doc(library/compiler/ir_interpreter): add a few comments
This commit is contained in:
Sebastian Ullrich
parent
d27cbe2dc5
commit
1732461a66
1 changed files with 131 additions and 57 deletions
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@ -3,6 +3,27 @@ Copyright (c) 2019 Microsoft Corporation. All rights reserved.
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Released under Apache 2.0 license as described in the file LICENSE.
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Author: Sebastian Ullrich
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A simple interpreter for evaluating λRC IR code.
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Motivation
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==========
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Even with a JIT compiler, we still have a need for a simpler interpreter on platforms LLVM JIT does not support (i.e.
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WebAssembly). Because this is mostly an edge case, we strive for simplicity instead of performance and thus reuse the
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existing compiler IR instead of inventing something like a new bytecode format.
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Implementation
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==============
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The interpreter mainly consists of a homogeneous stack of boxed `object *` values. IR variables are mapped to stack
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slots by adding the current base pointer to the variable index. Further stacks are used for storing join points and call
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stack metadata. The interpreted IR is taken directly from the environment. Whenever possible, we try to switch to native
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code by checking for the mangled symbol via dlsym/GetProcAddress, which is also how we can call external functions (but
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only if the file declaring them has already been compiled). We always call the "boxed" versions of native functions,
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which have a (relatively) homogeneous ABI that we can use without runtime code generation; see also `call/lookup_symbol`
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below.
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*/
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#include <string>
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#include <vector>
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@ -17,9 +38,12 @@ Author: Sebastian Ullrich
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namespace lean {
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namespace ir {
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// C++ wrappers of Lean data types
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typedef object_ref lit_val;
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typedef object_ref ctor_info;
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// TODO(Sebastian): move
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template<class T>
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inline T const & cnstr_get_ref_t(object_ref const & o, unsigned i) {
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static_assert(sizeof(T) == sizeof(object_ref), "unexpected object wrapper size");
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@ -35,7 +59,7 @@ nat const & lit_val_num(lit_val const & l) { lean_assert(lit_val_tag(l) == lit_v
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string_ref const & lit_val_str(lit_val const & l) { lean_assert(lit_val_tag(l) == lit_val_kind::Str); return cnstr_get_ref_t<string_ref>(l, 0); }
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name const & ctor_info_name(ctor_info const & c) { return cnstr_get_ref_t<name>(c, 0); }
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nat const & ctor_info_idx(ctor_info const & c) { return cnstr_get_ref_t<nat>(c, 1); }
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nat const & ctor_info_tag(ctor_info const & c) { return cnstr_get_ref_t<nat>(c, 1); }
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nat const & ctor_info_size(ctor_info const & c) { return cnstr_get_ref_t<nat>(c, 2); }
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nat const & ctor_info_usize(ctor_info const & c) { return cnstr_get_ref_t<nat>(c, 3); }
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nat const & ctor_info_ssize(ctor_info const & c) { return cnstr_get_ref_t<nat>(c, 4); }
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@ -54,7 +78,7 @@ nat const & expr_proj_idx(expr const & e) { lean_assert(expr_tag(e) == expr_kind
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var_id const & expr_proj_obj(expr const & e) { lean_assert(expr_tag(e) == expr_kind::Proj); return cnstr_get_ref_t<var_id>(e, 1); }
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nat const & expr_uproj_idx(expr const & e) { lean_assert(expr_tag(e) == expr_kind::UProj); return cnstr_get_ref_t<nat>(e, 0); }
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var_id const & expr_uproj_obj(expr const & e) { lean_assert(expr_tag(e) == expr_kind::UProj); return cnstr_get_ref_t<var_id>(e, 1); }
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nat const & expr_sproj_num_objs(expr const & e) { lean_assert(expr_tag(e) == expr_kind::SProj); return cnstr_get_ref_t<nat>(e, 0); }
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nat const & expr_sproj_idx(expr const & e) { lean_assert(expr_tag(e) == expr_kind::SProj); return cnstr_get_ref_t<nat>(e, 0); }
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nat const & expr_sproj_offset(expr const & e) { lean_assert(expr_tag(e) == expr_kind::SProj); return cnstr_get_ref_t<nat>(e, 1); }
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var_id const & expr_sproj_obj(expr const & e) { lean_assert(expr_tag(e) == expr_kind::SProj); return cnstr_get_ref_t<var_id>(e, 2); }
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fun_id const & expr_fap_fun(expr const & e) { lean_assert(expr_tag(e) == expr_kind::FAp); return cnstr_get_ref_t<fun_id>(e, 0); }
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@ -103,7 +127,7 @@ nat const & fn_body_uset_idx(fn_body const & b) { lean_assert(fn_body_tag(b) ==
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var_id const & fn_body_uset_arg(fn_body const & b) { lean_assert(fn_body_tag(b) == fn_body_kind::USet); return cnstr_get_ref_t<var_id>(b, 2); }
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fn_body const & fn_body_uset_cont(fn_body const & b) { lean_assert(fn_body_tag(b) == fn_body_kind::USet); return cnstr_get_ref_t<fn_body>(b, 3); }
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var_id const & fn_body_sset_target(fn_body const & b) { lean_assert(fn_body_tag(b) == fn_body_kind::SSet); return cnstr_get_ref_t<var_id>(b, 0); }
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nat const & fn_body_sset_num_objs(fn_body const & b) { lean_assert(fn_body_tag(b) == fn_body_kind::SSet); return cnstr_get_ref_t<nat>(b, 1); }
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nat const & fn_body_sset_idx(fn_body const & b) { lean_assert(fn_body_tag(b) == fn_body_kind::SSet); return cnstr_get_ref_t<nat>(b, 1); }
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nat const & fn_body_sset_offset(fn_body const & b) { lean_assert(fn_body_tag(b) == fn_body_kind::SSet); return cnstr_get_ref_t<nat>(b, 2); }
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var_id const & fn_body_sset_source(fn_body const & b) { lean_assert(fn_body_tag(b) == fn_body_kind::SSet); return cnstr_get_ref_t<var_id>(b, 3); }
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type fn_body_sset_type(fn_body const & b) { lean_assert(fn_body_tag(b) == fn_body_kind::SSet); return static_cast<type>(cnstr_get_uint8(b.raw(), sizeof(void *) * 5)); }
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@ -143,6 +167,7 @@ option_ref<decl> find_env_decl(environment const & env, name const & n) {
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static string_ref * g_mangle_prefix = nullptr;
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static string_ref * g_boxed_mangled_suffix = nullptr;
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// reuse the compiler's name mangling to compute native symbol names
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extern "C" object * lean_name_mangle(object * n, object * pre);
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string_ref name_mangle(name const & n, string_ref const & pre) {
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return string_ref(lean_name_mangle(n.to_obj_arg(), pre.to_obj_arg()));
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@ -153,37 +178,52 @@ format format_fn_body_head(fn_body const & b) {
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return format(lean_ir_format_fn_body_head(b.to_obj_arg()));
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}
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/** \pre Very simple debug output of arbitrary objects, should be extended. */
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void print_object(io_state_stream const & ios, object * o) {
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if (is_scalar(o)) {
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ios << unbox(o);
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} else if (o == nullptr) {
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ios << "0x0"; // confusingly printed as "0" by the default operator<<
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} else {
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// merely following the trace of object addresses is surprisingly helpful for debugging
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ios.get_stream() << o;
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}
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}
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class interpreter {
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// stack of IR variable slots
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std::vector<object *> m_arg_stack;
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// stack of join points
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std::vector<fn_body const *> m_jp_stack;
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struct frame {
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name m_fn;
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// base pointers into the stack above
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size_t m_arg_bp;
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size_t m_jp_bp;
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};
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std::vector<frame> m_call_stack;
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environment const & m_env;
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// caches values of nullary functions ("constants")
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name_map<object *> m_constant_cache;
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struct symbol_cache_entry { void * m_addr; bool m_boxed; };
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struct symbol_cache_entry {
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// symbol address; `nullptr` if function does not have native code
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void * m_addr;
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// true iff we chose the boxed version of a function where the IR uses the unboxed version
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bool m_boxed;
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};
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// caches symbol lookup successes _and_ failures
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name_map<symbol_cache_entry> m_symbol_cache;
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/** \brief Get current stack frame */
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inline frame & get_frame() {
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return m_call_stack.back();
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}
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/** \brief Get reference to stack slot of IR variable */
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inline object * & var(var_id const & v) {
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// variables are 1-indexed
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size_t i = get_frame().m_arg_bp + v.get_small_value() - 1;
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// we don't know the frame size (unless we do an additional IR pass), so we extend it dynamically
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if (i >= m_arg_stack.size()) {
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m_arg_stack.resize(i + 1);
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}
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@ -191,18 +231,24 @@ class interpreter {
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}
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object * eval_arg(arg const & a) {
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// an "irrelevant" argument is type- or proof-erased; we can use an arbitrary value for it
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return arg_is_irrelevant(a) ? box(0) : var(arg_var_id(a));
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}
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/** \brief Allocate constructor object with given tag and arguments */
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object * alloc_ctor(ctor_info const & i, array_ref<arg> const & args) {
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size_t idx = ctor_info_idx(i).get_small_value();
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size_t tag = ctor_info_tag(i).get_small_value();
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// number of boxed object fields
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size_t size = ctor_info_size(i).get_small_value();
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// number of unboxed USize fields (whose byte size the IR is ignorant of)
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size_t usize = ctor_info_usize(i).get_small_value();
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// byte size of all other unboxed fields
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size_t ssize = ctor_info_ssize(i).get_small_value();
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if (size == 0 && usize == 0 && ssize == 0) {
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return box(idx);
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// a constructor without data is optimized to a tagged pointer
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return box(tag);
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} else {
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object *o = alloc_cnstr(idx, size, usize * sizeof(void *) + ssize);
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object *o = alloc_cnstr(tag, size, usize * sizeof(void *) + ssize);
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for (size_t i = 0; i < args.size(); i++) {
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cnstr_set(o, i, eval_arg(args[i]));
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}
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@ -214,7 +260,7 @@ class interpreter {
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switch (expr_tag(e)) {
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case expr_kind::Ctor:
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return alloc_ctor(expr_ctor_info(e), expr_ctor_args(e));
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case expr_kind::Reset: {
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case expr_kind::Reset: { // release fields if unique reference in preparation for `Reuse` below
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object * o = var(expr_reset_obj(e));
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if (is_exclusive(o)) {
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for (size_t i = 0; i < expr_reset_num_objs(e).get_small_value(); i++) {
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@ -226,13 +272,16 @@ class interpreter {
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return box(0);
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}
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}
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case expr_kind::Reuse: {
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case expr_kind::Reuse: { // reuse dead allocation if possible
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object * o = var(expr_reuse_obj(e));
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// check if `Reset` above had a unique reference it consumed
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if (is_scalar(o)) {
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// fall back to regular allocation
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return alloc_ctor(expr_reuse_ctor(e), expr_reuse_args(e));
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} else {
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// create new constructor object in-place
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if (expr_reuse_update_header(e)) {
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cnstr_set_tag(o, ctor_info_idx(expr_reuse_ctor(e)).get_small_value());
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cnstr_set_tag(o, ctor_info_tag(expr_reuse_ctor(e)).get_small_value());
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}
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for (size_t i = 0; i < expr_reuse_args(e).size(); i++) {
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cnstr_set(o, i, eval_arg(expr_reuse_args(e)[i]));
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@ -240,12 +289,12 @@ class interpreter {
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return o;
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}
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}
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case expr_kind::Proj:
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case expr_kind::Proj: // object field access
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return cnstr_get(var(expr_proj_obj(e)), expr_proj_idx(e).get_small_value());
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case expr_kind::UProj:
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case expr_kind::UProj: // USize field access
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return box_size_t(cnstr_get_usize(var(expr_uproj_obj(e)), expr_uproj_idx(e).get_small_value()));
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case expr_kind::SProj: {
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size_t offset = expr_sproj_num_objs(e).get_small_value() * sizeof(void *) +
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case expr_kind::SProj: { // other unboxed field access
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size_t offset = expr_sproj_idx(e).get_small_value() * sizeof(void *) +
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expr_sproj_offset(e).get_small_value();
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object *o = var(expr_sproj_obj(e));
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switch (t) {
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@ -257,29 +306,39 @@ class interpreter {
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default: throw exception("invalid instruction");
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}
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}
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case expr_kind::FAp: {
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case expr_kind::FAp: { // satured ("full") application of top-level function
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if (expr_fap_args(e).size()) {
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return call(expr_fap_fun(e), expr_fap_args(e));
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} else {
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// nullary function ("constant"), cache
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object * const * cached = m_constant_cache.find(expr_fap_fun(e));
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if (cached) {
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return *cached;
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} else {
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object * r = load(expr_fap_fun(e), t);
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// the IR expects constants to be persistent
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// TODO(Sebastian): because of this, we currently leak these objects
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mark_persistent(r);
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m_constant_cache.insert(expr_fap_fun(e), r);
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return r;
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}
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}
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}
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case expr_kind::PAp: {
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case expr_kind::PAp: { // unsatured (partial) application of top-level function
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decl d = get_fdecl(expr_pap_fun(e));
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unsigned i = 0;
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object * cls;
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if (void * p = lookup_symbol(expr_pap_fun(e)).m_addr) {
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// point closure directly to native symbol
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cls = alloc_closure(p, decl_params(d).size(), expr_pap_args(e).size());
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} else {
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// point closure to interpreter stub taking interpreter data, declaration to be called, and partially
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// applied arguments
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// HACK: filling up closure to at least 16 arguments
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// Boxed functions of arity >= 16 use a single common signature, so we only need a single stub.
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cls = alloc_closure(reinterpret_cast<void *>(stub_m_aux), 16 + decl_params(d).size(), 16 + expr_pap_args(e).size());
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// FIXME: sharing the same interpreter instance including stack etc.; needs to be fixed to support
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// multithreading
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closure_set(cls, i++, box(reinterpret_cast<size_t>(this)));
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closure_set(cls, i++, d.to_obj_arg());
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for (; i < 16; i++) {
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@ -291,8 +350,9 @@ class interpreter {
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}
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return cls;
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}
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case expr_kind::Ap: {
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case expr_kind::Ap: { // (saturated or unsatured) application of closure; mostly handled by runtime
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size_t old_size = m_arg_stack.size();
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// optimization: use unused part of stack for temporarily storing evaluated arguments
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for (const auto & arg : expr_ap_args(e)) {
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m_arg_stack.push_back(eval_arg(arg));
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}
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@ -300,11 +360,11 @@ class interpreter {
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m_arg_stack.resize(old_size);
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return r;
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}
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case expr_kind::Box:
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case expr_kind::Box: // box unboxed value; no-op in interpreter
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return var(expr_box_obj(e));
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case expr_kind::Unbox:
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case expr_kind::Unbox: // unbox boxed value; no-op in interpreter
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return var(expr_unbox_obj(e));
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case expr_kind::Lit:
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case expr_kind::Lit: // load numeric or string literal
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switch (lit_val_tag(expr_lit_val(e))) {
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case lit_val_kind::Num: {
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nat const & n = lit_val_num(expr_lit_val(e));
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@ -312,9 +372,12 @@ class interpreter {
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case type::Float: throw exception("floats are not supported yet");
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case type::UInt8: return n.raw();
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case type::UInt16: return n.raw();
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// the following types might *not* use the same boxed representation as `nat`, so unbox and
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// re-box
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case type::UInt32: return box_uint32(n.get_small_value());
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case type::UInt64: return box_uint64(n.get_small_value());
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case type::USize: return box_size_t(n.get_small_value());
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// `nat` literal
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case type::Object:
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case type::TObject:
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return n.to_obj_arg();
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@ -339,34 +402,29 @@ class interpreter {
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std::reference_wrapper<fn_body const> b(b0);
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while (true) {
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DEBUG_CODE(lean_trace(name({"interpreter", "step"}),
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tout() << std::string(m_call_stack.size(), ' ') << format_fn_body_head(b) << "\n";);)
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tout() << std::string(m_call_stack.size(), ' ') << format_fn_body_head(b) << "\n";);)
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switch (fn_body_tag(b)) {
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case fn_body_kind::VDecl: {
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case fn_body_kind::VDecl: { // variable declaration
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expr const & e = fn_body_vdecl_expr(b);
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fn_body const & cont = fn_body_vdecl_cont(b);
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// tail recursion?
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if (expr_tag(e) == expr_kind::FAp && expr_fap_fun(e) == get_frame().m_fn &&
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fn_body_tag(cont) == fn_body_kind::Ret && !arg_is_irrelevant(fn_body_ret_arg(cont)) &&
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arg_var_id(fn_body_ret_arg(cont)) == fn_body_vdecl_var(b)) {
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// tail recursion
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fun_id const & fn = expr_fap_fun(e);
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decl d = get_decl(fn);
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if (!lookup_symbol(fn).m_addr) {
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if (decl_tag(d) == decl_kind::Extern) {
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throw exception(sstream() << "unexpected external declaration '" << fn << "'");
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}
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array_ref<arg> const & args = expr_fap_args(e);
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// copy bla bla
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size_t old_size = m_arg_stack.size();
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for (const auto & arg : args) {
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m_arg_stack.push_back(eval_arg(arg));
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}
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for (size_t i = 0; i < args.size(); i++) {
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m_arg_stack[get_frame().m_arg_bp + i] = m_arg_stack[old_size + i];
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}
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m_arg_stack.resize(get_frame().m_arg_bp + args.size());
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b = decl_fun_body(d);
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break;
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// tail recursion! copy argument values to parameter slots and reset `b`
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array_ref<arg> const & args = expr_fap_args(e);
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// argument and parameter slots may overlap, so first copy arguments to end of stack
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size_t old_size = m_arg_stack.size();
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for (const auto & arg : args) {
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m_arg_stack.push_back(eval_arg(arg));
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}
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// now copy to parameter slots
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for (size_t i = 0; i < args.size(); i++) {
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m_arg_stack[get_frame().m_arg_bp + i] = m_arg_stack[old_size + i];
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}
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m_arg_stack.resize(get_frame().m_arg_bp + args.size());
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b = decl_fun_body(get_decl(expr_fap_fun(e)));
|
||||
break;
|
||||
}
|
||||
var(fn_body_vdecl_var(b)) = eval_expr(fn_body_vdecl_expr(b), fn_body_vdecl_type(b));
|
||||
DEBUG_CODE(lean_trace(name({"interpreter", "step"}),
|
||||
|
|
@ -377,7 +435,7 @@ class interpreter {
|
|||
b = fn_body_vdecl_cont(b);
|
||||
break;
|
||||
}
|
||||
case fn_body_kind::JDecl: {
|
||||
case fn_body_kind::JDecl: { // join-point declaration; store in stack slot just like variables
|
||||
size_t i = get_frame().m_jp_bp + fn_body_jdecl_id(b).get_small_value();
|
||||
if (i >= m_jp_stack.size()) {
|
||||
m_jp_stack.resize(i + 1);
|
||||
|
|
@ -386,30 +444,30 @@ class interpreter {
|
|||
b = fn_body_jdecl_cont(b);
|
||||
break;
|
||||
}
|
||||
case fn_body_kind::Set: {
|
||||
case fn_body_kind::Set: { // set boxed field of unique reference
|
||||
object * o = var(fn_body_set_var(b));
|
||||
lean_assert(is_exclusive(o));
|
||||
cnstr_set(o, fn_body_set_idx(b).get_small_value(), eval_arg(fn_body_set_arg(b)));
|
||||
b = fn_body_set_cont(b);
|
||||
break;
|
||||
}
|
||||
case fn_body_kind::SetTag: {
|
||||
case fn_body_kind::SetTag: { // set constructor tag of unique reference
|
||||
object * o = var(fn_body_set_tag_var(b));
|
||||
lean_assert(is_exclusive(o));
|
||||
cnstr_set_tag(o, fn_body_set_tag_cidx(b).get_small_value());
|
||||
b = fn_body_set_tag_cont(b);
|
||||
break;
|
||||
}
|
||||
case fn_body_kind::USet: {
|
||||
case fn_body_kind::USet: { // set USize field of unique reference
|
||||
object * o = var(fn_body_uset_var(b));
|
||||
lean_assert(is_exclusive(o));
|
||||
cnstr_set_usize(o, fn_body_uset_idx(b).get_small_value(), unbox_size_t(eval_arg(fn_body_uset_arg(b))));
|
||||
b = fn_body_uset_cont(b);
|
||||
break;
|
||||
}
|
||||
case fn_body_kind::SSet: {
|
||||
case fn_body_kind::SSet: { // set other unboxed field of unique reference
|
||||
object * o = var(fn_body_sset_target(b));
|
||||
size_t offset = fn_body_sset_num_objs(b).get_small_value() * sizeof(void *) +
|
||||
size_t offset = fn_body_sset_idx(b).get_small_value() * sizeof(void *) +
|
||||
fn_body_sset_offset(b).get_small_value();
|
||||
object * v = var(fn_body_sset_source(b));
|
||||
lean_assert(is_exclusive(o));
|
||||
|
|
@ -424,11 +482,11 @@ class interpreter {
|
|||
b = fn_body_sset_cont(b);
|
||||
break;
|
||||
}
|
||||
case fn_body_kind::Inc:
|
||||
case fn_body_kind::Inc: // increment reference counter
|
||||
inc(var(fn_body_inc_var(b)), fn_body_inc_val(b).get_small_value());
|
||||
b = fn_body_inc_cont(b);
|
||||
break;
|
||||
case fn_body_kind::Dec: {
|
||||
case fn_body_kind::Dec: { // decrement reference counter
|
||||
size_t n = fn_body_dec_val(b).get_small_value();
|
||||
for (size_t i = 0; i < n; i++) {
|
||||
dec(var(fn_body_dec_var(b)));
|
||||
|
|
@ -436,20 +494,20 @@ class interpreter {
|
|||
b = fn_body_dec_cont(b);
|
||||
break;
|
||||
}
|
||||
case fn_body_kind::Del:
|
||||
case fn_body_kind::Del: // delete object of unique reference
|
||||
lean_free_object(var(fn_body_del_var(b)));
|
||||
b = fn_body_del_cont(b);
|
||||
break;
|
||||
case fn_body_kind::MData:
|
||||
case fn_body_kind::MData: // metadata; no-op
|
||||
b = fn_body_mdata_cont(b);
|
||||
break;
|
||||
case fn_body_kind::Case: {
|
||||
case fn_body_kind::Case: { // branch according to constructor tag
|
||||
object * o = var(fn_body_case_var(b));
|
||||
size_t tag = is_scalar(o) ? unbox(o) : cnstr_tag(o);
|
||||
for (alt_core const & a : fn_body_case_alts(b)) {
|
||||
switch (alt_core_tag(a)) {
|
||||
case alt_core_kind::Ctor:
|
||||
if (tag == ctor_info_idx(alt_core_ctor_info(a)).get_small_value()) {
|
||||
if (tag == ctor_info_tag(alt_core_ctor_info(a)).get_small_value()) {
|
||||
b = alt_core_ctor_cont(a);
|
||||
goto done;
|
||||
}
|
||||
|
|
@ -464,7 +522,7 @@ class interpreter {
|
|||
}
|
||||
case fn_body_kind::Ret:
|
||||
return eval_arg(fn_body_ret_arg(b));
|
||||
case fn_body_kind::Jmp: {
|
||||
case fn_body_kind::Jmp: { // jump to join-point
|
||||
fn_body const & jp = *m_jp_stack[get_frame().m_jp_bp + fn_body_jmp_jp(b).get_small_value()];
|
||||
lean_assert(fn_body_jdecl_params(jp).size() == fn_body_jmp_args(b).size());
|
||||
for (size_t i = 0; i < fn_body_jdecl_params(jp).size(); i++) {
|
||||
|
|
@ -479,6 +537,7 @@ class interpreter {
|
|||
}
|
||||
}
|
||||
|
||||
// specify argument base pointer explicitly because we've usually already pushed some function arguments
|
||||
void push_frame(name const & fn, size_t arg_bp) {
|
||||
DEBUG_CODE({
|
||||
lean_trace(name({"interpreter", "call"}),
|
||||
|
|
@ -505,6 +564,7 @@ class interpreter {
|
|||
});
|
||||
}
|
||||
|
||||
/** \brief Return cached lookup result for given unmangled function name in the current binary. */
|
||||
symbol_cache_entry lookup_symbol(name const & fn) {
|
||||
if (symbol_cache_entry const * e = m_symbol_cache.find(fn)) {
|
||||
return *e;
|
||||
|
|
@ -512,9 +572,11 @@ class interpreter {
|
|||
string_ref mangled = name_mangle(fn, *g_mangle_prefix);
|
||||
string_ref boxed_mangled(string_append(mangled.to_obj_arg(), g_boxed_mangled_suffix->raw()));
|
||||
symbol_cache_entry e_new;
|
||||
// check for boxed version first
|
||||
if (void *p_boxed = dlsym(RTLD_DEFAULT, boxed_mangled.data())) {
|
||||
e_new = symbol_cache_entry { p_boxed, true };
|
||||
} else if (void *p = dlsym(RTLD_DEFAULT, mangled.data())) {
|
||||
// if there is no boxed version, there are no unboxed parameters, so use default version
|
||||
e_new = symbol_cache_entry { p, false };
|
||||
} else {
|
||||
e_new = symbol_cache_entry { nullptr, false };
|
||||
|
|
@ -524,6 +586,7 @@ class interpreter {
|
|||
}
|
||||
}
|
||||
|
||||
/** \brief Retrieve Lean declaration from environment. */
|
||||
decl get_decl(name const & fn) {
|
||||
option_ref<decl> d = find_env_decl(m_env, fn);
|
||||
if (!d) {
|
||||
|
|
@ -532,6 +595,7 @@ class interpreter {
|
|||
return d.get().value();
|
||||
}
|
||||
|
||||
/** \brief Retrieve Lean definition from environment. */
|
||||
decl get_fdecl(name const & fn) {
|
||||
decl d = get_decl(fn);
|
||||
if (decl_tag(d) == decl_kind::Extern) {
|
||||
|
|
@ -540,9 +604,10 @@ class interpreter {
|
|||
return d;
|
||||
}
|
||||
|
||||
// evaluate 0-ary function
|
||||
/** \brief Evaluate nullary function ("constant"). */
|
||||
object * load(name const & fn, type t) {
|
||||
if (void * p = lookup_symbol(fn).m_addr) {
|
||||
// constants do not have boxed wrappers, but we'll survive
|
||||
switch (t) {
|
||||
case type::Float: throw exception("floats are not supported yet");
|
||||
case type::UInt8: return box(*static_cast<uint8 *>(p));
|
||||
|
|
@ -579,12 +644,17 @@ class interpreter {
|
|||
symbol_cache_entry e = lookup_symbol(fn);
|
||||
if (e.m_addr) {
|
||||
if (e.m_boxed) {
|
||||
// NOTE: If we chose the boxed version where the IR chose the unboxed one, we need to manually increment
|
||||
// originally borrowed parameters because the wrapper will decrement these after the call.
|
||||
// Basically the wrapper is more homogeneous (removing both boxed and borrowed parameters) than we
|
||||
// would need in this instance.
|
||||
for (size_t i = 0; i < args.size(); i++) {
|
||||
if (param_borrow(decl_params(d)[i])) {
|
||||
inc(m_arg_stack[old_size + i]);
|
||||
}
|
||||
}
|
||||
}
|
||||
// HACK: `curry` wants a closure object instead of just a function pointer
|
||||
object * cls = alloc_closure(e.m_addr, 2, 1);
|
||||
r = curry(cls, args.size(), &m_arg_stack[old_size]);
|
||||
free_heap_obj(cls);
|
||||
|
|
@ -603,7 +673,7 @@ public:
|
|||
uint32 run_main(int argc, char * argv[]) {
|
||||
decl d = get_fdecl("main");
|
||||
array_ref<param> const & params = decl_params(d);
|
||||
if (params.size() == 2) {
|
||||
if (params.size() == 2) { // List String -> IO UInt32
|
||||
lean_object * in = lean_box(0);
|
||||
int i = argc;
|
||||
while (i > 1) {
|
||||
|
|
@ -614,7 +684,7 @@ public:
|
|||
in = n;
|
||||
}
|
||||
m_arg_stack.push_back(in);
|
||||
} else {
|
||||
} else { // IO UInt32
|
||||
lean_assert(params.size() == 1);
|
||||
}
|
||||
object * w = io_mk_world();
|
||||
|
|
@ -623,6 +693,8 @@ public:
|
|||
w = eval_body(decl_fun_body(d));
|
||||
pop_frame(w);
|
||||
if (io_result_is_ok(w)) {
|
||||
// NOTE: in an awesome hack, `IO Unit` works just as well because `pure 0` and `pure ()` use the same
|
||||
// representation
|
||||
int ret = unbox(io_result_get_value(w));
|
||||
dec_ref(w);
|
||||
return ret;
|
||||
|
|
@ -633,6 +705,7 @@ public:
|
|||
}
|
||||
}
|
||||
|
||||
// closure stub
|
||||
object * stub_m(object ** args) {
|
||||
decl d(args[1]);
|
||||
size_t old_size = m_arg_stack.size();
|
||||
|
|
@ -645,6 +718,7 @@ public:
|
|||
return r;
|
||||
}
|
||||
|
||||
// closure stub stub
|
||||
static object * stub_m_aux(object ** args) {
|
||||
interpreter * self = reinterpret_cast<interpreter *>(unbox(args[0]));
|
||||
return self->stub_m(args);
|
||||
|
|
|
|||
Loading…
Add table
Reference in a new issue