From ad951b9c2696a62fddf2502e3b68352a81264f7c Mon Sep 17 00:00:00 2001 From: Philip Herron Date: Thu, 17 Apr 2025 16:19:35 +0100 Subject: [PATCH] gccrs: prealloc the initilizer vector There are two cases when initilizing an array, this is the const context which means we need to build the array ctor, which means using lots of memory, its super inefficient because we are using a big wrapper over the GCC internals here but preallocating the vectors here causes a: terminate called after throwing an instance of 'std::bad_alloc' So this is a handy error condition to rely on for this senario. Fixes Rust-GCC#3713 Fixes Rust-GCC#3727 gcc/rust/ChangeLog: * backend/rust-compile-expr.cc (CompileExpr::array_copied_expr): prealloc the vector Signed-off-by: Philip Herron --- gcc/rust/backend/rust-compile-expr.cc | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/gcc/rust/backend/rust-compile-expr.cc b/gcc/rust/backend/rust-compile-expr.cc index 1e09c6c155a..339317d8174 100644 --- a/gcc/rust/backend/rust-compile-expr.cc +++ b/gcc/rust/backend/rust-compile-expr.cc @@ -1972,8 +1972,12 @@ CompileExpr::array_copied_expr (location_t expr_locus, if (ctx->const_context_p ()) { size_t idx = 0; + std::vector indexes; std::vector constructor; + + indexes.reserve (len); + constructor.reserve (len); for (unsigned HOST_WIDE_INT i = 0; i < len; i++) { constructor.push_back (translated_expr); -- 2.47.2