From 7f06adf8b132821c704deb6b62c1f40468da191f Mon Sep 17 00:00:00 2001
From: Michael Williamson <mike@zwobble.org>
Date: Tue, 28 Nov 2023 22:13:23 +0000
Subject: Avoid restoring previous exception handler twice

---
 .../compiler/backends/llvm/LlvmPatioCodeGen.java   | 24 +++++++++++++---------
 1 file changed, 14 insertions(+), 10 deletions(-)

(limited to 'src/main/java')

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 31a23d55..9e8ffbef 100644
--- a/src/main/java/org/shedlang/compiler/backends/llvm/LlvmPatioCodeGen.java
+++ b/src/main/java/org/shedlang/compiler/backends/llvm/LlvmPatioCodeGen.java
@@ -686,10 +686,12 @@ public class LlvmPatioCodeGen {
                 var branches = new ArrayList<Branch>();
                 var llvmSwitchCases = new ArrayList<LlvmSwitch.Case>();
 
-                branches.add(Branch.of(
+                branches.add(new Branch(
                     tryBodyStartLabel,
                     tryBodyEndLabel,
-                    try_.body()
+                    List.of(),
+                    try_.body(),
+                    List.of(restorePreviousExceptionHandlerInstruction)
                 ));
                 llvmSwitchCases.add(new LlvmSwitch.Case(0, tryBodyStartLabel));
 
@@ -709,10 +711,9 @@ public class LlvmPatioCodeGen {
                     branches.add(new Branch(
                         catchBodyStartLabel,
                         catchBodyEndLabel,
-                        List.of(
-                            restorePreviousExceptionHandlerInstruction
-                        ),
-                        catchClause.body()
+                        List.of(restorePreviousExceptionHandlerInstruction),
+                        catchClause.body(),
+                        List.of()
                     ));
                     var tag = context.exceptionTag(catchClause.exceptionTypeName());
                     llvmSwitchCases.add(new LlvmSwitch.Case(tag, catchBodyStartLabel));
@@ -743,8 +744,6 @@ public class LlvmPatioCodeGen {
                     context
                 );
 
-                context = context.addInstruction(restorePreviousExceptionHandlerInstruction);
-
                 yield context;
             }
 
@@ -792,14 +791,15 @@ public class LlvmPatioCodeGen {
         LlvmVariableLocal startLabel,
         LlvmVariableLocal endLabel,
         List<LlvmInstruction> prefixInstructions,
-        PatioBlock body
+        PatioBlock body,
+        List<LlvmInstruction> suffixInstructions
     ) {
         public static Branch of(
             LlvmVariableLocal startLabel,
             LlvmVariableLocal endLabel,
             PatioBlock body
         ) {
-            return new Branch(startLabel, endLabel, List.of(), body);
+            return new Branch(startLabel, endLabel, List.of(), body, List.of());
         }
     }
 
@@ -819,6 +819,10 @@ public class LlvmPatioCodeGen {
 
             context = generateInstructions(branch.body.body(), context);
 
+            for (var suffixInstruction : branch.suffixInstructions) {
+                context = context.addInstruction(suffixInstruction);
+            }
+
             var endIsUnreachable = branch.body.body().stream()
                 .anyMatch(instruction -> instruction instanceof PatioUnreachable);
 
-- 
cgit v1.2.3