Ensure uniqueness of LLVM locals

3 files changed, 68 insertions, 19 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 144575c0..c72bed0a 100644
--- a/src/main/java/org/shedlang/compiler/backends/llvm/LlvmCompilerContext.java
+++ b/src/main/java/org/shedlang/compiler/backends/llvm/LlvmCompilerContext.java
@@ -1,13 +1,11 @@
 package org.shedlang.compiler.backends.llvm;
 
-import org.pcollections.Empty;
-import org.pcollections.PMap;
-import org.pcollections.PStack;
-import org.pcollections.PVector;
+import org.pcollections.*;
 import org.shedlang.compiler.backends.llvm.ir.ast.LlvmGlobalDefinition;
 import org.shedlang.compiler.backends.llvm.ir.ast.LlvmTopLevelEntity;
 import org.shedlang.compiler.backends.llvm.ir.ast.instructions.LlvmInstruction;
 import org.shedlang.compiler.backends.llvm.ir.ast.operands.LlvmOperand;
+import org.shedlang.compiler.backends.llvm.ir.ast.operands.LlvmVariableLocal;
 import org.shedlang.compiler.typechecker.TypeInfo;
 import org.shedlang.compiler.util.POrderedMap;
 
@@ -18,7 +16,8 @@ public record LlvmCompilerContext(
     PStack<LlvmOperand> stack,
     PMap<String, LlvmOperand> locals,
     PVector<LlvmInstruction> instructions,
-    POrderedMap<String, LlvmTopLevelEntity> topLevelEntitiesByName
+    POrderedMap<String, LlvmTopLevelEntity> topLevelEntitiesByName,
+    PSet<String> localVariableNames
 ) {
     public static LlvmCompilerContext EMPTY = fromTypeInfo(TypeInfo.EMPTY);
 
@@ -28,7 +27,8 @@ public record LlvmCompilerContext(
             Empty.stack(),
             Empty.map(),
             Empty.vector(),
-            POrderedMap.empty()
+            POrderedMap.empty(),
+            Empty.set()
         );
     }
 
@@ -38,7 +38,8 @@ public record LlvmCompilerContext(
             stack.plus(operand),
             locals,
             instructions,
-            topLevelEntitiesByName
+            topLevelEntitiesByName,
+            localVariableNames
         );
     }
 
@@ -48,7 +49,8 @@ public record LlvmCompilerContext(
             stack.minus(0),
             locals,
             instructions,
-            topLevelEntitiesByName
+            topLevelEntitiesByName,
+            localVariableNames
         ).toResult(stack.get(0));
     }
 
@@ -58,7 +60,8 @@ public record LlvmCompilerContext(
             stack,
             locals.plus(name, value),
             instructions,
-            topLevelEntitiesByName
+            topLevelEntitiesByName,
+            localVariableNames
         );
     }
 
@@ -72,7 +75,8 @@ public record LlvmCompilerContext(
             stack,
             locals,
             instructions.plus(instruction),
-            topLevelEntitiesByName
+            topLevelEntitiesByName,
+            localVariableNames
         );
     }
 
@@ -93,7 +97,8 @@ public record LlvmCompilerContext(
             stack,
             locals,
             instructions,
-            topLevelEntitiesByName.plus(globalDefinition.name(), globalDefinition)
+            topLevelEntitiesByName.plus(globalDefinition.name(), globalDefinition),
+            localVariableNames
         ).toResult(globalDefinition);
     }
 
@@ -107,11 +112,33 @@ public record LlvmCompilerContext(
         return name;
     }
 
-    public <T> LlvmCompilerResult<T> toResult(T value) {
-        return new LlvmCompilerResult<>(value, this);
-    }
-
     public Collection<LlvmTopLevelEntity> topLevelEntities() {
         return topLevelEntitiesByName.values();
     }
+
+    public LlvmCompilerResult<LlvmVariableLocal> generateVariableLocal(
+        LlvmCompilerLocalVariableSpace space,
+        String name
+    ) {
+        var index = 0;
+        while (true) {
+            var fullName = space + "__" + name + "__" + index;
+            if (localVariableNames.contains(fullName)) {
+                index++;
+            } else {
+                return new LlvmCompilerContext(
+                    typeInfo,
+                    stack,
+                    locals,
+                    instructions,
+                    topLevelEntitiesByName,
+                    localVariableNames.plus(fullName)
+                ).toResult(new LlvmVariableLocal(fullName));
+            }
+        }
+    }
+
+    public <T> LlvmCompilerResult<T> toResult(T value) {
+        return new LlvmCompilerResult<>(value, this);
+    }
 }
diff --git a/src/main/java/org/shedlang/compiler/backends/llvm/LlvmCompilerLocalVariableSpace.java b/src/main/java/org/shedlang/compiler/backends/llvm/LlvmCompilerLocalVariableSpace.java
new file mode 100644
index 00000000..a7bb515a
--- /dev/null
+++ b/src/main/java/org/shedlang/compiler/backends/llvm/LlvmCompilerLocalVariableSpace.java
@@ -0,0 +1,16 @@
+package org.shedlang.compiler.backends.llvm;
+
+public enum LlvmCompilerLocalVariableSpace {
+    FIELD_POINTER("fieldPointer");
+
+    private final String name;
+
+    LlvmCompilerLocalVariableSpace(String name) {
+        this.name = name;
+    }
+
+    @Override
+    public String toString() {
+        return name;
+    }
+}
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 43fd97c8..d4cd73f9 100644
--- a/src/main/java/org/shedlang/compiler/backends/llvm/LlvmCompilerNamespaces.java
+++ b/src/main/java/org/shedlang/compiler/backends/llvm/LlvmCompilerNamespaces.java
@@ -5,7 +5,6 @@ import org.shedlang.compiler.backends.llvm.ir.ast.instructions.LlvmStore;
 import org.shedlang.compiler.backends.llvm.ir.ast.operands.LlvmOperand;
 import org.shedlang.compiler.backends.llvm.ir.ast.operands.LlvmTypedOperand;
 import org.shedlang.compiler.backends.llvm.ir.ast.operands.LlvmVariableGlobal;
-import org.shedlang.compiler.backends.llvm.ir.ast.operands.LlvmVariableLocal;
 import org.shedlang.compiler.backends.llvm.ir.ast.types.LlvmType;
 import org.shedlang.compiler.backends.llvm.ir.ast.types.LlvmTypePointer;
 import org.shedlang.compiler.backends.llvm.ir.ast.types.LlvmTypeStructure;
@@ -45,9 +44,16 @@ public class LlvmCompilerNamespaces {
         LlvmCompilerContext context
     ) {
         var namespaceTypeInfo = context.typeInfo().namespaceTypeInfo(namespaceName);
-        var fieldPointerName = "fieldPointer__" + fieldName;
+
+        var fieldPointerResult = context.generateVariableLocal(
+            LlvmCompilerLocalVariableSpace.FIELD_POINTER,
+            fieldName
+        );
+        var fieldPointer = fieldPointerResult.value();
+        context = fieldPointerResult.context();
+
         return context.addInstruction(new LlvmGetElementPtr(
-            new LlvmVariableLocal(fieldPointerName),
+            fieldPointer,
             typeNamespacePointer(namespaceTypeInfo),
             operandNamespaceValue(namespaceName),
             List.of(
@@ -57,7 +63,7 @@ public class LlvmCompilerNamespaces {
         )).addInstruction(new LlvmStore(
             LlvmCompilerTypes.VALUE_TYPE,
             fieldValue,
-            new LlvmVariableLocal(fieldPointerName)
+            fieldPointer
         ));
     }
 }