feat: specify initial value for exec_scopes (#1772)

* feat: specify initial value for exec_scopes

Context: bootloader and Starknet OS support.

Added an `exec_scopes` parameter to `cairo_run_program` to pass
variables to the hints of the program being run.

We need a way to set initial variables inside the execution scopes to
pass bootloader/OS arguments. The Python VM relies on a program input file
and uses hints to deserialize this input. In most cases we do not want
to have to deserialize these input types, but rather pass them directly
as variables inside the root execution scope.

We did not extend this feature to `cairo_run` to keep the PR minimal for
discussion, TBD if it is desirable.

* changelog

* cairo_run_program_with_initial_scope

* fix: revert change to call to cairo_run_program

Author: odesenfans

CHANGELOG.md

@@ -8,6 +8,8 @@
   * Checks that only `Array<Felt252>` can be received by the program main function when running with with either `--proof_mode` or `--append_return_values`.
   * Copies the input value to the output segment right after the output in the format `[array_len, arr[0], arr[1],.., arr[n]]`.
 
+                  * feat: specify initial value for `exec_scopes` in `cairo_run_program` [1772](https://github.com/lambdaclass/cairo-vm/pull/1772)
+
 * fix: make MemorySegmentManager.finalize() public [#1771](https://github.com/lambdaclass/cairo-vm/pull/1771)
 
 * feat: load Cairo PIE from bytes [#1773](https://github.com/lambdaclass/cairo-vm/pull/1773)

vm/src/cairo_run.rs

@@ -15,6 +15,7 @@ use bincode::enc::write::Writer;
 
 use thiserror_no_std::Error;
 
+use crate::types::exec_scope::ExecutionScopes;
 #[cfg(feature = "test_utils")]
 use arbitrary::{self, Arbitrary};
 
@@ -46,10 +47,12 @@ impl<'a> Default for CairoRunConfig<'a> {
     }
 }
 
-pub fn cairo_run_program(
+/// Runs a program with a customized execution scope.
+pub fn cairo_run_program_with_initial_scope(
     program: &Program,
     cairo_run_config: &CairoRunConfig,
     hint_processor: &mut dyn HintProcessor,
+    exec_scopes: ExecutionScopes,
 ) -> Result<CairoRunner, CairoRunError> {
     let secure_run = cairo_run_config
         .secure_run
@@ -66,6 +69,8 @@ pub fn cairo_run_program(
         cairo_run_config.trace_enabled,
     )?;
 
+    cairo_runner.exec_scopes = exec_scopes;
+
     let end = cairo_runner.initialize(allow_missing_builtins)?;
     // check step calculation
 
@@ -95,6 +100,19 @@ pub fn cairo_run_program(
     Ok(cairo_runner)
 }
 
+pub fn cairo_run_program(
+    program: &Program,
+    cairo_run_config: &CairoRunConfig,
+    hint_processor: &mut dyn HintProcessor,
+) -> Result<CairoRunner, CairoRunError> {
+    cairo_run_program_with_initial_scope(
+        program,
+        cairo_run_config,
+        hint_processor,
+        ExecutionScopes::new(),
+    )
+}
+
 pub fn cairo_run(
     program_content: &[u8],
     cairo_run_config: &CairoRunConfig,