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-rw-r--r--Build/source/libs/luajit/LuaJIT-src/src/lj_gdbjit.c787
1 files changed, 787 insertions, 0 deletions
diff --git a/Build/source/libs/luajit/LuaJIT-src/src/lj_gdbjit.c b/Build/source/libs/luajit/LuaJIT-src/src/lj_gdbjit.c
new file mode 100644
index 00000000000..9b95e525840
--- /dev/null
+++ b/Build/source/libs/luajit/LuaJIT-src/src/lj_gdbjit.c
@@ -0,0 +1,787 @@
+/*
+** Client for the GDB JIT API.
+** Copyright (C) 2005-2015 Mike Pall. See Copyright Notice in luajit.h
+*/
+
+#define lj_gdbjit_c
+#define LUA_CORE
+
+#include "lj_obj.h"
+
+#if LJ_HASJIT
+
+#include "lj_gc.h"
+#include "lj_err.h"
+#include "lj_debug.h"
+#include "lj_frame.h"
+#include "lj_buf.h"
+#include "lj_strfmt.h"
+#include "lj_jit.h"
+#include "lj_dispatch.h"
+
+/* This is not compiled in by default.
+** Enable with -DLUAJIT_USE_GDBJIT in the Makefile and recompile everything.
+*/
+#ifdef LUAJIT_USE_GDBJIT
+
+/* The GDB JIT API allows JIT compilers to pass debug information about
+** JIT-compiled code back to GDB. You need at least GDB 7.0 or higher
+** to see it in action.
+**
+** This is a passive API, so it works even when not running under GDB
+** or when attaching to an already running process. Alas, this implies
+** enabling it always has a non-negligible overhead -- do not use in
+** release mode!
+**
+** The LuaJIT GDB JIT client is rather minimal at the moment. It gives
+** each trace a symbol name and adds a source location and frame unwind
+** information. Obviously LuaJIT itself and any embedding C application
+** should be compiled with debug symbols, too (see the Makefile).
+**
+** Traces are named TRACE_1, TRACE_2, ... these correspond to the trace
+** numbers from -jv or -jdump. Use "break TRACE_1" or "tbreak TRACE_1" etc.
+** to set breakpoints on specific traces (even ahead of their creation).
+**
+** The source location for each trace allows listing the corresponding
+** source lines with the GDB command "list" (but only if the Lua source
+** has been loaded from a file). Currently this is always set to the
+** location where the trace has been started.
+**
+** Frame unwind information can be inspected with the GDB command
+** "info frame". This also allows proper backtraces across JIT-compiled
+** code with the GDB command "bt".
+**
+** You probably want to add the following settings to a .gdbinit file
+** (or add them to ~/.gdbinit):
+** set disassembly-flavor intel
+** set breakpoint pending on
+**
+** Here's a sample GDB session:
+** ------------------------------------------------------------------------
+
+$ cat >x.lua
+for outer=1,100 do
+ for inner=1,100 do end
+end
+^D
+
+$ luajit -jv x.lua
+[TRACE 1 x.lua:2]
+[TRACE 2 (1/3) x.lua:1 -> 1]
+
+$ gdb --quiet --args luajit x.lua
+(gdb) tbreak TRACE_1
+Function "TRACE_1" not defined.
+Temporary breakpoint 1 (TRACE_1) pending.
+(gdb) run
+Starting program: luajit x.lua
+
+Temporary breakpoint 1, TRACE_1 () at x.lua:2
+2 for inner=1,100 do end
+(gdb) list
+1 for outer=1,100 do
+2 for inner=1,100 do end
+3 end
+(gdb) bt
+#0 TRACE_1 () at x.lua:2
+#1 0x08053690 in lua_pcall [...]
+[...]
+#7 0x0806ff90 in main [...]
+(gdb) disass TRACE_1
+Dump of assembler code for function TRACE_1:
+0xf7fd9fba <TRACE_1+0>: mov DWORD PTR ds:0xf7e0e2a0,0x1
+0xf7fd9fc4 <TRACE_1+10>: movsd xmm7,QWORD PTR [edx+0x20]
+[...]
+0xf7fd9ff8 <TRACE_1+62>: jmp 0xf7fd2014
+End of assembler dump.
+(gdb) tbreak TRACE_2
+Function "TRACE_2" not defined.
+Temporary breakpoint 2 (TRACE_2) pending.
+(gdb) cont
+Continuing.
+
+Temporary breakpoint 2, TRACE_2 () at x.lua:1
+1 for outer=1,100 do
+(gdb) info frame
+Stack level 0, frame at 0xffffd7c0:
+ eip = 0xf7fd9f60 in TRACE_2 (x.lua:1); saved eip 0x8053690
+ called by frame at 0xffffd7e0
+ source language unknown.
+ Arglist at 0xffffd78c, args:
+ Locals at 0xffffd78c, Previous frame's sp is 0xffffd7c0
+ Saved registers:
+ ebx at 0xffffd7ac, ebp at 0xffffd7b8, esi at 0xffffd7b0, edi at 0xffffd7b4,
+ eip at 0xffffd7bc
+(gdb)
+
+** ------------------------------------------------------------------------
+*/
+
+/* -- GDB JIT API --------------------------------------------------------- */
+
+/* GDB JIT actions. */
+enum {
+ GDBJIT_NOACTION = 0,
+ GDBJIT_REGISTER,
+ GDBJIT_UNREGISTER
+};
+
+/* GDB JIT entry. */
+typedef struct GDBJITentry {
+ struct GDBJITentry *next_entry;
+ struct GDBJITentry *prev_entry;
+ const char *symfile_addr;
+ uint64_t symfile_size;
+} GDBJITentry;
+
+/* GDB JIT descriptor. */
+typedef struct GDBJITdesc {
+ uint32_t version;
+ uint32_t action_flag;
+ GDBJITentry *relevant_entry;
+ GDBJITentry *first_entry;
+} GDBJITdesc;
+
+GDBJITdesc __jit_debug_descriptor = {
+ 1, GDBJIT_NOACTION, NULL, NULL
+};
+
+/* GDB sets a breakpoint at this function. */
+void LJ_NOINLINE __jit_debug_register_code()
+{
+ __asm__ __volatile__("");
+};
+
+/* -- In-memory ELF object definitions ------------------------------------ */
+
+/* ELF definitions. */
+typedef struct ELFheader {
+ uint8_t emagic[4];
+ uint8_t eclass;
+ uint8_t eendian;
+ uint8_t eversion;
+ uint8_t eosabi;
+ uint8_t eabiversion;
+ uint8_t epad[7];
+ uint16_t type;
+ uint16_t machine;
+ uint32_t version;
+ uintptr_t entry;
+ uintptr_t phofs;
+ uintptr_t shofs;
+ uint32_t flags;
+ uint16_t ehsize;
+ uint16_t phentsize;
+ uint16_t phnum;
+ uint16_t shentsize;
+ uint16_t shnum;
+ uint16_t shstridx;
+} ELFheader;
+
+typedef struct ELFsectheader {
+ uint32_t name;
+ uint32_t type;
+ uintptr_t flags;
+ uintptr_t addr;
+ uintptr_t ofs;
+ uintptr_t size;
+ uint32_t link;
+ uint32_t info;
+ uintptr_t align;
+ uintptr_t entsize;
+} ELFsectheader;
+
+#define ELFSECT_IDX_ABS 0xfff1
+
+enum {
+ ELFSECT_TYPE_PROGBITS = 1,
+ ELFSECT_TYPE_SYMTAB = 2,
+ ELFSECT_TYPE_STRTAB = 3,
+ ELFSECT_TYPE_NOBITS = 8
+};
+
+#define ELFSECT_FLAGS_WRITE 1
+#define ELFSECT_FLAGS_ALLOC 2
+#define ELFSECT_FLAGS_EXEC 4
+
+typedef struct ELFsymbol {
+#if LJ_64
+ uint32_t name;
+ uint8_t info;
+ uint8_t other;
+ uint16_t sectidx;
+ uintptr_t value;
+ uint64_t size;
+#else
+ uint32_t name;
+ uintptr_t value;
+ uint32_t size;
+ uint8_t info;
+ uint8_t other;
+ uint16_t sectidx;
+#endif
+} ELFsymbol;
+
+enum {
+ ELFSYM_TYPE_FUNC = 2,
+ ELFSYM_TYPE_FILE = 4,
+ ELFSYM_BIND_LOCAL = 0 << 4,
+ ELFSYM_BIND_GLOBAL = 1 << 4,
+};
+
+/* DWARF definitions. */
+#define DW_CIE_VERSION 1
+
+enum {
+ DW_CFA_nop = 0x0,
+ DW_CFA_offset_extended = 0x5,
+ DW_CFA_def_cfa = 0xc,
+ DW_CFA_def_cfa_offset = 0xe,
+ DW_CFA_offset_extended_sf = 0x11,
+ DW_CFA_advance_loc = 0x40,
+ DW_CFA_offset = 0x80
+};
+
+enum {
+ DW_EH_PE_udata4 = 3,
+ DW_EH_PE_textrel = 0x20
+};
+
+enum {
+ DW_TAG_compile_unit = 0x11
+};
+
+enum {
+ DW_children_no = 0,
+ DW_children_yes = 1
+};
+
+enum {
+ DW_AT_name = 0x03,
+ DW_AT_stmt_list = 0x10,
+ DW_AT_low_pc = 0x11,
+ DW_AT_high_pc = 0x12
+};
+
+enum {
+ DW_FORM_addr = 0x01,
+ DW_FORM_data4 = 0x06,
+ DW_FORM_string = 0x08
+};
+
+enum {
+ DW_LNS_extended_op = 0,
+ DW_LNS_copy = 1,
+ DW_LNS_advance_pc = 2,
+ DW_LNS_advance_line = 3
+};
+
+enum {
+ DW_LNE_end_sequence = 1,
+ DW_LNE_set_address = 2
+};
+
+enum {
+#if LJ_TARGET_X86
+ DW_REG_AX, DW_REG_CX, DW_REG_DX, DW_REG_BX,
+ DW_REG_SP, DW_REG_BP, DW_REG_SI, DW_REG_DI,
+ DW_REG_RA,
+#elif LJ_TARGET_X64
+ /* Yes, the order is strange, but correct. */
+ DW_REG_AX, DW_REG_DX, DW_REG_CX, DW_REG_BX,
+ DW_REG_SI, DW_REG_DI, DW_REG_BP, DW_REG_SP,
+ DW_REG_8, DW_REG_9, DW_REG_10, DW_REG_11,
+ DW_REG_12, DW_REG_13, DW_REG_14, DW_REG_15,
+ DW_REG_RA,
+#elif LJ_TARGET_ARM
+ DW_REG_SP = 13,
+ DW_REG_RA = 14,
+#elif LJ_TARGET_PPC
+ DW_REG_SP = 1,
+ DW_REG_RA = 65,
+ DW_REG_CR = 70,
+#elif LJ_TARGET_MIPS
+ DW_REG_SP = 29,
+ DW_REG_RA = 31,
+#else
+#error "Unsupported target architecture"
+#endif
+};
+
+/* Minimal list of sections for the in-memory ELF object. */
+enum {
+ GDBJIT_SECT_NULL,
+ GDBJIT_SECT_text,
+ GDBJIT_SECT_eh_frame,
+ GDBJIT_SECT_shstrtab,
+ GDBJIT_SECT_strtab,
+ GDBJIT_SECT_symtab,
+ GDBJIT_SECT_debug_info,
+ GDBJIT_SECT_debug_abbrev,
+ GDBJIT_SECT_debug_line,
+ GDBJIT_SECT__MAX
+};
+
+enum {
+ GDBJIT_SYM_UNDEF,
+ GDBJIT_SYM_FILE,
+ GDBJIT_SYM_FUNC,
+ GDBJIT_SYM__MAX
+};
+
+/* In-memory ELF object. */
+typedef struct GDBJITobj {
+ ELFheader hdr; /* ELF header. */
+ ELFsectheader sect[GDBJIT_SECT__MAX]; /* ELF sections. */
+ ELFsymbol sym[GDBJIT_SYM__MAX]; /* ELF symbol table. */
+ uint8_t space[4096]; /* Space for various section data. */
+} GDBJITobj;
+
+/* Combined structure for GDB JIT entry and ELF object. */
+typedef struct GDBJITentryobj {
+ GDBJITentry entry;
+ size_t sz;
+ GDBJITobj obj;
+} GDBJITentryobj;
+
+/* Template for in-memory ELF header. */
+static const ELFheader elfhdr_template = {
+ .emagic = { 0x7f, 'E', 'L', 'F' },
+ .eclass = LJ_64 ? 2 : 1,
+ .eendian = LJ_ENDIAN_SELECT(1, 2),
+ .eversion = 1,
+#if LJ_TARGET_LINUX
+ .eosabi = 0, /* Nope, it's not 3. */
+#elif defined(__FreeBSD__)
+ .eosabi = 9,
+#elif defined(__NetBSD__)
+ .eosabi = 2,
+#elif defined(__OpenBSD__)
+ .eosabi = 12,
+#elif defined(__DragonFly__)
+ .eosabi = 0,
+#elif (defined(__sun__) && defined(__svr4__))
+ .eosabi = 6,
+#else
+ .eosabi = 0,
+#endif
+ .eabiversion = 0,
+ .epad = { 0, 0, 0, 0, 0, 0, 0 },
+ .type = 1,
+#if LJ_TARGET_X86
+ .machine = 3,
+#elif LJ_TARGET_X64
+ .machine = 62,
+#elif LJ_TARGET_ARM
+ .machine = 40,
+#elif LJ_TARGET_PPC
+ .machine = 20,
+#elif LJ_TARGET_MIPS
+ .machine = 8,
+#else
+#error "Unsupported target architecture"
+#endif
+ .version = 1,
+ .entry = 0,
+ .phofs = 0,
+ .shofs = offsetof(GDBJITobj, sect),
+ .flags = 0,
+ .ehsize = sizeof(ELFheader),
+ .phentsize = 0,
+ .phnum = 0,
+ .shentsize = sizeof(ELFsectheader),
+ .shnum = GDBJIT_SECT__MAX,
+ .shstridx = GDBJIT_SECT_shstrtab
+};
+
+/* -- In-memory ELF object generation ------------------------------------- */
+
+/* Context for generating the ELF object for the GDB JIT API. */
+typedef struct GDBJITctx {
+ uint8_t *p; /* Pointer to next address in obj.space. */
+ uint8_t *startp; /* Pointer to start address in obj.space. */
+ GCtrace *T; /* Generate symbols for this trace. */
+ uintptr_t mcaddr; /* Machine code address. */
+ MSize szmcode; /* Size of machine code. */
+ MSize spadjp; /* Stack adjustment for parent trace or interpreter. */
+ MSize spadj; /* Stack adjustment for trace itself. */
+ BCLine lineno; /* Starting line number. */
+ const char *filename; /* Starting file name. */
+ size_t objsize; /* Final size of ELF object. */
+ GDBJITobj obj; /* In-memory ELF object. */
+} GDBJITctx;
+
+/* Add a zero-terminated string. */
+static uint32_t gdbjit_strz(GDBJITctx *ctx, const char *str)
+{
+ uint8_t *p = ctx->p;
+ uint32_t ofs = (uint32_t)(p - ctx->startp);
+ do {
+ *p++ = (uint8_t)*str;
+ } while (*str++);
+ ctx->p = p;
+ return ofs;
+}
+
+/* Append a decimal number. */
+static void gdbjit_catnum(GDBJITctx *ctx, uint32_t n)
+{
+ if (n >= 10) { uint32_t m = n / 10; n = n % 10; gdbjit_catnum(ctx, m); }
+ *ctx->p++ = '0' + n;
+}
+
+/* Add a SLEB128 value. */
+static void gdbjit_sleb128(GDBJITctx *ctx, int32_t v)
+{
+ uint8_t *p = ctx->p;
+ for (; (uint32_t)(v+0x40) >= 0x80; v >>= 7)
+ *p++ = (uint8_t)((v & 0x7f) | 0x80);
+ *p++ = (uint8_t)(v & 0x7f);
+ ctx->p = p;
+}
+
+/* Shortcuts to generate DWARF structures. */
+#define DB(x) (*p++ = (x))
+#define DI8(x) (*(int8_t *)p = (x), p++)
+#define DU16(x) (*(uint16_t *)p = (x), p += 2)
+#define DU32(x) (*(uint32_t *)p = (x), p += 4)
+#define DADDR(x) (*(uintptr_t *)p = (x), p += sizeof(uintptr_t))
+#define DUV(x) (p = (uint8_t *)lj_strfmt_wuleb128((char *)p, (x)))
+#define DSV(x) (ctx->p = p, gdbjit_sleb128(ctx, (x)), p = ctx->p)
+#define DSTR(str) (ctx->p = p, gdbjit_strz(ctx, (str)), p = ctx->p)
+#define DALIGNNOP(s) while ((uintptr_t)p & ((s)-1)) *p++ = DW_CFA_nop
+#define DSECT(name, stmt) \
+ { uint32_t *szp_##name = (uint32_t *)p; p += 4; stmt \
+ *szp_##name = (uint32_t)((p-(uint8_t *)szp_##name)-4); } \
+
+/* Initialize ELF section headers. */
+static void LJ_FASTCALL gdbjit_secthdr(GDBJITctx *ctx)
+{
+ ELFsectheader *sect;
+
+ *ctx->p++ = '\0'; /* Empty string at start of string table. */
+
+#define SECTDEF(id, tp, al) \
+ sect = &ctx->obj.sect[GDBJIT_SECT_##id]; \
+ sect->name = gdbjit_strz(ctx, "." #id); \
+ sect->type = ELFSECT_TYPE_##tp; \
+ sect->align = (al)
+
+ SECTDEF(text, NOBITS, 16);
+ sect->flags = ELFSECT_FLAGS_ALLOC|ELFSECT_FLAGS_EXEC;
+ sect->addr = ctx->mcaddr;
+ sect->ofs = 0;
+ sect->size = ctx->szmcode;
+
+ SECTDEF(eh_frame, PROGBITS, sizeof(uintptr_t));
+ sect->flags = ELFSECT_FLAGS_ALLOC;
+
+ SECTDEF(shstrtab, STRTAB, 1);
+ SECTDEF(strtab, STRTAB, 1);
+
+ SECTDEF(symtab, SYMTAB, sizeof(uintptr_t));
+ sect->ofs = offsetof(GDBJITobj, sym);
+ sect->size = sizeof(ctx->obj.sym);
+ sect->link = GDBJIT_SECT_strtab;
+ sect->entsize = sizeof(ELFsymbol);
+ sect->info = GDBJIT_SYM_FUNC;
+
+ SECTDEF(debug_info, PROGBITS, 1);
+ SECTDEF(debug_abbrev, PROGBITS, 1);
+ SECTDEF(debug_line, PROGBITS, 1);
+
+#undef SECTDEF
+}
+
+/* Initialize symbol table. */
+static void LJ_FASTCALL gdbjit_symtab(GDBJITctx *ctx)
+{
+ ELFsymbol *sym;
+
+ *ctx->p++ = '\0'; /* Empty string at start of string table. */
+
+ sym = &ctx->obj.sym[GDBJIT_SYM_FILE];
+ sym->name = gdbjit_strz(ctx, "JIT mcode");
+ sym->sectidx = ELFSECT_IDX_ABS;
+ sym->info = ELFSYM_TYPE_FILE|ELFSYM_BIND_LOCAL;
+
+ sym = &ctx->obj.sym[GDBJIT_SYM_FUNC];
+ sym->name = gdbjit_strz(ctx, "TRACE_"); ctx->p--;
+ gdbjit_catnum(ctx, ctx->T->traceno); *ctx->p++ = '\0';
+ sym->sectidx = GDBJIT_SECT_text;
+ sym->value = 0;
+ sym->size = ctx->szmcode;
+ sym->info = ELFSYM_TYPE_FUNC|ELFSYM_BIND_GLOBAL;
+}
+
+/* Initialize .eh_frame section. */
+static void LJ_FASTCALL gdbjit_ehframe(GDBJITctx *ctx)
+{
+ uint8_t *p = ctx->p;
+ uint8_t *framep = p;
+
+ /* Emit DWARF EH CIE. */
+ DSECT(CIE,
+ DU32(0); /* Offset to CIE itself. */
+ DB(DW_CIE_VERSION);
+ DSTR("zR"); /* Augmentation. */
+ DUV(1); /* Code alignment factor. */
+ DSV(-(int32_t)sizeof(uintptr_t)); /* Data alignment factor. */
+ DB(DW_REG_RA); /* Return address register. */
+ DB(1); DB(DW_EH_PE_textrel|DW_EH_PE_udata4); /* Augmentation data. */
+ DB(DW_CFA_def_cfa); DUV(DW_REG_SP); DUV(sizeof(uintptr_t));
+#if LJ_TARGET_PPC
+ DB(DW_CFA_offset_extended_sf); DB(DW_REG_RA); DSV(-1);
+#else
+ DB(DW_CFA_offset|DW_REG_RA); DUV(1);
+#endif
+ DALIGNNOP(sizeof(uintptr_t));
+ )
+
+ /* Emit DWARF EH FDE. */
+ DSECT(FDE,
+ DU32((uint32_t)(p-framep)); /* Offset to CIE. */
+ DU32(0); /* Machine code offset relative to .text. */
+ DU32(ctx->szmcode); /* Machine code length. */
+ DB(0); /* Augmentation data. */
+ /* Registers saved in CFRAME. */
+#if LJ_TARGET_X86
+ DB(DW_CFA_offset|DW_REG_BP); DUV(2);
+ DB(DW_CFA_offset|DW_REG_DI); DUV(3);
+ DB(DW_CFA_offset|DW_REG_SI); DUV(4);
+ DB(DW_CFA_offset|DW_REG_BX); DUV(5);
+#elif LJ_TARGET_X64
+ DB(DW_CFA_offset|DW_REG_BP); DUV(2);
+ DB(DW_CFA_offset|DW_REG_BX); DUV(3);
+ DB(DW_CFA_offset|DW_REG_15); DUV(4);
+ DB(DW_CFA_offset|DW_REG_14); DUV(5);
+ /* Extra registers saved for JIT-compiled code. */
+ DB(DW_CFA_offset|DW_REG_13); DUV(LJ_GC64 ? 10 : 9);
+ DB(DW_CFA_offset|DW_REG_12); DUV(LJ_GC64 ? 11 : 10);
+#elif LJ_TARGET_ARM
+ {
+ int i;
+ for (i = 11; i >= 4; i--) { DB(DW_CFA_offset|i); DUV(2+(11-i)); }
+ }
+#elif LJ_TARGET_PPC
+ {
+ int i;
+ DB(DW_CFA_offset_extended); DB(DW_REG_CR); DUV(55);
+ for (i = 14; i <= 31; i++) {
+ DB(DW_CFA_offset|i); DUV(37+(31-i));
+ DB(DW_CFA_offset|32|i); DUV(2+2*(31-i));
+ }
+ }
+#elif LJ_TARGET_MIPS
+ {
+ int i;
+ DB(DW_CFA_offset|30); DUV(2);
+ for (i = 23; i >= 16; i--) { DB(DW_CFA_offset|i); DUV(26-i); }
+ for (i = 30; i >= 20; i -= 2) { DB(DW_CFA_offset|32|i); DUV(42-i); }
+ }
+#else
+#error "Unsupported target architecture"
+#endif
+ if (ctx->spadjp != ctx->spadj) { /* Parent/interpreter stack frame size. */
+ DB(DW_CFA_def_cfa_offset); DUV(ctx->spadjp);
+ DB(DW_CFA_advance_loc|1); /* Only an approximation. */
+ }
+ DB(DW_CFA_def_cfa_offset); DUV(ctx->spadj); /* Trace stack frame size. */
+ DALIGNNOP(sizeof(uintptr_t));
+ )
+
+ ctx->p = p;
+}
+
+/* Initialize .debug_info section. */
+static void LJ_FASTCALL gdbjit_debuginfo(GDBJITctx *ctx)
+{
+ uint8_t *p = ctx->p;
+
+ DSECT(info,
+ DU16(2); /* DWARF version. */
+ DU32(0); /* Abbrev offset. */
+ DB(sizeof(uintptr_t)); /* Pointer size. */
+
+ DUV(1); /* Abbrev #1: DW_TAG_compile_unit. */
+ DSTR(ctx->filename); /* DW_AT_name. */
+ DADDR(ctx->mcaddr); /* DW_AT_low_pc. */
+ DADDR(ctx->mcaddr + ctx->szmcode); /* DW_AT_high_pc. */
+ DU32(0); /* DW_AT_stmt_list. */
+ )
+
+ ctx->p = p;
+}
+
+/* Initialize .debug_abbrev section. */
+static void LJ_FASTCALL gdbjit_debugabbrev(GDBJITctx *ctx)
+{
+ uint8_t *p = ctx->p;
+
+ /* Abbrev #1: DW_TAG_compile_unit. */
+ DUV(1); DUV(DW_TAG_compile_unit);
+ DB(DW_children_no);
+ DUV(DW_AT_name); DUV(DW_FORM_string);
+ DUV(DW_AT_low_pc); DUV(DW_FORM_addr);
+ DUV(DW_AT_high_pc); DUV(DW_FORM_addr);
+ DUV(DW_AT_stmt_list); DUV(DW_FORM_data4);
+ DB(0); DB(0);
+
+ ctx->p = p;
+}
+
+#define DLNE(op, s) (DB(DW_LNS_extended_op), DUV(1+(s)), DB((op)))
+
+/* Initialize .debug_line section. */
+static void LJ_FASTCALL gdbjit_debugline(GDBJITctx *ctx)
+{
+ uint8_t *p = ctx->p;
+
+ DSECT(line,
+ DU16(2); /* DWARF version. */
+ DSECT(header,
+ DB(1); /* Minimum instruction length. */
+ DB(1); /* is_stmt. */
+ DI8(0); /* Line base for special opcodes. */
+ DB(2); /* Line range for special opcodes. */
+ DB(3+1); /* Opcode base at DW_LNS_advance_line+1. */
+ DB(0); DB(1); DB(1); /* Standard opcode lengths. */
+ /* Directory table. */
+ DB(0);
+ /* File name table. */
+ DSTR(ctx->filename); DUV(0); DUV(0); DUV(0);
+ DB(0);
+ )
+
+ DLNE(DW_LNE_set_address, sizeof(uintptr_t)); DADDR(ctx->mcaddr);
+ if (ctx->lineno) {
+ DB(DW_LNS_advance_line); DSV(ctx->lineno-1);
+ }
+ DB(DW_LNS_copy);
+ DB(DW_LNS_advance_pc); DUV(ctx->szmcode);
+ DLNE(DW_LNE_end_sequence, 0);
+ )
+
+ ctx->p = p;
+}
+
+#undef DLNE
+
+/* Undef shortcuts. */
+#undef DB
+#undef DI8
+#undef DU16
+#undef DU32
+#undef DADDR
+#undef DUV
+#undef DSV
+#undef DSTR
+#undef DALIGNNOP
+#undef DSECT
+
+/* Type of a section initializer callback. */
+typedef void (LJ_FASTCALL *GDBJITinitf)(GDBJITctx *ctx);
+
+/* Call section initializer and set the section offset and size. */
+static void gdbjit_initsect(GDBJITctx *ctx, int sect, GDBJITinitf initf)
+{
+ ctx->startp = ctx->p;
+ ctx->obj.sect[sect].ofs = (uintptr_t)((char *)ctx->p - (char *)&ctx->obj);
+ initf(ctx);
+ ctx->obj.sect[sect].size = (uintptr_t)(ctx->p - ctx->startp);
+}
+
+#define SECTALIGN(p, a) \
+ ((p) = (uint8_t *)(((uintptr_t)(p) + ((a)-1)) & ~(uintptr_t)((a)-1)))
+
+/* Build in-memory ELF object. */
+static void gdbjit_buildobj(GDBJITctx *ctx)
+{
+ GDBJITobj *obj = &ctx->obj;
+ /* Fill in ELF header and clear structures. */
+ memcpy(&obj->hdr, &elfhdr_template, sizeof(ELFheader));
+ memset(&obj->sect, 0, sizeof(ELFsectheader)*GDBJIT_SECT__MAX);
+ memset(&obj->sym, 0, sizeof(ELFsymbol)*GDBJIT_SYM__MAX);
+ /* Initialize sections. */
+ ctx->p = obj->space;
+ gdbjit_initsect(ctx, GDBJIT_SECT_shstrtab, gdbjit_secthdr);
+ gdbjit_initsect(ctx, GDBJIT_SECT_strtab, gdbjit_symtab);
+ gdbjit_initsect(ctx, GDBJIT_SECT_debug_info, gdbjit_debuginfo);
+ gdbjit_initsect(ctx, GDBJIT_SECT_debug_abbrev, gdbjit_debugabbrev);
+ gdbjit_initsect(ctx, GDBJIT_SECT_debug_line, gdbjit_debugline);
+ SECTALIGN(ctx->p, sizeof(uintptr_t));
+ gdbjit_initsect(ctx, GDBJIT_SECT_eh_frame, gdbjit_ehframe);
+ ctx->objsize = (size_t)((char *)ctx->p - (char *)obj);
+ lua_assert(ctx->objsize < sizeof(GDBJITobj));
+}
+
+#undef SECTALIGN
+
+/* -- Interface to GDB JIT API -------------------------------------------- */
+
+/* Add new entry to GDB JIT symbol chain. */
+static void gdbjit_newentry(lua_State *L, GDBJITctx *ctx)
+{
+ /* Allocate memory for GDB JIT entry and ELF object. */
+ MSize sz = (MSize)(sizeof(GDBJITentryobj) - sizeof(GDBJITobj) + ctx->objsize);
+ GDBJITentryobj *eo = lj_mem_newt(L, sz, GDBJITentryobj);
+ memcpy(&eo->obj, &ctx->obj, ctx->objsize); /* Copy ELF object. */
+ eo->sz = sz;
+ ctx->T->gdbjit_entry = (void *)eo;
+ /* Link new entry to chain and register it. */
+ eo->entry.prev_entry = NULL;
+ eo->entry.next_entry = __jit_debug_descriptor.first_entry;
+ if (eo->entry.next_entry)
+ eo->entry.next_entry->prev_entry = &eo->entry;
+ eo->entry.symfile_addr = (const char *)&eo->obj;
+ eo->entry.symfile_size = ctx->objsize;
+ __jit_debug_descriptor.first_entry = &eo->entry;
+ __jit_debug_descriptor.relevant_entry = &eo->entry;
+ __jit_debug_descriptor.action_flag = GDBJIT_REGISTER;
+ __jit_debug_register_code();
+}
+
+/* Add debug info for newly compiled trace and notify GDB. */
+void lj_gdbjit_addtrace(jit_State *J, GCtrace *T)
+{
+ GDBJITctx ctx;
+ GCproto *pt = &gcref(T->startpt)->pt;
+ TraceNo parent = T->ir[REF_BASE].op1;
+ const BCIns *startpc = mref(T->startpc, const BCIns);
+ ctx.T = T;
+ ctx.mcaddr = (uintptr_t)T->mcode;
+ ctx.szmcode = T->szmcode;
+ ctx.spadjp = CFRAME_SIZE_JIT +
+ (MSize)(parent ? traceref(J, parent)->spadjust : 0);
+ ctx.spadj = CFRAME_SIZE_JIT + T->spadjust;
+ lua_assert(startpc >= proto_bc(pt) && startpc < proto_bc(pt) + pt->sizebc);
+ ctx.lineno = lj_debug_line(pt, proto_bcpos(pt, startpc));
+ ctx.filename = proto_chunknamestr(pt);
+ if (*ctx.filename == '@' || *ctx.filename == '=')
+ ctx.filename++;
+ else
+ ctx.filename = "(string)";
+ gdbjit_buildobj(&ctx);
+ gdbjit_newentry(J->L, &ctx);
+}
+
+/* Delete debug info for trace and notify GDB. */
+void lj_gdbjit_deltrace(jit_State *J, GCtrace *T)
+{
+ GDBJITentryobj *eo = (GDBJITentryobj *)T->gdbjit_entry;
+ if (eo) {
+ if (eo->entry.prev_entry)
+ eo->entry.prev_entry->next_entry = eo->entry.next_entry;
+ else
+ __jit_debug_descriptor.first_entry = eo->entry.next_entry;
+ if (eo->entry.next_entry)
+ eo->entry.next_entry->prev_entry = eo->entry.prev_entry;
+ __jit_debug_descriptor.relevant_entry = &eo->entry;
+ __jit_debug_descriptor.action_flag = GDBJIT_UNREGISTER;
+ __jit_debug_register_code();
+ lj_mem_free(J2G(J), eo, eo->sz);
+ }
+}
+
+#endif
+#endif