Change naming convention of object files to follow what Base Julia does (#930)

* Change naming convention of object files to follow what Base Julia does

* Add some comments linking to the PR and the bug report

Thus, future readers of the source code will understand why we use this naming convention.

[Applies suggestions from code review.]

* CI: Resume testing on Intel macOS (#967)

---------

Co-authored-by: Dilum Aluthge <[email protected]>

Author: gbaraldi

.github/workflows/ci.yml

@@ -57,7 +57,7 @@ jobs:
         os:
           - ubuntu-latest
           - windows-latest
-          # - macos-13 # macos-13 = Intel. # TODO: uncomment this line once we merge #930
+          - macos-13 # macos-13 = Intel.
           # TODO: uncomment the next line, so that we can start testing on macos-14:
           # - macos-14 # macos-14 = Apple Silicon.
         coverage:

src/PackageCompiler.jl

@@ -225,7 +225,11 @@ function create_fresh_base_sysimage(stdlibs::Vector{String}; cpu_target::String,
     sysimg_source_path = Base.find_source_file("sysimg.jl")
     base_dir = dirname(sysimg_source_path)
     tmp_corecompiler_ji = joinpath(tmp, "corecompiler.ji")
-    tmp_sys_o = joinpath(tmp, "sys.o")
+    tmp_sys_o = joinpath(tmp, "sys-o.a")
+    # This naming convention (`sys-o.a`) is necessary to make the sysimage
+    # work on macOS.
+    # Bug report: https://github.com/JuliaLang/PackageCompiler.jl/issues/738
+    # PR: https://github.com/JuliaLang/PackageCompiler.jl/pull/930
     tmp_sys_sl = joinpath(tmp, "sys." * Libdl.dlext)
 
     compiler_source_path = joinpath(base_dir, "compiler", "compiler.jl")
@@ -639,7 +643,11 @@ function create_sysimage(packages::Union{Nothing, Symbol, Vector{String}, Vector
     end
 
     # Create the sysimage
-    object_file = tempname() * ".o"
+    object_file = tempname() * "-o.a"
+    # This naming convention (`-o.a`) is necessary to make the sysimage
+    # work on macOS.
+    # Bug report: https://github.com/JuliaLang/PackageCompiler.jl/issues/738
+    # PR: https://github.com/JuliaLang/PackageCompiler.jl/pull/930
 
     create_sysimg_object_file(object_file, packages, packages_sysimg;
                             project,
@@ -1428,7 +1436,7 @@ function bundle_julia_libexec(ctx, dest_dir)
     p7zip_exe = basename(p7zip_path)
     cp(p7zip_path, joinpath(bundle_libexec_dir, p7zip_exe))
 
-    return 
+    return
 end
 
 function recursive_dir_size(path)