vm: add API to control trace mode

Add a public getter and setter to read and set the VM trace level
respectively. Use the new API to control the trace mode with a newly
introduced `-t` command line switch.

Drop support for honouring the `TRACE` environment variable as
host programs embedding ucode might want to prevent that behaviour
or handle it differently.

Signed-off-by: Jo-Philipp Wich <jo@mein.io>

1 files changed, 3 insertions, 0 deletions

diff --git a/vm.h b/vm.h
index 84b42fe..3d22105 100644
--- a/vm.h
+++ b/vm.h
@@ -123,6 +123,9 @@ uc_value_t *uc_vm_stack_peek(uc_vm *vm, size_t offset);
 uc_exception_handler_t *uc_vm_exception_handler_get(uc_vm *vm);
 void uc_vm_exception_handler_set(uc_vm *vm, uc_exception_handler_t *exhandler);
 
+uint32_t uc_vm_trace_get(uc_vm *vm);
+void uc_vm_trace_set(uc_vm *vm, uint32_t level);
+
 uc_exception_type_t uc_vm_call(uc_vm *vm, bool mcall, size_t nargs);
 
 void __attribute__((format(printf, 3, 0)))