Add option to prevent including metadata in target name

[wickerwaka]

Problem
When cargo builds a target is passes -C extra-filename=-... to rustc which produces an output file with a metadata suffix in the name. For windows targets this will produce foo-metadata.exe and foo-metadata.pdb files. It then copies and renames these files so the final result is foo.exe and foo.pdb.

However the debug data in a PE executable files stores the original name of the PDB file and this name is used when debuggers (Visual Studio, WinDbg or anything using dbghelp.dll) are searching for PDB files on symbol servers. So when looking for the PDB file for foo.exe, it will actually search for foo-metadata.pdb which has likely not been uploaded.

Possible Solution(s)
Ideally it would be possible to specify in the Cargo.toml that extra-filename should not be used for certain profiles, e.g.:

[profile.release]
add-extra-filename = false

Notes
Output of cargo version: cargo 1.33.0 (f099fe9 2019-02-12)

[arve0]

Adding: Specifying cargo rustc -- -o filename does not ignore -C extra-filename. Nor does -C extra-filename="". Also, rustc warns that -C extra-filename is ignored, but it is not:

$ mkdir output-filename
$ cd output-filename/
$ cargo init
    Created binary (application) package
$ cargo rustc -v --release -- -o filename
  Compiling output-filename v0.1.0 (/private/tmp/output-filename)
    Running `rustc --edition=2018 --crate-name output_filename src/main.rs --color always --crate-type bin --emit=dep-info,link -C opt-level=3 -o filename -C metadata=c961d75f8bcf3c48 -C extra-filename=-c961d75f8bcf3c48 --out-dir /private/tmp/output-filename/target/release/deps -L dependency=/private/tmp/output-filename/target/release/deps`
warning: due to multiple output types requested, the explicitly specified output file name will be adapted for each output type

warning: ignoring --out-dir flag due to -o flag

warning: ignoring -C extra-filename flag due to -o flag

    Finished release [optimized] target(s) in 0.39s
$ ls
Cargo.lock          filename-c961d75f8bcf3c48   src
Cargo.toml          filename-c961d75f8bcf3c48.d target

This may be a rustc issue?

[ehuss]

@arve0 I submitted a quick PR (rust-lang/rust#62128) for the extraneous warning.

[ehuss]

I think the root issue here is fixed (windows executables no longer have a hash in the filename) via #7400.