diff --git a/doc/extensions.html b/doc/extensions.html
index 7f712a62..368b527c 100644
--- a/doc/extensions.html
+++ b/doc/extensions.html
@@ -365,25 +365,30 @@ the toolchain used to compile LuaJIT:
| POSIX/x64, DWARF2 unwinding |
-GCC 4.3+ |
+GCC 4.3+, Clang |
Full |
-| Other platforms, DWARF2 unwinding |
-GCC |
-Limited |
+ARM -DLUAJIT_UNWIND_EXTERNAL |
+GCC, Clang |
+Full |
+| Other platforms, DWARF2 unwinding |
+GCC, Clang |
+Limited |
+
+
| Windows/x64 |
MSVC or WinSDK |
Full |
-
+
| Windows/x86 |
Any |
-No |
+Full |
-
+
| Other platforms |
Other compilers |
No |
@@ -432,14 +437,6 @@ C++ destructors.
Lua errors cannot be caught on the C++ side.
Throwing Lua errors across C++ frames will not call
C++ destructors.
-Additionally, on Windows/x86 with SEH-based C++ exceptions:
-it's not safe to throw a Lua error across any frames containing
-a C++ function with any try/catch construct or using variables with
-(implicit) destructors. This also applies to any functions which may be
-inlined in such a function. It doesn't matter whether lua_error()
-is called inside or outside of a try/catch or whether any object actually
-needs to be destroyed: the SEH chain is corrupted and this will eventually
-lead to the termination of the process.
diff --git a/src/host/buildvm.c b/src/host/buildvm.c
index 6d9e09e1..57b4dc97 100644
--- a/src/host/buildvm.c
+++ b/src/host/buildvm.c
@@ -110,7 +110,7 @@ static const char *sym_decorate(BuildCtx *ctx,
if (p) {
#if LJ_TARGET_X86ORX64
if (!LJ_64 && (ctx->mode == BUILD_coffasm || ctx->mode == BUILD_peobj))
- name[0] = '@';
+ name[0] = name[1] == 'R' ? '_' : '@'; /* Just for _RtlUnwind@16. */
else
*p = '\0';
#elif LJ_TARGET_PPC && !LJ_TARGET_CONSOLE
diff --git a/src/host/buildvm_peobj.c b/src/host/buildvm_peobj.c
index e8c927d8..42f6ac84 100644
--- a/src/host/buildvm_peobj.c
+++ b/src/host/buildvm_peobj.c
@@ -109,6 +109,8 @@ enum {
#if LJ_TARGET_X64
PEOBJ_SECT_PDATA,
PEOBJ_SECT_XDATA,
+#elif LJ_TARGET_X86
+ PEOBJ_SECT_SXDATA,
#endif
PEOBJ_SECT_RDATA_Z,
PEOBJ_NSECTIONS
@@ -208,6 +210,13 @@ void emit_peobj(BuildCtx *ctx)
sofs += (pesect[PEOBJ_SECT_XDATA].nreloc = 1) * PEOBJ_RELOC_SIZE;
/* Flags: 40 = read, 30 = align4, 40 = initialized data. */
pesect[PEOBJ_SECT_XDATA].flags = 0x40300040;
+#elif LJ_TARGET_X86
+ memcpy(pesect[PEOBJ_SECT_SXDATA].name, ".sxdata", sizeof(".sxdata")-1);
+ pesect[PEOBJ_SECT_SXDATA].ofs = sofs;
+ sofs += (pesect[PEOBJ_SECT_SXDATA].size = 4);
+ pesect[PEOBJ_SECT_SXDATA].relocofs = sofs;
+ /* Flags: 40 = read, 30 = align4, 02 = lnk_info, 40 = initialized data. */
+ pesect[PEOBJ_SECT_SXDATA].flags = 0x40300240;
#endif
memcpy(pesect[PEOBJ_SECT_RDATA_Z].name, ".rdata$Z", sizeof(".rdata$Z")-1);
@@ -232,7 +241,7 @@ void emit_peobj(BuildCtx *ctx)
nrsym = ctx->nrelocsym;
pehdr.nsyms = 1+PEOBJ_NSECTIONS*2 + 1+ctx->nsym + nrsym;
#if LJ_TARGET_X64
- pehdr.nsyms += 1; /* Symbol for lj_err_unwind_win64. */
+ pehdr.nsyms += 1; /* Symbol for lj_err_unwind_win. */
#endif
/* Write PE object header and all sections. */
@@ -312,6 +321,19 @@ void emit_peobj(BuildCtx *ctx)
reloc.type = PEOBJ_RELOC_ADDR32NB;
owrite(ctx, &reloc, PEOBJ_RELOC_SIZE);
}
+#elif LJ_TARGET_X86
+ /* Write .sxdata section. */
+ for (i = 0; i < nrsym; i++) {
+ if (!strcmp(ctx->relocsym[i], "_lj_err_unwind_win")) {
+ uint32_t symidx = 1+2+i;
+ owrite(ctx, &symidx, 4);
+ break;
+ }
+ }
+ if (i == nrsym) {
+ fprintf(stderr, "Error: extern lj_err_unwind_win not used\n");
+ exit(1);
+ }
#endif
/* Write .rdata$Z section. */
@@ -333,8 +355,10 @@ void emit_peobj(BuildCtx *ctx)
#if LJ_TARGET_X64
emit_peobj_sym_sect(ctx, pesect, PEOBJ_SECT_PDATA);
emit_peobj_sym_sect(ctx, pesect, PEOBJ_SECT_XDATA);
- emit_peobj_sym(ctx, "lj_err_unwind_win64", 0,
+ emit_peobj_sym(ctx, "lj_err_unwind_win", 0,
PEOBJ_SECT_UNDEF, PEOBJ_TYPE_FUNC, PEOBJ_SCL_EXTERN);
+#elif LJ_TARGET_X86
+ emit_peobj_sym_sect(ctx, pesect, PEOBJ_SECT_SXDATA);
#endif
emit_peobj_sym(ctx, ctx->beginsym, 0,
diff --git a/src/lj_err.c b/src/lj_err.c
index a847ca07..1314c8db 100644
--- a/src/lj_err.c
+++ b/src/lj_err.c
@@ -46,7 +46,8 @@
** the wrapper function feature. Lua errors thrown through C++ frames
** cannot be caught by C++ code and C++ destructors are not run.
**
-** EXT is the default on x64 systems, INT is the default on all other systems.
+** EXT is the default on x64 systems and on Windows, INT is the default on all
+** other systems.
**
** EXT can be manually enabled on POSIX systems using GCC and DWARF2 stack
** unwinding with -DLUAJIT_UNWIND_EXTERNAL. *All* C code must be compiled
@@ -55,7 +56,6 @@
** and all C libraries that have callbacks which may be used to call back
** into Lua. C++ code must *not* be compiled with -fno-exceptions.
**
-** EXT cannot be enabled on WIN32 since system exceptions use code-driven SEH.
** EXT is mandatory on WIN64 since the calling convention has an abundance
** of callee-saved registers (rbx, rbp, rsi, rdi, r12-r15, xmm6-xmm15).
** The POSIX/x64 interpreter only saves r12/r13 for INT (e.g. PS4).
@@ -63,7 +63,7 @@
#if defined(__GNUC__) && (LJ_TARGET_X64 || defined(LUAJIT_UNWIND_EXTERNAL)) && !LJ_NO_UNWIND
#define LJ_UNWIND_EXT 1
-#elif LJ_TARGET_X64 && LJ_TARGET_WINDOWS
+#elif LJ_TARGET_WINDOWS
#define LJ_UNWIND_EXT 1
#endif
@@ -384,7 +384,7 @@ static void err_raise_ext(int errcode)
#endif /* LJ_TARGET_ARM */
-#elif LJ_TARGET_X64 && LJ_ABI_WIN
+#elif LJ_ABI_WIN
/*
** Someone in Redmond owes me several days of my life. A lot of this is
@@ -402,6 +402,7 @@ static void err_raise_ext(int errcode)
#define WIN32_LEAN_AND_MEAN
#include
+#if LJ_TARGET_X64
/* Taken from: http://www.nynaeve.net/?p=99 */
typedef struct UndocumentedDispatcherContext {
ULONG64 ControlPc;
@@ -416,11 +417,14 @@ typedef struct UndocumentedDispatcherContext {
ULONG ScopeIndex;
ULONG Fill0;
} UndocumentedDispatcherContext;
+#else
+typedef void *UndocumentedDispatcherContext;
+#endif
/* Another wild guess. */
extern void __DestructExceptionObject(EXCEPTION_RECORD *rec, int nothrow);
-#ifdef MINGW_SDK_INIT
+#if LJ_TARGET_X64 && defined(MINGW_SDK_INIT)
/* Workaround for broken MinGW64 declaration. */
VOID RtlUnwindEx_FIXED(PVOID,PVOID,PVOID,PVOID,PVOID,PVOID) asm("RtlUnwindEx");
#define RtlUnwindEx RtlUnwindEx_FIXED
@@ -434,10 +438,15 @@ VOID RtlUnwindEx_FIXED(PVOID,PVOID,PVOID,PVOID,PVOID,PVOID) asm("RtlUnwindEx");
#define LJ_EXCODE_CHECK(cl) (((cl) ^ LJ_EXCODE) <= 0xff)
#define LJ_EXCODE_ERRCODE(cl) ((int)((cl) & 0xff))
-/* Win64 exception handler for interpreter frame. */
-LJ_FUNCA EXCEPTION_DISPOSITION lj_err_unwind_win64(EXCEPTION_RECORD *rec,
- void *cf, CONTEXT *ctx, UndocumentedDispatcherContext *dispatch)
+/* Windows exception handler for interpreter frame. */
+LJ_FUNCA EXCEPTION_DISPOSITION lj_err_unwind_win(EXCEPTION_RECORD *rec,
+ void *f, CONTEXT *ctx, UndocumentedDispatcherContext *dispatch)
{
+#if LJ_TARGET_X64
+ void *cf = f;
+#else
+ void *cf = (char *)f - CFRAME_OFS_SEH;
+#endif
lua_State *L = cframe_L(cf);
int errcode = LJ_EXCODE_CHECK(rec->ExceptionCode) ?
LJ_EXCODE_ERRCODE(rec->ExceptionCode) : LUA_ERRRUN;
@@ -457,6 +466,7 @@ LJ_FUNCA EXCEPTION_DISPOSITION lj_err_unwind_win64(EXCEPTION_RECORD *rec,
/* Don't catch access violations etc. */
return ExceptionContinueSearch;
}
+#if LJ_TARGET_X64
/* Unwind the stack and call all handlers for all lower C frames
** (including ourselves) again with EH_UNWINDING set. Then set
** rsp = cf, rax = errcode and jump to the specified target.
@@ -466,6 +476,18 @@ LJ_FUNCA EXCEPTION_DISPOSITION lj_err_unwind_win64(EXCEPTION_RECORD *rec,
lj_vm_unwind_c_eh),
rec, (void *)(uintptr_t)errcode, ctx, dispatch->HistoryTable);
/* RtlUnwindEx should never return. */
+#else
+ UNUSED(ctx);
+ UNUSED(dispatch);
+ /* Call all handlers for all lower C frames (including ourselves) again
+ ** with EH_UNWINDING set. Then call the specified function, passing cf
+ ** and errcode.
+ */
+ lj_vm_rtlunwind(cf, (void *)rec,
+ (cframe_unwind_ff(cf2) && errcode != LUA_YIELD) ?
+ (void *)lj_vm_unwind_ff : (void *)lj_vm_unwind_c, errcode);
+ /* lj_vm_rtlunwind does not return. */
+#endif
}
}
return ExceptionContinueSearch;
diff --git a/src/lj_frame.h b/src/lj_frame.h
index fc0e281c..db2e4da1 100644
--- a/src/lj_frame.h
+++ b/src/lj_frame.h
@@ -116,6 +116,17 @@ enum { LJ_CONT_TAILCALL, LJ_CONT_FFI_CALLBACK }; /* Special continuations. */
/* These definitions must match with the arch-specific *.dasc files. */
#if LJ_TARGET_X86
+#if LJ_ABI_WIN
+#define CFRAME_OFS_ERRF (19*4)
+#define CFRAME_OFS_NRES (18*4)
+#define CFRAME_OFS_PREV (17*4)
+#define CFRAME_OFS_L (16*4)
+#define CFRAME_OFS_SEH (9*4)
+#define CFRAME_OFS_PC (6*4)
+#define CFRAME_OFS_MULTRES (5*4)
+#define CFRAME_SIZE (16*4)
+#define CFRAME_SHIFT_MULTRES 0
+#else
#define CFRAME_OFS_ERRF (15*4)
#define CFRAME_OFS_NRES (14*4)
#define CFRAME_OFS_PREV (13*4)
@@ -124,6 +135,7 @@ enum { LJ_CONT_TAILCALL, LJ_CONT_FFI_CALLBACK }; /* Special continuations. */
#define CFRAME_OFS_MULTRES (5*4)
#define CFRAME_SIZE (12*4)
#define CFRAME_SHIFT_MULTRES 0
+#endif
#elif LJ_TARGET_X64
#if LJ_ABI_WIN
#define CFRAME_OFS_PREV (13*8)
diff --git a/src/lj_vm.h b/src/lj_vm.h
index be35295d..d605b143 100644
--- a/src/lj_vm.h
+++ b/src/lj_vm.h
@@ -17,6 +17,10 @@ LJ_ASMF int lj_vm_cpcall(lua_State *L, lua_CFunction func, void *ud,
LJ_ASMF int lj_vm_resume(lua_State *L, TValue *base, int nres1, ptrdiff_t ef);
LJ_ASMF_NORET void LJ_FASTCALL lj_vm_unwind_c(void *cframe, int errcode);
LJ_ASMF_NORET void LJ_FASTCALL lj_vm_unwind_ff(void *cframe);
+#if LJ_ABI_WIN && LJ_TARGET_X86
+LJ_ASMF_NORET void LJ_FASTCALL lj_vm_rtlunwind(void *cframe, void *excptrec,
+ void *unwinder, int errcode);
+#endif
LJ_ASMF void lj_vm_unwind_c_eh(void);
LJ_ASMF void lj_vm_unwind_ff_eh(void);
#if LJ_TARGET_X86ORX64
diff --git a/src/vm_x86.dasc b/src/vm_x86.dasc
index f108c0b5..39ccaa2e 100644
--- a/src/vm_x86.dasc
+++ b/src/vm_x86.dasc
@@ -121,19 +121,68 @@
|//-----------------------------------------------------------------------
|.if not X64 // x86 stack layout.
|
+|.if WIN
+|
+|.define CFRAME_SPACE, aword*9 // Delta for esp (see <--).
+|.macro saveregs_
+| push edi; push esi; push ebx
+| push extern lj_err_unwind_win
+| fs; push dword [0]
+| fs; mov [0], esp
+| sub esp, CFRAME_SPACE
+|.endmacro
+|.macro restoreregs
+| add esp, CFRAME_SPACE
+| fs; pop dword [0]
+| pop edi // Short for esp += 4.
+| pop ebx; pop esi; pop edi; pop ebp
+|.endmacro
+|
+|.else
+|
|.define CFRAME_SPACE, aword*7 // Delta for esp (see <--).
|.macro saveregs_
| push edi; push esi; push ebx
| sub esp, CFRAME_SPACE
|.endmacro
-|.macro saveregs
-| push ebp; saveregs_
-|.endmacro
|.macro restoreregs
| add esp, CFRAME_SPACE
| pop ebx; pop esi; pop edi; pop ebp
|.endmacro
|
+|.endif
+|
+|.macro saveregs
+| push ebp; saveregs_
+|.endmacro
+|
+|.if WIN
+|.define SAVE_ERRF, aword [esp+aword*19] // vm_pcall/vm_cpcall only.
+|.define SAVE_NRES, aword [esp+aword*18]
+|.define SAVE_CFRAME, aword [esp+aword*17]
+|.define SAVE_L, aword [esp+aword*16]
+|//----- 16 byte aligned, ^^^ arguments from C caller
+|.define SAVE_RET, aword [esp+aword*15] //<-- esp entering interpreter.
+|.define SAVE_R4, aword [esp+aword*14]
+|.define SAVE_R3, aword [esp+aword*13]
+|.define SAVE_R2, aword [esp+aword*12]
+|//----- 16 byte aligned
+|.define SAVE_R1, aword [esp+aword*11]
+|.define SEH_FUNC, aword [esp+aword*10]
+|.define SEH_NEXT, aword [esp+aword*9] //<-- esp after register saves.
+|.define UNUSED2, aword [esp+aword*8]
+|//----- 16 byte aligned
+|.define UNUSED1, aword [esp+aword*7]
+|.define SAVE_PC, aword [esp+aword*6]
+|.define TMP2, aword [esp+aword*5]
+|.define TMP1, aword [esp+aword*4]
+|//----- 16 byte aligned
+|.define ARG4, aword [esp+aword*3]
+|.define ARG3, aword [esp+aword*2]
+|.define ARG2, aword [esp+aword*1]
+|.define ARG1, aword [esp] //<-- esp while in interpreter.
+|//----- 16 byte aligned, ^^^ arguments for C callee
+|.else
|.define SAVE_ERRF, aword [esp+aword*15] // vm_pcall/vm_cpcall only.
|.define SAVE_NRES, aword [esp+aword*14]
|.define SAVE_CFRAME, aword [esp+aword*13]
@@ -154,6 +203,7 @@
|.define ARG2, aword [esp+aword*1]
|.define ARG1, aword [esp] //<-- esp while in interpreter.
|//----- 16 byte aligned, ^^^ arguments for C callee
+|.endif
|
|// FPARGx overlaps ARGx and ARG(x+1) on x86.
|.define FPARG3, qword [esp+qword*1]
@@ -554,6 +604,10 @@ static void build_subroutines(BuildCtx *ctx)
|.else
| mov eax, FCARG2 // Error return status for vm_pcall.
| mov esp, FCARG1
+ |.if WIN
+ | lea FCARG1, SEH_NEXT
+ | fs; mov [0], FCARG1
+ |.endif
|.endif
|->vm_unwind_c_eh: // Landing pad for external unwinder.
| mov L:RB, SAVE_L
@@ -577,6 +631,10 @@ static void build_subroutines(BuildCtx *ctx)
|.else
| and FCARG1, CFRAME_RAWMASK
| mov esp, FCARG1
+ |.if WIN
+ | lea FCARG1, SEH_NEXT
+ | fs; mov [0], FCARG1
+ |.endif
|.endif
|->vm_unwind_ff_eh: // Landing pad for external unwinder.
| mov L:RB, SAVE_L
@@ -590,6 +648,19 @@ static void build_subroutines(BuildCtx *ctx)
| set_vmstate INTERP
| jmp ->vm_returnc // Increments RD/MULTRES and returns.
|
+ |.if WIN and not X64
+ |->vm_rtlunwind@16: // Thin layer around RtlUnwind.
+ | // (void *cframe, void *excptrec, void *unwinder, int errcode)
+ | mov [esp], FCARG1 // Return value for RtlUnwind.
+ | push FCARG2 // Exception record for RtlUnwind.
+ | push 0 // Ignored by RtlUnwind.
+ | push dword [FCARG1+CFRAME_OFS_SEH]
+ | call extern RtlUnwind@16 // Violates ABI (clobbers too much).
+ | mov FCARG1, eax
+ | mov FCARG2, [esp+4] // errcode (for vm_unwind_c).
+ | ret // Jump to unwinder.
+ |.endif
+ |
|//-----------------------------------------------------------------------
|//-- Grow stack for calls -----------------------------------------------
|//-----------------------------------------------------------------------