From 045a5e924ce9abe239634545b0ad35576cc2fafc Mon Sep 17 00:00:00 2001
From: Jacob Young <jacobly0@users.noreply.github.com>
Date: Tue, 7 Nov 2023 12:11:57 -0500
Subject: [PATCH 1/2] Sema: implement vararg integer promotions

---
 src/Sema.zig | 31 ++++++++++++++++++++++++++++---
 1 file changed, 28 insertions(+), 3 deletions(-)

diff --git a/src/Sema.zig b/src/Sema.zig
index 8e34c9e4dc..241f65a9a0 100644
--- a/src/Sema.zig
+++ b/src/Sema.zig
@@ -29418,10 +29418,10 @@ fn coerceVarArgParam(
             "integer and float literals passed to variadic function must be casted to a fixed-size number type",
             .{},
         ),
-        .Fn => blk: {
+        .Fn => fn_ptr: {
             const fn_val = try sema.resolveConstDefinedValue(block, .unneeded, inst, undefined);
             const fn_decl = fn_val.pointerDecl(mod).?;
-            break :blk try sema.analyzeDeclRef(fn_decl);
+            break :fn_ptr try sema.analyzeDeclRef(fn_decl);
         },
         .Array => return sema.fail(block, inst_src, "arrays must be passed by reference to variadic function", .{}),
         .Float => float: {
@@ -29435,7 +29435,32 @@ fn coerceVarArgParam(
                 else => unreachable,
             }
         },
-        else => inst,
+        else => if (uncasted_ty.isAbiInt(mod)) int: {
+            const target = sema.mod.getTarget();
+            const uncasted_info = uncasted_ty.intInfo(mod);
+            if (uncasted_info.bits <= target.c_type_bit_size(switch (uncasted_info.signedness) {
+                .signed => .int,
+                .unsigned => .uint,
+            })) break :int try sema.coerce(block, switch (uncasted_info.signedness) {
+                .signed => Type.c_int,
+                .unsigned => Type.c_uint,
+            }, inst, inst_src);
+            if (uncasted_info.bits <= target.c_type_bit_size(switch (uncasted_info.signedness) {
+                .signed => .long,
+                .unsigned => .ulong,
+            })) break :int try sema.coerce(block, switch (uncasted_info.signedness) {
+                .signed => Type.c_long,
+                .unsigned => Type.c_ulong,
+            }, inst, inst_src);
+            if (uncasted_info.bits <= target.c_type_bit_size(switch (uncasted_info.signedness) {
+                .signed => .longlong,
+                .unsigned => .ulonglong,
+            })) break :int try sema.coerce(block, switch (uncasted_info.signedness) {
+                .signed => Type.c_longlong,
+                .unsigned => Type.c_ulonglong,
+            }, inst, inst_src);
+            break :int inst;
+        } else inst,
     };
 
     const coerced_ty = sema.typeOf(coerced);

From 52d8099daeb34edc00898ef8cc34bd6f136949aa Mon Sep 17 00:00:00 2001
From: Jacob Young <jacobly0@users.noreply.github.com>
Date: Wed, 8 Nov 2023 14:42:45 -0500
Subject: [PATCH 2/2] Sema: don't allow passing non-extern types to varargs
 parameters

---
 src/Sema.zig | 1 +
 1 file changed, 1 insertion(+)

diff --git a/src/Sema.zig b/src/Sema.zig
index 241f65a9a0..0911f75feb 100644
--- a/src/Sema.zig
+++ b/src/Sema.zig
@@ -29436,6 +29436,7 @@ fn coerceVarArgParam(
             }
         },
         else => if (uncasted_ty.isAbiInt(mod)) int: {
+            if (!try sema.validateExternType(uncasted_ty, .param_ty)) break :int inst;
             const target = sema.mod.getTarget();
             const uncasted_info = uncasted_ty.intInfo(mod);
             if (uncasted_info.bits <= target.c_type_bit_size(switch (uncasted_info.signedness) {