libgccjit: Fix infinite recursion in gt_ggc_mx_lang_tree_node
This issue happened when compiling rustc with rustc_codegen_gcc, more
specifically when compiling its rustc_parse crate.
gcc/jit/
PR target/105827
* dummy-frontend.cc: Fix lang_tree_node.
* jit-common.h: New function (jit_tree_chain_next) used by
lang_tree_node.
diff --git a/gcc/jit/dummy-frontend.cc b/gcc/jit/dummy-frontend.cc
index 2e85e54..b0fcdd5 100644
--- a/gcc/jit/dummy-frontend.cc
+++ b/gcc/jit/dummy-frontend.cc
@@ -970,12 +970,13 @@
/* The resulting tree type. */
+/* See lang_tree_node in gcc/c/c-decl.cc. */
union GTY((desc ("TREE_CODE (&%h.generic) == IDENTIFIER_NODE"),
- chain_next ("CODE_CONTAINS_STRUCT (TREE_CODE (&%h.generic), TS_COMMON) ? ((union lang_tree_node *) TREE_CHAIN (&%h.generic)) : NULL")))
-lang_tree_node
+ chain_next ("(union lang_tree_node *) jit_tree_chain_next (&%h.generic)"))) lang_tree_node
{
union tree_node GTY((tag ("0"),
- desc ("tree_node_structure (&%h)"))) generic;
+ desc ("tree_node_structure (&%h)")))
+ generic;
struct lang_identifier GTY((tag ("1"))) identifier;
};
diff --git a/gcc/jit/jit-common.h b/gcc/jit/jit-common.h
index 50bb849..e32bd88 100644
--- a/gcc/jit/jit-common.h
+++ b/gcc/jit/jit-common.h
@@ -93,6 +93,21 @@
End of comment for inclusion in the docs. */
+/* See c_tree_chain_next in gcc/c-family/c-common.h. */
+static inline tree
+jit_tree_chain_next (tree t)
+{
+ /* TREE_CHAIN of a type is TYPE_STUB_DECL, which is different
+ kind of object, never a long chain of nodes. Prefer
+ TYPE_NEXT_VARIANT for types. */
+ if (CODE_CONTAINS_STRUCT (TREE_CODE (t), TS_TYPE_COMMON))
+ return TYPE_NEXT_VARIANT (t);
+ /* Otherwise, if there is TREE_CHAIN, return it. */
+ if (CODE_CONTAINS_STRUCT (TREE_CODE (t), TS_COMMON))
+ return TREE_CHAIN (t);
+ return NULL;
+}
+
namespace gcc {
namespace jit {
