Move everything around - delete old Haskell code, clean up build.

compile.c

@@ -0,0 +1,613 @@
+#include <assert.h>
+#include <string.h>
+#include <stdlib.h>
+#include "opcode.h"
+#include "compile.h"
+#include "locfile.h"
+
+struct inst {
+  struct inst* next;
+  struct inst* prev;
+
+  opcode op;
+  
+  union {
+    uint16_t intval;
+    struct inst* target;
+    jv constant;
+    struct cfunction* cfunc;
+  } imm;
+
+  location source;
+
+  // Binding
+  // An instruction requiring binding (for parameters/variables)
+  // is in one of three states:
+  //   bound_by = NULL  - Unbound free variable
+  //   bound_by = self  - This instruction binds a variable
+  //   bound_by = other - Uses variable bound by other instruction
+  // The immediate field is generally not meaningful until instructions
+  // are bound, and even then only for instructions which bind.
+  struct inst* bound_by;
+  char* symbol;
+  block subfn;
+
+  // This instruction is compiled as part of which function?
+  // (only used during block_compile)
+  struct bytecode* compiled;
+
+  int bytecode_pos; // position just after this insn
+};
+
+static inst* inst_new(opcode op) {
+  inst* i = malloc(sizeof(inst));
+  i->next = i->prev = 0;
+  i->op = op;
+  i->bytecode_pos = -1;
+  i->bound_by = 0;
+  i->symbol = 0;
+  i->subfn = gen_noop();
+  i->source = UNKNOWN_LOCATION;
+  return i;
+}
+
+static void inst_free(struct inst* i) {
+  free(i->symbol);
+  if (opcode_describe(i->op)->flags & OP_HAS_BLOCK) {
+    block_free(i->subfn);
+  }
+  if (opcode_describe(i->op)->flags & OP_HAS_CONSTANT) {
+    jv_free(i->imm.constant);
+  }
+  free(i);
+}
+
+static block inst_block(inst* i) {
+  block b = {i,i};
+  return b;
+}
+
+static int block_is_single(block b) {
+  return b.first && b.first == b.last;
+}
+
+static inst* block_take(block* b) {
+  if (b->first == 0) return 0;
+  inst* i = b->first;
+  if (i->next) {
+    i->next->prev = 0;
+    b->first = i->next;
+    i->next = 0;
+  } else {
+    b->first = 0;
+    b->last = 0;
+  }
+  return i;
+}
+
+block gen_location(location loc, block b) {
+  for (inst* i = b.first; i; i = i->next) {
+    if (i->source.start == UNKNOWN_LOCATION.start &&
+        i->source.end == UNKNOWN_LOCATION.end) {
+      i->source = loc;
+    }
+  }
+  return b;
+}
+
+block gen_noop() {
+  block b = {0,0};
+  return b;
+}
+
+block gen_op_simple(opcode op) {
+  assert(opcode_describe(op)->length == 1);
+  return inst_block(inst_new(op));
+}
+
+
+block gen_op_const(opcode op, jv constant) {
+  assert(opcode_describe(op)->flags & OP_HAS_CONSTANT);
+  inst* i = inst_new(op);
+  i->imm.constant = constant;
+  return inst_block(i);
+}
+
+block gen_op_target(opcode op, block target) {
+  assert(opcode_describe(op)->flags & OP_HAS_BRANCH);
+  assert(target.last);
+  inst* i = inst_new(op);
+  i->imm.target = target.last;
+  return inst_block(i);
+}
+
+block gen_op_targetlater(opcode op) {
+  assert(opcode_describe(op)->flags & OP_HAS_BRANCH);
+  inst* i = inst_new(op);
+  i->imm.target = 0;
+  return inst_block(i);
+}
+void inst_set_target(block b, block target) {
+  assert(block_is_single(b));
+  assert(opcode_describe(b.first->op)->flags & OP_HAS_BRANCH);
+  assert(target.last);
+  b.first->imm.target = target.last;
+}
+
+block gen_op_var_unbound(opcode op, const char* name) {
+  assert(opcode_describe(op)->flags & OP_HAS_VARIABLE);
+  inst* i = inst_new(op);
+  i->symbol = strdup(name);
+  return inst_block(i);
+}
+
+block gen_op_var_bound(opcode op, block binder) {
+  assert(block_is_single(binder));
+  block b = gen_op_var_unbound(op, binder.first->symbol);
+  b.first->bound_by = binder.first;
+  return b;
+}
+
+block gen_op_symbol(opcode op, const char* sym) {
+  assert(opcode_describe(op)->flags & OP_HAS_SYMBOL);
+  inst* i = inst_new(op);
+  i->symbol = strdup(sym);
+  return inst_block(i);
+}
+
+block gen_op_block_defn(opcode op, const char* name, block block) {
+  assert(opcode_describe(op)->flags & OP_IS_CALL_PSEUDO);
+  assert(opcode_describe(op)->flags & OP_HAS_BLOCK);
+  inst* i = inst_new(op);
+  i->subfn = block;
+  i->symbol = strdup(name);
+  return inst_block(i);
+}
+
+static void block_bind_subblock(block binder, block body, int bindflags);
+block gen_op_block_defn_rec(opcode op, const char* name, block blk) {
+  block b = gen_op_block_defn(op, name, blk);
+  block_bind_subblock(b, b, OP_IS_CALL_PSEUDO | OP_HAS_BINDING);
+  return b;
+}
+
+block gen_op_block_unbound(opcode op, const char* name) {
+  assert(opcode_describe(op)->flags & OP_IS_CALL_PSEUDO);
+  inst* i = inst_new(op);
+  i->symbol = strdup(name);
+  return inst_block(i);
+}
+
+block gen_op_block_bound(opcode op, block binder) {
+  assert(block_is_single(binder));
+  block b = gen_op_block_unbound(op, binder.first->symbol);
+  b.first->bound_by = binder.first;
+  return b;
+}
+
+block gen_op_call(opcode op, block arglist) {
+  assert(opcode_describe(op)->flags & OP_HAS_VARIABLE_LENGTH_ARGLIST);
+  inst* i = inst_new(op);
+  block prelude = gen_noop();
+  block call = inst_block(i);
+  int nargs = 0;
+  inst* curr = 0;
+  while ((curr = block_take(&arglist))) {
+    assert(opcode_describe(curr->op)->flags & OP_IS_CALL_PSEUDO);
+    block bcurr = inst_block(curr);
+    switch (curr->op) {
+    default: assert(0 && "Unknown type of parameter"); break;
+    case CLOSURE_REF:
+      block_append(&call, bcurr);
+      break;
+    case CLOSURE_CREATE:
+      block_append(&prelude, bcurr);
+      block_append(&call, gen_op_block_bound(CLOSURE_REF, bcurr));
+      break;
+    }
+    nargs++;
+  }
+  assert(nargs < 100); //FIXME
+  i->imm.intval = nargs;
+  return block_join(prelude, call);
+}
+
+static void inst_join(inst* a, inst* b) {
+  assert(a && b);
+  assert(!a->next);
+  assert(!b->prev);
+  a->next = b;
+  b->prev = a;
+}
+
+void block_append(block* b, block b2) {
+  if (b2.first) {
+    if (b->last) {
+      inst_join(b->last, b2.first);
+    } else {
+      b->first = b2.first;
+    }
+    b->last = b2.last;
+  }
+}
+
+block block_join(block a, block b) {
+  block c = a;
+  block_append(&c, b);
+  return c;
+}
+
+int block_has_only_binders(block binders, int bindflags) {
+  bindflags |= OP_HAS_BINDING;
+  for (inst* curr = binders.first; curr; curr = curr->next) {
+    if ((opcode_describe(curr->op)->flags & bindflags) != bindflags) {
+      return 0;
+    }
+  }
+  return 1;
+}
+
+static void block_bind_subblock(block binder, block body, int bindflags) {
+  assert(block_is_single(binder));
+  assert((opcode_describe(binder.first->op)->flags & bindflags) == bindflags);
+  assert(binder.first->symbol);
+  assert(binder.first->bound_by == 0 || binder.first->bound_by == binder.first);
+
+  binder.first->bound_by = binder.first;
+  for (inst* i = body.first; i; i = i->next) {
+    int flags = opcode_describe(i->op)->flags;
+    if ((flags & bindflags) == bindflags &&
+        i->bound_by == 0 &&
+        !strcmp(i->symbol, binder.first->symbol)) {
+      // bind this instruction
+      i->bound_by = binder.first;
+    }
+    if (flags & OP_HAS_BLOCK) {
+      // binding recurses into closures
+      block_bind_subblock(binder, i->subfn, bindflags);
+    }
+  }
+}
+
+block block_bind(block binder, block body, int bindflags) {
+  assert(block_has_only_binders(binder, bindflags));
+  bindflags |= OP_HAS_BINDING;
+  for (inst* curr = binder.first; curr; curr = curr->next) {
+    block_bind_subblock(inst_block(curr), body, bindflags);
+  }
+  return block_join(binder, body);
+}
+
+
+block gen_subexp(block a) {
+  block c = gen_noop();
+  block_append(&c, gen_op_simple(DUP));
+  block_append(&c, a);
+  block_append(&c, gen_op_simple(SWAP));
+  return c;
+}
+
+block gen_both(block a, block b) {
+  block c = gen_noop();
+  block jump = gen_op_targetlater(JUMP);
+  block fork = gen_op_targetlater(FORK);
+  block_append(&c, fork);
+  block_append(&c, a);
+  block_append(&c, jump);
+  inst_set_target(fork, c);
+  block_append(&c, b);
+  inst_set_target(jump, c);
+  return c;
+}
+
+
+block gen_collect(block expr) {
+  block c = gen_noop();
+  block_append(&c, gen_op_simple(DUP));
+  block_append(&c, gen_op_const(LOADK, jv_array()));
+  block array_var = block_bind(gen_op_var_unbound(STOREV, "collect"),
+                               gen_noop(), OP_HAS_VARIABLE);
+  block_append(&c, array_var);
+
+  block tail = {0};
+  block_append(&tail, gen_op_simple(DUP));
+  block_append(&tail, gen_op_var_bound(LOADV, array_var));
+  block_append(&tail, gen_op_simple(SWAP));
+  block_append(&tail, gen_op_simple(APPEND));
+  block_append(&tail, gen_op_var_bound(STOREV, array_var));
+  block_append(&tail, gen_op_simple(BACKTRACK));
+
+  block_append(&c, gen_op_target(FORK, tail));
+  block_append(&c, expr);
+  block_append(&c, tail);
+
+  block_append(&c, gen_op_var_bound(LOADV, array_var));
+
+  return c;
+}
+
+block gen_assign(block expr) {
+  block c = gen_noop();
+  block_append(&c, gen_op_simple(DUP));
+  block result_var = block_bind(gen_op_var_unbound(STOREV, "result"),
+                                gen_noop(), OP_HAS_VARIABLE);
+  block_append(&c, result_var);
+
+  block loop = gen_noop();
+  block_append(&loop, gen_op_simple(DUP));
+  block_append(&loop, expr);
+  block_append(&loop, gen_op_var_bound(ASSIGN, result_var));
+  block_append(&loop, gen_op_simple(BACKTRACK));
+
+  block_append(&c, gen_op_target(FORK, loop));
+  block_append(&c, loop);
+  block_append(&c, gen_op_var_bound(LOADV, result_var));
+  return c;
+}
+
+block gen_definedor(block a, block b) {
+  // var found := false
+  block c = gen_op_simple(DUP);
+  block_append(&c, gen_op_const(LOADK, jv_false()));
+  block found_var = block_bind(gen_op_var_unbound(STOREV, "found"),
+                               gen_noop(), OP_HAS_VARIABLE);
+  block_append(&c, found_var);
+
+  // if found, backtrack. Otherwise execute b
+  block tail = gen_op_simple(DUP);
+  block_append(&tail, gen_op_var_bound(LOADV, found_var));
+  block backtrack = gen_op_simple(BACKTRACK);
+  block_append(&tail, gen_op_target(JUMP_F, backtrack));
+  block_append(&tail, backtrack);
+  block_append(&tail, gen_op_simple(POP));
+  block_append(&tail, b);
+
+  // try again
+  block if_notfound = gen_op_simple(BACKTRACK);
+
+  // found := true, produce result
+  block if_found = gen_op_simple(DUP);
+  block_append(&if_found, gen_op_const(LOADK, jv_true()));
+  block_append(&if_found, gen_op_var_bound(STOREV, found_var));
+  block_append(&if_found, gen_op_target(JUMP, tail));
+
+  block_append(&c, gen_op_target(FORK, if_notfound));
+  block_append(&c, a);
+  block_append(&c, gen_op_target(JUMP_F, if_found));
+  block_append(&c, if_found);
+  block_append(&c, if_notfound);
+  block_append(&c, tail);
+
+  return c;
+}
+
+block gen_condbranch(block iftrue, block iffalse) {
+  block b = gen_noop();
+  block_append(&iftrue, gen_op_target(JUMP, iffalse));
+  block_append(&b, gen_op_target(JUMP_F, iftrue));
+  block_append(&b, iftrue);
+  block_append(&b, iffalse);
+  return b;
+}
+
+block gen_and(block a, block b) {
+  // a and b = if a then (if b then true else false) else false
+  block code = gen_op_simple(DUP);
+  block_append(&code, a);
+
+  block if_a_true = gen_op_simple(POP);
+  block_append(&if_a_true, b);
+  block_append(&if_a_true, gen_condbranch(gen_op_const(LOADK, jv_true()),
+                                          gen_op_const(LOADK, jv_false())));
+  block_append(&code, gen_condbranch(if_a_true,
+                                     block_join(gen_op_simple(POP), gen_op_const(LOADK, jv_false()))));
+  return code;
+}
+
+block gen_or(block a, block b) {
+  // a or b = if a then true else (if b then true else false)
+  block code = gen_op_simple(DUP);
+  block_append(&code, a);
+
+  block if_a_false = gen_op_simple(POP);
+  block_append(&if_a_false, b);
+  block_append(&if_a_false, gen_condbranch(gen_op_const(LOADK, jv_true()),
+                                           gen_op_const(LOADK, jv_false())));
+  block_append(&code, gen_condbranch(block_join(gen_op_simple(POP), gen_op_const(LOADK, jv_true())),
+                                     if_a_false));
+  return code;
+}
+
+block gen_cond(block cond, block iftrue, block iffalse) {
+  block b = gen_op_simple(DUP);
+  block_append(&b, cond);
+  block_append(&b, gen_condbranch(block_join(gen_op_simple(POP), iftrue),
+                                  block_join(gen_op_simple(POP), iffalse)));
+  return b;
+}
+
+block gen_cbinding(struct symbol_table* t, block code) {
+  for (int cfunc=0; cfunc<t->ncfunctions; cfunc++) {
+    inst* i = inst_new(CLOSURE_CREATE_C);
+    i->imm.cfunc = &t->cfunctions[cfunc];
+    i->symbol = strdup(i->imm.cfunc->name);
+    code = block_bind(inst_block(i), code, OP_IS_CALL_PSEUDO);
+  }
+  return code;
+}
+
+static uint16_t nesting_level(struct bytecode* bc, inst* target) {
+  uint16_t level = 0;
+  assert(bc && target->compiled);
+  while (bc && target->compiled != bc) {
+    level++;
+    bc = bc->parent;
+  }
+  assert(bc && bc == target->compiled);
+  return level;
+}
+
+static int count_cfunctions(block b) {
+  int n = 0;
+  for (inst* i = b.first; i; i = i->next) {
+    if (i->op == CLOSURE_CREATE_C) n++;
+    if (opcode_describe(i->op)->flags & OP_HAS_BLOCK)
+      n += count_cfunctions(i->subfn);
+  }
+  return n;
+}
+
+static int compile(struct locfile* locations, struct bytecode* bc, block b) {
+  int errors = 0;
+  int pos = 0;
+  int var_frame_idx = 0;
+  bc->nsubfunctions = 0;
+  bc->nclosures = 0;
+  for (inst* curr = b.first; curr; curr = curr->next) {
+    if (!curr->next) assert(curr == b.last);
+    pos += opcode_length(curr->op);
+    curr->bytecode_pos = pos;
+    curr->compiled = bc;
+
+    int opflags = opcode_describe(curr->op)->flags;
+    if (opflags & OP_HAS_BINDING) {
+      if (!curr->bound_by) {
+        locfile_locate(locations, curr->source, "error: %s is not defined", curr->symbol);
+        errors++;
+      }
+    }
+    if ((opflags & OP_HAS_VARIABLE) &&
+        curr->bound_by == curr) {
+      curr->imm.intval = var_frame_idx++;
+    }
+    if (opflags & OP_HAS_BLOCK) {
+      assert(curr->bound_by == curr);
+      curr->imm.intval = bc->nsubfunctions++;
+    }
+    if (curr->op == CLOSURE_PARAM) {
+      assert(curr->bound_by == curr);
+      curr->imm.intval = bc->nclosures++;
+    }
+    if (curr->op == CLOSURE_CREATE_C) {
+      assert(curr->bound_by == curr);
+      int idx = bc->globals->ncfunctions++;
+      bc->globals->cfunctions[idx] = *curr->imm.cfunc;
+      curr->imm.intval = idx;
+    }
+  }
+  if (bc->nsubfunctions) {
+    bc->subfunctions = malloc(sizeof(struct bytecode*) * bc->nsubfunctions);
+    for (inst* curr = b.first; curr; curr = curr->next) {
+      if (!(opcode_describe(curr->op)->flags & OP_HAS_BLOCK))
+        continue;
+      struct bytecode* subfn = malloc(sizeof(struct bytecode));
+      bc->subfunctions[curr->imm.intval] = subfn;
+      subfn->globals = bc->globals;
+      subfn->parent = bc;
+      errors += compile(locations, subfn, curr->subfn);
+    }
+  } else {
+    bc->subfunctions = 0;
+  }
+  bc->codelen = pos;
+  uint16_t* code = malloc(sizeof(uint16_t) * bc->codelen);
+  bc->code = code;
+  pos = 0;
+  jv constant_pool = jv_array();
+  int maxvar = -1;
+  if (!errors) for (inst* curr = b.first; curr; curr = curr->next) {
+    const struct opcode_description* op = opcode_describe(curr->op);
+    if (op->length == 0)
+      continue;
+    uint16_t* opcode_rewrite = &code[pos];
+    code[pos++] = curr->op;
+    int opflags = op->flags;
+    assert(!(op->flags & OP_IS_CALL_PSEUDO));
+    if (opflags & OP_HAS_VARIABLE_LENGTH_ARGLIST) {
+      int nargs = curr->imm.intval;
+      assert(nargs > 0);
+      code[pos++] = (uint16_t)nargs;
+      int desired_params;
+      for (int i=0; i<nargs; i++) {
+        curr = curr->next;
+        assert(curr && opcode_describe(curr->op)->flags & OP_IS_CALL_PSEUDO);
+        code[pos++] = nesting_level(bc, curr->bound_by);
+        switch (curr->bound_by->op) {
+        default: assert(0 && "Unknown type of argument");
+        case CLOSURE_CREATE:
+          code[pos++] = curr->bound_by->imm.intval | ARG_NEWCLOSURE;
+          if (i == 0) {
+            inst* i = curr->bound_by;
+            desired_params = i->compiled->subfunctions[i->imm.intval]->nclosures;
+          }
+          break;
+        case CLOSURE_PARAM:
+          code[pos++] = curr->bound_by->imm.intval;
+          if (i == 0) desired_params = 0;
+          break;
+        case CLOSURE_CREATE_C:
+          code[pos++] = curr->bound_by->imm.intval;
+          *opcode_rewrite = bc->globals->cfunctions[curr->bound_by->imm.intval].callop;
+          if (i == 0) desired_params = 0;
+          break;
+        }
+      }
+      assert(nargs - 1 == desired_params);
+    } else if (opflags & OP_HAS_CONSTANT) {
+      code[pos++] = jv_array_length(jv_copy(constant_pool));
+      constant_pool = jv_array_append(constant_pool, jv_copy(curr->imm.constant));
+    } else if (opflags & OP_HAS_VARIABLE) {
+      code[pos++] = nesting_level(bc, curr->bound_by);
+      uint16_t var = (uint16_t)curr->bound_by->imm.intval;
+      code[pos++] = var;
+      if (var > maxvar) maxvar = var;
+    } else if (opflags & OP_HAS_BRANCH) {
+      assert(curr->imm.target->bytecode_pos != -1);
+      assert(curr->imm.target->bytecode_pos > pos); // only forward branches
+      code[pos] = curr->imm.target->bytecode_pos - (pos + 1);
+      pos++;
+    } else if (opflags & OP_HAS_CFUNC) {
+      assert(curr->symbol);
+      int found = 0;
+      for (int i=0; i<bc->globals->ncfunctions; i++) {
+        if (!strcmp(curr->symbol, bc->globals->cfunctions[i].name)) {
+          code[pos++] = i;
+          found = 1;
+          break;
+        }
+      }
+      assert(found);
+    } else if (op->length > 1) {
+      assert(0 && "codegen not implemented for this operation");
+    }
+  }
+  bc->constants = constant_pool;
+  bc->nlocals = maxvar + 2; // FIXME: frames of size zero?
+  return errors;
+}
+
+int block_compile(block b, struct locfile* locations, struct bytecode** out) {
+  struct bytecode* bc = malloc(sizeof(struct bytecode));
+  bc->parent = 0;
+  bc->globals = malloc(sizeof(struct symbol_table));
+  int ncfunc = count_cfunctions(b);
+  bc->globals->ncfunctions = 0;
+  bc->globals->cfunctions = malloc(sizeof(struct cfunction) * ncfunc);
+  int nerrors = compile(locations, bc, b);
+  assert(bc->globals->ncfunctions == ncfunc);
+  if (nerrors > 0) {
+    bytecode_free(bc);
+    *out = 0;
+  } else {
+    *out = bc;
+  }
+  return nerrors;
+}
+
+void block_free(block b) {
+  struct inst* next;
+  for (struct inst* curr = b.first; curr; curr = next) {
+    next = curr->next;
+    inst_free(curr);
+  }
+}