Generate top level entity for minimal function

4 files changed, 67 insertions, 5 deletions

diff --git a/src/main/java/org/shedlang/compiler/backends/llvm/LlvmCompiler.java b/src/main/java/org/shedlang/compiler/backends/llvm/LlvmCompiler.java
index 7fc14092..2ad82eef 100644
--- a/src/main/java/org/shedlang/compiler/backends/llvm/LlvmCompiler.java
+++ b/src/main/java/org/shedlang/compiler/backends/llvm/LlvmCompiler.java
@@ -1,5 +1,9 @@
 package org.shedlang.compiler.backends.llvm;
 
+import org.shedlang.compiler.backends.llvm.ir.ast.LlvmBasicBlock;
+import org.shedlang.compiler.backends.llvm.ir.ast.LlvmFunctionDefinition;
+import org.shedlang.compiler.backends.llvm.ir.ast.LlvmParam;
+import org.shedlang.compiler.backends.llvm.ir.ast.instructions.LlvmReturn;
 import org.shedlang.compiler.backends.llvm.ir.ast.operands.LlvmOperand;
 import org.shedlang.compiler.backends.llvm.ir.ast.operands.LlvmOperandInt;
 import org.shedlang.compiler.stackir.instructions.*;
@@ -49,8 +53,38 @@ public class LlvmCompiler {
                     args
                 );
             }
-            case DefineFunctionInstruction defineFunctionInstruction -> {
-                throw new UnsupportedOperationException("TODO");
+            case DefineFunctionInstruction defineFunction -> {
+                var topLevelEntityName = context.generateTopLevelEntityName(
+                    LlvmCompilerTopLevelEntitySpace.FUNCTION,
+                    defineFunction.name()
+                );
+
+                var functionContext = context.enterFunction();
+                for (var bodyInstruction : defineFunction.body()) {
+                    functionContext = compileInstruction(bodyInstruction, functionContext);
+                }
+                // TODO: rejoin function context with context
+                // TODO: assert stack has exactly one element
+                var returnValue = functionContext.stack().get(0);
+
+                yield context.addTopLevelEntity(new LlvmFunctionDefinition(
+                    topLevelEntityName,
+                    LlvmCompilerTypes.VALUE_TYPE,
+                    List.of(
+                        new LlvmParam(
+                            LlvmCompilerClosures.typeClosureEnvironmentPointer(),
+                            // TODO: allocate name properly
+                            "shed__env__0"
+                        )
+                    ),
+                    List.of(
+                        new LlvmBasicBlock(
+                            Optional.empty(),
+                            List.of(),
+                            new LlvmReturn(LlvmCompilerTypes.VALUE_TYPE, returnValue)
+                        )
+                    )
+                ));
             }
             case DiscardInstruction discardInstruction ->
                 context.pop().context();
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 e1925e24..d558f483 100644
--- a/src/main/java/org/shedlang/compiler/backends/llvm/LlvmCompilerContext.java
+++ b/src/main/java/org/shedlang/compiler/backends/llvm/LlvmCompilerContext.java
@@ -93,21 +93,36 @@ public record LlvmCompilerContext(
             builder.unnamedAddr()
         );
 
+        return addTopLevelEntity(globalDefinition).toResult(globalDefinition);
+    }
+
+    public LlvmCompilerContext addTopLevelEntity(LlvmTopLevelEntity topLevelEntity) {
         return new LlvmCompilerContext(
             typeInfo,
             stack,
             locals,
             instructions,
-            topLevelEntitiesByName.plus(globalDefinition.name(), globalDefinition),
+            topLevelEntitiesByName.plus(topLevelEntity.name(), topLevelEntity),
             localVariableNames
-        ).toResult(globalDefinition);
+        );
+    }
+
+    public String generateTopLevelEntityName(LlvmCompilerTopLevelEntitySpace space, String name) {
+        return generateTopLevelEntityName(space, Optional.of(name));
     }
 
     private String generateTopLevelEntityName(LlvmCompilerTopLevelEntitySpace space) {
+        return generateTopLevelEntityName(space, Optional.empty());
+    }
+
+    private String generateTopLevelEntityName(
+        LlvmCompilerTopLevelEntitySpace space,
+        Optional<String> name
+    ) {
         return NameAllocator.generateName(
             topLevelEntitiesByName::containsKey,
             "shed__" + space,
-            Optional.empty()
+            name
         );
     }
 
@@ -146,4 +161,15 @@ public record LlvmCompilerContext(
     public <T> LlvmCompilerResult<T> toResult(T value) {
         return new LlvmCompilerResult<>(value, this);
     }
+
+    public LlvmCompilerContext enterFunction() {
+        return new LlvmCompilerContext(
+            typeInfo,
+            Empty.stack(),
+            Empty.map(),
+            Empty.vector(),
+            topLevelEntitiesByName,
+            NameAllocator.empty()
+        );
+    }
 }
diff --git a/src/main/java/org/shedlang/compiler/backends/llvm/LlvmCompilerTopLevelEntitySpace.java b/src/main/java/org/shedlang/compiler/backends/llvm/LlvmCompilerTopLevelEntitySpace.java
index 7ca7a06b..87b0a60b 100644
--- a/src/main/java/org/shedlang/compiler/backends/llvm/LlvmCompilerTopLevelEntitySpace.java
+++ b/src/main/java/org/shedlang/compiler/backends/llvm/LlvmCompilerTopLevelEntitySpace.java
@@ -1,6 +1,7 @@
 package org.shedlang.compiler.backends.llvm;
 
 public enum LlvmCompilerTopLevelEntitySpace {
+    FUNCTION("fun"),
     STRING("string");
 
     private final String name;
diff --git a/src/main/java/org/shedlang/compiler/backends/llvm/ir/ast/LlvmTopLevelEntity.java b/src/main/java/org/shedlang/compiler/backends/llvm/ir/ast/LlvmTopLevelEntity.java
index 86b3efc3..b1cabfa0 100644
--- a/src/main/java/org/shedlang/compiler/backends/llvm/ir/ast/LlvmTopLevelEntity.java
+++ b/src/main/java/org/shedlang/compiler/backends/llvm/ir/ast/LlvmTopLevelEntity.java
@@ -1,4 +1,5 @@
 package org.shedlang.compiler.backends.llvm.ir.ast;
 
 public sealed interface LlvmTopLevelEntity permits LlvmFunctionDefinition, LlvmGlobalDefinition {
+    String name();
 }