Merge branch 'master' of ssh://codereview.qt-project.org:29418/playground/v4vm into v4

This is the initial merge of the v4vm JS engine, designed specifically for QML.

The engine is tested on Linux and Mac OS X, works on x86, x86-64 and ARM.

Change-Id: I826b72cfa3d3575007b70d78604080582db568db

Reviewed-by: Lars Knoll <lars.knoll@digia.com>

1 files changed, 372 insertions, 0 deletions

diff --git a/tools/fdegen/main.cpp b/tools/fdegen/main.cpp
new file mode 100644
index 0000000000..313be40351
--- /dev/null
+++ b/tools/fdegen/main.cpp
@@ -0,0 +1,372 @@
+/****************************************************************************
+**
+** Copyright (C) 2012 Digia Plc and/or its subsidiary(-ies).
+** Contact: http://www.qt-project.org/legal
+**
+** This file is part of the V4VM module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and Digia.  For licensing terms and
+** conditions see http://qt.digia.com/licensing.  For further information
+** use the contact form at http://qt.digia.com/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 2.1 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL included in the
+** packaging of this file.  Please review the following information to
+** ensure the GNU Lesser General Public License version 2.1 requirements
+** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** In addition, as a special exception, Digia gives you certain additional
+** rights.  These rights are described in the Digia Qt LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 3.0 as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL included in the
+** packaging of this file.  Please review the following information to
+** ensure the GNU General Public License version 3.0 requirements will be
+** met: http://www.gnu.org/copyleft/gpl.html.
+**
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include <libdwarf.h>
+#include <dwarf.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <unistd.h>
+
+#define DEBUG
+
+#ifdef DEBUG
+#include <libelf.h>
+#endif
+
+#include <qglobal.h>
+
+enum DwarfRegs {
+#if defined(Q_PROCESSOR_X86_64)
+    // X86-64
+    RAX = 0,
+    RDX = 1,
+    RCX = 2,
+    RBX = 3,
+    RSI = 4,
+    RDI = 5,
+    RBP = 6,
+    RSP = 7,
+    R8 = 8,
+    R9 = 9,
+    R10 = 10,
+    R11 = 11,
+    R12 = 12,
+    R13 = 13,
+    R14 = 14,
+    R15 = 15,
+    RIP = 16,
+
+    InstructionPointerRegister = RIP,
+    StackPointerRegister = RSP,
+    StackFrameRegister = RBP
+#elif defined(Q_PROCESSOR_X86)
+    // x86
+    EAX = 0,
+    EDX = 1,
+    ECX = 2,
+    EBX = 3,
+    ESI = 4,
+    EDI = 5,
+    EBP = 6,
+    ESP = 7,
+    EIP = 8,
+
+    InstructionPointerRegister = EIP,
+    StackPointerRegister = ESP,
+    StackFrameRegister = EBP
+#else
+#error Not ported yet
+#endif
+};
+
+static const DwarfRegs calleeSavedRegisters[] = {
+#if defined(Q_PROCESSOR_X86_64)
+    R12,
+    R14
+#endif
+};
+static const int calleeSavedRegisterCount = sizeof(calleeSavedRegisters) / sizeof(calleeSavedRegisters[0]);
+
+#if QT_POINTER_SIZE == 8
+#define Elf_Ehdr Elf64_Ehdr
+#define elf_newehdr elf64_newehdr
+#define Elf_Shdr Elf64_Shdr
+#define elf_getshdr elf64_getshdr
+#else
+#define Elf_Ehdr Elf32_Ehdr
+#define elf_newehdr elf32_newehdr
+#define Elf_Shdr Elf32_Shdr
+#define elf_getshdr elf32_getshdr
+#endif
+
+static void die(const char *msg)
+{
+    fprintf(stderr, "error: %s\n", msg);
+    exit(1);
+}
+
+static int createSectionCallback(
+        char *name,
+        int size,
+        Dwarf_Unsigned  /*type*/,
+        Dwarf_Unsigned  /*flags*/,
+        Dwarf_Unsigned  /*link*/,
+        Dwarf_Unsigned  /*info*/,
+        Dwarf_Unsigned* /*sect_name_index*/,
+        void *          /*user_data*/,
+        int*            /*error*/)
+{
+    if (strcmp(name, ".debug_frame"))
+        return 0;
+    fprintf(stderr, "createsection called with %s and size %d\n", name, size);
+    return 1;
+}
+
+static unsigned char cie_init_instructions[] = {
+    DW_CFA_def_cfa, StackPointerRegister, /*offset in bytes */QT_POINTER_SIZE,
+    DW_CFA_offset | InstructionPointerRegister, 1,
+};
+
+int main()
+{
+    Dwarf_Error error = 0;
+    Dwarf_P_Debug dw = dwarf_producer_init_c(DW_DLC_WRITE | DW_DLC_SIZE_64,
+                                             createSectionCallback,
+                                             /* error handler */0,
+                                             /* error arg */0,
+                                             /* user data */0,
+                                             &error);
+    if (error != 0)
+        die("dwarf_producer_init_c failed");
+
+    Dwarf_Unsigned cie = dwarf_add_frame_cie(dw,
+                                             "",
+                                             /* code alignment factor */QT_POINTER_SIZE,
+                                             /* data alignment factor */-QT_POINTER_SIZE,
+                                             /* return address reg*/InstructionPointerRegister,
+                                             cie_init_instructions,
+                                             sizeof(cie_init_instructions),
+                                             &error);
+    if (error != 0)
+        die("dwarf_add_frame_cie failed");
+
+    Dwarf_P_Fde fde = dwarf_new_fde(dw, &error);
+    if (error != 0)
+        die("dwarf_new_fde failed");
+
+    /* New entry in state machine for code offset 1 after push rbp instruction */
+    dwarf_add_fde_inst(fde,
+                       DW_CFA_advance_loc,
+                       /*offset in code alignment units*/ 1,
+                       /* unused*/ 0,
+                       &error);
+
+    /* After "push rbp" the offset to the CFA is now 2 instead of 1 */
+    dwarf_add_fde_inst(fde,
+                       DW_CFA_def_cfa_offset_sf,
+                       /*offset in code alignment units*/ -2,
+                       /* unused*/ 0,
+                       &error);
+
+    /* After "push rbp" the value of rbp is now stored at offset 1 from CFA */
+    dwarf_add_fde_inst(fde,
+                       DW_CFA_offset,
+                       StackFrameRegister,
+                       2,
+                       &error);
+
+    /* New entry in state machine for code offset 3 for mov rbp, rsp instruction */
+    dwarf_add_fde_inst(fde,
+                       DW_CFA_advance_loc,
+                       /*offset in code alignment units*/ 3,
+                       /* unused */ 0,
+                       &error);
+
+    /* After "mov rbp, rsp" the cfa is reachable via rbp */
+    dwarf_add_fde_inst(fde,
+                       DW_CFA_def_cfa_register,
+                       StackFrameRegister,
+                       /* unused */0,
+                       &error);
+
+    /* Callee saved registers */
+    for (int i = 0; i < calleeSavedRegisterCount; ++i) {
+        dwarf_add_fde_inst(fde,
+                           DW_CFA_offset,
+                           calleeSavedRegisters[i],
+                           i + 3,
+                           &error);
+    }
+
+    dwarf_add_frame_fde(dw, fde,
+                        /* die */0,
+                        cie,
+                        /*virt addr */0,
+                        /* length of code */0,
+                        /* symbol index */0,
+                        &error);
+    if (error != 0)
+        die("dwarf_add_frame_fde failed");
+
+    dwarf_transform_to_disk_form(dw, &error);
+    if (error != 0)
+        die("dwarf_transform_to_disk_form failed");
+
+    Dwarf_Unsigned len = 0;
+    Dwarf_Signed elfIdx = 0;
+    unsigned char *bytes = (unsigned char *)dwarf_get_section_bytes(dw, /* section */1,
+                                              &elfIdx, &len, &error);
+    if (error != 0)
+        die("dwarf_get_section_bytes failed");
+
+    // libdwarf doesn't add a terminating FDE with zero length, so let's add one
+    // ourselves.
+    unsigned char *newBytes = (unsigned char *)alloca(len + 4);
+    memcpy(newBytes, bytes, len);
+    newBytes[len] = 0;
+    newBytes[len + 1] = 0;
+    newBytes[len + 2] = 0;
+    newBytes[len + 3] = 0;
+    newBytes[len + 4] = 0;
+    bytes = newBytes;
+    len += 4;
+
+    // Reset CIE-ID back to 0 as expected for .eh_frames
+    bytes[4] = 0;
+    bytes[5] = 0;
+    bytes[6] = 0;
+    bytes[7] = 0;
+
+    unsigned fde_offset = bytes[0] + 4;
+
+    bytes[fde_offset + 4] = fde_offset + 4;
+
+    printf("static const unsigned char cie_fde_data[] = {\n");
+    int i = 0;
+    while (i < len) {
+        printf("    ");
+        for (int j = 0; i < len && j < 8; ++j, ++i)
+            printf("0x%x, ", bytes[i]);
+        printf("\n");
+    }
+    printf("};\n");
+
+    printf("static const int fde_offset = %d;\n", fde_offset);
+    printf("static const int initial_location_offset = %d;\n", fde_offset + 8);
+    printf("static const int address_range_offset = %d;\n", fde_offset + 8 + QT_POINTER_SIZE);
+
+#ifdef DEBUG
+    {
+        if (elf_version(EV_CURRENT) == EV_NONE)
+            die("wrong elf version");
+        int fd = open("debug.o", O_WRONLY | O_CREAT, 0777);
+        if (fd < 0)
+            die("cannot create debug.o");
+
+        Elf *e = elf_begin(fd, ELF_C_WRITE, 0);
+        if (!e)
+            die("elf_begin failed");
+
+        Elf_Ehdr *ehdr = elf_newehdr(e);
+        if (!ehdr)
+            die(elf_errmsg(-1));
+
+        ehdr->e_ident[EI_DATA] = ELFDATA2LSB;
+#if defined(Q_PROCESSOR_X86_64)
+        ehdr->e_machine = EM_X86_64;
+#elif defined(Q_PROCESSOR_X86)
+        ehdr->e_machine = EM_386;
+#else
+#error port me :)
+#endif
+        ehdr->e_type = ET_EXEC;
+        ehdr->e_version = EV_CURRENT;
+
+        Elf_Scn *section = elf_newscn(e);
+        if (!section)
+            die("elf_newscn failed");
+
+        Elf_Data *data = elf_newdata(section);
+        if (!data)
+            die(elf_errmsg(-1));
+        data->d_align = 4;
+        data->d_off = 0;
+        data->d_buf = bytes;
+        data->d_size = len;
+        data->d_type = ELF_T_BYTE;
+        data->d_version = EV_CURRENT;
+
+        Elf_Shdr *shdr = elf_getshdr(section);
+        if (!shdr)
+            die(elf_errmsg(-1));
+
+        shdr->sh_name = 1;
+        shdr->sh_type = SHT_PROGBITS;
+        shdr->sh_entsize = 0;
+
+        char stringTable[] = {
+            0,
+            '.', 'e', 'h', '_', 'f', 'r', 'a', 'm', 'e', 0,
+            '.', 's', 'h', 's', 't', 'r', 't', 'a', 'b', 0
+        };
+
+        section = elf_newscn(e);
+        if (!section)
+            die("elf_newscn failed");
+
+        data = elf_newdata(section);
+        if (!data)
+            die(elf_errmsg(-1));
+        data->d_align = 1;
+        data->d_off = 0;
+        data->d_buf = stringTable;
+        data->d_size = sizeof(stringTable);
+        data->d_type = ELF_T_BYTE;
+        data->d_version = EV_CURRENT;
+
+        shdr = elf_getshdr(section);
+        if (!shdr)
+            die(elf_errmsg(-1));
+
+        shdr->sh_name = 11;
+        shdr->sh_type = SHT_STRTAB;
+        shdr->sh_flags = SHF_STRINGS | SHF_ALLOC;
+        shdr->sh_entsize = 0;
+
+        ehdr->e_shstrndx = elf_ndxscn(section);
+
+        if (elf_update(e, ELF_C_WRITE) < 0)
+            die(elf_errmsg(-1));
+
+        elf_end(e);
+        close(fd);
+    }
+#endif
+
+    dwarf_producer_finish(dw, &error);
+    if (error != 0)
+        die("dwarf_producer_finish failed");
+    return 0;
+}