From b51059a7cbec54cc89811dd8e78d1bd3e55ca081 Mon Sep 17 00:00:00 2001
From: Michael Williamson <mike@zwobble.org>
Date: Thu, 21 Dec 2023 16:45:59 +0000
Subject: Extract explicit notion of WasmRelocationSection

---
 .../structure/binary/WasmBinaryFormatLinking.java  | 15 ++++++-------
 .../wasm/structure/binary/WasmBinaryWriter.java    | 13 +++++------
 .../structure/binary/WasmRelocationSection.java    | 25 ++++++++++++++++++++++
 3 files changed, 38 insertions(+), 15 deletions(-)
 create mode 100644 src/main/java/org/shedlang/compiler/backends/wasm/structure/binary/WasmRelocationSection.java

(limited to 'src/main/java')

diff --git a/src/main/java/org/shedlang/compiler/backends/wasm/structure/binary/WasmBinaryFormatLinking.java b/src/main/java/org/shedlang/compiler/backends/wasm/structure/binary/WasmBinaryFormatLinking.java
index 255cc52e..34b98eca 100644
--- a/src/main/java/org/shedlang/compiler/backends/wasm/structure/binary/WasmBinaryFormatLinking.java
+++ b/src/main/java/org/shedlang/compiler/backends/wasm/structure/binary/WasmBinaryFormatLinking.java
@@ -34,10 +34,9 @@ public class WasmBinaryFormatLinking {
         SymbolTable symbolTable,
         WasmBinaryWriter writer
     ) throws IOException {
-        for (var relocationEntriesForSection : writer.relocationEntries().entrySet()) {
+        for (var relocationSection : writer.relocationSections()) {
             writeRelocationSection(
-                relocationEntriesForSection.getKey(),
-                relocationEntriesForSection.getValue(),
+                relocationSection,
                 symbolTable,
                 writer
             );
@@ -45,16 +44,14 @@ public class WasmBinaryFormatLinking {
     }
 
     private static void writeRelocationSection(
-        int sectionIndex,
-        List<WasmRelocationEntry> relocationEntries,
+        WasmRelocationSection relocationSection,
         SymbolTable symbolTable,
         WasmBinaryWriter writer
     ) throws IOException {
-        // TODO: don't assume CODE
-        writeCustomSection("reloc.CODE", writer, () -> {
-            writer.writeUnsignedInt32(sectionIndex);
+        writeCustomSection("reloc." + relocationSection.relocatedSectionName(), writer, () -> {
+            writer.writeUnsignedInt32(relocationSection.relocatedSectionIndex());
             writer.writeVec(
-                relocationEntries,
+                relocationSection.entries(),
                 relocationEntry -> writeRelocationEntry(relocationEntry, symbolTable, writer)
             );
         });
diff --git a/src/main/java/org/shedlang/compiler/backends/wasm/structure/binary/WasmBinaryWriter.java b/src/main/java/org/shedlang/compiler/backends/wasm/structure/binary/WasmBinaryWriter.java
index f13bd2f1..c8fc458b 100644
--- a/src/main/java/org/shedlang/compiler/backends/wasm/structure/binary/WasmBinaryWriter.java
+++ b/src/main/java/org/shedlang/compiler/backends/wasm/structure/binary/WasmBinaryWriter.java
@@ -14,7 +14,7 @@ import java.util.*;
 
 public class WasmBinaryWriter {
     private final BinaryWriter writer = new BinaryWriter();
-    private final Map<Integer, List<WasmRelocationEntry>> relocationEntries = new HashMap<>();
+    private final Map<Integer, WasmRelocationSection> relocationSections = new HashMap<>();
     private final WasmIndexTable indexTable;
     private Optional<WasmSectionId> currentSection = Optional.empty();
     private int sectionIndex = -1;
@@ -131,10 +131,11 @@ public class WasmBinaryWriter {
                 writePaddedUnsignedInt32(value);
             }
 
-            if (!relocationEntries.containsKey(sectionIndex)) {
-                relocationEntries.put(sectionIndex, new ArrayList<>());
+            if (!relocationSections.containsKey(sectionIndex)) {
+                // TODO: don't assume CODE
+                relocationSections.put(sectionIndex, WasmRelocationSection.empty(sectionIndex, "CODE"));
             }
-            relocationEntries.get(sectionIndex).add(new WasmRelocationEntry(
+            relocationSections.get(sectionIndex).addEntry(new WasmRelocationEntry(
                 relocationType,
                 sectionContentsOffset,
                 index
@@ -192,8 +193,8 @@ public class WasmBinaryWriter {
         WasmBinaryFormatSize.writeSize(writer, writeContents);
     }
 
-    public Map<Integer, List<WasmRelocationEntry>> relocationEntries() {
-        return relocationEntries;
+    public Collection<WasmRelocationSection> relocationSections() {
+        return relocationSections.values();
     }
 
     public byte[] toBytes() {
diff --git a/src/main/java/org/shedlang/compiler/backends/wasm/structure/binary/WasmRelocationSection.java b/src/main/java/org/shedlang/compiler/backends/wasm/structure/binary/WasmRelocationSection.java
new file mode 100644
index 00000000..120b9fab
--- /dev/null
+++ b/src/main/java/org/shedlang/compiler/backends/wasm/structure/binary/WasmRelocationSection.java
@@ -0,0 +1,25 @@
+package org.shedlang.compiler.backends.wasm.structure.binary;
+
+import java.util.ArrayList;
+import java.util.List;
+
+public record WasmRelocationSection(
+    int relocatedSectionIndex,
+    String relocatedSectionName,
+    List<WasmRelocationEntry> entries
+) {
+    public static WasmRelocationSection empty(
+        int relocatedSectionIndex,
+        String relocatedSectionName
+    ) {
+        return new WasmRelocationSection(
+            relocatedSectionIndex,
+            relocatedSectionName,
+            new ArrayList<>()
+        );
+    }
+
+    public void addEntry(WasmRelocationEntry entry) {
+        this.entries.add(entry);
+    }
+}
-- 
cgit v1.2.3