cl: initLinknameByDoc

cl/_testrt/concat/in.go

@@ -0,0 +1,9 @@
+package main
+
+import (
+	"github.com/goplus/llgo/internal/runtime/c"
+)
+
+func main() {
+	c.Fprintf(c.Stderr, c.Str("Hello %d\n"), 100)
+}

cl/_testrt/concat/out.ll

@@ -0,0 +1,32 @@
+; ModuleID = 'main'
+source_filename = "main"
+
+@"main.init$guard" = global ptr null
+@__stderrp = external global ptr
+@0 = private unnamed_addr constant [10 x i8] c"Hello %d\0A\00", align 1
+
+define void @main.init() {
+_llgo_0:
+  %0 = load i1, ptr @"main.init$guard", align 1
+  br i1 %0, label %_llgo_2, label %_llgo_1
+
+_llgo_1:                                          ; preds = %_llgo_0
+  store i1 true, ptr @"main.init$guard", align 1
+  br label %_llgo_2
+
+_llgo_2:                                          ; preds = %_llgo_1, %_llgo_0
+  ret void
+}
+
+define void @main() {
+_llgo_0:
+  call void @"github.com/goplus/llgo/internal/runtime.init"()
+  call void @main.init()
+  %0 = load ptr, ptr @__stderrp, align 8
+  %1 = call i32 (ptr, ptr, ...) @fprintf(ptr %0, ptr @0, i64 100)
+  ret void
+}
+
+declare void @"github.com/goplus/llgo/internal/runtime.init"()
+
+declare i32 @fprintf(ptr, ptr, ...)

cl/_testrt/fprintf/in.go

@@ -1,9 +1,16 @@
 package main
 
-import (
-	"github.com/goplus/llgo/internal/runtime/c"
-)
+import "unsafe"
+
+//go:linkname cstr llgo.cstr
+func cstr(string) *int8
+
+//go:linkname stderr __stderrp
+var stderr unsafe.Pointer
+
+//go:linkname fprintf C.fprintf
+func fprintf(fp unsafe.Pointer, format *int8, __llgo_va_list ...any)
 
 func main() {
-	c.Fprintf(c.Stderr, c.Str("Hello %d\n"), 100)
+	fprintf(stderr, cstr("Hello %d\n"), 100)
 }

cl/_testrt/fprintf/out.ll

@@ -5,6 +5,8 @@ source_filename = "main"
 @__stderrp = external global ptr
 @0 = private unnamed_addr constant [10 x i8] c"Hello %d\0A\00", align 1
 
+declare void @fprintf(ptr, ptr, ...)
+
 define void @main.init() {
 _llgo_0:
   %0 = load i1, ptr @"main.init$guard", align 1
@@ -23,10 +25,8 @@ _llgo_0:
   call void @"github.com/goplus/llgo/internal/runtime.init"()
   call void @main.init()
   %0 = load ptr, ptr @__stderrp, align 8
-  %1 = call i32 (ptr, ptr, ...) @fprintf(ptr %0, ptr @0, i64 100)
+  call void (ptr, ptr, ...) @fprintf(ptr %0, ptr @0, i64 100)
   ret void
 }
 
 declare void @"github.com/goplus/llgo/internal/runtime.init"()
-
-declare i32 @fprintf(ptr, ptr, ...)

cl/compile.go

@@ -177,7 +177,7 @@ func (p *context) compileMethods(pkg llssa.Package, typ types.Type) {
 // Global variable.
 func (p *context) compileGlobal(pkg llssa.Package, gbl *ssa.Global) {
 	typ := gbl.Type()
-	name := p.varName(gbl.Pkg.Pkg, gbl)
+	name, isDef := p.varName(gbl.Pkg.Pkg, gbl)
 	if ignoreName(name) || checkCgo(gbl.Name()) {
 		return
 	}
@@ -185,7 +185,9 @@ func (p *context) compileGlobal(pkg llssa.Package, gbl *ssa.Global) {
 		log.Println("==> NewVar", name, typ)
 	}
 	g := pkg.NewVar(name, typ)
-	g.Init(p.prog.Null(g.Type))
+	if isDef {
+		g.Init(p.prog.Null(g.Type))
+	}
 }
 
 func (p *context) compileFunc(pkg llssa.Package, pkgTypes *types.Package, f *ssa.Function) {

cl/import.go

@@ -107,20 +107,29 @@ func (p *context) importPkg(pkg *types.Package, i *pkgInfo) {
 func (p *context) initFiles(pkgPath string, files []*ast.File) {
 	for _, file := range files {
 		for _, decl := range file.Decls {
-			if decl, ok := decl.(*ast.FuncDecl); ok {
+			switch decl := decl.(type) {
+			case *ast.FuncDecl:
 				if decl.Recv == nil {
-					if doc := decl.Doc; doc != nil {
-						if n := len(doc.List); n > 0 {
-							line := doc.List[n-1].Text
-							p.initLinkname(pkgPath, line, false)
-						}
-					}
+					p.initLinknameByDoc(decl.Doc, pkgPath, false)
+				}
+			case *ast.GenDecl:
+				if decl.Tok == token.VAR && len(decl.Specs) == 1 {
+					p.initLinknameByDoc(decl.Doc, pkgPath, true)
 				}
 			}
 		}
 	}
 }
 
+func (p *context) initLinknameByDoc(doc *ast.CommentGroup, pkgPath string, isVar bool) {
+	if doc != nil {
+		if n := len(doc.List); n > 0 {
+			line := doc.List[n-1].Text
+			p.initLinkname(pkgPath, line, isVar)
+		}
+	}
+}
+
 func (p *context) initLinknameByPos(fset *token.FileSet, pos token.Pos, pkgPath string, contents contentMap, isVar bool) {
 	f := fset.File(pos)
 	if fp := f.Position(pos); fp.Line > 2 {
@@ -210,12 +219,12 @@ func (p *context) funcName(pkg *types.Package, fn *ssa.Function, ignore bool) (s
 	return name, goFunc
 }
 
-func (p *context) varName(pkg *types.Package, v *ssa.Global) string {
+func (p *context) varName(pkg *types.Package, v *ssa.Global) (vName string, isDef bool) {
 	name := llssa.FullName(pkg, v.Name())
 	if v, ok := p.link[name]; ok {
-		return v
+		return v, false
 	}
-	return name
+	return name, true
 }
 
 // funcOf returns a function by name and set ftype = goFunc, cFunc, etc.
@@ -246,7 +255,7 @@ func (p *context) funcOf(fn *ssa.Function) (ret llssa.Function, ftype int) {
 func (p *context) varOf(v *ssa.Global) (ret llssa.Global) {
 	pkgTypes := p.ensureLoaded(v.Pkg.Pkg)
 	pkg := p.pkg
-	name := p.varName(pkgTypes, v)
+	name, _ := p.varName(pkgTypes, v)
 	if ret = pkg.VarOf(name); ret == nil {
 		ret = pkg.NewVar(name, v.Type())
 	}