From 4b9fd57aa86a480f2afd6ba117fcc7ef6eace572 Mon Sep 17 00:00:00 2001
From: Evan Haas <evan@lagerdata.com>
Date: Tue, 8 Mar 2022 10:38:51 -0800
Subject: [PATCH] translate-c: use nested scope for comma operator in macros

Fixes #11040
---
 src/translate_c.zig                  |  2 +-
 test/behavior/translate_c_macros.h   |  2 ++
 test/behavior/translate_c_macros.zig |  6 ++++++
 test/run_translated_c.zig            | 10 ++++++++++
 4 files changed, 19 insertions(+), 1 deletion(-)

diff --git a/src/translate_c.zig b/src/translate_c.zig
index 09e720d289..8b79dd53ab 100644
--- a/src/translate_c.zig
+++ b/src/translate_c.zig
@@ -5563,7 +5563,7 @@ fn parseCExpr(c: *Context, m: *MacroCtx, scope: *Scope) ParseError!Node {
         const ignore = try Tag.discard.create(c.arena, .{ .should_skip = false, .value = last });
         try block_scope.statements.append(ignore);
 
-        last = try parseCCondExpr(c, m, scope);
+        last = try parseCCondExpr(c, m, &block_scope.base);
         if (m.next().? != .Comma) {
             m.i -= 1;
             break;
diff --git a/test/behavior/translate_c_macros.h b/test/behavior/translate_c_macros.h
index bec73e20d6..490ca35726 100644
--- a/test/behavior/translate_c_macros.h
+++ b/test/behavior/translate_c_macros.h
@@ -37,3 +37,5 @@ union U {
 #define IGNORE_ME_10(x) (volatile const void)(x)
 
 #define UNION_CAST(X) (union U)(X)
+
+#define NESTED_COMMA_OPERATOR (1, (2, 3))
diff --git a/test/behavior/translate_c_macros.zig b/test/behavior/translate_c_macros.zig
index a67d315ffc..7f8a35f5a1 100644
--- a/test/behavior/translate_c_macros.zig
+++ b/test/behavior/translate_c_macros.zig
@@ -56,3 +56,9 @@ test "casting to union with a macro" {
     casted = h.UNION_CAST(d);
     try expectEqual(d, casted.d);
 }
+
+test "nested comma operator" {
+    if (builtin.zig_backend == .stage2_c) return error.SkipZigTest; // TODO
+
+    try expectEqual(@as(c_int, 3), h.NESTED_COMMA_OPERATOR);
+}
diff --git a/test/run_translated_c.zig b/test/run_translated_c.zig
index bc37b07661..1e8f081c11 100644
--- a/test/run_translated_c.zig
+++ b/test/run_translated_c.zig
@@ -1851,4 +1851,14 @@ pub fn addCases(cases: *tests.RunTranslatedCContext) void {
         \\    return 0;
         \\}
     , "");
+
+    cases.add("Nested comma operator in macro. Issue #11040",
+        \\#include <stdlib.h>
+        \\#define FOO (1, (2,  3))
+        \\int main(void) {
+        \\    int x = FOO;
+        \\    if (x != 3) abort();
+        \\    return 0;
+        \\}
+    , "");
 }