mirrors/janet
1
0
Fork 0
mirror of https://github.com/janet-lang/janet synced 2026-08-03 08:58:51 +00:00
Code Issues 1 Releases Wiki Activity

Add conservative checks large registers in emit.c

Browse Source 
We make some assumptions about the index range of slots in emit.c that
is not tracked by the C type system, so add some asserts and conversions
to be safe.
This commit is contained in:
Calvin Rose
2026-04-22 20:01:18 -05:00
parent 5b5844b469
commit e118f57220
1 changed files with 12 additions and 1 deletions
Download Patch File Download Diff File Expand all files Collapse all files
src/core/emit.c
+12 -1
View File
@@ -114,6 +114,7 @@ static void janetc_loadconst(JanetCompiler *c, Janet k, int32_t reg) {
static void janetc_movenear(JanetCompiler *c,
int32_t dest,
JanetSlot src) {
janet_assert(dest <= 255, "dest slot index must be <= 255");
if (src.flags & (JANET_SLOT_CONSTANT | JANET_SLOT_REF)) {
janetc_loadconst(c, src.constant, dest);
/* If we also are a reference, deref the one element array */
@@ -138,7 +139,7 @@ static void janetc_movenear(JanetCompiler *c,
}
}
/* Move a near register to a Slot. */
/* Move a near or far register to a Slot. */
static void janetc_moveback(JanetCompiler *c,
JanetSlot dest,
int32_t src) {
@@ -151,6 +152,11 @@ static void janetc_moveback(JanetCompiler *c,
JOP_PUT_INDEX);
janetc_regalloc_freetemp(&c->scope->ra, refreg, JANETC_REGTEMP_5);
} else if (dest.envindex >= 0) {
/* Convert src to near reg */
if (src > 255) {
janetc_emit(c, JOP_MOVE_NEAR | ((uint32_t)(src) << 16) | (JANETC_REGTEMP_5 << 8));
src = JANETC_REGTEMP_5;
}
janetc_emit(c,
((uint32_t)(dest.index) << 24) |
((uint32_t)(dest.envindex) << 16) |
@@ -158,6 +164,11 @@ static void janetc_moveback(JanetCompiler *c,
JOP_SET_UPVALUE);
} else if (dest.index != src) {
janet_assert(dest.index >= 0, "bad slot");
/* Convert src to near reg */
if (src > 255) {
janetc_emit(c, JOP_MOVE_NEAR | ((uint32_t)(src) << 16) | (JANETC_REGTEMP_5 << 8));
src = JANETC_REGTEMP_5;
}
janetc_emit(c,
((uint32_t)(dest.index) << 16) |
((uint32_t)(src) << 8) |