GlueGen: Add 'PascalString' string semantics (length + value-ptr), added prelim code for JavaCallback use-case emitBodyMapCToJNIType()

It is common in toolkit APIs that a string might not be passed as a 'nul' terminated (EOS) C string,
but as a Pascal string with a given length argument.

A C string is specied as
  ArgumentIsString alEventCallbackInject 3
while allowing multiple indices ..

A Pascal string can be specified as
  ArgumentIsPascalString ALEVENTPROCSOFT 3 4
while allowing multiple indice-tuples for length and value ..

The tuple consist of the length agrument-index first (usually an int)
followed by the value argument-index (usually a 'char*').

+++

CMethodBindingEmitter.emitBodyMapCToJNIType(), where PascalString is implemented,
is currently being used for
- JNI return statement (no PascalString impact possible)
- JavaCallback C type -> JNI type, PascalString impacting

1 files changed, 27 insertions, 3 deletions

diff --git a/src/java/com/jogamp/gluegen/CMethodBindingEmitter.java b/src/java/com/jogamp/gluegen/CMethodBindingEmitter.java
index 9c7ed0b..e20a1cb 100644
--- a/src/java/com/jogamp/gluegen/CMethodBindingEmitter.java
+++ b/src/java/com/jogamp/gluegen/CMethodBindingEmitter.java
@@ -1176,12 +1176,36 @@ public class CMethodBindingEmitter extends FunctionEmitter {
             unit.emitln("   */");
         }
     } else if (javaType.isString()) {
+        final boolean pascalString = javaType.isPascalStringVariant();
+        final String lenArgName;
+        if( pascalString ) {
+            final int lenIdx = cfg.pascalStringLengthIndex(getCSymbol(), argIdx);
+            lenArgName = 0 <= lenIdx ? binding.getArgumentName(lenIdx) : null;
+        } else {
+            lenArgName = null;
+        }
         if( addLocalVar ) {
-            unit.emit("  "+javaType.jniTypeName()+" "+javaArgName+" = ");
+            unit.emitln("  "+javaType.jniTypeName()+" "+javaArgName+";");
+        }
+        if( null != lenArgName ) {
+            unit.emitln("  if (NULL == "+cArgName+" || 0 >= "+lenArgName+" ) {");
         } else {
-            unit.emit("  "+javaArgName+" = ");
+            unit.emitln("  if (NULL == "+cArgName+") {");
+        }
+        unit.emitln("    "+javaArgName+" = NULL;");
+        unit.emitln("  } else {");
+        if( null != lenArgName ) {
+            unit.emitln("    char* "+cArgName+"_cstr = calloc("+lenArgName+"+1, sizeof(char)); // PascalString -> Add EOS");
+            unit.emitln("    memcpy("+cArgName+"_cstr, "+cArgName+", "+lenArgName+");");
         }
-        unit.emitln("(NULL == "+cArgName+") ? NULL : (*env)->NewStringUTF(env, (const char *)"+cArgName+");");
+        unit.emit  ("    "+javaArgName+" = ");
+        if( null != lenArgName ) {
+            unit.emitln("(*env)->NewStringUTF(env, (const char *)"+cArgName+"_cstr);");
+            unit.emitln("    free("+cArgName+"_cstr);");
+        } else {
+            unit.emitln("(*env)->NewStringUTF(env, (const char *)"+cArgName+");");
+        }
+        unit.emitln("  }");
     } else if (javaType.isArrayOfCompoundTypeWrappers() ||
               ( javaType.isArray() && javaType.isNIOByteBufferArray() ) )
     {