[Tarantool-patches] [PATCH luajit 09/19] FFI: Eliminate hardcoded string hashes.
Sergey Bronnikov
sergeyb at tarantool.org
Wed Aug 16 20:04:52 MSK 2023
Hi, Sergey
Thanks for the patch! LGTM
On 8/15/23 16:07, Maxim Kokryashkin wrote:
> Hi, Sergey!
> Thanks for the patch!
> LGTM, except for a few comments below.
>
> On Wed, Aug 09, 2023 at 06:35:58PM +0300, Sergey Kaplun via Tarantool-patches wrote:
>> From: Mike Pall <mike>
>>
>> (cherry-picked from commit 70f4b15ee45a6137fe6b48b941faea79d72f7159)
>>
>> This patch refactors FFI parsing of supported C attributes and pragmas,
>> `ffi.abi()` parameter check. It replaces usage of comparison (with
> Typo: s/usage/the usage/
>> hardcoded string hashes) with search in the given string with the
> Typo: s/with search/with a search/
>> format: "\XXXattribute1\XXXattribute2", where `\XXX` is the length of
>> "attribute" name.
>>
>> Sergey Kaplun:
>> * added the description for the commit
>>
>> Part of tarantool/tarantool#8825
>> ---
>> src/lib_ffi.c | 35 ++++++++++------------
>> src/lj_cparse.c | 77 +++++++++++++++++++++++++++++++------------------
>> src/lj_cparse.h | 2 ++
>> 3 files changed, 67 insertions(+), 47 deletions(-)
>>
>> diff --git a/src/lib_ffi.c b/src/lib_ffi.c
>> index d1fe1a14..62af54c1 100644
>> --- a/src/lib_ffi.c
>> +++ b/src/lib_ffi.c
>> @@ -720,50 +720,47 @@ LJLIB_CF(ffi_fill) LJLIB_REC(.)
>> return 0;
>> }
>>
>> -#define H_(le, be) LJ_ENDIAN_SELECT(0x##le, 0x##be)
>> -
>> /* Test ABI string. */
>> LJLIB_CF(ffi_abi) LJLIB_REC(.)
>> {
>> GCstr *s = lj_lib_checkstr(L, 1);
>> - int b = 0;
>> - switch (s->hash) {
>> + int b = lj_cparse_case(s,
>> #if LJ_64
>> - case H_(849858eb,ad35fd06): b = 1; break; /* 64bit */
>> + "\00564bit"
>> #else
>> - case H_(662d3c79,d0e22477): b = 1; break; /* 32bit */
>> + "\00532bit"
>> #endif
>> #if LJ_ARCH_HASFPU
>> - case H_(e33ee463,e33ee463): b = 1; break; /* fpu */
>> + "\003fpu"
>> #endif
>> #if LJ_ABI_SOFTFP
>> - case H_(61211a23,c2e8c81c): b = 1; break; /* softfp */
>> + "\006softfp"
>> #else
>> - case H_(539417a8,8ce0812f): b = 1; break; /* hardfp */
>> + "\006hardfp"
>> #endif
>> #if LJ_ABI_EABI
>> - case H_(2182df8f,f2ed1152): b = 1; break; /* eabi */
>> + "\004eabi"
>> #endif
>> #if LJ_ABI_WIN
>> - case H_(4ab624a8,4ab624a8): b = 1; break; /* win */
>> + "\003win"
>> #endif
>> #if LJ_TARGET_UWP
>> - case H_(a40f0bcb,a40f0bcb): b = 1; break; /* uwp */
>> + "\003uwp"
>> +#endif
>> +#if LJ_LE
>> + "\002le"
>> +#else
>> + "\002be"
>> #endif
>> - case H_(3af93066,1f001464): b = 1; break; /* le/be */
>> #if LJ_GC64
>> - case H_(9e89d2c9,13c83c92): b = 1; break; /* gc64 */
>> + "\004gc64"
>> #endif
>> - default:
>> - break;
>> - }
>> + ) >= 0;
>> setboolV(L->top-1, b);
>> setboolV(&G(L)->tmptv2, b); /* Remember for trace recorder. */
>> return 1;
>> }
>>
>> -#undef H_
>> -
>> LJLIB_PUSH(top-8) LJLIB_SET(!) /* Store reference to miscmap table. */
>>
>> LJLIB_CF(ffi_metatype)
>> diff --git a/src/lj_cparse.c b/src/lj_cparse.c
>> index fb440567..07c643d4 100644
>> --- a/src/lj_cparse.c
>> +++ b/src/lj_cparse.c
>> @@ -28,6 +28,24 @@
>> ** If in doubt, please check the input against your favorite C compiler.
>> */
>>
>> +/* -- Miscellaneous ------------------------------------------------------- */
>> +
>> +/* Match string against a C literal. */
>> +#define cp_str_is(str, k) \
>> + ((str)->len == sizeof(k)-1 && !memcmp(strdata(str), k, sizeof(k)-1))
>> +
>> +/* Check string against a linear list of matches. */
>> +int lj_cparse_case(GCstr *str, const char *match)
>> +{
>> + MSize len;
>> + int n;
>> + for (n = 0; (len = (MSize)*match++); n++, match += len) {
>> + if (str->len == len && !memcmp(match, strdata(str), len))
>> + return n;
>> + }
>> + return -1;
>> +}
>> +
>> /* -- C lexer ------------------------------------------------------------- */
>>
>> /* C lexer token names. */
>> @@ -930,8 +948,6 @@ static CTypeID cp_decl_intern(CPState *cp, CPDecl *decl)
>>
>> /* -- C declaration parser ------------------------------------------------ */
>>
>> -#define H_(le, be) LJ_ENDIAN_SELECT(0x##le, 0x##be)
>> -
>> /* Reset declaration state to declaration specifier. */
>> static void cp_decl_reset(CPDecl *decl)
>> {
>> @@ -1071,44 +1087,57 @@ static void cp_decl_gccattribute(CPState *cp, CPDecl *decl)
>> attrstr = lj_str_new(cp->L, c+2, attrstr->len-4);
>> #endif
>> cp_next(cp);
>> - switch (attrstr->hash) {
>> - case H_(64a9208e,8ce14319): case H_(8e6331b2,95a282af): /* aligned */
>> + switch (lj_cparse_case(attrstr,
>> + "\007aligned" "\013__aligned__"
>> + "\006packed" "\012__packed__"
>> + "\004mode" "\010__mode__"
>> + "\013vector_size" "\017__vector_size__"
>> +#if LJ_TARGET_X86
>> + "\007regparm" "\013__regparm__"
>> + "\005cdecl" "\011__cdecl__"
>> + "\010thiscall" "\014__thiscall__"
>> + "\010fastcall" "\014__fastcall__"
>> + "\007stdcall" "\013__stdcall__"
>> + "\012sseregparm" "\016__sseregparm__"
>> +#endif
>> + )) {
>> + case 0: case 1: /* aligned */
>> cp_decl_align(cp, decl);
>> break;
>> - case H_(42eb47de,f0ede26c): case H_(29f48a09,cf383e0c): /* packed */
>> + case 2: case 3: /* packed */
>> decl->attr |= CTFP_PACKED;
>> break;
>> - case H_(0a84eef6,8dfab04c): case H_(995cf92c,d5696591): /* mode */
>> + case 4: case 5: /* mode */
>> cp_decl_mode(cp, decl);
>> break;
>> - case H_(0ab31997,2d5213fa): case H_(bf875611,200e9990): /* vector_size */
>> + case 6: case 7: /* vector_size */
>> {
>> CTSize vsize = cp_decl_sizeattr(cp);
>> if (vsize) CTF_INSERT(decl->attr, VSIZEP, lj_fls(vsize));
>> }
>> break;
>> #if LJ_TARGET_X86
>> - case H_(5ad22db8,c689b848): case H_(439150fa,65ea78cb): /* regparm */
>> + case 8: case 9: /* regparm */
>> CTF_INSERT(decl->fattr, REGPARM, cp_decl_sizeattr(cp));
>> decl->fattr |= CTFP_CCONV;
>> break;
>> - case H_(18fc0b98,7ff4c074): case H_(4e62abed,0a747424): /* cdecl */
>> + case 10: case 11: /* cdecl */
>> CTF_INSERT(decl->fattr, CCONV, CTCC_CDECL);
>> decl->fattr |= CTFP_CCONV;
>> break;
>> - case H_(72b2e41b,494c5a44): case H_(f2356d59,f25fc9bd): /* thiscall */
>> + case 12: case 13: /* thiscall */
>> CTF_INSERT(decl->fattr, CCONV, CTCC_THISCALL);
>> decl->fattr |= CTFP_CCONV;
>> break;
>> - case H_(0d0ffc42,ab746f88): case H_(21c54ba1,7f0ca7e3): /* fastcall */
>> + case 14: case 15: /* fastcall */
>> CTF_INSERT(decl->fattr, CCONV, CTCC_FASTCALL);
>> decl->fattr |= CTFP_CCONV;
>> break;
>> - case H_(ef76b040,9412e06a): case H_(de56697b,c750e6e1): /* stdcall */
>> + case 16: case 17: /* stdcall */
>> CTF_INSERT(decl->fattr, CCONV, CTCC_STDCALL);
>> decl->fattr |= CTFP_CCONV;
>> break;
>> - case H_(ea78b622,f234bd8e): case H_(252ffb06,8d50f34b): /* sseregparm */
>> + case 18: case 19: /* sseregparm */
>> decl->fattr |= CTF_SSEREGPARM;
>> decl->fattr |= CTFP_CCONV;
>> break;
>> @@ -1140,16 +1169,13 @@ static void cp_decl_msvcattribute(CPState *cp, CPDecl *decl)
>> while (cp->tok == CTOK_IDENT) {
>> GCstr *attrstr = cp->str;
>> cp_next(cp);
>> - switch (attrstr->hash) {
>> - case H_(bc2395fa,98f267f8): /* align */
>> + if (cp_str_is(attrstr, "align")) {
>> cp_decl_align(cp, decl);
>> - break;
>> - default: /* Ignore all other attributes. */
>> + } else { /* Ignore all other attributes. */
>> if (cp_opt(cp, '(')) {
>> while (cp->tok != ')' && cp->tok != CTOK_EOF) cp_next(cp);
>> cp_check(cp, ')');
>> }
>> - break;
>> }
>> }
>> cp_check(cp, ')');
>> @@ -1729,17 +1755,16 @@ static CTypeID cp_decl_abstract(CPState *cp)
>> static void cp_pragma(CPState *cp, BCLine pragmaline)
>> {
>> cp_next(cp);
>> - if (cp->tok == CTOK_IDENT &&
>> - cp->str->hash == H_(e79b999f,42ca3e85)) { /* pack */
>> + if (cp->tok == CTOK_IDENT && cp_str_is(cp->str, "pack")) {
>> cp_next(cp);
>> cp_check(cp, '(');
>> if (cp->tok == CTOK_IDENT) {
>> - if (cp->str->hash == H_(738e923c,a1b65954)) { /* push */
>> + if (cp_str_is(cp->str, "push")) {
>> if (cp->curpack < CPARSE_MAX_PACKSTACK) {
>> cp->packstack[cp->curpack+1] = cp->packstack[cp->curpack];
>> cp->curpack++;
>> }
>> - } else if (cp->str->hash == H_(6c71cf27,6c71cf27)) { /* pop */
>> + } else if (cp_str_is(cp->str, "pop")) {
>> if (cp->curpack > 0) cp->curpack--;
>> } else {
>> cp_errmsg(cp, cp->tok, LJ_ERR_XSYMBOL);
>> @@ -1788,13 +1813,11 @@ static void cp_decl_multi(CPState *cp)
>> if (tok == CTOK_INTEGER) {
>> cp_line(cp, hashline);
>> continue;
>> - } else if (tok == CTOK_IDENT &&
>> - cp->str->hash == H_(187aab88,fcb60b42)) { /* line */
>> + } else if (tok == CTOK_IDENT && cp_str_is(cp->str, "line")) {
>> if (cp_next(cp) != CTOK_INTEGER) cp_err_token(cp, tok);
>> cp_line(cp, hashline);
>> continue;
>> - } else if (tok == CTOK_IDENT &&
>> - cp->str->hash == H_(f5e6b4f8,1d509107)) { /* pragma */
>> + } else if (tok == CTOK_IDENT && cp_str_is(cp->str, "pragma")) {
>> cp_pragma(cp, hashline);
>> continue;
>> } else {
>> @@ -1865,8 +1888,6 @@ static void cp_decl_single(CPState *cp)
>> if (cp->tok != CTOK_EOF) cp_err_token(cp, CTOK_EOF);
>> }
>>
>> -#undef H_
>> -
>> /* ------------------------------------------------------------------------ */
>>
>> /* Protected callback for C parser. */
>> diff --git a/src/lj_cparse.h b/src/lj_cparse.h
>> index bad1060b..e40b4047 100644
>> --- a/src/lj_cparse.h
>> +++ b/src/lj_cparse.h
>> @@ -60,6 +60,8 @@ typedef struct CPState {
>>
>> LJ_FUNC int lj_cparse(CPState *cp);
>>
>> +LJ_FUNC int lj_cparse_case(GCstr *str, const char *match);
>> +
>> #endif
>>
>> #endif
>> --
>> 2.41.0
>>
More information about the Tarantool-patches
mailing list