From 76afb429ee7a8a4c9eddb20bf29a2246192f8a28 Mon Sep 17 00:00:00 2001 From: Rob Browning Date: Thu, 28 Nov 2024 13:01:01 -0600 Subject: [PATCH] Eight byte align statically allocated stringbufs Previously they were unaligned, unlike their parent strings, and so could end up with the wrong pointer tag. Observed on i686-linux-gnu, where they ended up tagged as immediates (SCM_IMP()), causing failures in TYP7 related checks. * libguile/strings.h (SCM_IMMUTABLE_STRINGBUF): align resulting buffer via SCM_ALIGNED(8). --- NEWS | 3 +++ libguile/strings.h | 2 +- 2 files changed, 4 insertions(+), 1 deletion(-) diff --git a/NEWS b/NEWS index e910addb1..c86426cde 100644 --- a/NEWS +++ b/NEWS @@ -49,6 +49,9 @@ arguments. The new syntax is documented in the Guile Reference manual. () ** Fix compilation with GCC 14 and musl on 32-bit systems () +** Immutable stringbufs are now 8-byte aligned on all systems + Previously they could end up with an alignment that violated the type + tag for their type (e.g. ending up tagged as immediates SCM_IMP()). Changes in 3.0.10 (since 3.0.9) diff --git a/libguile/strings.h b/libguile/strings.h index f28ef3246..d417514f8 100644 --- a/libguile/strings.h +++ b/libguile/strings.h @@ -184,7 +184,7 @@ SCM_API SCM scm_makfromstrs (int argc, char **argv); #ifdef SCM_SUPPORT_STATIC_ALLOCATION #define SCM_IMMUTABLE_STRINGBUF(c_name, contents) \ - static SCM_UNUSED const \ + static SCM_UNUSED SCM_ALIGNED(8) const \ struct \ { \ scm_t_bits word_0; \