool value_dependent_expression_p (tree); -extern bool instantiation_dependent_expression_p (tree); extern bool instantiation_dependent_uneval_expression_p (tree); extern bool any_value_dependent_elements_p (const_tree); extern bool dependent_omp_for_p (tree, tree, tree, tree); diff --git a/gcc/testsuite/g++.dg/warn/Wduplicated-cond3.C b/gcc/testsuite/g++.dg/warn/Wduplicated-cond3.C new file mode 100644 index 0000000..3da054e --- /dev/null +++ b/gcc/testsuite/g++.dg/warn/Wduplicated-cond3.C @@ -0,0 +1,38 @@ +// PR c++/107593 +// { dg-do compile } +// { dg-options "-Wduplicated-cond" } + +template +void +foo () +{ + if (T() && T() && int()) + ; + else if (T() && T() && int()) + ; +} + +template +void bar(T a) +{ + if (a) + ; + else if (a) + ; +} + +template +void baz(int a) +{ + if (a) + ; + else if (a) // { dg-warning "duplicated" } + ; +} +void +f () +{ + foo(); + bar(1); + baz(1); +} diff --git a/gcc/testsuite/g++.dg/warn/Wduplicated-cond4.C b/gcc/testsuite/g++.dg/warn/Wduplicated-cond4.C new file mode 100644 index 0000000..41bb9f0 --- /dev/null +++ b/gcc/testsuite/g++.dg/warn/Wduplicated-cond4.C @@ -0,0 +1,17 @@ +// PR c++/107593 +// { dg-do compile } +// { dg-options "-Wduplicated-cond" } + +int n; + +template bool g() { n = 42; return false; } + +template +void f() { + if (n) + ; + else if (g()) + ; + else if (n) + ; +} diff --git a/gcc/testsuite/g++.dg/warn/Wduplicated-cond5.C b/gcc/testsuite/g++.dg/warn/Wduplicated-cond5.C new file mode 100644 index 0000000..23a0bf2 --- /dev/null +++ b/gcc/testsuite/g++.dg/warn/Wduplicated-cond5.C @@ -0,0 +1,16 @@ +// PR c++/108597 +// { dg-do compile } +// { dg-options "-Wduplicated-cond" } + +template +struct MyStruct { + + void check(int &x) { + if (&x == &_a) { + } else if (&x == &_b) { + } + } + + int _a; + int _b; +}; -- 2.7.4