Implement 64-Bit System Clock Runtime & Secured Integer Parser

[LucasChen1108]

Implement 64-Bit System Clock Runtime & Secured Integer Parser

Overview

This pull request addresses two unimplemented stubs within Sinter's default core specification: returning exact VM uptimes via runtime(), and decoding strings securely into integers via parse_int().

The runtime() logic has been adapted to map cleanly with EV3/POSIX <time.h> standards, and a separate web-compatible implementation has been added to lib.c for the Sinter WebAssembly demo.

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What's Changed

• Web Demo Clock Support (lib.c): Added get_time_ms implementation for the WebAssembly target, enabling runtime() to function correctly in the browser-based Sinter demo.
• Configured EV3 OS Runner Hooks: Sinter runner on Linux target platforms now natively hooks into clock_gettime(CLOCK_MONOTONIC) and bridges hardware execution time accurately into sivmfn_primitives.
• 64-Bit High Precision Upgrade: Transitioned sinter_get_time_ms to a uint64_t interface to handle long-running programs safely.
• Dynamic Capacity Fallback: runtime() evaluates whether elapsed uptime exceeds NANBOX_INTMAX limits. If the timestamp overflows, it safely falls back to NANBOX_OFFLOAT, preventing crashes on long-running robots.
• Registered Implementations: Replaced sivmfn_prim_unimpl stubs for parse_int and runtime in the primitives dispatch table (sivmfn_primitives[]) with the new implementations, activating both functions in the VM for the first time.
• Spec-Compliant parse_int Parser: primitives.c leverages sistrobj_tocharptr to extract chars from internal C string structs directly.
• Hardened Validation:
  • Validates radices per JavaScript conventions (rejecting values < 2 or > 36)
  • Catches unsafe float conversions using !isfinite(fv) || truncf(fv) != fv
  • Captures endptr == str from strtol to ensure unresolved strings return NANBOX_CANONICAL_NAN

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Type of Patch

• ✅ New feature (non-breaking change which adds functionality)

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Test Plan

Native EV3/Linux:
Compiled via GCC and tested with:

./sinter_runner test_programs/prim_parse_int.svm
./sinter_runner test_programs/prim_get_time.svm

Execution generated 0 faults locally.

Web Demo:
Tested on the browser-based Sinter demo with the following Source program:

const start_time = get_time();
let current_amount = 0;
let binary_test = 0;
let hex_test = 0;
let standard_test = 0;

let i = 0;
while (i < 1000000) {
    binary_test = parse_int("1010", 2);
    hex_test = parse_int("FF", 16);
    standard_test = parse_int("42", 10);
    current_amount = current_amount + binary_test + hex_test + standard_test;
    i = i + 1;
}

const end_time = get_time();
display("Total parsed amount:");
display(current_amount);
display("Time in ms:");
display(end_time - start_time);

Successfully returns correct parsed values and elapsed time in milliseconds.

[gemini-code-assist]

Code Review

This pull request implements the parse_int and runtime primitives for the Sinter VM. It introduces a cross-platform mechanism to retrieve the current time in milliseconds and adds a 1MB heap allocation for the native runner. Feedback was provided regarding the missing return value check for malloc in the runner, which could lead to a segmentation fault, and the lack of ERANGE error handling when using strtol in the parse_int implementation.