cc_library.additional_compiler_inputs should be subject to $(location ...) substitution

[filmil]

Description of the feature request:

Consider the following situation. I'm trying to compile libfst from https://github.com/gtkwave/gtkwave/tree/master/lib/libfst

Now, someone had the great idea to do #include FST_CONFIG_INCLUDE in fstapi.c here: https://github.com/gtkwave/gtkwave/blob/master/lib/libfst/fstapi.c#L41

This, of course, conflicts with bazel's idea about file placement. I added the file config.h, but it wouldn't go into either srcs or hdrs of the target :libfst below:

  1 cc_library(                                                                                                                               
  2     name = "libfst",                                                                                                                      
  3     srcs = [ "@libfst//:all_c"],                                                                                                          
  4     hdrs = [ "@libfst//:all_h",],                                                                                                         
  5     deps = [                                                                                                                              
  6     ¦   "//third_party/libjudy",                                                                                                          
  7     ],                                                                                                                                    
  8     defines = [                                                                                                                           
  9     ¦   'FST_CONFIG_INCLUDE=\\"third_party/libfst/config.h\\"',                                                                           
 10     ],                                                                                                                                    
 11     additional_compiler_inputs = [                                                                                                        
 12     ¦   ":config",                                                                                                                        
 13     ]
 14                                                                                                                                           
 15
 16 filegroup(                                                                                                                                
 17     name = "config",                                                                                                                      
 18     srcs = [ "config.h" ],                                                                                                                
 19 )                                                                                                                     
 14 )     

I wanted to define FST_CONFIG_INCLUDE=\\"$(location :config)\\", but this would not do because additional_compiler_inputs is not subject to $(location ...) substitution apparently. Placing the file elsewhere, e.g. in deps would allow it, but since deps requires CCInfo or some such, then I can't place the filegroup there. The :config target can not be a cc_library since that leads to:

ERROR: /home/fmil/tmp/bazel_delib/third_party/libfst/BUILD.bazel:1:11: in cc_library rule //third_party/libfst:libfst: label '//third_party/libfst:config' in $(location) expression expands to no files

Which category does this issue belong to?

No response

What underlying problem are you trying to solve with this feature?

I want to refer to a $(location) in a cc_library.defines.

Which operating system are you running Bazel on?

Linux. I don't think that maters.

What is the output of bazel info release?

╰─>$ bazel info release release 7.3.0

If bazel info release returns development version or (@non-git), tell us how you built Bazel.

No response

What's the output of git remote get-url origin; git rev-parse HEAD ?

No response

Have you found anything relevant by searching the web?

No response

Any other information, logs, or outputs that you want to share?

No response

[keith]

i think this is what you want? #23102

[filmil]

If you can do $(location ...) in defines or local_defines, I suppose so.

I am not seeing a test for both? But I don't know what the difference is.

[keith]

we're not adding it to defines, related quote from that thread:

but I would suggest disabling expansion for defines. There is no way to add files to downstream compilation actions, so it also wouldn't make sense to emit paths into them.

[filmil]

Oh, so defines will propagate downstream? I don't think my bug has a use case for that. So I suppose local_defines only is fine.

[iancha1992]

A fix for this issue has been included in Bazel 7.4.0 RC1. Please test out the release candidate and report any issues as soon as possible.
If you're using Bazelisk, you can point to the latest RC by setting USE_BAZEL_VERSION=7.4.0rc1. Thanks!