fixup! Implement skipping for any field with known size.

zeek · Jan 16, 2024 · 1b175d1 · 1b175d1
1 parent 620edb4
commit 1b175d1
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Showing 2 changed files with 26 additions and 16 deletions.
diff --git a/spicy/toolchain/include/compiler/detail/codegen/parser-builder.h b/spicy/toolchain/include/compiler/detail/codegen/parser-builder.h
@@ -355,6 +355,15 @@ class ParserBuilder {
      */
     void waitForEod();
 
+    /*
+     * Generates code which waits for given input length to be available to
+     * immediately consume and trim it.
+     *
+     * @param size an unsigned integer specifying the length of the input to skip
+     * @param location location associated with the operation
+     */
+    void skip(const Expression& size, const Meta& location = {});
+
     /** Returns a boolean expression that's true if EOD has been reached. */
     Expression atEod();
 

diff --git a/spicy/toolchain/src/compiler/codegen/parser-builder.cc b/spicy/toolchain/src/compiler/codegen/parser-builder.cc
@@ -1,5 +1,7 @@
 // Copyright (c) 2020-2023 by the Zeek Project. See LICENSE for details.
 
+#include "compiler/detail/codegen/parser-builder.h"
+
 #include <algorithm>
 #include <numeric>
 #include <optional>
@@ -30,7 +32,6 @@
 #include <spicy/ast/types/unit-items/sink.h>
 #include <spicy/compiler/detail/codegen/codegen.h>
 #include <spicy/compiler/detail/codegen/grammar.h>
-#include <spicy/compiler/detail/codegen/parser-builder.h>
 #include <spicy/compiler/detail/codegen/production.h>
 #include <spicy/compiler/detail/codegen/productions/all.h>
 
@@ -1699,20 +1700,6 @@ struct ProductionVisitor
     }
 
     void operator()(const production::Skip& p) {
-        auto consumeFixedSize = [&](const Expression& size) {
-            assert(size.type().template isA<type::UnsignedInteger>());
-
-            auto n = builder()->addTmp("skip", size);
-            auto loop = builder()->addWhile(builder::greater(n, builder::integer(0U)));
-            pushBuilder(loop, [&]() {
-                pb->waitForInput(builder::integer(1U), "not enough bytes for skipping", p.location());
-                auto consume = builder()->addTmp("consume", builder::min(builder::size(state().cur), size));
-                pb->advanceInput(consume);
-                builder()->addAssign(n, builder::difference(n, consume));
-                builder()->addDebugMsg("spicy-verbose", "- skipped %u bytes (%u left to skip)", {consume, n});
-            });
-        };
-
         if ( auto c = p.field().condition() )
             pushBuilder(builder()->addIf(*c));
 
@@ -1721,7 +1708,7 @@ struct ProductionVisitor
         }
 
         else if ( const auto& size = p.field().size() )
-            consumeFixedSize(*size);
+            pb->skip(*size, p.location());
 
         else if ( p.field().parseType().isA<type::Bytes>() ) {
             // Bytes with fixed size already handled above.
@@ -2403,6 +2390,20 @@ void ParserBuilder::waitForEod() {
     builder()->addCall("spicy_rt::waitForEod", {state().data, state().cur, _filters(state())});
 }
 
+void ParserBuilder::skip(const Expression& size, const Meta& location) {
+    assert(size.type().template isA<type::UnsignedInteger>());
+
+    auto n = builder()->addTmp("skip", size);
+    auto loop = builder()->addWhile(builder::greater(n, builder::integer(0U)));
+    pushBuilder(loop, [&]() {
+        waitForInput(builder::integer(1U), "not enough bytes for skipping", location);
+        auto consume = builder()->addTmp("consume", builder::min(builder::size(state().cur), size));
+        advanceInput(consume);
+        builder()->addAssign(n, builder::difference(n, consume));
+        builder()->addDebugMsg("spicy-verbose", "- skipped %u bytes (%u left to skip)", {consume, n});
+    });
+}
+
 void ParserBuilder::parseError(const Expression& error_msg, const Meta& location) {
     builder()->addThrow(builder::exception(builder::typeByID("spicy_rt::ParseError"), error_msg, location), location);
 }