Fine-tune bytes literal parsing further.

This now optimizes the generated code for parsing a `bytes` literal
based on what we're going to use it for, or not (require literal vs.
look-ahead vs skip).

The standard case of a parsing an expected literal now looks like
this:

```
    # Begin parsing production: Ctor: b1  -> b"abc" (const bytes)
    (*self).b1 = spicy_rt::expectBytesLiteral(__data, __cur, b"abc", "../tests/spicy/types/bytes/parse-length.spicy:20:10-20:15", Null);
    __cur = __cur.advance(3);

    if ( __trim )
        (*__data).trim(begin(__cur));

    # End parsing production: Ctor: b1  -> b"abc" (const bytes)
```

spicy/lib/spicy_rt.hlt

@@ -94,6 +94,6 @@ declare public void backtrack() &cxxname="spicy::rt::detail::backtrack" &have_pr
 declare public void initializeParsedUnit(inout ParsedUnit punit, any unit, TypeInfo ti) &cxxname="spicy::rt::ParsedUnit::initialize" &have_prototype;
 
 declare public bytes extractBytes(inout value_ref<stream> data, view<stream> cur, uint<64> n, bool eod_ok, string location, inout strong_ref<Filters> filters) &cxxname="spicy::rt::detail::extractBytes" &have_prototype;
-declare public void expectBytesLiteral(inout value_ref<stream> data, view<stream> cur, bytes literal, string location, inout strong_ref<Filters> filters) &cxxname="spicy::rt::detail::expectBytesLiteral" &have_prototype;
+declare public bytes expectBytesLiteral(inout value_ref<stream> data, view<stream> cur, bytes literal, string location, inout strong_ref<Filters> filters) &cxxname="spicy::rt::detail::expectBytesLiteral" &have_prototype;
 
 }

spicy/runtime/include/parser.h

@@ -553,11 +553,13 @@ hilti::rt::Bytes extractBytes(hilti::rt::ValueReference<hilti::rt::Stream>& data
  * @param literal raw bytes representation of the literal to extract
  * @param location location associated with the situation
  * @param filters filter state associated with current unit instance (which may be null)
+ * @returns `literal` (for convenience)
  * @throws ParseError if the literal isn't found at the beginning of *cur*
  */
-void expectBytesLiteral(hilti::rt::ValueReference<hilti::rt::Stream>& data, const hilti::rt::stream::View& cur,
-                        const hilti::rt::Bytes& literal, std::string_view location,
-                        const hilti::rt::StrongReference<spicy::rt::filter::detail::Filters>& filters);
+hilti::rt::Bytes expectBytesLiteral(hilti::rt::ValueReference<hilti::rt::Stream>& data,
+                                    const hilti::rt::stream::View& cur, hilti::rt::Bytes literal,
+                                    std::string_view location,
+                                    const hilti::rt::StrongReference<spicy::rt::filter::detail::Filters>& filters);
 
 } // namespace detail
 } // namespace spicy::rt

spicy/runtime/src/parser.cc

@@ -200,9 +200,9 @@ hilti::rt::Bytes detail::extractBytes(hilti::rt::ValueReference<hilti::rt::Strea
     return cur.sub(cur.begin() + size).data();
 }
 
-void detail::expectBytesLiteral(hilti::rt::ValueReference<hilti::rt::Stream>& data, const hilti::rt::stream::View& cur,
-                                const hilti::rt::Bytes& literal, std::string_view location,
-                                const hilti::rt::StrongReference<spicy::rt::filter::detail::Filters>& filters) {
+hilti::rt::Bytes detail::expectBytesLiteral(
+    hilti::rt::ValueReference<hilti::rt::Stream>& data, const hilti::rt::stream::View& cur, hilti::rt::Bytes literal,
+    std::string_view location, const hilti::rt::StrongReference<spicy::rt::filter::detail::Filters>& filters) {
     detail::waitForInput(data, cur, literal.size(),
                          hilti::rt::fmt("expected %" PRIu64 R"( bytes for bytes literal "%s")", literal.size(),
                                         literal),
@@ -212,4 +212,6 @@ void detail::expectBytesLiteral(hilti::rt::ValueReference<hilti::rt::Stream>& da
         throw ParseError(hilti::rt::fmt(R"(expected bytes literal "%s" but input starts with "%s")", literal, content),
                          location);
     }
+
+    return literal;
 }

spicy/runtime/src/tests/parser.cc

@@ -454,7 +454,7 @@ TEST_CASE("expectBytesLiteral") {
     data->freeze();
     auto view = data->view();
 
-    CHECK_NOTHROW(detail::expectBytesLiteral(data, data->view(), "123"_b, "<location>", {}));
+    CHECK_EQ(detail::expectBytesLiteral(data, data->view(), "123"_b, "<location>", {}), "123"_b);
     CHECK_THROWS_WITH_AS(detail::expectBytesLiteral(data, data->view(), "abc"_b, "<location>", {}),
                          "expected bytes literal \"abc\" but input starts with \"123\" (<location>)",
                          const spicy::rt::ParseError&);

spicy/toolchain/src/compiler/codegen/parsers/literals.cc

@@ -89,32 +89,39 @@ struct Visitor : public visitor::PreOrder {
                     pb()->parseError("unexpected token to consume", n->meta());
                     popBuilder();
 
-                    pushBuilder(
-                        builder()->addIf(builder()->unequal(builder()->expression(n),
-                                                            builder()->memberCall(state().cur, "sub",
-                                                                                  {builder()->begin(state().cur),
-                                                                                   state().lahead_end}))));
+                    auto literal = builder()->addTmp("literal", builder()->expression(n));
+
+                    pushBuilder(builder()->addIf(
+                        builder()->unequal(literal, builder()->memberCall(state().cur, "sub",
+                                                                          {builder()->begin(state().cur),
+                                                                           state().lahead_end}))));
                     pb()->parseError("unexpected data when consuming token", n->meta());
                     popBuilder();
 
+                    builder()->addAssign(lp->destination(n->type()->type()), literal);
+
                     pb()->consumeLookAhead();
                     popBuilder();
 
                     pushBuilder(no_lah);
                 }
 
-                builder()->addCall("spicy_rt::expectBytesLiteral",
-                                   {state().data, state().cur, builder()->expression(n),
-                                    builder()->expression(n->meta()), pb()->currentFilters(state())});
+                auto expect_bytes_literal =
+                    builder()->call("spicy_rt::expectBytesLiteral",
+                                    {state().data, state().cur, builder()->expression(n),
+                                     builder()->expression(n->meta()), pb()->currentFilters(state())});
+
+
+                if ( state().literal_mode != LiteralMode::Skip )
+                    builder()->addAssign(lp->destination(n->type()->type()), expect_bytes_literal);
+                else
+                    builder()->addExpression(expect_bytes_literal);
 
                 pb()->advanceInput(len);
 
                 if ( check_for_look_ahead )
                     popBuilder();
 
-                if ( state().literal_mode != LiteralMode::Skip )
-                    builder()->addAssign(lp->destination(n->type()->type()), builder()->expression(n));
-
                 result = builder()->expression(n);
                 return;
             }

tests/Baseline/spicy.types.function.cxxname-normalization/output

@@ -59,7 +59,7 @@
 [debug/resolver] [spicy_rt.hlt:92:33-92:71] Attribute "&cxxname="spicy::rt::detail::backtrack"" -> Attribute "&cxxname="::spicy::rt::detail::backtrack""
 [debug/resolver] [spicy_rt.hlt:94:89-94:132] Attribute "&cxxname="spicy::rt::ParsedUnit::initialize"" -> Attribute "&cxxname="::spicy::rt::ParsedUnit::initialize""
 [debug/resolver] [spicy_rt.hlt:96:160-96:201] Attribute "&cxxname="spicy::rt::detail::extractBytes"" -> Attribute "&cxxname="::spicy::rt::detail::extractBytes""
-[debug/resolver] [spicy_rt.hlt:97:155-97:202] Attribute "&cxxname="spicy::rt::detail::expectBytesLiteral"" -> Attribute "&cxxname="::spicy::rt::detail::expectBytesLiteral""
+[debug/resolver] [spicy_rt.hlt:97:156-97:203] Attribute "&cxxname="spicy::rt::detail::expectBytesLiteral"" -> Attribute "&cxxname="::spicy::rt::detail::expectBytesLiteral""
 [debug/resolver] [spicy.spicy:14:3-14:37] Attribute "&cxxname="hilti::rt::AddressFamily"" -> Attribute "&cxxname="::hilti::rt::AddressFamily""
 [debug/resolver] [spicy.spicy:23:3-23:41] Attribute "&cxxname="hilti::rt::integer::BitOrder"" -> Attribute "&cxxname="::hilti::rt::integer::BitOrder""
 [debug/resolver] [spicy.spicy:31:3-31:33] Attribute "&cxxname="hilti::rt::ByteOrder"" -> Attribute "&cxxname="::hilti::rt::ByteOrder""

tests/Baseline/spicy.types.unit.hooks-across-imports/.stderr

@@ -1,55 +1,55 @@
 ### BTest baseline data generated by btest-diff. Do not edit. Use "btest -U/-u" to update. Requires BTest >= 0.63.
-[debug/ast-stats] garbage collected 1098 nodes in 12 rounds, 8159 left retained
-[debug/ast-stats] garbage collected 479 nodes in 11 rounds, 9404 left retained
-[debug/ast-stats] garbage collected 170 nodes in 6 rounds, 9807 left retained
-[debug/ast-stats] garbage collected 78 nodes in 3 rounds, 9807 left retained
-[debug/ast-stats] garbage collected 78 nodes in 3 rounds, 9807 left retained
+[debug/ast-stats] garbage collected 1098 nodes in 12 rounds, 8163 left retained
+[debug/ast-stats] garbage collected 479 nodes in 11 rounds, 9412 left retained
+[debug/ast-stats] garbage collected 170 nodes in 6 rounds, 9815 left retained
+[debug/ast-stats] garbage collected 78 nodes in 3 rounds, 9815 left retained
+[debug/ast-stats] garbage collected 78 nodes in 3 rounds, 9815 left retained
 [debug/ast-stats] # [Spicy] AST statistics:
 [debug/ast-stats]   - # AST rounds 5
 [debug/ast-stats]   - max tree depth: 16
 [debug/ast-stats]   - # context declarations: 67
 [debug/ast-stats]   - # context types: 47
 [debug/ast-stats]   - # context modules: 5
-[debug/ast-stats]   - # nodes reachable in AST: 3201
-[debug/ast-stats]   - # nodes live: 9807
-[debug/ast-stats]   - # nodes retained: 9807
+[debug/ast-stats]   - # nodes reachable in AST: 3205
+[debug/ast-stats]   - # nodes live: 9815
+[debug/ast-stats]   - # nodes retained: 9815
 [debug/ast-stats]   - # nodes live > 1%:
 [debug/ast-stats]     - Attribute: 171
 [debug/ast-stats]     - AttributeSet: 341
-[debug/ast-stats]     - QualifiedType: 3318
+[debug/ast-stats]     - QualifiedType: 3322
 [debug/ast-stats]     - ctor::String: 120
 [debug/ast-stats]     - declaration::Parameter: 138
 [debug/ast-stats]     - expression::Ctor: 209
 [debug/ast-stats]     - type::Bool: 157
-[debug/ast-stats]     - type::Bytes: 151
+[debug/ast-stats]     - type::Bytes: 153
 [debug/ast-stats]     - type::Function: 134
 [debug/ast-stats]     - type::Member: 175
 [debug/ast-stats]     - type::OperandList: 670
 [debug/ast-stats]     - type::String: 215
 [debug/ast-stats]     - type::Unknown: 157
-[debug/ast-stats]     - type::UnsignedInteger: 533
-[debug/ast-stats]     - type::Void: 116
-[debug/ast-stats]     - type::bytes::Iterator: 179
+[debug/ast-stats]     - type::UnsignedInteger: 535
+[debug/ast-stats]     - type::Void: 114
+[debug/ast-stats]     - type::bytes::Iterator: 181
 [debug/ast-stats]     - type::operand_list::Operand: 1257
 [debug/ast-stats]     - type::stream::Iterator: 141
-[debug/ast-stats] garbage collected 8966 nodes in 14 rounds, 21095 left retained
-[debug/ast-stats] garbage collected 2310 nodes in 16 rounds, 24911 left retained
-[debug/ast-stats] garbage collected 2346 nodes in 8 rounds, 26329 left retained
-[debug/ast-stats] garbage collected 4594 nodes in 11 rounds, 27547 left retained
-[debug/ast-stats] garbage collected 412 nodes in 3 rounds, 27547 left retained
+[debug/ast-stats] garbage collected 8966 nodes in 14 rounds, 21103 left retained
+[debug/ast-stats] garbage collected 2310 nodes in 16 rounds, 24919 left retained
+[debug/ast-stats] garbage collected 2346 nodes in 8 rounds, 26337 left retained
+[debug/ast-stats] garbage collected 4594 nodes in 11 rounds, 27555 left retained
+[debug/ast-stats] garbage collected 412 nodes in 3 rounds, 27555 left retained
 [debug/ast-stats] # [HILTI] AST statistics:
 [debug/ast-stats]   - # AST rounds 5
 [debug/ast-stats]   - max tree depth: 27
 [debug/ast-stats]   - # context declarations: 254
 [debug/ast-stats]   - # context types: 55
 [debug/ast-stats]   - # context modules: 8
-[debug/ast-stats]   - # nodes reachable in AST: 18587
-[debug/ast-stats]   - # nodes live: 27547
-[debug/ast-stats]   - # nodes retained: 27547
+[debug/ast-stats]   - # nodes reachable in AST: 18591
+[debug/ast-stats]   - # nodes live: 27555
+[debug/ast-stats]   - # nodes retained: 27555
 [debug/ast-stats]   - # nodes live > 1%:
 [debug/ast-stats]     - Attribute: 301
 [debug/ast-stats]     - AttributeSet: 765
-[debug/ast-stats]     - QualifiedType: 9116
+[debug/ast-stats]     - QualifiedType: 9120
 [debug/ast-stats]     - declaration::Parameter: 399
 [debug/ast-stats]     - expression::Ctor: 770
 [debug/ast-stats]     - expression::Member: 314
@@ -61,10 +61,10 @@
 [debug/ast-stats]     - type::Optional: 465
 [debug/ast-stats]     - type::String: 441
 [debug/ast-stats]     - type::Tuple: 324
-[debug/ast-stats]     - type::UnsignedInteger: 1695
+[debug/ast-stats]     - type::UnsignedInteger: 1697
 [debug/ast-stats]     - type::operand_list::Operand: 1557
 [debug/ast-stats]     - type::stream::Iterator: 1016
 [debug/ast-stats]     - type::stream::View: 550
 [debug/ast-stats]     - type::tuple::Element: 673
-[debug/ast-stats] garbage collected 32191 nodes in 18 rounds, 0 left retained
+[debug/ast-stats] garbage collected 32199 nodes in 18 rounds, 0 left retained
 [debug/ast-stats] garbage collected 0 nodes in 1 round, 0 left retained

tests/Baseline/spicy.types.unit.sub-unit/.stderr

@@ -1,54 +1,54 @@
 ### BTest baseline data generated by btest-diff. Do not edit. Use "btest -U/-u" to update. Requires BTest >= 0.63.
-[debug/ast-stats] garbage collected 1086 nodes in 12 rounds, 7903 left retained
-[debug/ast-stats] garbage collected 282 nodes in 11 rounds, 9057 left retained
-[debug/ast-stats] garbage collected 70 nodes in 2 rounds, 9413 left retained
-[debug/ast-stats] garbage collected 70 nodes in 2 rounds, 9413 left retained
+[debug/ast-stats] garbage collected 1086 nodes in 12 rounds, 7907 left retained
+[debug/ast-stats] garbage collected 282 nodes in 11 rounds, 9065 left retained
+[debug/ast-stats] garbage collected 70 nodes in 2 rounds, 9421 left retained
+[debug/ast-stats] garbage collected 70 nodes in 2 rounds, 9421 left retained
 [debug/ast-stats] # [Spicy] AST statistics:
 [debug/ast-stats]   - # AST rounds 4
 [debug/ast-stats]   - max tree depth: 16
 [debug/ast-stats]   - # context declarations: 60
 [debug/ast-stats]   - # context types: 43
 [debug/ast-stats]   - # context modules: 4
-[debug/ast-stats]   - # nodes reachable in AST: 2805
-[debug/ast-stats]   - # nodes live: 9413
-[debug/ast-stats]   - # nodes retained: 9413
+[debug/ast-stats]   - # nodes reachable in AST: 2809
+[debug/ast-stats]   - # nodes live: 9421
+[debug/ast-stats]   - # nodes retained: 9421
 [debug/ast-stats]   - # nodes live > 1%:
 [debug/ast-stats]     - Attribute: 166
 [debug/ast-stats]     - AttributeSet: 317
-[debug/ast-stats]     - QualifiedType: 3188
+[debug/ast-stats]     - QualifiedType: 3192
 [debug/ast-stats]     - ctor::String: 112
 [debug/ast-stats]     - declaration::Parameter: 138
 [debug/ast-stats]     - expression::Ctor: 196
 [debug/ast-stats]     - type::Bool: 157
-[debug/ast-stats]     - type::Bytes: 120
+[debug/ast-stats]     - type::Bytes: 122
 [debug/ast-stats]     - type::Function: 127
 [debug/ast-stats]     - type::Member: 167
 [debug/ast-stats]     - type::OperandList: 670
 [debug/ast-stats]     - type::String: 207
 [debug/ast-stats]     - type::Unknown: 157
-[debug/ast-stats]     - type::UnsignedInteger: 508
-[debug/ast-stats]     - type::Void: 109
-[debug/ast-stats]     - type::bytes::Iterator: 148
+[debug/ast-stats]     - type::UnsignedInteger: 510
+[debug/ast-stats]     - type::Void: 107
+[debug/ast-stats]     - type::bytes::Iterator: 150
 [debug/ast-stats]     - type::operand_list::Operand: 1257
 [debug/ast-stats]     - type::stream::Iterator: 141
-[debug/ast-stats] garbage collected 5080 nodes in 12 rounds, 17788 left retained
-[debug/ast-stats] garbage collected 2884 nodes in 16 rounds, 20614 left retained
-[debug/ast-stats] garbage collected 1582 nodes in 8 rounds, 21511 left retained
-[debug/ast-stats] garbage collected 3397 nodes in 11 rounds, 22304 left retained
-[debug/ast-stats] garbage collected 286 nodes in 3 rounds, 22304 left retained
+[debug/ast-stats] garbage collected 5080 nodes in 12 rounds, 17796 left retained
+[debug/ast-stats] garbage collected 2884 nodes in 16 rounds, 20622 left retained
+[debug/ast-stats] garbage collected 1582 nodes in 8 rounds, 21519 left retained
+[debug/ast-stats] garbage collected 3397 nodes in 11 rounds, 22312 left retained
+[debug/ast-stats] garbage collected 286 nodes in 3 rounds, 22312 left retained
 [debug/ast-stats] # [HILTI] AST statistics:
 [debug/ast-stats]   - # AST rounds 5
 [debug/ast-stats]   - max tree depth: 27
 [debug/ast-stats]   - # context declarations: 189
 [debug/ast-stats]   - # context types: 49
 [debug/ast-stats]   - # context modules: 6
-[debug/ast-stats]   - # nodes reachable in AST: 14254
-[debug/ast-stats]   - # nodes live: 22304
-[debug/ast-stats]   - # nodes retained: 22304
+[debug/ast-stats]   - # nodes reachable in AST: 14258
+[debug/ast-stats]   - # nodes live: 22312
+[debug/ast-stats]   - # nodes retained: 22312
 [debug/ast-stats]   - # nodes live > 1%:
 [debug/ast-stats]     - Attribute: 251
 [debug/ast-stats]     - AttributeSet: 593
-[debug/ast-stats]     - QualifiedType: 7347
+[debug/ast-stats]     - QualifiedType: 7351
 [debug/ast-stats]     - ctor::String: 290
 [debug/ast-stats]     - declaration::Parameter: 307
 [debug/ast-stats]     - expression::Ctor: 695
@@ -60,11 +60,11 @@
 [debug/ast-stats]     - type::Optional: 339
 [debug/ast-stats]     - type::String: 536
 [debug/ast-stats]     - type::Tuple: 269
-[debug/ast-stats]     - type::UnsignedInteger: 1290
-[debug/ast-stats]     - type::Void: 253
+[debug/ast-stats]     - type::UnsignedInteger: 1292
+[debug/ast-stats]     - type::Void: 251
 [debug/ast-stats]     - type::operand_list::Operand: 1451
 [debug/ast-stats]     - type::stream::Iterator: 763
 [debug/ast-stats]     - type::stream::View: 417
 [debug/ast-stats]     - type::tuple::Element: 600
-[debug/ast-stats] garbage collected 23630 nodes in 18 rounds, 0 left retained
+[debug/ast-stats] garbage collected 23638 nodes in 18 rounds, 0 left retained
 [debug/ast-stats] garbage collected 0 nodes in 1 round, 0 left retained

tests/spicy/types/bytes/parse-length.spicy

@@ -5,7 +5,7 @@
 # @TEST-EXEC: spicyc -p %INPUT | grep -q 'b2 = spicy_rt::extractBytes'
 #
 # Ensure literal-specific optimization kicks in.
-# @TEST-EXEC: spicyc -p %INPUT | grep -q '^ *spicy_rt::expectBytesLiteral'
+# @TEST-EXEC: spicyc -p %INPUT | grep -q ' = spicy_rt::expectBytesLiteral'
 #
 # Ensure we don't get any look-ahead checks when parsing the literals, we don't need them here.
 # @TEST-EXEC: spicyc -p %INPUT | grep -vq 'if.*lah'