src/jdk.incubator.jextract/share/classes/jdk/incubator/jextract/tool/HandleSourceFactory.java

*** 76,85 ****
--- 76,103 ----
          this.libraryPaths = libraryPaths;
          this.clsName = clsName;
          this.pkgName = pkgName;
      }
  
+     private static String getCLangConstantsHolder() {
+         String prefix = "jdk.incubator.foreign.MemoryLayouts.";
+         String arch = System.getProperty("os.arch");
+         String os = System.getProperty("os.name");
+         if (arch.equals("amd64") || arch.equals("x86_64")) {
+             if (os.startsWith("Windows")) {
+                 return prefix + "WinABI";
+             } else {
+                 return prefix + "SysV";
+             }
+         } else if (arch.equals("aarch64")) {
+             return prefix + "AArch64ABI";
+         }
+         throw new UnsupportedOperationException("Unsupported os or arch: " + os + ", " + arch);
+     }
+ 
+     private static final String C_LANG_CONSTANTS_HOLDER = getCLangConstantsHolder();
+ 
      public JavaFileObject[] generate(Declaration.Scoped decl) {
          builder.addPackagePrefix(pkgName);
          builder.classBegin(clsName);
          builder.addLibraries(libraryNames.toArray(new String[0]),
                  libraryPaths != null ? libraryPaths.toArray(new String[0]) : null);
*** 97,107 ****
          try {
              return new JavaFileObject[] {
                      fileFromString(pkgName, clsName, src),
                      fileFromString(pkgName,"RuntimeHelper", (pkgName.isEmpty()? "" : "package " + pkgName + ";\n") +
                              Files.readAllLines(Paths.get(runtimeHelper.toURI()))
!                             .stream().collect(Collectors.joining("\n")))
              };
          } catch (IOException ex) {
              throw new UncheckedIOException(ex);
          } catch (URISyntaxException ex2) {
              throw new RuntimeException(ex2);
--- 115,125 ----
          try {
              return new JavaFileObject[] {
                      fileFromString(pkgName, clsName, src),
                      fileFromString(pkgName,"RuntimeHelper", (pkgName.isEmpty()? "" : "package " + pkgName + ";\n") +
                              Files.readAllLines(Paths.get(runtimeHelper.toURI()))
!                             .stream().collect(Collectors.joining("\n")).replace("${C_LANG}", C_LANG_CONSTANTS_HOLDER))
              };
          } catch (IOException ex) {
              throw new UncheckedIOException(ex);
          } catch (URISyntaxException ex2) {
              throw new RuntimeException(ex2);