zig fmt: parse extra comma in asm expressions

4 files changed, 120 insertions, 29 deletions

diff --git a/std/zig/ast.zig b/std/zig/ast.zig
index 6c848b4a54..addd3a37e8 100644
--- a/std/zig/ast.zig
+++ b/std/zig/ast.zig
@@ -2071,7 +2071,7 @@ pub const Node = struct {
 
         const OutputList = SegmentedList(&AsmOutput, 2);
         const InputList = SegmentedList(&AsmInput, 2);
-        const ClobberList = SegmentedList(&Node, 2);
+        const ClobberList = SegmentedList(TokenIndex, 2);
 
         pub fn iterate(self: &Asm, index: usize) ?&Node {
             var i = index;
diff --git a/std/zig/parse.zig b/std/zig/parse.zig
index a6eb22a2d0..1bc64c3ddb 100644
--- a/std/zig/parse.zig
+++ b/std/zig/parse.zig
@@ -1153,9 +1153,11 @@ pub fn parse(allocator: &mem.Allocator, source: []const u8) !ast.Tree {
                 continue;
             },
             State.AsmClobberItems => |items| {
-                stack.append(State{ .AsmClobberItems = items }) catch unreachable;
-                try stack.append(State{ .IfToken = Token.Id.Comma });
-                try stack.append(State{ .StringLiteral = OptionalCtx{ .Required = try items.addOne() } });
+                while (eatToken(&tok_it, &tree, Token.Id.StringLiteral)) |strlit| {
+                    try items.push(strlit);
+                    if (eatToken(&tok_it, &tree, Token.Id.Comma) == null)
+                        break;
+                }
                 continue;
             },
 
diff --git a/std/zig/parser_test.zig b/std/zig/parser_test.zig
index d321f78668..ab15ca3a58 100644
--- a/std/zig/parser_test.zig
+++ b/std/zig/parser_test.zig
@@ -1,3 +1,44 @@
+test "zig fmt: simple asm" {
+    try testTransform(
+        \\comptime {
+        \\    asm volatile (
+        \\        \\.globl aoeu;
+        \\        \\.type aoeu, @function;
+        \\        \\.set aoeu, derp;
+        \\    );
+        \\
+        \\    asm ("not real assembly"
+        \\        :[a] "x" (x),);
+        \\    asm ("not real assembly"
+        \\        :[a] "x" (->i32),:[a] "x" (1),);
+        \\    asm ("still not real assembly"
+        \\        :::"a","b",);
+        \\}
+    ,
+        \\comptime {
+        \\    asm volatile (
+        \\        \\.globl aoeu;
+        \\        \\.type aoeu, @function;
+        \\        \\.set aoeu, derp;
+        \\    );
+        \\
+        \\    asm ("not real assembly"
+        \\        : [a] "x" (x)
+        \\    );
+        \\    asm ("not real assembly"
+        \\        : [a] "x" (-> i32)
+        \\        : [a] "x" (1)
+        \\    );
+        \\    asm ("still not real assembly"
+        \\        :
+        \\        :
+        \\        : "a", "b"
+        \\    );
+        \\}
+        \\
+    );
+}
+
 test "zig fmt: nested struct literal with one item" {
     try testCanonical(
         \\const a = foo{
@@ -1295,7 +1336,8 @@ test "zig fmt: inline asm" {
         \\        : [ret] "={rax}" (-> usize)
         \\        : [number] "{rax}" (number),
         \\          [arg1] "{rdi}" (arg1)
-        \\        : "rcx", "r11");
+        \\        : "rcx", "r11"
+        \\    );
         \\}
         \\
     );
diff --git a/std/zig/render.zig b/std/zig/render.zig
index 04939324a8..c37f6e37c7 100644
--- a/std/zig/render.zig
+++ b/std/zig/render.zig
@@ -1203,19 +1203,35 @@ fn renderExpression(allocator: &mem.Allocator, stream: var, tree: &ast.Tree, ind
                 try renderToken(tree, stream, tree.nextToken(asm_node.asm_token), indent, Space.None); // (
             }
 
+            if (asm_node.outputs.len == 0 and asm_node.inputs.len == 0 and asm_node.clobbers.len == 0) {
+                try renderExpression(allocator, stream, tree, indent, asm_node.template, Space.None);
+                try renderToken(tree, stream, asm_node.rparen, indent, space);
+                return;
+            }
+
             try renderExpression(allocator, stream, tree, indent, asm_node.template, Space.Newline);
+
             const indent_once = indent + indent_delta;
             try stream.writeByteNTimes(' ', indent_once);
-            try stream.print(": ");
+
+            const colon1 = tree.nextToken(asm_node.template.lastToken());
             const indent_extra = indent_once + 2;
 
-            {
+            const colon2 = if (asm_node.outputs.len == 0) blk: {
+                try renderToken(tree, stream, colon1, indent, Space.Newline); // :
+                try stream.writeByteNTimes(' ', indent_once);
+
+                break :blk tree.nextToken(colon1);
+            } else blk: {
+                try renderToken(tree, stream, colon1, indent, Space.Space); // :
+
                 var it = asm_node.outputs.iterator(0);
-                while (it.next()) |asm_output| {
+                while (true) {
+                    const asm_output = ??it.next();
                     const node = &(asm_output.*).base;
-                    try renderExpression(allocator, stream, tree, indent_extra, node, Space.None);
 
                     if (it.peek()) |next_asm_output| {
+                        try renderExpression(allocator, stream, tree, indent_extra, node, Space.None);
                         const next_node = &(next_asm_output.*).base;
 
                         const comma = tree.prevToken(next_asm_output.*.firstToken());
@@ -1223,21 +1239,38 @@ fn renderExpression(allocator: &mem.Allocator, stream: var, tree: &ast.Tree, ind
                         try renderExtraNewline(tree, stream, next_node);
 
                         try stream.writeByteNTimes(' ', indent_extra);
+                    } else if (asm_node.inputs.len == 0 and asm_node.clobbers.len == 0) {
+                        try renderExpression(allocator, stream, tree, indent_extra, node, Space.Newline);
+                        try stream.writeByteNTimes(' ', indent);
+                        try renderToken(tree, stream, asm_node.rparen, indent, space);
+                        return;
+                    } else {
+                        try renderExpression(allocator, stream, tree, indent_extra, node, Space.Newline);
+                        try stream.writeByteNTimes(' ', indent_once);
+                        const comma_or_colon = tree.nextToken(node.lastToken());
+                        break :blk switch (tree.tokens.at(comma_or_colon).id) {
+                            Token.Id.Comma => tree.nextToken(comma_or_colon),
+                            else => comma_or_colon,
+                        };
                     }
                 }
-            }
+            };
 
-            try stream.write("\n");
-            try stream.writeByteNTimes(' ', indent_once);
-            try stream.write(": ");
+            const colon3 = if (asm_node.inputs.len == 0) blk: {
+                try renderToken(tree, stream, colon2, indent, Space.Newline); // :
+                try stream.writeByteNTimes(' ', indent_once);
+
+                break :blk tree.nextToken(colon2);
+            } else blk: {
+                try renderToken(tree, stream, colon2, indent, Space.Space); // :
 
-            {
                 var it = asm_node.inputs.iterator(0);
-                while (it.next()) |asm_input| {
+                while (true) {
+                    const asm_input = ??it.next();
                     const node = &(asm_input.*).base;
-                    try renderExpression(allocator, stream, tree, indent_extra, node, Space.None);
 
                     if (it.peek()) |next_asm_input| {
+                        try renderExpression(allocator, stream, tree, indent_extra, node, Space.None);
                         const next_node = &(next_asm_input.*).base;
 
                         const comma = tree.prevToken(next_asm_input.*.firstToken());
@@ -1245,26 +1278,40 @@ fn renderExpression(allocator: &mem.Allocator, stream: var, tree: &ast.Tree, ind
                         try renderExtraNewline(tree, stream, next_node);
 
                         try stream.writeByteNTimes(' ', indent_extra);
+                    } else if (asm_node.clobbers.len == 0) {
+                        try renderExpression(allocator, stream, tree, indent_extra, node, Space.Newline);
+                        try stream.writeByteNTimes(' ', indent);
+                        try renderToken(tree, stream, asm_node.rparen, indent, space); // )
+                        return;
+                    } else {
+                        try renderExpression(allocator, stream, tree, indent_extra, node, Space.Newline);
+                        try stream.writeByteNTimes(' ', indent_once);
+                        const comma_or_colon = tree.nextToken(node.lastToken());
+                        break :blk switch (tree.tokens.at(comma_or_colon).id) {
+                            Token.Id.Comma => tree.nextToken(comma_or_colon),
+                            else => comma_or_colon,
+                        };
                     }
                 }
-            }
+            };
 
-            try stream.write("\n");
-            try stream.writeByteNTimes(' ', indent_once);
-            try stream.write(": ");
+            try renderToken(tree, stream, colon3, indent, Space.Space); // :
 
-            {
-                var it = asm_node.clobbers.iterator(0);
-                while (it.next()) |node| {
-                    try renderExpression(allocator, stream, tree, indent_once, node.*, Space.None);
+            var it = asm_node.clobbers.iterator(0);
+            while (true) {
+                const clobber_token = ??it.next();
 
-                    if (it.peek() != null) {
-                        try stream.write(", ");
-                    }
+                if (it.peek() == null) {
+                    try renderToken(tree, stream, clobber_token.*, indent_once, Space.Newline);
+                    try stream.writeByteNTimes(' ', indent);
+                    try renderToken(tree, stream, asm_node.rparen, indent, space);
+                    return;
+                } else {
+                    try renderToken(tree, stream, clobber_token.*, indent_once, Space.None);
+                    const comma = tree.nextToken(clobber_token.*);
+                    try renderToken(tree, stream, comma, indent_once, Space.Space); // ,
                 }
             }
-
-            try renderToken(tree, stream, asm_node.rparen, indent, space);
         },
 
         ast.Node.Id.AsmInput => {