Add 'wasm_import_module' option to the @[Link] annotation

spec/compiler/semantic/lib_spec.cr

@@ -345,7 +345,7 @@ describe "Semantic: lib" do
       lib LibFoo
       end
       ),
-      "unknown link argument: 'boo' (valid arguments are 'lib', 'ldflags', 'static', 'pkg_config' and 'framework')"
+      "unknown link argument: 'boo' (valid arguments are 'lib', 'ldflags', 'static', 'pkg_config', 'framework', and 'wasm_import_module')"
   end
 
   it "errors if lib already specified with positional argument" do

src/compiler/crystal/codegen/fun.cr

@@ -202,6 +202,17 @@ class Crystal::CodeGenVisitor
         end
       end
 
+      if @program.has_flag?("wasm32")
+        if target_def.is_a?(External) && (wasm_import_module = target_def.wasm_import_module)
+          context.fun.add_target_dependent_attribute("wasm-import-name", target_def.real_name)
+          context.fun.add_target_dependent_attribute("wasm-import-module", wasm_import_module)
+        end
+
+        if is_exported_fun
+          context.fun.add_target_dependent_attribute("wasm-export-name", mangled_name)
+        end
+      end
+
       context.fun
     end
   end

src/compiler/crystal/codegen/link.cr

@@ -4,8 +4,9 @@ module Crystal
     getter pkg_config : String?
     getter ldflags : String?
     getter framework : String?
+    getter wasm_import_module : String?
 
-    def initialize(@lib = nil, @pkg_config = @lib, @ldflags = nil, @static = false, @framework = nil)
+    def initialize(@lib = nil, @pkg_config = @lib, @ldflags = nil, @static = false, @framework = nil, @wasm_import_module = nil)
     end
 
     def static?
@@ -25,6 +26,7 @@ module Crystal
       lib_static = false
       lib_pkg_config = nil
       lib_framework = nil
+      lib_wasm_import_module = nil
       count = 0
 
       args.each do |arg|
@@ -71,12 +73,15 @@ module Crystal
         when "pkg_config"
           named_arg.raise "'pkg_config' link argument must be a String" unless value.is_a?(StringLiteral)
           lib_pkg_config = value.value
+        when "wasm_import_module"
+          named_arg.raise "'wasm_import_module' link argument must be a String" unless value.is_a?(StringLiteral)
+          lib_wasm_import_module = value.value
         else
-          named_arg.raise "unknown link argument: '#{named_arg.name}' (valid arguments are 'lib', 'ldflags', 'static', 'pkg_config' and 'framework')"
+          named_arg.raise "unknown link argument: '#{named_arg.name}' (valid arguments are 'lib', 'ldflags', 'static', 'pkg_config', 'framework', and 'wasm_import_module')"
         end
       end
 
-      new(lib_name, lib_pkg_config, lib_ldflags, lib_static, lib_framework)
+      new(lib_name, lib_pkg_config, lib_ldflags, lib_static, lib_framework, lib_wasm_import_module)
     end
   end
 

src/compiler/crystal/semantic/ast.cr

@@ -716,6 +716,7 @@ module Crystal
     property real_name : String
     property! fun_def : FunDef
     property call_convention : LLVM::CallConvention?
+    property wasm_import_module : String?
 
     property? dead = false
     property? used = false

src/compiler/crystal/semantic/top_level_visitor.cr

@@ -483,6 +483,8 @@ class Crystal::TopLevelVisitor < Crystal::SemanticVisitor
 
     type.private = true if node.visibility.private?
 
+    wasm_import_module = nil
+
     process_annotations(annotations) do |annotation_type, ann|
       case annotation_type
       when @program.link_annotation
@@ -496,6 +498,12 @@ class Crystal::TopLevelVisitor < Crystal::SemanticVisitor
           @program.report_warning(ann, "using non-named arguments for Link annotations is deprecated")
         end
 
+        if wasm_import_module && link_annotation.wasm_import_module
+          ann.raise "multiple wasm import modules specified for lib #{node.name}"
+        end
+
+        wasm_import_module = link_annotation.wasm_import_module
+
         type.add_link_annotation(link_annotation)
       when @program.call_convention_annotation
         type.call_convention = parse_call_convention(ann, type.call_convention)
@@ -903,6 +911,10 @@ class Crystal::TopLevelVisitor < Crystal::SemanticVisitor
       call_convention = scope.call_convention
     end
 
+    if scope.is_a?(LibType)
+      external.wasm_import_module = scope.wasm_import_module
+    end
+
     # We fill the arguments and return type in TypeDeclarationVisitor
     external.doc = node.doc
     external.call_convention = call_convention

src/compiler/crystal/types.cr

@@ -2600,6 +2600,10 @@ module Crystal
     def type_desc
       "lib"
     end
+
+    def wasm_import_module
+      (@link_annotations.try &.find &.wasm_import_module).try &.wasm_import_module
+    end
   end
 
   # A `type` (typedef) type inside a `lib` declaration.