[nasm:master] Fix wrong size calculation for "Dx ?" larger than DB

nasm-bot for Marco Bonelli marco at mebeim.net
Mon Nov 7 17:12:18 PST 2022

Commit-ID:  d167b3d4f3dd011bd3e8995ee5f38aa5d646b5ee
Gitweb:     http://repo.or.cz/w/nasm.git?a=commitdiff;h=d167b3d4f3dd011bd3e8995ee5f38aa5d646b5ee
Author:     Marco Bonelli <marco at mebeim.net>
AuthorDate: Sat, 20 Nov 2021 23:53:27 +0300
Committer:  Cyrill Gorcunov <gorcunov at gmail.com>
CommitDate: Sat, 20 Nov 2021 23:53:40 +0300

Fix wrong size calculation for "Dx ?" larger than DB

The size calculation done in len_extops() (called by insn_size()) for
EOT_DB_RESERVE (i.e. uninitialized storage "?" token) does not take
into account the element size (e->elem), thus calculating a wrong
size for any Dx larger than DB (DW, DQ, etc).

The bug is silent, but it makes NASM error out if a "Dx ?" (larger
than DB) is followed by any label because the label offset gets
mismatched in the final code generation stage:

    $ cat test.asm
    [section .bss]
    DW ?

    $ nasm test.asm
    test.asm:3: error: label `x' changed during code generation [-w+error=label-redef-late]

See also: https://stackoverflow.com/q/70012188/3889449

Signed-off-by: Marco Bonelli <marco at mebeim.net>
Signed-off-by: Cyrill Gorcunov <gorcunov at gmail.com>

 asm/assemble.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/asm/assemble.c b/asm/assemble.c
index 593045bf..cd3f4693 100644
--- a/asm/assemble.c
+++ b/asm/assemble.c
@@ -1111,7 +1111,7 @@ static int64_t len_extops(const extop *e)
         case EOT_DB_RESERVE:
-            isize += e->dup;
+            isize += e->dup * e->elem;

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