Small changes to illustrate problems with the code.

- Feel free to remove this commit from the PR when fixing the problems.

src/runtime/local/context/DaphneContext.h

@@ -97,10 +97,11 @@ struct DaphneContext {
 
         if(!stringRefCount.empty()) {
             // This should not happen
+            std::cerr << "Deleting " << stringRefCount.size() << " remaining string refs in ~DaphneContext()" << std::endl;
             logger->debug("Deleting {} remaining string refs in ~DaphneContext()", stringRefCount.size());
-            for (auto &ref: stringRefCount) {
-                delete[] reinterpret_cast<char *>(ref.first);
-            }
+            // for (auto &ref: stringRefCount) {
+            //     delete[] reinterpret_cast<char *>(ref.first);
+            // }
         }
     }
 

src/runtime/local/kernels/DecRef.h

@@ -41,13 +41,17 @@ struct DecRef<char> {
     static void apply(const char* arg, DCTX(ctx)) {
         auto ptr = reinterpret_cast<uintptr_t>(arg);
         if(auto found = ctx->stringRefCount.find(ptr); found != ctx->stringRefCount.end()) {
+            std::cerr << "DecRef: " << ptr << " (found)" << std::endl;
             found->second--;
             if(found->second == 0) {
                 ctx->logger->debug("DecRef deleting: {}", arg);
-                delete [] reinterpret_cast<char *>(found->first);
+                // delete [] reinterpret_cast<char *>(found->first);
                 ctx->stringRefCount.erase(found);
             }
         }
+        else {
+            std::cerr << "DecRef: " << ptr << " (not found)" << std::endl;
+        }
     }
 };
 

src/runtime/local/kernels/IncRef.h

@@ -40,9 +40,13 @@ struct IncRef<char> {
     static void apply(const char* arg, DCTX(ctx)) {
         auto ptr = reinterpret_cast<uintptr_t>(arg);
         if(auto found = ctx->stringRefCount.find(ptr); found != ctx->stringRefCount.end()) {
+            std::cerr << "IncRef: " << ptr << " (found)" << std::endl;
             ctx->logger->info("IncRef: {}", arg);
             found->second++;
         }
+        else {
+            std::cerr << "IncRef: " << ptr << " (not found)" << std::endl;
+        }
     }
 };
 

test/api/cli/controlflow/strings_1.daphne

@@ -0,0 +1,9 @@
+// Get a string from a string literal, pass it to a function, and get back a modified string.
+
+def foo(s:str) -> str {
+    return s + 123;
+}
+
+s = "abc"; # string literal, no kernel call
+s = foo(s);
+print(s);

test/api/cli/controlflow/strings_1.txt

@@ -0,0 +1 @@
+abc123

test/api/cli/controlflow/strings_2.daphne

@@ -0,0 +1,9 @@
+// Get a string from a kernel, pass it to a function, and get back a modified string.
+
+def foo(s:str) -> str {
+    return s + " is my favorite number";
+}
+
+s = as.str(123); # kernel call (but could be constant folded in the future)
+s = foo(s);
+print(s);

test/api/cli/controlflow/strings_2.txt

@@ -0,0 +1 @@
+123 is my favorite number