From d7ef7d1258d8ef715be29dea0788a3e410c1d279 Mon Sep 17 00:00:00 2001 From: Lewis Hyatt Date: Sat, 2 Nov 2024 21:59:24 -0400 Subject: [PATCH] c++: Fix tree_contains_struct for TRAIT_EXPR CODE_CONTAINS_STRUCT () currently reports that a TRAIT_EXPR contains a TS_EXP struct, but it does not actually start with a TS_EXP as an initial sequence. In modules.cc, when we stream out a tree, we explicitly check for the TS_EXP case and call note_location(t->exp.locus) if so. Currently, this actually queries the tree_common::chain field of a tree_trait_expr, which seems not to be used, returning 0, which is interpreted as UNKNOWN_LOCATION and does no harm. If location_t will change to be 64 bytes, as is under discussion, then on 32-bit platforms (well those, such as sparc, on which uint64_t has higher alignment requirement than a pointer), reading t->exp.locus will end up reading a different field (tree_trait_expr::type1) due to padding offsets. That field is not generally 0, and the resulting bogus location_t is sufficiently problematic to cause an ICE in the line_map code. Pretty much any modules testcase displays the issue, such as partial-2_a.C. Resolve by initializing tree_contains_struct with the correct value for TRAIT_EXPR, namely TS_TYPED. gcc/cp/ChangeLog: * cp-objcp-common.cc (cp_common_init_ts): Change TRAIT_EXPR from TS_EXP to TS_TYPED. --- gcc/cp/cp-objcp-common.cc | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/gcc/cp/cp-objcp-common.cc b/gcc/cp/cp-objcp-common.cc index 7a0636f1653..1e43db31db8 100644 --- a/gcc/cp/cp-objcp-common.cc +++ b/gcc/cp/cp-objcp-common.cc @@ -617,6 +617,7 @@ cp_common_init_ts (void) MARK_TS_TYPED (PTRMEM_CST); MARK_TS_TYPED (LAMBDA_EXPR); MARK_TS_TYPED (TYPE_ARGUMENT_PACK); + MARK_TS_TYPED (TRAIT_EXPR); /* Random new trees. */ MARK_TS_COMMON (BASELINK); @@ -684,7 +685,6 @@ cp_common_init_ts (void) MARK_TS_EXP (TAG_DEFN); MARK_TS_EXP (TEMPLATE_ID_EXPR); MARK_TS_EXP (THROW_EXPR); - MARK_TS_EXP (TRAIT_EXPR); MARK_TS_EXP (TYPEID_EXPR); MARK_TS_EXP (TYPE_EXPR); MARK_TS_EXP (UNARY_PLUS_EXPR);