Why does formatOnType on for-loop affect other lines?

[ykadowak]

Let's say there is a code like this with formatOnType option and using clang-format

for(int i = 0;) // <- the ";" triggers formatting


int foo = 0;

The result is

for (int i = 0;) int foo = 0;

Here my question is why is the int foo = 0 line affected by the formatting of the for loop line?

In other case, formatOnType only formats the line that is being typed. For example,

int foo=0;
int bar=0; // <- Let's say this ";" is just typed

is formatted like below

int foo=0; // <- this line is not affected
int bar = 0;

So why is the first example different?

[sean-mcmanus]

I'm not able to repro the bug. Can you provide more repro details? What clang-format version are you using? What other clang-format settings are you using? It may be a bug with clang-format itself.

If you set C_Cpp.loggingLevel to "Debug", the "C/C++" Output panel will show some formatting logging, i.e. inputs and raw outputs from clang-format which might help.

[ykadowak]

VSCode: Version: 1.72.0 (Universal)
Commit: 64bbfbf67ada9953918d72e1df2f4d8e537d340e
Date: 2022-10-04T23:21:58.256Z
Electron: 19.0.17
Chromium: 102.0.5005.167
Node.js: 16.14.2
V8: 10.2.154.15-electron.0
OS: Darwin arm64 21.6.0
Sandboxed: No
Cpp-tools: v1.12.4

Using clang-format that is bundled with VSCode. .clang-format setting is BasedOnType: Google only.

Repro process:

I edited the question because I forgot to put the close brace for the for-loop statement.

1. With the environment above(also formatOnType is on), prepare the code below.

for(int i = 0)


int foo = 0;

2. Type ; at the end of the if statement

for(int i = 0;)


int foo = 0;

3. Formats like below

for(int i = 0;) int foo = 0;

Log
This is the log(somehow in Japanese even though my VSCode is in English 🤔 )
So it seems like VSCode is sending the int foo = 0; line as well. Is it by design or a bug? Also FormatSelection has the same behavior.

IMO, when you try to format the for-loop statement, it should not affect the lines that is more than one empty lines away.

cpptools/formatOnType: /Users/xxxx/main.cpp (id: 637)
入力の書式設定:
for (int i = 0;)


int foo = 0;

ドキュメントの書式設定: file:///Users/xxxx/main.cpp
Formatting Engine: clangFormat
未加工の出力の書式設定:
{ "Cursor": 15, "IncompleteFormat": false }
for (int i = 0;) int foo = 0;

[sean-mcmanus]

Thanks for the info. I repro the issue now. I've filed #10016 to track it.