From f86cd74a98c9c0b4a11ca195e411094b57354369 Mon Sep 17 00:00:00 2001
From: xushiwei <x@goplus.org>
Date: Fri, 26 Apr 2024 13:09:24 +0800
Subject: [PATCH] cl: go:linkname specifies call convention by C.xxx

---
 cl/_testcgo/strlen/in.go    |  4 ++--
 cl/_testdata/method/in.go   |  2 +-
 cl/_testdata/printf/in.go   |  2 +-
 cl/_testdata/printval/in.go |  2 +-
 cl/_testdata/ptrmthd/in.go  |  2 +-
 cl/builtin_test.go          | 14 ++++++++++++--
 cl/import.go                |  8 ++++++--
 cl/internal/libc/libc.go    |  4 ++--
 cl/internal/stdio/printf.go |  2 +-
 9 files changed, 27 insertions(+), 13 deletions(-)

diff --git a/cl/_testcgo/strlen/in.go b/cl/_testcgo/strlen/in.go
index edaa5e9d..7a81d54c 100644
--- a/cl/_testcgo/strlen/in.go
+++ b/cl/_testcgo/strlen/in.go
@@ -3,10 +3,10 @@ package main
 import "C"
 import _ "unsafe"
 
-//go:linkname printf printf
+//go:linkname printf C.printf
 func printf(format *int8, __llgo_va_list ...any)
 
-//go:linkname strlen strlen
+//go:linkname strlen C.strlen
 func strlen(str *int8) C.int
 
 var format = [...]int8{'H', 'e', 'l', 'l', 'o', ' ', '%', 'd', '\n', 0}
diff --git a/cl/_testdata/method/in.go b/cl/_testdata/method/in.go
index 991b92b0..ab3a8676 100644
--- a/cl/_testdata/method/in.go
+++ b/cl/_testdata/method/in.go
@@ -8,7 +8,7 @@ func (a T) Add(b T) T {
 	return a + b
 }
 
-//go:linkname printf printf
+//go:linkname printf C.printf
 func printf(format *int8, __llgo_va_list ...any)
 
 var format = [...]int8{'H', 'e', 'l', 'l', 'o', ' ', '%', 'd', '\n', 0}
diff --git a/cl/_testdata/printf/in.go b/cl/_testdata/printf/in.go
index 8d7d1264..812130f1 100644
--- a/cl/_testdata/printf/in.go
+++ b/cl/_testdata/printf/in.go
@@ -2,7 +2,7 @@ package main
 
 import _ "unsafe"
 
-//go:linkname printf printf
+//go:linkname printf C.printf
 func printf(format *int8, __llgo_va_list ...any)
 
 var hello = [...]int8{'H', 'e', 'l', 'l', 'o', '\n', 0}
diff --git a/cl/_testdata/printval/in.go b/cl/_testdata/printval/in.go
index 93d49b80..192c66df 100644
--- a/cl/_testdata/printval/in.go
+++ b/cl/_testdata/printval/in.go
@@ -2,7 +2,7 @@ package main
 
 import _ "unsafe"
 
-//go:linkname printf printf
+//go:linkname printf C.printf
 func printf(format *int8, __llgo_va_list ...any)
 
 var format = [...]int8{'H', 'e', 'l', 'l', 'o', ' ', '%', 'd', '\n', 0}
diff --git a/cl/_testdata/ptrmthd/in.go b/cl/_testdata/ptrmthd/in.go
index 16ee3b42..5a61f4b0 100644
--- a/cl/_testdata/ptrmthd/in.go
+++ b/cl/_testdata/ptrmthd/in.go
@@ -2,7 +2,7 @@ package main
 
 import _ "unsafe"
 
-//go:linkname printf printf
+//go:linkname printf C.printf
 func printf(format *int8, __llgo_va_list ...any)
 
 type T int8
diff --git a/cl/builtin_test.go b/cl/builtin_test.go
index 23738745..1d116134 100644
--- a/cl/builtin_test.go
+++ b/cl/builtin_test.go
@@ -30,13 +30,23 @@ func TestIgnoreName(t *testing.T) {
 	}
 }
 
-func TestImport(t *testing.T) {
+func TestErrImport(t *testing.T) {
 	var ctx context
 	pkg := types.NewPackage("foo", "foo")
 	ctx.importPkg(pkg)
 }
 
-func TestVarOf(t *testing.T) {
+func TestErrInitLinkname(t *testing.T) {
+	defer func() {
+		if r := recover(); r == nil {
+			t.Fatal("initLinkname: no error?")
+		}
+	}()
+	var ctx context
+	ctx.initLinkname("foo", "//go:linkname Printf printf")
+}
+
+func TestErrVarOf(t *testing.T) {
 	defer func() {
 		if r := recover(); r == nil {
 			t.Fatal("varOf: no error?")
diff --git a/cl/import.go b/cl/import.go
index 9a02ec0b..53b42d21 100644
--- a/cl/import.go
+++ b/cl/import.go
@@ -98,9 +98,13 @@ func (p *context) initLinkname(pkgPath, line string) {
 	if strings.HasPrefix(line, linkname) {
 		text := strings.TrimSpace(line[len(linkname):])
 		if idx := strings.IndexByte(text, ' '); idx > 0 {
-			name := pkgPath + "." + text[:idx]
 			link := strings.TrimLeft(text[idx+1:], " ")
-			p.link[name] = link
+			if strings.Contains(link, ".") { // eg. C.printf, C.strlen
+				name := pkgPath + "." + text[:idx]
+				p.link[name] = link[2:]
+			} else {
+				panic(line + ": no specified call convention. eg. //go:linkname Printf C.printf")
+			}
 		}
 	}
 }
diff --git a/cl/internal/libc/libc.go b/cl/internal/libc/libc.go
index ef5d228a..8828a4df 100644
--- a/cl/internal/libc/libc.go
+++ b/cl/internal/libc/libc.go
@@ -7,8 +7,8 @@ const (
 	LLGoPackage = true
 )
 
-//go:linkname Printf printf
+//go:linkname Printf C.printf
 func Printf(format *int8, __llgo_va_list ...any)
 
-//go:linkname Strlen strlen
+//go:linkname Strlen C.strlen
 func Strlen(str *int8) C.int
diff --git a/cl/internal/stdio/printf.go b/cl/internal/stdio/printf.go
index ac080937..7f97aeb0 100644
--- a/cl/internal/stdio/printf.go
+++ b/cl/internal/stdio/printf.go
@@ -6,7 +6,7 @@ const (
 	LLGoPackage = true
 )
 
-//go:linkname Printf printf
+//go:linkname Printf C.printf
 func Printf(format *int8, __llgo_va_list ...any)
 
 func Max(a, b int) int {