Support string-add in LLVM backend

3 files changed, 51 insertions, 14 deletions

diff --git a/src/main/java/org/shedlang/compiler/backends/llvm/LlvmCodeGen.java b/src/main/java/org/shedlang/compiler/backends/llvm/LlvmCodeGen.java
index 875fb799..e2236dcc 100644
--- a/src/main/java/org/shedlang/compiler/backends/llvm/LlvmCodeGen.java
+++ b/src/main/java/org/shedlang/compiler/backends/llvm/LlvmCodeGen.java
@@ -149,8 +149,10 @@ public class LlvmCodeGen {
 
             case IntAddInstruction intAdd ->
                 generateBinaryOperation(
-                    (target, left, right) ->
-                        new LlvmAdd(target, LlvmCodeGenTypes.INT_TYPE, left, right),
+                    (target, left, right, operationContext) ->
+                        operationContext.addInstruction(
+                            new LlvmAdd(target, LlvmCodeGenTypes.INT_TYPE, left, right)
+                        ),
                     context
                 );
 
@@ -162,8 +164,10 @@ public class LlvmCodeGen {
 
             case IntSubInstruction intSub ->
                 generateBinaryOperation(
-                    (target, left, right) ->
-                        new LlvmSub(target, LlvmCodeGenTypes.INT_TYPE, left, right),
+                    (target, left, right, operationContext) ->
+                        operationContext.addInstruction(
+                            new LlvmSub(target, LlvmCodeGenTypes.INT_TYPE, left, right)
+                        ),
                     context
                 );
 
@@ -230,15 +234,20 @@ public class LlvmCodeGen {
             }
 
             case StringAddInstruction stringAdd ->
-                throw new UnsupportedOperationException("TODO");
+                generateBinaryOperation(
+                    (target, left, right, operationContext) ->
+                        LlvmCodeGenStrings.add(target, left, right, operationContext),
+                    context
+                );
         };
     }
 
     interface BinaryOperation {
-        LlvmInstruction generate(
+        LlvmCodeGenContext generate(
             LlvmVariable target,
             LlvmOperand left,
-            LlvmOperand right
+            LlvmOperand right,
+            LlvmCodeGenContext context
         );
     }
 
@@ -258,13 +267,7 @@ public class LlvmCodeGen {
         var target = targetResult.value();
         context = targetResult.context();
 
-        return context
-            .addInstruction(operation.generate(
-                target,
-                left,
-                right
-            ))
-            .push(target);
+        return operation.generate(target, left, right, context).push(target);
     }
 
     private static LlvmCodeGenContext generateBinaryComparison(
diff --git a/src/main/java/org/shedlang/compiler/backends/llvm/LlvmCodeGenStrings.java b/src/main/java/org/shedlang/compiler/backends/llvm/LlvmCodeGenStrings.java
index 8165e3c8..6c9c782d 100644
--- a/src/main/java/org/shedlang/compiler/backends/llvm/LlvmCodeGenStrings.java
+++ b/src/main/java/org/shedlang/compiler/backends/llvm/LlvmCodeGenStrings.java
@@ -1,6 +1,9 @@
 package org.shedlang.compiler.backends.llvm;
 
+import org.shedlang.compiler.backends.llvm.ir.ast.LlvmFunctionDeclaration;
 import org.shedlang.compiler.backends.llvm.ir.ast.LlvmGlobalDefinition;
+import org.shedlang.compiler.backends.llvm.ir.ast.LlvmParam;
+import org.shedlang.compiler.backends.llvm.ir.ast.instructions.LlvmCall;
 import org.shedlang.compiler.backends.llvm.ir.ast.operands.*;
 import org.shedlang.compiler.backends.llvm.ir.ast.types.LlvmType;
 import org.shedlang.compiler.backends.llvm.ir.ast.types.LlvmTypePointer;
@@ -67,4 +70,34 @@ public class LlvmCodeGenStrings {
             LlvmCodeGenTypes.VALUE_TYPE
         );
     }
+
+    public static LlvmCodeGenContext add(
+        LlvmVariable target,
+        LlvmOperand left,
+        LlvmOperand right,
+        LlvmCodeGenContext context
+    ) {
+        var runtimeAddName = "shed__runtime__string_add";
+
+        if (!context.hasTopLevelEntity(runtimeAddName)) {
+            context = context.addTopLevelEntity(new LlvmFunctionDeclaration(
+                runtimeAddName,
+                LlvmCodeGenTypes.STRING_TYPE,
+                List.of(
+                    new LlvmParam(LlvmCodeGenTypes.STRING_TYPE, "left"),
+                    new LlvmParam(LlvmCodeGenTypes.STRING_TYPE, "right")
+                )
+            ));
+        }
+
+        return context.addInstruction(new LlvmCall(
+            target,
+            LlvmCodeGenTypes.STRING_TYPE,
+            new LlvmVariableGlobal(runtimeAddName),
+            List.of(
+                new LlvmTypedOperand(LlvmCodeGenTypes.STRING_TYPE, left),
+                new LlvmTypedOperand(LlvmCodeGenTypes.STRING_TYPE, right)
+            )
+        ));
+    }
 }
diff --git a/src/main/java/org/shedlang/compiler/backends/llvm/LlvmCodeGenTypes.java b/src/main/java/org/shedlang/compiler/backends/llvm/LlvmCodeGenTypes.java
index a8367384..e2d37a8a 100644
--- a/src/main/java/org/shedlang/compiler/backends/llvm/LlvmCodeGenTypes.java
+++ b/src/main/java/org/shedlang/compiler/backends/llvm/LlvmCodeGenTypes.java
@@ -9,4 +9,5 @@ public class LlvmCodeGenTypes {
 
     public static final LlvmTypeScalar VALUE_TYPE = LlvmTypes.INT_64;
     public static final LlvmTypeScalar INT_TYPE = LlvmTypes.INT_64;
+    public static final LlvmTypeScalar STRING_TYPE = VALUE_TYPE;
 }