Excise Random from the system image

Author: vchuravy

base/Base.jl

@@ -621,8 +621,29 @@ end
 # enable threads support
 @eval PCRE PCRE_COMPILE_LOCK = Threads.SpinLock()
 
+# stdlib shims
+let Random_PkgID = PkgId(UUID(0x9a3f8284_a2c9_5f02_9a11_845980a1fd5c), "Random")
+    global rand, randn
+
+    RANDOM_MODULE_REF = Ref{Module}()
+    # functions defined in Random
+    function rand(args...)
+        if !isassigned(RANDOM_MODULE_REF)
+            RANDOM_MODULE_REF[] = require(Random_PkgID)
+        end
+        invokelatest(rand, args...)
+    end
+
+    function randn(args...)
+        if !isassigned(RANDOM_MODULE_REF)
+            RANDOM_MODULE_REF[] = require(Random_PkgID)
+        end
+        invokelatest(randn, args...)
+    end
 end
 
+end # is_primary_base_module
+
 # Ensure this file is also tracked
 @assert !isassigned(_included_files, 1)
 _included_files[1] = (parentmodule(Base), abspath(@__FILE__))

base/sysimg.jl

@@ -34,7 +34,6 @@ let
         :FileWatching, # used by loading.jl -- implicit assumption that init runs
         :Libdl, # Transitive through LinAlg
         :Artifacts, # Transitive through LinAlg
-        :SHA, # transitive through Random
         :Sockets, # used by stream.jl
 
         # Transitive through LingAlg
@@ -43,7 +42,6 @@ let
 
         # 1-depth packages
         :LinearAlgebra, # Commits type-piracy and GEMM
-        :Random, # Can't be removed due to rand being exported by Base
     ]
     # PackageCompiler can filter out stdlibs so it can be empty
     maxlen = maximum(textwidth.(string.(stdlibs)); init=0)

stdlib/Random/src/RNGs.jl

@@ -386,12 +386,6 @@ for T in BitInteger_types
     @eval rand!(::_GLOBAL_RNG, A::Array{$T}, I::SamplerType{$T}) = rand!(default_rng(), A, I)
 end
 
-function __init__()
-    seed!(GLOBAL_RNG)
-    ccall(:jl_gc_init_finalizer_rng_state, Cvoid, ())
-end
-
-
 ### generation
 
 # MersenneTwister produces natively Float64

stdlib/Random/src/Random.jl

@@ -31,6 +31,39 @@ export rand!, randn!,
 
 ## general definitions
 
+# Remove the shim methods
+# TODO: If we could support this as part of package loading
+#       That would be much nicer.
+# for m in Base.methods(rand)
+#     if m.module == Base
+#         Base.delete_method(m)
+#     end
+# end
+
+function __init__()
+    seed!(GLOBAL_RNG)
+    ccall(:jl_gc_init_finalizer_rng_state, Cvoid, ())
+
+    # Remove the shim methods
+    # Is this too coarse? We want to only delete the method
+    # in Base, not any added by the user later on.
+    # We are currently not allowed to run this during any precompilation
+    # so we must guard it until "normal runtime".
+    # TODO: What to do when we are including Random into a sysimg.
+    if !Base.generating_output()
+        for m in Base.methods(rand)
+            if m.module == Base
+                Base.delete_method(m)
+            end
+        end
+        for m in Base.methods(randn)
+            if m.module == Base
+                Base.delete_method(m)
+            end
+        end
+    end
+end
+
 """
     AbstractRNG
 

stdlib/stdlib.mk

@@ -1,12 +1,12 @@
 STDLIBS_WITHIN_SYSIMG := \
-	Artifacts FileWatching Libdl SHA libblastrampoline_jll OpenBLAS_jll Random \
+	Artifacts FileWatching Libdl libblastrampoline_jll OpenBLAS_jll \
 	LinearAlgebra Sockets
 
 INDEPENDENT_STDLIBS := \
 	ArgTools Base64 CRC32c Dates DelimitedFiles Distributed Downloads Future \
 	InteractiveUtils LazyArtifacts LibGit2 LibCURL Logging Markdown Mmap \
-	NetworkOptions Profile Printf Pkg REPL Serialization SharedArrays SparseArrays \
-	Statistics Tar Test TOML Unicode UUIDs \
+	NetworkOptions Profile Printf Pkg Random REPL Serialization SharedArrays \
+	SparseArrays Statistics SHA Tar Test TOML Unicode UUIDs \
 	dSFMT_jll GMP_jll libLLVM_jll LLD_jll LLVMLibUnwind_jll LibUnwind_jll LibUV_jll \
 	LibCURL_jll LibSSH2_jll LibGit2_jll nghttp2_jll  MozillaCACerts_jll MbedTLS_jll \
 	MPFR_jll OpenLibm_jll PCRE2_jll p7zip_jll Zlib_jll