Backport #10347 (#10349)

Fix incorrect warning target with Zeitwerk and support warning with Bootsnap.

lib/bundled_gems.rb

@@ -95,8 +95,10 @@ def self.find_gem(path)
   end
 
   def self.warning?(name, specs: nil)
-    feature = File.path(name) # name can be a feature name or a file path with String or Pathname
-    name = feature.tr("/", "-")
+    # name can be a feature name or a file path with String or Pathname
+    feature = File.path(name)
+    # bootsnap expand `require "csv"` to `require "#{LIBDIR}/csv.rb"`
+    name = feature.delete_prefix(LIBDIR).chomp(".rb").tr("/", "-")
     name.sub!(LIBEXT, "")
     return if specs.include?(name)
     _t, path = $:.resolve_feature_path(feature)
@@ -109,12 +111,7 @@ def self.warning?(name, specs: nil)
     else
       return
     end
-    # Warning feature is not working correctly with Bootsnap.
-    # caller_locations returns:
-    #   lib/ruby/3.3.0+0/bundled_gems.rb:65:in `block (2 levels) in replace_require'
-    #   $GEM_HOME/gems/bootsnap-1.17.0/lib/bootsnap/load_path_cache/core_ext/kernel_require.rb:32:in `require'"
-    #   ...
-    return if caller_locations(2).find {|c| c&.path.match?(/bootsnap/) }
+
     return if WARNED[name]
     WARNED[name] = true
     if gem == true
@@ -134,11 +131,29 @@ def self.build_message(gem)
 
     if defined?(Bundler)
       msg += " Add #{gem} to your Gemfile or gemspec."
+
       # We detect the gem name from caller_locations. We need to skip 2 frames like:
       # lib/ruby/3.3.0+0/bundled_gems.rb:90:in `warning?'",
       # lib/ruby/3.3.0+0/bundler/rubygems_integration.rb:247:in `block (2 levels) in replace_require'",
-      location = caller_locations(3,1)[0]&.path
-      if File.file?(location) && !location.start_with?(Gem::BUNDLED_GEMS::LIBDIR)
+      #
+      # Additionally, we need to skip Bootsnap and Zeitwerk if present, these
+      # gems decorate Kernel#require, so they are not really the ones issuing
+      # the require call users should be warned about. Those are upwards.
+      frames_to_skip = 2
+      location = nil
+      Thread.each_caller_location do |cl|
+        if frames_to_skip >= 1
+          frames_to_skip -= 1
+          next
+        end
+
+        unless cl.path.match?(/bootsnap|zeitwerk/)
+          location = cl.path
+          break
+        end
+      end
+
+      if location && File.file?(location) && !location.start_with?(Gem::BUNDLED_GEMS::LIBDIR)
         caller_gem = nil
         Gem.path.each do |path|
           if location =~ %r{#{path}/gems/([\w\-\.]+)}