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.canonical-ids-with-import/output

@@ -990,9 +990,8 @@
 [debug/ast-declarations]             - Parameter "__lahe" (a::__lahe_3)
 [debug/ast-declarations]             - Parameter "__error" (a::__error_4)
 [debug/ast-declarations]             - LocalVariable "__result" (a::__result)
-[debug/ast-declarations]                 - LocalVariable "__begin" (a::__begin_5)
-[debug/ast-declarations]                 - LocalVariable "filtered" (a::filtered)
-[debug/ast-declarations]               - Parameter "__except" (a::__except_2)
+[debug/ast-declarations]               - LocalVariable "__begin" (a::__begin_5)
+[debug/ast-declarations]               - LocalVariable "filtered" (a::filtered)
 [debug/ast-declarations]     - Function "a::X::__parse_a__X_stage2" (a::a::X::__parse_a__X_stage2)
 [debug/ast-declarations]             - Parameter "__data" (a::__data_7)
 [debug/ast-declarations]             - Parameter "__begin" (a::__begin_6)
@@ -1281,6 +1280,19 @@
 [debug/ast-declarations]             - Parameter "punit" (spicy_rt::punit)
 [debug/ast-declarations]             - Parameter "unit" (spicy_rt::unit_9)
 [debug/ast-declarations]             - Parameter "ti" (spicy_rt::ti_3)
+[debug/ast-declarations]     - Function "extractBytes" (spicy_rt::extractBytes)
+[debug/ast-declarations]             - Parameter "data" (spicy_rt::data_10)
+[debug/ast-declarations]             - Parameter "cur" (spicy_rt::cur_9)
+[debug/ast-declarations]             - Parameter "n" (spicy_rt::n_3)
+[debug/ast-declarations]             - Parameter "eod_ok" (spicy_rt::eod_ok)
+[debug/ast-declarations]             - Parameter "location" (spicy_rt::location_3)
+[debug/ast-declarations]             - Parameter "filters" (spicy_rt::filters_7)
+[debug/ast-declarations]     - Function "expectBytesLiteral" (spicy_rt::expectBytesLiteral)
+[debug/ast-declarations]             - Parameter "data" (spicy_rt::data_11)
+[debug/ast-declarations]             - Parameter "cur" (spicy_rt::cur_10)
+[debug/ast-declarations]             - Parameter "literal" (spicy_rt::literal)
+[debug/ast-declarations]             - Parameter "location" (spicy_rt::location_4)
+[debug/ast-declarations]             - Parameter "filters" (spicy_rt::filters_8)
 [debug/ast-declarations]   - Module "spicy" (spicy)
 [debug/ast-declarations]     - Property "%skip-implementation" (spicy::%skip-implementation)
 [debug/ast-declarations]     - Type "AddressFamily" (spicy::AddressFamily)

tests/Baseline/spicy.types.unit.canonical-ids/output

@@ -1131,9 +1131,8 @@
 [debug/ast-declarations]             - Parameter "__lahe" (DNS::__lahe_5)
 [debug/ast-declarations]             - Parameter "__error" (DNS::__error_7)
 [debug/ast-declarations]             - LocalVariable "__result" (DNS::__result)
-[debug/ast-declarations]                 - LocalVariable "__begin" (DNS::__begin_8)
-[debug/ast-declarations]                 - LocalVariable "filtered" (DNS::filtered)
-[debug/ast-declarations]               - Parameter "__except" (DNS::__except_3)
+[debug/ast-declarations]               - LocalVariable "__begin" (DNS::__begin_8)
+[debug/ast-declarations]               - LocalVariable "filtered" (DNS::filtered)
 [debug/ast-declarations]     - Function "DNS::Label::__parse_DNS__Label_stage2" (DNS::DNS::Label::__parse_DNS__Label_stage2)
 [debug/ast-declarations]             - Parameter "__data" (DNS::__data_12)
 [debug/ast-declarations]             - Parameter "__begin" (DNS::__begin_9)
@@ -1161,9 +1160,8 @@
 [debug/ast-declarations]             - Parameter "__lahe" (DNS::__lahe_7)
 [debug/ast-declarations]             - Parameter "__error" (DNS::__error_12)
 [debug/ast-declarations]             - LocalVariable "__result" (DNS::__result_3)
-[debug/ast-declarations]                 - LocalVariable "__begin" (DNS::__begin_11)
-[debug/ast-declarations]                 - LocalVariable "filtered" (DNS::filtered_2)
-[debug/ast-declarations]               - Parameter "__except" (DNS::__except_4)
+[debug/ast-declarations]               - LocalVariable "__begin" (DNS::__begin_11)
+[debug/ast-declarations]               - LocalVariable "filtered" (DNS::filtered_2)
 [debug/ast-declarations]     - Function "DNS::Pointer::__parse_DNS__Pointer_2_stage2" (DNS::DNS::Pointer::__parse_DNS__Pointer_2_stage2)
 [debug/ast-declarations]             - Parameter "__data" (DNS::__data_17)
 [debug/ast-declarations]             - Parameter "__begin" (DNS::__begin_12)
@@ -1416,6 +1414,19 @@
 [debug/ast-declarations]             - Parameter "punit" (spicy_rt::punit)
 [debug/ast-declarations]             - Parameter "unit" (spicy_rt::unit_9)
 [debug/ast-declarations]             - Parameter "ti" (spicy_rt::ti_3)
+[debug/ast-declarations]     - Function "extractBytes" (spicy_rt::extractBytes)
+[debug/ast-declarations]             - Parameter "data" (spicy_rt::data_10)
+[debug/ast-declarations]             - Parameter "cur" (spicy_rt::cur_9)
+[debug/ast-declarations]             - Parameter "n" (spicy_rt::n_3)
+[debug/ast-declarations]             - Parameter "eod_ok" (spicy_rt::eod_ok)
+[debug/ast-declarations]             - Parameter "location" (spicy_rt::location_3)
+[debug/ast-declarations]             - Parameter "filters" (spicy_rt::filters_7)
+[debug/ast-declarations]     - Function "expectBytesLiteral" (spicy_rt::expectBytesLiteral)
+[debug/ast-declarations]             - Parameter "data" (spicy_rt::data_11)
+[debug/ast-declarations]             - Parameter "cur" (spicy_rt::cur_10)
+[debug/ast-declarations]             - Parameter "literal" (spicy_rt::literal)
+[debug/ast-declarations]             - Parameter "location" (spicy_rt::location_4)
+[debug/ast-declarations]             - Parameter "filters" (spicy_rt::filters_8)
 [debug/ast-declarations]   - Module "spicy" (spicy)
 [debug/ast-declarations]     - Property "%skip-implementation" (spicy::%skip-implementation)
 [debug/ast-declarations]     - Type "AddressFamily" (spicy::AddressFamily)