Support external global definitions

7 files changed, 41 insertions, 14 deletions

diff --git a/src/main/java/org/shedlang/compiler/backends/llvm/LlvmCompilerContext.java b/src/main/java/org/shedlang/compiler/backends/llvm/LlvmCompilerContext.java
index 60e6515b..980249e2 100644
--- a/src/main/java/org/shedlang/compiler/backends/llvm/LlvmCompilerContext.java
+++ b/src/main/java/org/shedlang/compiler/backends/llvm/LlvmCompilerContext.java
@@ -123,7 +123,7 @@ public record LlvmCompilerContext(
         var globalDefinition = new LlvmGlobalDefinition(
             generateTopLevelEntityName(builder.namePrefix().orElseThrow()),
             builder.type().orElseThrow(),
-            builder.value().orElseThrow(),
+            builder.value(),
             builder.constant(),
             builder.isPrivate(),
             builder.unnamedAddr()
diff --git a/src/main/java/org/shedlang/compiler/backends/llvm/LlvmCompilerNamespaces.java b/src/main/java/org/shedlang/compiler/backends/llvm/LlvmCompilerNamespaces.java
index 949ffa9c..5c0bbca5 100644
--- a/src/main/java/org/shedlang/compiler/backends/llvm/LlvmCompilerNamespaces.java
+++ b/src/main/java/org/shedlang/compiler/backends/llvm/LlvmCompilerNamespaces.java
@@ -12,6 +12,7 @@ import org.shedlang.compiler.types.NamespaceTypeInfo;
 
 import java.util.Collections;
 import java.util.List;
+import java.util.Optional;
 import java.util.stream.IntStream;
 
 public class LlvmCompilerNamespaces {
@@ -44,14 +45,14 @@ public class LlvmCompilerNamespaces {
         return new LlvmGlobalDefinition(
             globalNameNamespaceValue(namespaceName),
             typeNamespaceStruct(namespaceTypeInfo),
-            new LlvmOperandStructure(
+            Optional.of(new LlvmOperandStructure(
                 IntStream.range(0, namespaceTypeInfo.fieldCount())
                     .mapToObj(ignored -> new LlvmTypedOperand(
                         LlvmCompilerTypes.VALUE_TYPE,
                         new LlvmOperandInt(0)
                     ))
                     .toList()
-            ),
+            )),
             false,
             false,
             false
diff --git a/src/main/java/org/shedlang/compiler/backends/llvm/ir/LlvmIrSerializer.java b/src/main/java/org/shedlang/compiler/backends/llvm/ir/LlvmIrSerializer.java
index 5853fd6d..74a271ed 100644
--- a/src/main/java/org/shedlang/compiler/backends/llvm/ir/LlvmIrSerializer.java
+++ b/src/main/java/org/shedlang/compiler/backends/llvm/ir/LlvmIrSerializer.java
@@ -207,11 +207,16 @@ public class LlvmIrSerializer {
                 if (globalDefinition.unnamedAddr()) {
                     builder.append("unnamed_addr ");
                 }
+                if (globalDefinition.value().isEmpty()) {
+                    builder.append("external ");
+                }
                 builder.append(globalDefinition.constant() ? "constant" : "global");
                 builder.append(" ");
                 serializeType(globalDefinition.type(), builder);
-                builder.append(" ");
-                serializeOperand(globalDefinition.value(), builder);
+                if (globalDefinition.value().isPresent()) {
+                    builder.append(" ");
+                    serializeOperand(globalDefinition.value().get(), builder);
+                }
                 builder.append("\n");
             }
         }
diff --git a/src/main/java/org/shedlang/compiler/backends/llvm/ir/ast/LlvmGlobalDefinition.java b/src/main/java/org/shedlang/compiler/backends/llvm/ir/ast/LlvmGlobalDefinition.java
index 68c9cd67..2f5f2e72 100644
--- a/src/main/java/org/shedlang/compiler/backends/llvm/ir/ast/LlvmGlobalDefinition.java
+++ b/src/main/java/org/shedlang/compiler/backends/llvm/ir/ast/LlvmGlobalDefinition.java
@@ -3,10 +3,12 @@ package org.shedlang.compiler.backends.llvm.ir.ast;
 import org.shedlang.compiler.backends.llvm.ir.ast.operands.LlvmOperand;
 import org.shedlang.compiler.backends.llvm.ir.ast.types.LlvmType;
 
+import java.util.Optional;
+
 public record LlvmGlobalDefinition(
     String name,
     LlvmType type,
-    LlvmOperand value,
+    Optional<LlvmOperand> value,
     boolean constant,
     boolean isPrivate,
     boolean unnamedAddr
diff --git a/src/test/java/org/shedlang/compiler/backends/llvm/LlvmCompilerPushStringTests.java b/src/test/java/org/shedlang/compiler/backends/llvm/LlvmCompilerPushStringTests.java
index 9a6324a8..b62ac757 100644
--- a/src/test/java/org/shedlang/compiler/backends/llvm/LlvmCompilerPushStringTests.java
+++ b/src/test/java/org/shedlang/compiler/backends/llvm/LlvmCompilerPushStringTests.java
@@ -36,7 +36,7 @@ public class LlvmCompilerPushStringTests {
                     LlvmTypes.INT_64,
                     LlvmTypes.array(5, LlvmTypes.INT_8)
                 )))),
-                has("value", x -> x.value(), equalTo(LlvmIr.operandStructure(List.of(
+                has("value", x -> x.value(), isOptionalOf(equalTo(LlvmIr.operandStructure(List.of(
                     LlvmIr.typedOperand(LlvmTypes.INT_64, LlvmIr.operandInt(5)),
                     LlvmIr.typedOperand(
                         LlvmTypes.array(5, LlvmTypes.INT_8),
@@ -48,7 +48,7 @@ public class LlvmCompilerPushStringTests {
                             LlvmIr.operandInt(111)
                         ))
                     )
-                )))),
+                ))))),
                 has("constant", x -> x.constant(), equalTo(true)),
                 has("isPrivate", x -> x.isPrivate(), equalTo(true)),
                 has("unnamedAddr", x -> x.unnamedAddr(), equalTo(true))
diff --git a/src/test/java/org/shedlang/compiler/backends/llvm/ir/LlvmIrSerializerGlobalDefinitionTests.java b/src/test/java/org/shedlang/compiler/backends/llvm/ir/LlvmIrSerializerGlobalDefinitionTests.java
index c2460540..85d94127 100644
--- a/src/test/java/org/shedlang/compiler/backends/llvm/ir/LlvmIrSerializerGlobalDefinitionTests.java
+++ b/src/test/java/org/shedlang/compiler/backends/llvm/ir/LlvmIrSerializerGlobalDefinitionTests.java
@@ -5,6 +5,8 @@ import org.shedlang.compiler.backends.llvm.ir.ast.LlvmGlobalDefinition;
 import org.shedlang.compiler.backends.llvm.ir.ast.LlvmIr;
 import org.shedlang.compiler.backends.llvm.ir.ast.types.LlvmTypes;
 
+import java.util.Optional;
+
 import static org.shedlang.compiler.backends.llvm.ir.LlvmIrSerializerTesting.serializeToString;
 import static org.zwobble.precisely.AssertThat.assertThat;
 import static org.zwobble.precisely.Matchers.equalTo;
@@ -15,7 +17,7 @@ public class LlvmIrSerializerGlobalDefinitionTests {
         var definition = new LlvmGlobalDefinition(
             "x",
             LlvmTypes.INT_64,
-            LlvmIr.operandInt(42),
+            Optional.of(LlvmIr.operandInt(42)),
             false,
             false,
             false
@@ -27,11 +29,27 @@ public class LlvmIrSerializerGlobalDefinitionTests {
     }
 
     @Test
+    public void canSerializeExternal() {
+        var definition = new LlvmGlobalDefinition(
+            "x",
+            LlvmTypes.INT_64,
+            Optional.empty(),
+            false,
+            false,
+            false
+        );
+
+        var result = serializeToString(definition, LlvmIrSerializer::serializeTopLevelEntity);
+
+        assertThat(result, equalTo("@x = external global i64\n"));
+    }
+
+    @Test
     public void canSerializeConstant() {
         var definition = new LlvmGlobalDefinition(
             "x",
             LlvmTypes.INT_64,
-            LlvmIr.operandInt(42),
+            Optional.of(LlvmIr.operandInt(42)),
             true,
             false,
             false
@@ -47,7 +65,7 @@ public class LlvmIrSerializerGlobalDefinitionTests {
         var definition = new LlvmGlobalDefinition(
             "x",
             LlvmTypes.INT_64,
-            LlvmIr.operandInt(42),
+            Optional.of(LlvmIr.operandInt(42)),
             false,
             true,
             false
@@ -63,7 +81,7 @@ public class LlvmIrSerializerGlobalDefinitionTests {
         var definition = new LlvmGlobalDefinition(
             "x",
             LlvmTypes.INT_64,
-            LlvmIr.operandInt(42),
+            Optional.of(LlvmIr.operandInt(42)),
             false,
             false,
             true
diff --git a/src/test/java/org/shedlang/compiler/backends/llvm/ir/LlvmIrSerializerModuleTests.java b/src/test/java/org/shedlang/compiler/backends/llvm/ir/LlvmIrSerializerModuleTests.java
index 1f32ddf3..c9cf5e95 100644
--- a/src/test/java/org/shedlang/compiler/backends/llvm/ir/LlvmIrSerializerModuleTests.java
+++ b/src/test/java/org/shedlang/compiler/backends/llvm/ir/LlvmIrSerializerModuleTests.java
@@ -6,6 +6,7 @@ import org.shedlang.compiler.backends.llvm.ir.ast.LlvmIr;
 import org.shedlang.compiler.backends.llvm.ir.ast.types.LlvmTypes;
 
 import java.util.List;
+import java.util.Optional;
 
 import static org.shedlang.compiler.backends.llvm.ir.LlvmIrSerializerTesting.serializeToString;
 import static org.zwobble.precisely.AssertThat.assertThat;
@@ -18,7 +19,7 @@ public class LlvmIrSerializerModuleTests {
             new LlvmGlobalDefinition(
                 "x",
                 LlvmTypes.INT_64,
-                LlvmIr.operandInt(42),
+                Optional.of(LlvmIr.operandInt(42)),
                 false,
                 false,
                 false
@@ -26,7 +27,7 @@ public class LlvmIrSerializerModuleTests {
             new LlvmGlobalDefinition(
                 "y",
                 LlvmTypes.INT_64,
-                LlvmIr.operandInt(42),
+                Optional.of(LlvmIr.operandInt(42)),
                 false,
                 false,
                 false