libmiqt: move binding helpers to standalone package, support const_char

cmd/genbindings/emitcabi.go

@@ -480,6 +480,7 @@ func emitBindingHeader(src *CppParsedHeader, filename string) (string, error) {
 
 	includeGuard := "GEN_" + strings.ToUpper(strings.Replace(filename, `.`, `_`, -1))
 
+	bindingInclude := "../libmiqt/libmiqt.h"
 	ret.WriteString(`#ifndef ` + includeGuard + `
 #define ` + includeGuard + `
 
@@ -489,7 +490,7 @@ func emitBindingHeader(src *CppParsedHeader, filename string) (string, error) {
 
 #pragma GCC diagnostic ignored "-Wdeprecated-declarations"
 
-#include "binding.h"
+#include "` + bindingInclude + `"
 
 #ifdef __cplusplus
 extern "C" {

cmd/genbindings/emitgo.go

@@ -134,7 +134,8 @@ func (p CppParameter) parameterTypeCgo() string {
 	}
 
 	tmp := strings.Replace(p.RenderTypeCabi(), `*`, "", -1)
-	if strings.HasPrefix(tmp, "const ") {
+
+	if strings.HasPrefix(tmp, "const ") && tmp != "const char" { // Special typedef to make this work for const char* signal parameters
 		tmp = tmp[6:] // Constness doesn't survive the CABI boundary
 	}
 	if strings.HasPrefix(tmp, "unsigned ") {
@@ -234,7 +235,8 @@ func (gfs *goFileState) emitParameterGo2CABIForwarding(p CppParameter) (preamble
 		// Go: convert string -> miqt_string*
 		// CABI: convert miqt_string* -> real QString
 
-		preamble += nameprefix + "_ms := miqt_strdupg(" + p.ParameterName + ")\n"
+		gfs.imports["libmiqt"] = struct{}{}
+		preamble += nameprefix + "_ms := libmiqt.Strdupg(" + p.ParameterName + ")\n"
 		preamble += "defer C.free(" + nameprefix + "_ms)\n"
 
 		rvalue = "(*C.struct_miqt_string)(" + nameprefix + "_ms)"
@@ -660,14 +662,17 @@ import "C"
 	if len(gfs.imports) > 0 {
 		allImports := make([]string, 0, len(gfs.imports))
 		for k, _ := range gfs.imports {
-			allImports = append(allImports, `"`+k+`"`)
+			if k == "libmiqt" {
+				allImports = append(allImports, `"`+BaseModule+`/libmiqt"`)
+			} else {
+				allImports = append(allImports, `"`+k+`"`)
+			}
 		}
+
 		sort.Strings(allImports)
 		goSrc = strings.Replace(goSrc, `%%_IMPORTLIBS_%%`, "import (\n\t"+strings.Join(allImports, "\n\t")+"\n)", 1)
-
 	} else {
 		goSrc = strings.Replace(goSrc, `%%_IMPORTLIBS_%%`, "", 1)
-
 	}
 
 	// Run gofmt over the result

cmd/genbindings/main.go

@@ -15,6 +15,7 @@ import (
 
 const (
 	ClangSubprocessCount = 3
+	BaseModule           = "github.com/mappu/miqt"
 )
 
 func cacheFilePath(inputHeader string) string {

libmiqt/libmiqt.cpp

@@ -1,7 +1,4 @@
-#include <string.h>
+#include "libmiqt.h"
-#include <stdlib.h>
-
-#include "binding.h"
 
 struct miqt_string* miqt_strdup(const char* src, size_t len) {
     struct miqt_string* ret = (struct miqt_string*)( malloc(len + sizeof(size_t)) );

libmiqt/libmiqt.h

@@ -1,6 +1,9 @@
 #ifndef MIQT_BINDING_H
 #define MIQT_BINDING_H
 
+#include <string.h>
+#include <stdlib.h>
+
 #ifdef __cplusplus
 extern "C" {
 #endif
@@ -15,10 +18,10 @@ struct miqt_array {
     void* data; // Separate, second allocation
 };
 
-// miqt_strdup allocates a miqt_string and copies C data into it.
-// The function is defined in C++.
 struct miqt_string* miqt_strdup(const char* src, size_t len);
 
+typedef const char const_char;
+
 #ifdef __cplusplus
 }
 #endif

libmiqt/strings.go

@@ -1,10 +1,10 @@
-package qt
+package libmiqt
 
 // SPDX-License-Identifier: MIT
 
 /*
 
-#include "binding.h"
+#include "libmiqt.h"
 
 struct miqt_string* miqt_strdupg(_GoString_ gs) {
 	return miqt_strdup(_GoStringPtr(gs), _GoStringLen(gs));
@@ -17,9 +17,9 @@ import (
 	"unsafe"
 )
 
-// miqt_strdupg will strdup a Go string into a miqt_string*.
+// Strdupg will strdup a Go string into a miqt_string*.
 // It is typed as returning an unsafe.Pointer because Cgo types cannot be shared
 // across Go file boundaries.
-func miqt_strdupg(s string) unsafe.Pointer {
+func Strdupg(s string) unsafe.Pointer {
 	return unsafe.Pointer(C.miqt_strdupg(s))
 }