C backend: improve representation of string literals, fix them for various corner cases

core/src/main/java/org/teavm/backend/c/generate/ClassGenerator.java

@@ -130,7 +130,7 @@ public class ClassGenerator {
         generateStaticGCRoots();
         generateLayoutArray();
 
-        new StringPoolGenerator(stringPoolWriter, context.getNames()).generate(context.getStringPool().getStrings());
+        new StringPoolGenerator(stringPoolWriter).generate(context.getStringPool().getStrings());
 
         for (String include : includes) {
             includesWriter.println("#include " + include);

core/src/main/java/org/teavm/backend/c/generate/NameProvider.java

@@ -69,6 +69,8 @@ public class NameProvider {
 
         memberFieldNames.put(new FieldReference(RuntimeObject.class.getName(), "classReference"), "header");
         memberFieldNames.put(new FieldReference(RuntimeArray.class.getName(), "size"), "size");
+        memberFieldNames.put(new FieldReference(String.class.getName(), "characters"), "characters");
+        memberFieldNames.put(new FieldReference(String.class.getName(), "hashCode"), "hashCode");
 
         occupiedClassNames.put(RuntimeObject.class.getName(), new HashSet<>(Arrays.asList("header")));
         occupiedClassNames.put(RuntimeArray.class.getName(), new HashSet<>(Arrays.asList("length")));

core/src/main/java/org/teavm/backend/c/generate/StringPoolGenerator.java

@@ -16,56 +16,46 @@
 package org.teavm.backend.c.generate;
 
 import java.util.List;
-import org.teavm.model.FieldReference;
 
 public class StringPoolGenerator {
     private CodeWriter writer;
-    private NameProvider names;
 
-    public StringPoolGenerator(CodeWriter writer, NameProvider names) {
+    public StringPoolGenerator(CodeWriter writer) {
         this.writer = writer;
-        this.names = names;
     }
 
     public void generate(List<? extends String> strings) {
-        generateStringArrays(strings);
-        generateStringObjects(strings);
-    }
-
-    private void generateStringArrays(List<? extends String> strings) {
-        for (int i = 0; i < strings.size(); ++i) {
-            String s = strings.get(i);
-            writer.print("static struct { JavaArray hdr; char16_t data[" + (s.length() + 1) + "]; } str_array_" + i)
-                    .println(" = {").indent();
-            writer.println(".hdr = { .size = " + s.length() + "},");
-            writer.print(".data = ");
-            generateStringLiteral(s);
-            writer.println();
-
-            writer.outdent().println("};");
-        }
-    }
-
-    private void generateStringObjects(List<? extends String> strings) {
-        String charactersName = names.forMemberField(new FieldReference(String.class.getName(), "characters"));
-        String hashCodeName = names.forMemberField(new FieldReference(String.class.getName(), "hashCode"));
-
         writer.println("static JavaString stringPool[" + strings.size() + "] = {").indent();
         for (int i = 0; i < strings.size(); ++i) {
-            writer.println("{").indent();
+            String s = strings.get(i);
-            writer.println("." + charactersName + " = (JavaArray*) &str_array_" + i + ",");
+            boolean codes = hasBadCharacters(s);
-            writer.println("." + hashCodeName + " = INT32_C(" + strings.get(i).hashCode() + ")");
+            String macroName = codes ? "TEAVM_STRING_FROM_CODES" : "TEAVM_STRING";
-            writer.outdent().print("}");
+            writer.print(macroName + "(" + s.length() + ", " + s.hashCode() + ",");
-
+            if (codes) {
-            if (i < strings.size() - 1) {
+                generateNumericStringLiteral(s);
-                writer.print(",");
+            } else {
+                generateSimpleStringLiteral(s);
             }
+            writer.print(")");
+
+            writer.print(i < strings.size() - 1 ? "," : " ");
+            writer.print(" // string #" + i);
             writer.println();
         }
         writer.outdent().println("};");
     }
 
-    private void generateStringLiteral(String string) {
+    private boolean hasBadCharacters(String string) {
+        for (int i = 0; i < string.length(); ++i) {
+            char c = string.charAt(i);
+            if (c == 0 || Character.isSurrogate(c)) {
+                return true;
+            }
+        }
+        return false;
+    }
+
+    private void generateSimpleStringLiteral(String string) {
         writer.print("u\"");
 
         for (int j = 0; j < string.length(); ++j) {
@@ -88,7 +78,7 @@ public class StringPoolGenerator {
                     break;
                 default:
                     if (c < 32) {
-                        writer.print("\\x" + Character.forDigit(c >> 4, 16) + Character.forDigit(c & 0xF, 16));
+                        writer.print("\\0" + Character.forDigit(c >> 3, 8) + Character.forDigit(c & 0x7, 8));
                     } else if (c > 127) {
                         writer.print("\\u"
                                 + Character.forDigit(c >> 12, 16)
@@ -104,4 +94,14 @@ public class StringPoolGenerator {
 
         writer.print("\"");
     }
+
+    private void generateNumericStringLiteral(String string) {
+        for (int i = 0; i < string.length(); ++i) {
+            if (i > 0) {
+                writer.print(", ");
+            }
+            int c = string.charAt(i);
+            writer.print(Integer.toString(c));
+        }
+    }
 }

core/src/main/resources/org/teavm/backend/c/runtime.c

@@ -80,6 +80,22 @@ static inline void* checkcast(void*, int32_t (*)(JavaClass*));
 #define ADDRESS_ADD(address, offset) ((char *) (address) + (offset))
 #define STRUCTURE_ADD(structure, address, offset) (((structure*) (address)) + offset)
 
+#define TEAVM_STRING(length, hash, s) { \
+    .characters = (JavaArray*) & (struct { JavaArray hdr; char16_t data[length]; }) { \
+        .hdr = { .size = length }, \
+        .data = s \
+    }, \
+    .hashCode = INT32_C(hash) \
+}
+
+#define TEAVM_STRING_FROM_CODES(length, hash, ...) { \
+    .characters = (JavaArray*) & (struct { JavaArray hdr; char16_t data[length]; }) { \
+        .hdr = { .size = length }, \
+        .data = { __VA_ARGS__ } \
+    }, \
+    .hashCode = INT32_C(hash) \
+}
+
 static void** stackTop;
 
 static void* gc_gcStorageAddress = NULL;