From f499572ffea4cab93d28e2480bcc9a4234f59089 Mon Sep 17 00:00:00 2001
From: chloe caruso <git@paperclover.net>
Date: Sun, 2 Jun 2024 21:29:31 -0700
Subject: [PATCH] fix(sema): quit block analysis when hitting `noreturn`

---
 CHANGELOG.md        |  1 +
 src/core/JsLink.zig |  7 +++++--
 src/core/Sema.zig   | 18 +++++++++++++++---
 3 files changed, 21 insertions(+), 5 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 7fc10bd6e5508a5477d5bbfa780c74c98600168e..7f574b564835296081b7cfcade1d085527db0bd6 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,7 @@
 
 - fix(sema): miscompilation using left side of all binary expression for both sides
 - fix(sema): handle recursive function calls
+- fix(sema): quit block analysis when hitting `noreturn`
 
 ## 0.1.3
 
diff --git a/src/core/JsLink.zig b/src/core/JsLink.zig
index 7c9975be09458410f563d5ba057867727df1e40e..8b046e5624dec2fce61a50ce5b71b6282c46ee20 100644
--- a/src/core/JsLink.zig
+++ b/src/core/JsLink.zig
@@ -147,12 +147,15 @@ fn printDecl(link: *JsLink, decl_index: Decl.Index, writer: anytype) !void {
     const decl = link.comp.intern_pool.declPtrConst(decl_index);
     const tree = &decl.codegen.?;
 
-    try writer.writeAll("(");
+    if (tree.param_count != 1)
+        try writer.writeAll("(");
     for (0..tree.param_count) |id| {
         try link.printLocal(@intCast(id), writer);
         if (id != tree.param_count - 1) try writer.writeAll(", ");
     }
-    try writer.writeAll(") => ");
+    if (tree.param_count != 1)
+        try writer.writeAll(")");
+    try writer.writeAll(" => ");
 
     const stmts = tree.mainStatements();
     if (stmts.len == 1 and tree.nodeTag(stmts[0]) == .stmt_return) {
diff --git a/src/core/Sema.zig b/src/core/Sema.zig
index 6c610b1b64933c06c2dc99cf8aa7aa12e0f3f3e8..2a73d9f080a482ed10d4266479c88e97ef39cf3a 100644
--- a/src/core/Sema.zig
+++ b/src/core/Sema.zig
@@ -33,7 +33,10 @@ pub const Error = error{
 
     // TODO: add handling of this
     TooManyValues,
+    // TODO: add handling of this
     HasNulls,
+    // TODO: remove this from the primary error set
+    HitNoReturn,
 
     OutOfMemory,
 } || Comp.File.GetTegError;
@@ -210,11 +213,14 @@ pub fn analyzeBlock(s: *Sema, in: Teg.Inst.Index) Error!Air.Inst.Ref {
     const block = try s.addBlock();
     try s.inst_map.add(in, block.block_index.toRef());
 
-    var last: Air.Inst.Ref = undefined;
+    var last: Air.Inst.Ref = Value.void.toAir();
     const instructions = s.code.blockInstructions(in);
     assert(instructions.len != 0);
     for (instructions) |inst| {
-        last = try s.analyzeCode(inst);
+        last = s.analyzeCode(inst) catch |err| switch (err) {
+            error.HitNoReturn => break,
+            else => return err,
+        };
     }
 
     if (scratch_top + 1 == s.scratch.items.len) {
@@ -585,7 +591,10 @@ fn analyzeRefToBlock(s: *Sema, in: Teg.Inst.Ref) Error!Air.Inst.Ref {
     const scratch_top = s.scratch.items.len;
     defer s.scratch.shrinkRetainingCapacity(scratch_top);
 
-    const visited = try s.resolveRefRuntime(in);
+    const visited = s.resolveRefRuntime(in) catch |err| switch (err) {
+        error.HitNoReturn => Value.void.toAir(),
+        else => return err,
+    };
 
     if (scratch_top == s.scratch.items.len and visited.kind == .value) {
         return visited;
@@ -665,6 +674,9 @@ fn coerceRef(s: *Sema, src: InstOp, value: Air.Inst.Ref, to: Type) !Air.Inst.Ref
     if (from == to) {
         return value;
     }
+    if (from == .noreturn) {
+        return error.HitNoReturn;
+    }
     if (from == .@"opaque") {
         return value;
     }
-- 
2.54.0