> + /* If the next declaration is a PARM_DECL pointing to theDECL, > + we need to adjust its VALUE_EXPR directly, since chains of > + VALUE_EXPRs run afoul of garbage collection. This occurs > + in Ada for Out parameters that aren't copied in. */ > + if (next > + && TREE_CODE (next) == PARM_DECL > + && DECL_HAS_VALUE_EXPR_P (next) > + && DECL_VALUE_EXPR (next) == decl) > + SET_DECL_VALUE_EXPR (next, x); > > maybe you can explain the GC issue a bit.
It's the issue with GCed tables pointing to each other (which one is marked first?) applied to the VALUE_EXPR table. Not clear it's worth verifying since it's marginal, but I guess it's cheap enough to do in decl_value_expr_insert. -- Eric Botcazou
