diff options
Diffstat (limited to 'archive/2.vm/041jump_target.cc')
| -rw-r--r-- | archive/2.vm/041jump_target.cc | 220 |
1 files changed, 0 insertions, 220 deletions
diff --git a/archive/2.vm/041jump_target.cc b/archive/2.vm/041jump_target.cc deleted file mode 100644 index ec7adede..00000000 --- a/archive/2.vm/041jump_target.cc +++ /dev/null @@ -1,220 +0,0 @@ -//: Support jumps to a specific label (the 'jump target') in the same recipe. -//: Jump targets must be unique and unambiguous within any recipe. -//: -//: The 'break' and 'loop' pseudo instructions can also take jump targets. -//: Which instruction you use is just documentation about intent; use 'break' -//: to indicate you're exiting one or more loop nests, and 'loop' to indicate -//: you're skipping to the next iteration of some containing loop nest. - -//: Since they have to be unique in a recipe, not all labels can be jump -//: targets. -bool is_jump_target(const string& label) { - if (label == "{" || label == "}") return false; - // End is_jump_target Special-cases - return is_label_word(label); -} - -void test_jump_to_label() { - run( - "def main [\n" - " jump +target:label\n" - " 1:num <- copy 0\n" - " +target\n" - "]\n" - ); - CHECK_TRACE_DOESNT_CONTAIN("mem: storing 0 in location 1"); -} - -:(before "End Mu Types Initialization") -put(Type_ordinal, "label", 0); - -:(before "End Instruction Modifying Transforms") -Transform.push_back(transform_labels); // idempotent - -:(code) -void transform_labels(const recipe_ordinal r) { - map<string, int> offset; - for (int i = 0; i < SIZE(get(Recipe, r).steps); ++i) { - const instruction& inst = get(Recipe, r).steps.at(i); - if (!inst.is_label) continue; - if (is_jump_target(inst.label)) { - if (!contains_key(offset, inst.label)) { - put(offset, inst.label, i); - } - else { - raise << maybe(get(Recipe, r).name) << "duplicate label '" << inst.label << "'" << end(); - // have all jumps skip some random but noticeable and deterministic amount of code - put(offset, inst.label, 9999); - } - } - } - for (int i = 0; i < SIZE(get(Recipe, r).steps); ++i) { - instruction& inst = get(Recipe, r).steps.at(i); - if (inst.name == "jump") { - if (inst.ingredients.empty()) { - raise << maybe(get(Recipe, r).name) << "'" << to_original_string(inst) << "' expects an ingredient but got 0\n" << end(); - return; - } - replace_offset(inst.ingredients.at(0), offset, i, r); - } - if (inst.name == "jump-if" || inst.name == "jump-unless") { - if (SIZE(inst.ingredients) < 2) { - raise << maybe(get(Recipe, r).name) << "'" << to_original_string(inst) << "' expects 2 ingredients but got " << SIZE(inst.ingredients) << '\n' << end(); - return; - } - replace_offset(inst.ingredients.at(1), offset, i, r); - } - if ((inst.name == "loop" || inst.name == "break") - && SIZE(inst.ingredients) >= 1) { - replace_offset(inst.ingredients.at(0), offset, i, r); - } - if ((inst.name == "loop-if" || inst.name == "loop-unless" - || inst.name == "break-if" || inst.name == "break-unless") - && SIZE(inst.ingredients) >= 2) { - replace_offset(inst.ingredients.at(1), offset, i, r); - } - } -} - -void replace_offset(reagent& x, /*const*/ map<string, int>& offset, const int current_offset, const recipe_ordinal r) { - if (!is_literal(x)) { - raise << maybe(get(Recipe, r).name) << "jump target must be offset or label but is '" << x.original_string << "'\n" << end(); - x.set_value(0); // no jump by default - return; - } - if (x.initialized) return; - if (is_integer(x.name)) return; // non-labels will be handled like other number operands - if (!is_jump_target(x.name)) { - raise << maybe(get(Recipe, r).name) << "can't jump to label '" << x.name << "'\n" << end(); - x.set_value(0); // no jump by default - return; - } - if (!contains_key(offset, x.name)) { - raise << maybe(get(Recipe, r).name) << "can't find label '" << x.name << "'\n" << end(); - x.set_value(0); // no jump by default - return; - } - x.set_value(get(offset, x.name) - current_offset); -} - -void test_break_to_label() { - run( - "def main [\n" - " {\n" - " {\n" - " break +target:label\n" - " 1:num <- copy 0\n" - " }\n" - " }\n" - " +target\n" - "]\n" - ); - CHECK_TRACE_DOESNT_CONTAIN("mem: storing 0 in location 1"); -} - -void test_jump_if_to_label() { - run( - "def main [\n" - " {\n" - " {\n" - " jump-if 1, +target:label\n" - " 1:num <- copy 0\n" - " }\n" - " }\n" - " +target\n" - "]\n" - ); - CHECK_TRACE_DOESNT_CONTAIN("mem: storing 0 in location 1"); -} - -void test_loop_unless_to_label() { - run( - "def main [\n" - " {\n" - " {\n" - " loop-unless 0, +target:label\n" // loop/break with a label don't care about braces - " 1:num <- copy 0\n" - " }\n" - " }\n" - " +target\n" - "]\n" - ); - CHECK_TRACE_DOESNT_CONTAIN("mem: storing 0 in location 1"); -} - -void test_jump_runs_code_after_label() { - run( - "def main [\n" - // first a few lines of padding to exercise the offset computation - " 1:num <- copy 0\n" - " 2:num <- copy 0\n" - " 3:num <- copy 0\n" - " jump +target:label\n" - " 4:num <- copy 0\n" - " +target\n" - " 5:num <- copy 0\n" - "]\n" - ); - CHECK_TRACE_CONTENTS( - "mem: storing 0 in location 5\n" - ); - CHECK_TRACE_DOESNT_CONTAIN("mem: storing 0 in location 4"); -} - -void test_jump_fails_without_target() { - Hide_errors = true; - run( - "def main [\n" - " jump\n" - "]\n" - ); - CHECK_TRACE_CONTENTS( - "error: main: 'jump' expects an ingredient but got 0\n" - ); -} - -void test_jump_fails_without_target_2() { - Hide_errors = true; - run( - "def main [\n" - " jump-if true\n" - "]\n" - ); - CHECK_TRACE_CONTENTS( - "error: main: 'jump-if true' expects 2 ingredients but got 1\n" - ); -} - -void test_recipe_fails_on_duplicate_jump_target() { - Hide_errors = true; - run( - "def main [\n" - " +label\n" - " 1:num <- copy 0\n" - " +label\n" - " 2:num <- copy 0\n" - "]\n" - ); - CHECK_TRACE_CONTENTS( - "error: main: duplicate label '+label'\n" - ); -} - -void test_jump_ignores_nontarget_label() { - Hide_errors = true; - run( - "def main [\n" - // first a few lines of padding to exercise the offset computation - " 1:num <- copy 0\n" - " 2:num <- copy 0\n" - " 3:num <- copy 0\n" - " jump $target:label\n" - " 4:num <- copy 0\n" - " $target\n" - " 5:num <- copy 0\n" - "]\n" - ); - CHECK_TRACE_CONTENTS( - "error: main: can't jump to label '$target'\n" - ); -} |