Support use of exception value in LLVM backend

1 files changed, 22 insertions, 1 deletions

diff --git a/src/main/java/org/shedlang/compiler/backends/llvm/LlvmPatioCodeGen.java b/src/main/java/org/shedlang/compiler/backends/llvm/LlvmPatioCodeGen.java
index 9e8ffbef..a5d31993 100644
--- a/src/main/java/org/shedlang/compiler/backends/llvm/LlvmPatioCodeGen.java
+++ b/src/main/java/org/shedlang/compiler/backends/llvm/LlvmPatioCodeGen.java
@@ -46,6 +46,15 @@ public class LlvmPatioCodeGen {
         false
     );
 
+    private static final LlvmGlobalDefinition EXCEPTION_VALUE_DECLARATION = new LlvmGlobalDefinition(
+        "patio__runtime__exceptions_exception_value",
+        LlvmTypes.INT_64,
+        Optional.empty(),
+        false,
+        false,
+        false
+    );
+
     private static final LlvmFunctionDeclaration THROW_DECLARATION = new LlvmFunctionDeclaration(
         "patio__runtime__exceptions_throw",
         LlvmTypes.pointer(LlvmTypes.VOID),
@@ -67,6 +76,7 @@ public class LlvmPatioCodeGen {
         var context = ModuleContext.EMPTY
             .addTopLevelEntity(SETJMP_DECLARATION)
             .addTopLevelEntity(EXCEPTION_HANDLER_DECLARATION)
+            .addTopLevelEntity(EXCEPTION_VALUE_DECLARATION)
             .addTopLevelEntity(THROW_DECLARATION)
             .addTopLevelEntity(RETHROW_DECLARATION);
 
@@ -708,10 +718,21 @@ public class LlvmPatioCodeGen {
                     var catchBodyEndLabel = catchBodyEndLabelResult.value();
                     context = catchBodyEndLabelResult.context();
 
+                    var exceptionValueTargetResult = context.addPatioLocalToLlvmLocal(catchClause.target());
+                    var exceptionValueTarget = exceptionValueTargetResult.value;
+                    context = exceptionValueTargetResult.context;
+
                     branches.add(new Branch(
                         catchBodyStartLabel,
                         catchBodyEndLabel,
-                        List.of(restorePreviousExceptionHandlerInstruction),
+                        List.of(
+                            restorePreviousExceptionHandlerInstruction,
+                            new LlvmLoad(
+                                exceptionValueTarget,
+                                LlvmTypes.INT_64,
+                                new LlvmVariableGlobal(EXCEPTION_VALUE_DECLARATION.name())
+                            )
+                        ),
                         catchClause.body(),
                         List.of()
                     ));