/* Copyright (c) 2002-2018 Pigeonhole authors, see the included COPYING file

 */

#include "lib.h"

#include "mempool.h"

#include "sieve-common.h"

#include "sieve-script.h"

#include "sieve-extensions.h"

#include "sieve-commands.h"

#include "sieve-code.h"

#include "sieve-binary.h"

#include "sieve-generator.h"

/*

 * Jump list

 */

struct sieve_jumplist *

sieve_jumplist_create(pool_t pool, struct sieve_binary_block *sblock)

{

  struct sieve_jumplist *jlist;

  jlist = p_new(pool, struct sieve_jumplist, 1);

  jlist->block = sblock;

  p_array_init(&jlist->jumps, pool, 4);

  return jlist;

}

void sieve_jumplist_init_temp(struct sieve_jumplist *jlist,

            struct sieve_binary_block *sblock)

{

  jlist->block = sblock;

  t_array_init(&jlist->jumps, 4);

}

void sieve_jumplist_reset(struct sieve_jumplist *jlist)

{

  array_clear(&jlist->jumps);

}

void sieve_jumplist_add(struct sieve_jumplist *jlist, sieve_size_t jump)

{

  array_append(&jlist->jumps, &jump, 1);

}

void sieve_jumplist_resolve(struct sieve_jumplist *jlist)

{

  unsigned int i;

  for (i = 0; i < array_count(&jlist->jumps); i++) {

    const sieve_size_t *jump = array_idx(&jlist->jumps, i);

    sieve_binary_resolve_offset(jlist->block, *jump);

  }

}

/*

 * Code Generator

 */

struct sieve_generator {

  pool_t pool;

  struct sieve_instance *instance;

  struct sieve_error_handler *ehandler;

  struct sieve_codegen_env genenv;

  struct sieve_binary_debug_writer *dwriter;

  ARRAY(void *) ext_contexts;

};

struct sieve_generator *

sieve_generator_create(struct sieve_ast *ast,

           struct sieve_error_handler *ehandler,

           enum sieve_compile_flags flags)

{

  pool_t pool;

  struct sieve_generator *gentr;

  struct sieve_script *script;

  struct sieve_instance *svinst;

  pool = pool_alloconly_create("sieve_generator", 4096);

  gentr = p_new(pool, struct sieve_generator, 1);

  gentr->pool = pool;

  gentr->ehandler = ehandler;

  sieve_error_handler_ref(ehandler);

  gentr->genenv.gentr = gentr;

  gentr->genenv.flags = flags;

  gentr->genenv.ast = ast;

  sieve_ast_ref(ast);

  script = sieve_ast_script(ast);

  svinst = sieve_script_svinst(script);

  gentr->genenv.script = script;

  gentr->genenv.svinst = svinst;

  /* Setup storage for extension contexts */

  p_array_init(&gentr->ext_contexts, pool,

         sieve_extensions_get_count(svinst));

  return gentr;

}

void sieve_generator_free(struct sieve_generator **gentr)

{

  sieve_ast_unref(&(*gentr)->genenv.ast);

  sieve_error_handler_unref(&(*gentr)->ehandler);

  sieve_binary_debug_writer_deinit(&(*gentr)->dwriter);

  sieve_binary_unref(&(*gentr)->genenv.sbin);

  pool_unref(&((*gentr)->pool));

  *gentr = NULL;

}

/*

 * Accessors

 */

struct sieve_error_handler *

sieve_generator_error_handler(struct sieve_generator *gentr)

{

  return gentr->ehandler;

}

pool_t sieve_generator_pool(struct sieve_generator *gentr)

{

  return gentr->pool;

}

struct sieve_script *sieve_generator_script(struct sieve_generator *gentr)

{

  return gentr->genenv.script;

}

struct sieve_binary *sieve_generator_get_binary(struct sieve_generator *gentr)

{

  return gentr->genenv.sbin;

}

struct sieve_binary_block *

sieve_generator_get_block(struct sieve_generator *gentr)

{

  return gentr->genenv.sblock;

}

/*

 * Extension support

 */

void sieve_generator_extension_set_context(struct sieve_generator *gentr,

             const struct sieve_extension *ext,

             void *context)

{

  if (ext->id < 0)

    return;

  array_idx_set(&gentr->ext_contexts, (unsigned int) ext->id, &context);

}

const void *

sieve_generator_extension_get_context(struct sieve_generator *gentr,

              const struct sieve_extension *ext)

{

  void *const *ctx;

  if (ext->id < 0 || ext->id >= (int) array_count(&gentr->ext_contexts))

    return NULL;

  ctx = array_idx(&gentr->ext_contexts, (unsigned int) ext->id);

  return *ctx;

}

/*

 * Code generation API

 */

static void

sieve_generate_debug_from_ast_node(const struct sieve_codegen_env *cgenv,

           struct sieve_ast_node *ast_node)

{

  sieve_size_t address = sieve_binary_block_get_size(cgenv->sblock);

  unsigned int line = sieve_ast_node_line(ast_node);

  sieve_binary_debug_emit(cgenv->gentr->dwriter, address, line, 0);

}

static void

sieve_generate_debug_from_ast_argument(const struct sieve_codegen_env *cgenv,

               struct sieve_ast_argument *ast_arg)

{

  sieve_size_t address = sieve_binary_block_get_size(cgenv->sblock);

  unsigned int line = sieve_ast_argument_line(ast_arg);

  sieve_binary_debug_emit(cgenv->gentr->dwriter, address, line, 0);

}

bool sieve_generate_argument(const struct sieve_codegen_env *cgenv,

           struct sieve_ast_argument *arg,

           struct sieve_command *cmd)

{

  const struct sieve_argument_def *arg_def;

  if (arg->argument == NULL || arg->argument->def == NULL)

    return FALSE;

  arg_def = arg->argument->def;

  if (arg_def->generate == NULL)

    return TRUE;

  sieve_generate_debug_from_ast_argument(cgenv, arg);

  return arg_def->generate(cgenv, arg, cmd);

}

bool sieve_generate_arguments(const struct sieve_codegen_env *cgenv,

            struct sieve_command *cmd,

            struct sieve_ast_argument **last_arg_r)

{

  enum { ARG_START, ARG_OPTIONAL, ARG_POSITIONAL } state = ARG_START;

  struct sieve_ast_argument *arg =

    sieve_ast_argument_first(cmd->ast_node);

  /* Generate all arguments with assigned generator function */

  while (arg != NULL) {

    const struct sieve_argument *argument;

    const struct sieve_argument_def *arg_def;

    if (arg->argument == NULL || arg->argument->def == NULL)

      return FALSE;

    argument = arg->argument;

    arg_def = argument->def;

    switch (state) {

    case ARG_START:

      if (argument->id_code == 0)

        state = ARG_POSITIONAL;

      else {

        /* Mark start of optional operands with 0

           operand identifier */

        sieve_binary_emit_byte(cgenv->sblock,

                   SIEVE_OPERAND_OPTIONAL);

        /* Emit argument id for optional operand */

        sieve_binary_emit_byte(

          cgenv->sblock,

          (unsigned char)argument->id_code);

        state = ARG_OPTIONAL;

      }

      break;

    case ARG_OPTIONAL:

      if (argument->id_code == 0)

        state = ARG_POSITIONAL;

      /* Emit argument id for optional operand (0 marks the

         end of the optionals) */

      sieve_binary_emit_byte(

        cgenv->sblock,

        (unsigned char)argument->id_code);

      break;

    case ARG_POSITIONAL:

      if (argument->id_code != 0)

        return FALSE;

      break;

    }

    /* Call the generation function for the argument */

    if (arg_def->generate != NULL) {

      sieve_generate_debug_from_ast_argument(cgenv, arg);

      if (!arg_def->generate(cgenv, arg, cmd))

        return FALSE;

    } else if (state == ARG_POSITIONAL) {

      break;

    }

    arg = sieve_ast_argument_next(arg);

  }

  /* Mark end of optional list if it is still open */

  if (state == ARG_OPTIONAL)

    sieve_binary_emit_byte(cgenv->sblock, 0);

  if (last_arg_r != NULL)

    *last_arg_r = arg;

  return TRUE;

}

bool sieve_generate_argument_parameters(const struct sieve_codegen_env *cgenv,

          struct sieve_command *cmd,

          struct sieve_ast_argument *arg)

{

  struct sieve_ast_argument *param = arg->parameters;

  /* Generate all parameters with assigned generator function */

  while (param != NULL) {

    if (param->argument != NULL && param->argument->def != NULL) {

      const struct sieve_argument_def *parameter =

        param->argument->def;

      /* Call the generation function for the parameter */

      if (parameter->generate != NULL) {

        sieve_generate_debug_from_ast_argument(

          cgenv, param);

        if (!parameter->generate(cgenv, param, cmd))

          return FALSE;

      }

    }

    param = sieve_ast_argument_next(param);

  }

  return TRUE;

}

bool sieve_generate_test(const struct sieve_codegen_env *cgenv,

       struct sieve_ast_node *tst_node,

       struct sieve_jumplist *jlist, bool jump_true)

{

  struct sieve_command *test;

  const struct sieve_command_def *tst_def;

  i_assert(tst_node->command != NULL && tst_node->command->def != NULL);

  test = tst_node->command;

  tst_def = test->def;

  if (tst_def->control_generate != NULL) {

    sieve_generate_debug_from_ast_node(cgenv, tst_node);

    if (tst_def->control_generate(cgenv, test, jlist, jump_true))

      return TRUE;

    return FALSE;

  }

  if (tst_def->generate != NULL) {

    sieve_generate_debug_from_ast_node(cgenv, tst_node);

    if (tst_def->generate(cgenv, test)) {

      if (jump_true) {

        sieve_operation_emit(cgenv->sblock, NULL,

                 &sieve_jmptrue_operation);

      } else {

        sieve_operation_emit(cgenv->sblock, NULL,

                 &sieve_jmpfalse_operation);

      }

      sieve_jumplist_add(

        jlist,

        sieve_binary_emit_offset(cgenv->sblock, 0));

      return TRUE;

    }

    return FALSE;

  }

  return TRUE;

}

static bool

sieve_generate_command(const struct sieve_codegen_env *cgenv,

           struct sieve_ast_node *cmd_node)

{

  struct sieve_command *command;

  const struct sieve_command_def *cmd_def;

  i_assert(cmd_node->command != NULL && cmd_node->command->def != NULL);

  command = cmd_node->command;

  cmd_def = command->def;

  if (cmd_def->generate != NULL) {

    sieve_generate_debug_from_ast_node(cgenv, cmd_node);

    return cmd_def->generate(cgenv, command);

  }

  return TRUE;

}

bool sieve_generate_block(const struct sieve_codegen_env *cgenv,

        struct sieve_ast_node *block)

{

  bool result = TRUE;

  struct sieve_ast_node *cmd_node;

  T_BEGIN {

    cmd_node = sieve_ast_command_first(block);

    while (result && cmd_node != NULL) {

      result = sieve_generate_command(cgenv, cmd_node);

      cmd_node = sieve_ast_command_next(cmd_node);

    }

  } T_END;

  return result;

}

struct sieve_binary *

sieve_generator_run(struct sieve_generator *gentr,

        struct sieve_binary_block **sblock_r)

{

  bool topmost = (sblock_r == NULL || *sblock_r == NULL);

  struct sieve_binary *sbin;

  struct sieve_binary_block *sblock, *debug_block;

  const struct sieve_extension *const *extensions;

  unsigned int i, ext_count;

  bool result = TRUE;

  /* Initialize */

  if (topmost) {

    sbin = sieve_binary_create_new(

      sieve_ast_script(gentr->genenv.ast));

    sblock = sieve_binary_block_get(

      sbin, SBIN_SYSBLOCK_MAIN_PROGRAM);

  } else {

    sblock = *sblock_r;

    sbin = sieve_binary_block_get_binary(sblock);

  }

  i_assert(sbin != NULL);

  gentr->genenv.sbin = sbin;

  gentr->genenv.sblock = sblock;

  sieve_binary_ref(gentr->genenv.sbin);

  /* Create debug block */

  debug_block = sieve_binary_block_create(sbin);

  gentr->dwriter = sieve_binary_debug_writer_init(debug_block);

  (void)sieve_binary_emit_unsigned(

    sblock, sieve_binary_block_get_id(debug_block));

  /* Load extensions linked to the AST and emit a list in code */

  extensions = sieve_ast_extensions_get(gentr->genenv.ast, &ext_count);

  (void) sieve_binary_emit_unsigned(sblock, ext_count);

  for (i = 0; i < ext_count; i++) {

    const struct sieve_extension *ext = extensions[i];

    bool deferred;

    /* Link to binary */

    (void)sieve_binary_extension_link(sbin, ext);

    /* Emit */

    sieve_binary_emit_extension(sblock, ext, 0);

    /* Emit deferred flag */

    deferred = !sieve_ast_extension_is_required(

      gentr->genenv.ast, ext);

    sieve_binary_emit_byte(sblock, (deferred ? 1 : 0));

    /* Load */

    if (ext->def != NULL && ext->def->generator_load != NULL &&

        !ext->def->generator_load(ext, &gentr->genenv))

      result = FALSE;

  }

  /* Generate code */

  if (result) {

    if (!sieve_generate_block(&gentr->genenv,

            sieve_ast_root(gentr->genenv.ast))) {

      result = FALSE;

    } else if (topmost) {

      sieve_binary_activate(sbin);

    }

  }

  /* Cleanup */

  sieve_binary_unref(&gentr->genenv.sbin);

  gentr->genenv.sblock = NULL;

  if (!result) {

    if (topmost) {

      sieve_binary_unref(&sbin);

      if (sblock_r != NULL)

        *sblock_r = NULL;

    }

    sbin = NULL;

  } else {

    if (sblock_r != NULL)

      *sblock_r = sblock;

  }

  return sbin;

}

/*

 * Error handling

 */

#undef sieve_generator_error

void sieve_generator_error(struct sieve_generator *gentr,

         const char *csrc_filename, unsigned int csrc_linenum,

         unsigned int source_line, const char *fmt, ...)

{

  struct sieve_error_params params = {

    .log_type = LOG_TYPE_ERROR,

    .csrc = {

      .filename = csrc_filename,

      .linenum = csrc_linenum,

    },

  };

  va_list args;

  params.location =

    sieve_error_script_location(gentr->genenv.script, source_line);

  va_start(args, fmt);

  sieve_logv(gentr->ehandler, &params, fmt, args);

  va_end(args);

}

#undef sieve_generator_warning

void sieve_generator_warning(struct sieve_generator *gentr,

           const char *csrc_filename,

           unsigned int csrc_linenum,

           unsigned int source_line, const char *fmt, ...)

{

  struct sieve_error_params params = {

    .log_type = LOG_TYPE_WARNING,

    .csrc = {

      .filename = csrc_filename,

      .linenum = csrc_linenum,

    },

  };

  va_list args;

  params.location =

    sieve_error_script_location(gentr->genenv.script, source_line);

  va_start(args, fmt);

  sieve_logv(gentr->ehandler, &params, fmt, args);

  va_end(args);

}

#undef sieve_generator_critical

void sieve_generator_critical(struct sieve_generator *gentr,

            const char *csrc_filename,

            unsigned int csrc_linenum,

            unsigned int source_line, const char *fmt, ...)

{

  struct sieve_error_params params = {

    .log_type = LOG_TYPE_ERROR,

    .csrc = {

      .filename = csrc_filename,

      .linenum = csrc_linenum,

    },

  };

  va_list args;

  params.location =

    sieve_error_script_location(gentr->genenv.script, source_line);

  va_start(args, fmt);

  sieve_criticalv(gentr->genenv.svinst, gentr->ehandler, &params,

      "Code generation failed", fmt, args);

  va_end(args);

}