From: Stefan Sperling <stsp@stsp.name>
Subject: Re: got diff chomps trailing \r
To: Christian Weisgerber <naddy@mips.inka.de>
Cc: gameoftrees@openbsd.org
Date: Wed, 10 May 2023 17:44:48 +0200

On Wed, May 10, 2023 at 05:29:31PM +0200, Christian Weisgerber wrote:
> Last night I tried to generate a diff between OpenBSD src "master" and
> an updated "llvm15" branch.  Unfortunately, the output of "got diff"
> would not apply to a checked-out src tree and I had to resort to git.
> 
> Some of the LLVM files have \r\n line endings.  The problem is that
> got diff simply drops the \r from all context, - and + lines.
>
> ===> got diff | cat -v
> 
> --- gnu/llvm/clang/lib/Tooling/DumpTool/ClangSrcLocDump.cpp
> +++ gnu/llvm/clang/lib/Tooling/DumpTool/ClangSrcLocDump.cpp
> @@ -91,12 +91,8 @@ int main(int argc, const char **argv) {^M
>    llvm::transform(Args, Argv.begin(),
>                    [](const std::string &Arg) { return Arg.c_str(); });
>  
> -  IntrusiveRefCntPtr<DiagnosticOptions> DiagOpts = new DiagnosticOptions();
> -  unsigned MissingArgIndex, MissingArgCount;
> -  auto Opts = driver::getDriverOptTable();
> -  auto ParsedArgs = Opts.ParseArgs(llvm::makeArrayRef(Argv).slice(1),
> -                                   MissingArgIndex, MissingArgCount);
> -  ParseDiagnosticArgs(*DiagOpts, ParsedArgs);
> +  IntrusiveRefCntPtr<DiagnosticOptions> DiagOpts =
> +      CreateAndPopulateDiagOpts(Argv);
>  
>    // Don't output diagnostics, because common scenarios such as
>    // cross-compiling fail with diagnostics.  This is not fatal, but
> 
> ===> git diff | cat -v
> 
> --- a/gnu/llvm/clang/lib/Tooling/DumpTool/ClangSrcLocDump.cpp
> +++ b/gnu/llvm/clang/lib/Tooling/DumpTool/ClangSrcLocDump.cpp
> @@ -91,12 +91,8 @@ int main(int argc, const char **argv) {
>    llvm::transform(Args, Argv.begin(),^M
>                    [](const std::string &Arg) { return Arg.c_str(); });^M
>  ^M
> -  IntrusiveRefCntPtr<DiagnosticOptions> DiagOpts = new DiagnosticOptions();^M
> -  unsigned MissingArgIndex, MissingArgCount;^M
> -  auto Opts = driver::getDriverOptTable();^M
> -  auto ParsedArgs = Opts.ParseArgs(llvm::makeArrayRef(Argv).slice(1),^M
> -                                   MissingArgIndex, MissingArgCount);^M
> -  ParseDiagnosticArgs(*DiagOpts, ParsedArgs);^M
> +  IntrusiveRefCntPtr<DiagnosticOptions> DiagOpts =^M
> +      CreateAndPopulateDiagOpts(Argv);^M
>  ^M
>    // Don't output diagnostics, because common scenarios such as^M
>    // cross-compiling fail with diagnostics.  This is not fatal, but^M
> 
> 
> Ironically, got preserves the \r for the function name line, but
> git doesn't.

Thanks! This should not be too hard to fix.

As a first step it would be nice to have is a regression test.
The fix will probably require work in diff.git which has its own set of
tests. But I would be happy with a test for 'got diff' just the same.

Does anyone want to write a test? I am short on time now but could look
into fixing this during the next few days.