Support -static and -dynamic .lib suffixes on Windows

src/compiler/crystal/compiler.cr

@@ -366,14 +366,29 @@ module Crystal
         @link_flags.try { |flags| link_args << flags }
 
         {% if flag?(:msvc) %}
-          if program.has_flag?("preview_dll") && !program.has_flag?("no_win32_delay_load")
-            # "LINK : warning LNK4199: /DELAYLOAD:foo.dll ignored; no imports found from foo.dll"
-            # it is harmless to skip this error because not all import libraries are always used, much
-            # less the individual DLLs they refer to
-            link_args << "/IGNORE:4199"
-
-            Loader.search_dlls(Process.parse_arguments_windows(link_args.join(' '))).each do |dll|
-              link_args << "/DELAYLOAD:#{dll}"
+          unless @cross_compile
+            extra_suffix = program.has_flag?("preview_dll") ? "-dynamic" : "-static"
+            search_result = Loader.search_libraries(Process.parse_arguments_windows(link_args.join(' ').gsub('\n', ' ')), extra_suffix: extra_suffix)
+            if not_found = search_result.not_found?
+              error "Cannot locate the .lib files for the following libraries: #{not_found.join(", ")}"
+            end
+
+            link_args = search_result.remaining_args.concat(search_result.library_paths).map { |arg| Process.quote_windows(arg) }
+
+            if !program.has_flag?("no_win32_delay_load")
+              # "LINK : warning LNK4199: /DELAYLOAD:foo.dll ignored; no imports found from foo.dll"
+              # it is harmless to skip this error because not all import libraries are always used, much
+              # less the individual DLLs they refer to
+              link_args << "/IGNORE:4199"
+
+              dlls = Set(String).new
+              search_result.library_paths.each do |library_path|
+                Crystal::System::LibraryArchive.imported_dlls(library_path).each do |dll|
+                  dlls << dll.downcase
+                end
+              end
+              dlls.delete "kernel32.dll"
+              dlls.each { |dll| link_args << "/DELAYLOAD:#{dll}" }
             end
           end
         {% end %}

src/compiler/crystal/loader/msvc.cr

@@ -32,28 +32,53 @@ class Crystal::Loader
     end
   end
 
-  # Returns the list of DLLs imported from the libraries specified in the given
-  # linker arguments. Used by the compiler for delay-loaded DLL support.
-  def self.search_dlls(args : Array(String), *, search_paths : Array(String) = default_search_paths) : Set(String)
-    search_paths, libnames = parse_args(args, search_paths)
-    dlls = Set(String).new
+  struct SearchLibResult
+    getter library_paths = [] of String
+    getter remaining_args = [] of String
+    getter(not_found) { [] of String }
+
+    def not_found?
+      @not_found
+    end
+  end
+
+  # Extracts the command-line arguments from *args* that add libraries and
+  # expands them to their absolute paths. Returns a `SearchLibResult` with those
+  # expanded paths, plus unused arguments and libraries that were not found.
+  def self.search_libraries(args : Array(String), *, search_paths : Array(String) = default_search_paths, extra_suffix : String? = nil) : SearchLibResult
+    result = SearchLibResult.new
+    search_paths, libnames = parse_args(args, search_paths, remaining: result.remaining_args)
 
     libnames.each do |libname|
-      search_paths.each do |directory|
-        library_path = File.join(directory, library_filename(libname))
-        next unless File.file?(library_path)
+      if found_path = search_library(libname, search_paths, extra_suffix)
+        result.library_paths << found_path
+      else
+        result.not_found << libname
+      end
+    end
+
+    result
+  end
 
-        Crystal::System::LibraryArchive.imported_dlls(library_path).each do |dll|
-          dlls << dll unless dll.compare("kernel32.dll", case_insensitive: true).zero?
+  private def self.search_library(libname, search_paths, extra_suffix)
+    if ::Path::SEPARATORS.any? { |separator| libname.includes?(separator) }
+      libname = File.expand_path(libname)
+      library_path = library_filename(libname)
+      return library_path if File.file?(library_path)
+    else
+      search_paths.each do |directory|
+        if extra_suffix
+          library_path = File.join(directory, library_filename(libname + extra_suffix))
+          return library_path if File.file?(library_path)
         end
-        break
+
+        library_path = File.join(directory, library_filename(libname))
+        return library_path if File.file?(library_path)
       end
     end
-
-    dlls
   end
 
-  private def self.parse_args(args, search_paths)
+  def self.parse_args(args, search_paths, *, remaining = nil)
     libnames = [] of String
 
     # NOTE: `/LIBPATH`s are prepended before the default paths:
@@ -68,10 +93,14 @@ class Crystal::Loader
         extra_search_paths << lib_path
       elsif !arg.starts_with?('/') && (name = arg.rchop?(".lib"))
         libnames << name
+      elsif remaining
+        remaining << arg
       end
     end
 
     search_paths = extra_search_paths + search_paths
+    search_paths.uniq! &.downcase
+    libnames.uniq! &.downcase
     {search_paths, libnames}
   end
 

src/crystal/system/win32/delay_load.cr

@@ -122,11 +122,12 @@ fun __delayLoadHelper2(pidd : LibC::ImgDelayDescr*, ppfnIATEntry : LibC::FARPROC
 
   pitd = idd.pINT + iINT
 
-  dli.dlp.fImportByName = pitd.value.u1.ordinal & LibC::IMAGE_ORDINAL_FLAG == 0
+  import_by_name = (pitd.value.u1.ordinal & LibC::IMAGE_ORDINAL_FLAG) == 0
+  dli.dlp.fImportByName = import_by_name ? 1 : 0
 
-  if dli.dlp.fImportByName
-    import_by_name = p_from_rva(LibC::RVA.new!(pitd.value.u1.addressOfData))
-    dli.dlp.union.szProcName = import_by_name + offsetof(LibC::IMAGE_IMPORT_BY_NAME, @name)
+  if import_by_name
+    image_import_by_name = p_from_rva(LibC::RVA.new!(pitd.value.u1.addressOfData))
+    dli.dlp.union.szProcName = image_import_by_name + offsetof(LibC::IMAGE_IMPORT_BY_NAME, @name)
   else
     dli.dlp.union.dwOrdinal = LibC::DWORD.new!(pitd.value.u1.ordinal & 0xFFFF)
   end

src/crystal/system/win32/library_archive.cr

@@ -70,8 +70,11 @@ module Crystal::System::LibraryArchive
       sig2 = io.read_bytes(UInt16, IO::ByteFormat::LittleEndian)
       return unless sig2 == 0xFFFF
 
-      # version(2) + machine(2) + time(4) + size(4) + ordinal/hint(2) + flags(2)
-      io.skip(16)
+      version = io.read_bytes(UInt16, IO::ByteFormat::LittleEndian)
+      return unless version == 0 # 1 and 2 are used by object files (ANON_OBJECT_HEADER)
+
+      # machine(2) + time(4) + size(4) + ordinal/hint(2) + flags(2)
+      io.skip(14)
 
       # TODO: is there a way to do this without constructing a temporary string,
       # but with the optimizations present in `IO#gets`?