[WIP] fuzz: block fuzzing

src/flamenco/runtime/fd_runtime.h

@@ -159,6 +159,9 @@ fd_runtime_execute_txns_in_waves_tpool( fd_exec_slot_ctx_t * slot_ctx,
                                         fd_spad_t * * spads, 
                                         ulong spads_cnt );
 
+int
+fd_runtime_block_sysvar_update_pre_execute( fd_exec_slot_ctx_t * slot_ctx );
+
 void
 fd_runtime_calculate_fee ( fd_exec_txn_ctx_t * txn_ctx,
                            fd_txn_t const * txn_descriptor,

src/flamenco/runtime/tests/fd_exec_instr_test.h

@@ -8,6 +8,7 @@
 #include "generated/invoke.pb.h"
 #include "generated/txn.pb.h"
 #include "generated/vm.pb.h"
+#include "generated/block.pb.h"
 #include "../../../funk/fd_funk.h"
 #include "../../vm/fd_vm.h"
 #include "../../../ballet/murmur3/fd_murmur3.h"
@@ -111,6 +112,22 @@ fd_exec_txn_test_run( fd_exec_instr_test_runner_t * runner, // Runner only conta
                       void *                        output_buf,
                       ulong                         output_bufsz );
 
+/* 
+   Executes several transactions within a single slot. A few things to know when using this harness...
+   - All sysvars are assumed to have been provided in the context
+   - This does not test sigverify
+   - Epoch boundaries are NOT tested
+   - Tested Firedancer code is `fd_runtime_execute_txns_in_waves_tpool` and `fd_runtime_block_execute_finalize_tpool`
+   - Associated entrypoint tested in Agave is `confirm_slot_entries` (except sigverify is removed and verify_ticks is included) 
+   - Recent blockhashes sysvar account must NOT be provided in the input account states. Instead, the sysvar is populated through the input blockhash queue.
+*/
+ulong
+fd_exec_block_test_run( fd_exec_instr_test_runner_t * runner,
+                        void const *                  input_,
+                        void **                       output_,
+                        void *                        output_buf,
+                        ulong                         output_bufsz );
+
 /* Loads an ELF binary (in input->elf.data()). 
    output_buf points to a memory region of output_bufsz bytes where the
    result is allocated into. During execution, the contents of

src/flamenco/runtime/tests/fd_exec_sol_compat.c

@@ -664,6 +664,42 @@ sol_compat_txn_execute_v1( uchar *       out,
   return ok;
 }
 
+int
+sol_compat_block_execute_v1( uchar *       out,
+                             ulong *       out_sz,
+                             uchar const * in,
+                             ulong         in_sz ) {
+  // Setup
+  ulong fmem[ 64 ];
+  fd_exec_instr_test_runner_t * runner = sol_compat_setup_scratch_and_runner( fmem );
+
+  // Decode context
+  fd_exec_test_txn_context_t input[1] = {0};
+  void * res = sol_compat_decode( &input, in, in_sz, &fd_exec_test_txn_context_t_msg );
+  if ( res==NULL ) {
+    sol_compat_cleanup_scratch_and_runner( runner );
+    return 0;
+  }
+
+  // Execute
+  void * output = NULL;
+  sol_compat_execute_wrapper( runner, input, &output, fd_exec_block_test_run );
+
+  // Encode effects
+  int ok = 0;
+  if( output ) {
+    ok = !!sol_compat_encode( out, out_sz, output, &fd_exec_test_txn_result_t_msg );
+  }
+
+  // Cleanup
+  pb_release( &fd_exec_test_txn_context_t_msg, input );
+  sol_compat_cleanup_scratch_and_runner( runner );
+
+  // Check wksp usage is 0
+  sol_compat_check_wksp_usage();
+  return ok;
+}
+
 int
 sol_compat_elf_loader_v1( uchar *       out,
                           ulong *       out_sz,