compiler: close upvalues on loop control statements

When removing locals from all scopes, upvalues need to be considered like
in uc_compiler_leave_scope(). Closing them is required to avoid leaving
lingering references to stack values that went out of scope, which would
lead to invalid memory accesses in subsequent code when such upvalues are
used by closures.

Fixes: #187
Signed-off-by: Felix Fietkau <nbd@nbd.name>
[add testcase, reword commit message]
Signed-off-by: Jo-Philipp Wich <jo@mein.io>

1 files changed, 2 insertions, 1 deletions

diff --git a/compiler.c b/compiler.c
index 17c0249..1ea0c65 100644
--- a/compiler.c
+++ b/compiler.c
@@ -2969,7 +2969,8 @@ uc_compiler_compile_control(uc_compiler_t *compiler)
 
 	/* pop locals in all scopes covered by the target patchlist */
 	for (i = locals->count; i > 0 && (size_t)locals->entries[i - 1].depth > p->depth; i--)
-		uc_compiler_emit_insn(compiler, 0, I_POP);
+		uc_compiler_emit_insn(compiler, 0,
+			locals->entries[i - 1].captured ? I_CUPV : I_POP);
 
 	uc_vector_grow(p);