From 7b375a1c4a88d7751bd2d5e713108a16df9cb103 Mon Sep 17 00:00:00 2001
From: LemonBoy <thatlemon@gmail.com>
Date: Fri, 3 Jan 2020 10:17:40 +0100
Subject: [PATCH 1/2] Revert "Revert "Trailing comma is respected for builtin
 calls""

This reverts commit f83411b0b1b857c7f8679e3b90d2093ba60621d4.
---
 lib/std/zig/parser_test.zig | 21 +++++++++++++++++++++
 lib/std/zig/render.zig      | 37 ++++++++++++++++++++++++++++++-------
 2 files changed, 51 insertions(+), 7 deletions(-)

diff --git a/lib/std/zig/parser_test.zig b/lib/std/zig/parser_test.zig
index f193e1b6ef..c5500091fc 100644
--- a/lib/std/zig/parser_test.zig
+++ b/lib/std/zig/parser_test.zig
@@ -26,6 +26,27 @@ test "zig fmt: c pointer type" {
     );
 }
 
+test "zig fmt: builtin call with trailing comma" {
+    try testCanonical(
+        \\pub fn main() void {
+        \\    _ = @intToPtr(
+        \\        a,
+        \\        b,
+        \\    );
+        \\    _ = @ptrCast(
+        \\        a,
+        \\        b,
+        \\    );
+        \\    _ = @call(
+        \\        a,
+        \\        b,
+        \\        c,
+        \\    );
+        \\}
+        \\
+    );
+}
+
 test "zig fmt: asm expression with comptime content" {
     try testCanonical(
         \\comptime {
diff --git a/lib/std/zig/render.zig b/lib/std/zig/render.zig
index 6e1ee4a601..1f377e71bd 100644
--- a/lib/std/zig/render.zig
+++ b/lib/std/zig/render.zig
@@ -1263,17 +1263,40 @@ fn renderExpression(
                 try renderToken(tree, stream, builtin_call.builtin_token, indent, start_col, Space.None); // @name
             }
 
-            try renderToken(tree, stream, tree.nextToken(builtin_call.builtin_token), indent, start_col, Space.None); // (
+            const src_params_trailing_comma = blk: {
+                const maybe_comma = tree.prevToken(builtin_call.rparen_token);
+                break :blk tree.tokens.at(maybe_comma).id == .Comma;
+            };
 
-            var it = builtin_call.params.iterator(0);
-            while (it.next()) |param_node| {
-                try renderExpression(allocator, stream, tree, indent, start_col, param_node.*, Space.None);
+            const lparen = tree.nextToken(builtin_call.builtin_token);
 
-                if (it.peek() != null) {
-                    const comma_token = tree.nextToken(param_node.*.lastToken());
-                    try renderToken(tree, stream, comma_token, indent, start_col, Space.Space); // ,
+            if (!src_params_trailing_comma) {
+                try renderToken(tree, stream, lparen, indent, start_col, Space.None); // (
+
+                // render all on one line, no trailing comma
+                var it = builtin_call.params.iterator(0);
+                while (it.next()) |param_node| {
+                    try renderExpression(allocator, stream, tree, indent, start_col, param_node.*, Space.None);
+                    // try renderParamDecl(allocator, stream, tree, indent, start_col, param_node.*, Space.None);
+
+                    if (it.peek() != null) {
+                        const comma_token = tree.nextToken(param_node.*.lastToken());
+                        try renderToken(tree, stream, comma_token, indent, start_col, Space.Space); // ,
+                    }
                 }
+            } else {
+                // one param per line
+                const new_indent = indent + indent_delta;
+                try renderToken(tree, stream, lparen, new_indent, start_col, Space.Newline); // (
+
+                var it = builtin_call.params.iterator(0);
+                while (it.next()) |param_node| {
+                    try stream.writeByteNTimes(' ', new_indent);
+                    try renderExpression(allocator, stream, tree, indent, start_col, param_node.*, Space.Comma);
+                }
+                try stream.writeByteNTimes(' ', indent);
             }
+
             return renderToken(tree, stream, builtin_call.rparen_token, indent, start_col, space); // )
         },
 

From e6485282d36d58e24b812ee6dd76e97d25658dc6 Mon Sep 17 00:00:00 2001
From: LemonBoy <thatlemon@gmail.com>
Date: Fri, 3 Jan 2020 11:43:48 +0100
Subject: [PATCH 2/2] Better logic for last-param rendering

---
 lib/std/zig/parser_test.zig | 10 ++--------
 lib/std/zig/render.zig      |  5 +++--
 2 files changed, 5 insertions(+), 10 deletions(-)

diff --git a/lib/std/zig/parser_test.zig b/lib/std/zig/parser_test.zig
index c5500091fc..2e7a376684 100644
--- a/lib/std/zig/parser_test.zig
+++ b/lib/std/zig/parser_test.zig
@@ -29,14 +29,8 @@ test "zig fmt: c pointer type" {
 test "zig fmt: builtin call with trailing comma" {
     try testCanonical(
         \\pub fn main() void {
-        \\    _ = @intToPtr(
-        \\        a,
-        \\        b,
-        \\    );
-        \\    _ = @ptrCast(
-        \\        a,
-        \\        b,
-        \\    );
+        \\    @breakpoint();
+        \\    _ = @boolToInt(a);
         \\    _ = @call(
         \\        a,
         \\        b,
diff --git a/lib/std/zig/render.zig b/lib/std/zig/render.zig
index 1f377e71bd..d3553bb0bd 100644
--- a/lib/std/zig/render.zig
+++ b/lib/std/zig/render.zig
@@ -1264,7 +1264,9 @@ fn renderExpression(
             }
 
             const src_params_trailing_comma = blk: {
-                const maybe_comma = tree.prevToken(builtin_call.rparen_token);
+                if (builtin_call.params.len < 2) break :blk false;
+                const last_node = builtin_call.params.at(builtin_call.params.len - 1).*;
+                const maybe_comma = tree.nextToken(last_node.lastToken());
                 break :blk tree.tokens.at(maybe_comma).id == .Comma;
             };
 
@@ -1277,7 +1279,6 @@ fn renderExpression(
                 var it = builtin_call.params.iterator(0);
                 while (it.next()) |param_node| {
                     try renderExpression(allocator, stream, tree, indent, start_col, param_node.*, Space.None);
-                    // try renderParamDecl(allocator, stream, tree, indent, start_col, param_node.*, Space.None);
 
                     if (it.peek() != null) {
                         const comma_token = tree.nextToken(param_node.*.lastToken());