Working directory in search paths for libraries

[m-kru]

Shouldn't the working directory by default be included in the search paths for libraries? During the analysis, for --work the path is optional, and by the default it is a directory in the current working directory. However, during the elaboration/run one must provide -L . for libraries in the current working directory to be found.

[nickg]

It's the same for analysis: you have to pass -L . for any library that is not the working library.

[m-kru]

I think we are not on the same page here. Let's suppose I have analyzed some entity into library lib. The lib directory was created in the working directory. However, I am not able to elaborate the top entity without adding -L ., even though the lib directory is in the working directory. In other words, the current working directory is not included in the libraries search paths during elaboration and run. However, when I analyze a file and I provide only the library name (without library path) the library directory is created in the working directory.

[nickg]

That's because the working library is implicitly a directory called work if you don't specify it with --work=. So in your example you need to do nvc --work=lib -e toplev.

[m-kru]

Still, this is not what I mean. Have a look at my working directory tree:

.
├── simple
│   ├── _index
│   ├── _NVC_LIB
│   ├── SIMPLE.BINARY_COUNTER
│   └── SIMPLE.BINARY_COUNTER-RTL
└── work
    ├── _index
    ├── _NVC_LIB
    ├── WORK.TB_BINARY_COUNTER_RESET
    ├── WORK.TB_BINARY_COUNTER_RESET.elab
    ├── _WORK.TB_BINARY_COUNTER_RESET.elab.so
    └── WORK.TB_BINARY_COUNTER_RESET-TEST

To elaborate my top entity I have to call nvc --std=2019 -L. -e tb_binary_counter_reset. If I remove -L. from the command, it will fail because the simple library is not found.

[nickg]

This is working as designed. By default only $PREFIX/lib and $HOME/.local/lib/nvc are searched for libraries, everything else needs to be specified on the command line.

[m-kru]

$PREFIX? Is this nvc specific environment variable?

It seemed reasonable to me to search for libraries in the current working directory by default. However, if it is designed in a different way, then ok.

[nickg]

$PREFIX? Is this nvc specific environment variable?

I just meant the installation prefix (e.g. /usr/local or whatever you passed as --prefix= when you ran configure).

It seemed reasonable to me to search for libraries in the current working directory by default. However, if it is designed in a different way, then ok.

The problem with searching the current directory by default is that you may get different behaviour depending on which directory you run the nvc command in. If you specify the --work= argument as an absolute path, and pass absolute paths to source files, then there wouldn't be any dependency on the working directory and the build will be completely reproducible. Adding -L . by default would lose that and there's no way to remove a library from the search list.

If a project is big enough that it's split over multiple libraries then it will be built with a script or makefile rather than typing the command by hand so passing -L . explicitly is not a big burden and as a general rule I prefer behaviours like this to be explicit rather implicit.