Prevent the full-file "error[E0601]: main function not found in crate" error
#24
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The What
When using the
#[async_attributes::main]macro and compiling a rust program with a syntax error in the main function, the user would be met with a big, intrusive, unhelpful error that there is no main function in the file. This can get very annoying, especially when paired with rust-analyzer and its on screen errors (taking up the whole file).The Why
This error is caused when the
mainproc-macro fails to parse the inputted function with thesyn::parse_macro_input!, causing it to return early, producing no main function.The Fix
This PR uses the
syn::parsefunction directly so that a parsing error can be caught, producing a placeholder empty main function to suppress the extraneous error. This placeholder main function will never be able to compile into a final executable since the macro also emits acompiler_error!.