From 15bcfcd36865fca75b93dc6ce52c904292b62a81 Mon Sep 17 00:00:00 2001
From: Andrew Kelley <andrew@ziglang.org>
Date: Tue, 18 Aug 2020 15:11:43 -0700
Subject: [PATCH] stage2: fix use-after-free when printing ZIR

---
 src-self-hosted/zir.zig |  6 ++++--
 test/stage2/zir.zig     | 18 +++++++++---------
 2 files changed, 13 insertions(+), 11 deletions(-)

diff --git a/src-self-hosted/zir.zig b/src-self-hosted/zir.zig
index 276db6d522..793fdff031 100644
--- a/src-self-hosted/zir.zig
+++ b/src-self-hosted/zir.zig
@@ -872,6 +872,8 @@ pub const Module = struct {
     };
 
     pub fn deinit(self: *Module, allocator: *Allocator) void {
+        self.metadata.deinit();
+        self.body_metadata.deinit();
         allocator.free(self.decls);
         self.arena.deinit();
         self.* = undefined;
@@ -1543,8 +1545,8 @@ pub fn emit(allocator: *Allocator, old_module: IrModule) !Module {
         .metadata = std.AutoHashMap(*Inst, Module.MetaData).init(allocator),
         .body_metadata = std.AutoHashMap(*Module.Body, Module.BodyMetaData).init(allocator),
     };
-    defer ctx.metadata.deinit();
-    defer ctx.body_metadata.deinit();
+    errdefer ctx.metadata.deinit();
+    errdefer ctx.body_metadata.deinit();
     defer ctx.block_table.deinit();
     defer ctx.loop_table.deinit();
     defer ctx.decls.deinit(allocator);
diff --git a/test/stage2/zir.zig b/test/stage2/zir.zig
index f77c950052..225a7f58cd 100644
--- a/test/stage2/zir.zig
+++ b/test/stage2/zir.zig
@@ -28,7 +28,7 @@ pub fn addCases(ctx: *TestContext) !void {
         \\@unnamed$5 = export(@unnamed$4, "entry")
         \\@unnamed$6 = fntype([], @void, cc=C)
         \\@entry = fn(@unnamed$6, {
-        \\  %0 = returnvoid()
+        \\  %0 = returnvoid() ; deaths=0b1000000000000000
         \\})
         \\
     );
@@ -75,7 +75,7 @@ pub fn addCases(ctx: *TestContext) !void {
         \\@3 = int(3)
         \\@unnamed$6 = fntype([], @void, cc=C)
         \\@entry = fn(@unnamed$6, {
-        \\  %0 = returnvoid()
+        \\  %0 = returnvoid() ; deaths=0b1000000000000000
         \\})
         \\@entry__anon_1 = str("2\x08\x01\n")
         \\@9 = declref("9__anon_0")
@@ -117,18 +117,18 @@ pub fn addCases(ctx: *TestContext) !void {
             \\@unnamed$5 = export(@unnamed$4, "entry")
             \\@unnamed$6 = fntype([], @void, cc=C)
             \\@entry = fn(@unnamed$6, {
-            \\  %0 = call(@a, [], modifier=auto)
-            \\  %1 = returnvoid()
+            \\  %0 = call(@a, [], modifier=auto) ; deaths=0b1000000000000001
+            \\  %1 = returnvoid() ; deaths=0b1000000000000000
             \\})
             \\@unnamed$8 = fntype([], @void, cc=C)
             \\@a = fn(@unnamed$8, {
-            \\  %0 = call(@b, [], modifier=auto)
-            \\  %1 = returnvoid()
+            \\  %0 = call(@b, [], modifier=auto) ; deaths=0b1000000000000001
+            \\  %1 = returnvoid() ; deaths=0b1000000000000000
             \\})
             \\@unnamed$10 = fntype([], @void, cc=C)
             \\@b = fn(@unnamed$10, {
-            \\  %0 = call(@a, [], modifier=auto)
-            \\  %1 = returnvoid()
+            \\  %0 = call(@a, [], modifier=auto) ; deaths=0b1000000000000001
+            \\  %1 = returnvoid() ; deaths=0b1000000000000000
             \\})
             \\
         );
@@ -193,7 +193,7 @@ pub fn addCases(ctx: *TestContext) !void {
             \\@unnamed$5 = export(@unnamed$4, "entry")
             \\@unnamed$6 = fntype([], @void, cc=C)
             \\@entry = fn(@unnamed$6, {
-            \\  %0 = returnvoid()
+            \\  %0 = returnvoid() ; deaths=0b1000000000000000
             \\})
             \\
         );