Function same_symbol 

pub fn same_symbol(left: &str, right: &str) -> bool

Whether two logical symbols name the same function. 两个逻辑符号是否指向同一个函数。

A live trace names a function by its bare symbol (button) while a MIR candidate carries the fully qualified path (crate::ui::button), so the match must also accept one side being a path suffix of the other. The suffix has to start right after a :: boundary: a bare ends_with would treat button as a suffix of fastbutton and silently discard a real candidate. strip_suffix plus the boundary check preserves the original behaviour without allocating the two format!("::{right}") strings on every comparison — this runs in the nested merge loop, so those allocations were paid per relation per candidate. live trace 用裸符号（button）命名函数，而 MIR 候选取的是全限定路径 （crate::ui::button），因此匹配还须接受一方是另一方路径后缀。后缀必须紧接 :: 边界：裸的 ends_with 会把 button 当成 fastbutton 的后缀，静默丢掉一个真实候选。 strip_suffix 加边界检查在保持原行为的同时，不再每次比较都分配两个 format!("::{right}") 字符串——这段代码跑在归并的嵌套循环里，这些分配是按“每条关系 × 每个候选”付出的。 Pinned by same_symbol_requires_a_path_boundary_before_the_suffix. 由 same_symbol_requires_a_path_boundary_before_the_suffix 钉住。