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author | Roberto Ierusalimschy <roberto@inf.puc-rio.br> | 2024-01-11 13:44:16 -0300 |
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committer | Roberto Ierusalimschy <roberto@inf.puc-rio.br> | 2024-01-11 13:44:16 -0300 |
commit | e288c5a91883793d14ed9e9d93464f6ee0b08915 (patch) | |
tree | f563f9b4d218c9e35ff3e56eda068cfddb039651 /ldebug.c | |
parent | 5853c37a83ec66ccb45094f9aeac23dfdbcde671 (diff) | |
download | lua-e288c5a91883793d14ed9e9d93464f6ee0b08915.tar.gz lua-e288c5a91883793d14ed9e9d93464f6ee0b08915.tar.bz2 lua-e288c5a91883793d14ed9e9d93464f6ee0b08915.zip |
Bug: Yielding in a hook stops in the wrong instruction
Yielding in a hook must decrease the program counter, because it already
counted an instruction that, in the end, was not executed. However,
that decrement should be done only when about to restart the thread.
Otherwise, inspecting the thread with the debug library shows it one
instruction behind of where it really is.
Diffstat (limited to 'ldebug.c')
-rw-r--r-- | ldebug.c | 5 |
1 files changed, 2 insertions, 3 deletions
@@ -925,12 +925,12 @@ int luaG_traceexec (lua_State *L, const Instruction *pc) { | |||
925 | } | 925 | } |
926 | pc++; /* reference is always next instruction */ | 926 | pc++; /* reference is always next instruction */ |
927 | ci->u.l.savedpc = pc; /* save 'pc' */ | 927 | ci->u.l.savedpc = pc; /* save 'pc' */ |
928 | counthook = (--L->hookcount == 0 && (mask & LUA_MASKCOUNT)); | 928 | counthook = (mask & LUA_MASKCOUNT) && (--L->hookcount == 0); |
929 | if (counthook) | 929 | if (counthook) |
930 | resethookcount(L); /* reset count */ | 930 | resethookcount(L); /* reset count */ |
931 | else if (!(mask & LUA_MASKLINE)) | 931 | else if (!(mask & LUA_MASKLINE)) |
932 | return 1; /* no line hook and count != 0; nothing to be done now */ | 932 | return 1; /* no line hook and count != 0; nothing to be done now */ |
933 | if (ci->callstatus & CIST_HOOKYIELD) { /* called hook last time? */ | 933 | if (ci->callstatus & CIST_HOOKYIELD) { /* hook yielded last time? */ |
934 | ci->callstatus &= ~CIST_HOOKYIELD; /* erase mark */ | 934 | ci->callstatus &= ~CIST_HOOKYIELD; /* erase mark */ |
935 | return 1; /* do not call hook again (VM yielded, so it did not move) */ | 935 | return 1; /* do not call hook again (VM yielded, so it did not move) */ |
936 | } | 936 | } |
@@ -952,7 +952,6 @@ int luaG_traceexec (lua_State *L, const Instruction *pc) { | |||
952 | if (L->status == LUA_YIELD) { /* did hook yield? */ | 952 | if (L->status == LUA_YIELD) { /* did hook yield? */ |
953 | if (counthook) | 953 | if (counthook) |
954 | L->hookcount = 1; /* undo decrement to zero */ | 954 | L->hookcount = 1; /* undo decrement to zero */ |
955 | ci->u.l.savedpc--; /* undo increment (resume will increment it again) */ | ||
956 | ci->callstatus |= CIST_HOOKYIELD; /* mark that it yielded */ | 955 | ci->callstatus |= CIST_HOOKYIELD; /* mark that it yielded */ |
957 | luaD_throw(L, LUA_YIELD); | 956 | luaD_throw(L, LUA_YIELD); |
958 | } | 957 | } |