From 6666c44509a51b407ab8d2b94a3d5a91c63cc59f Mon Sep 17 00:00:00 2001 From: shamb0 Date: Tue, 3 Dec 2024 08:49:50 +0530 Subject: [PATCH] Improve timezone handling in 'localtime_r()' using 'allocate_bytes()' Signed-off-by: shamb0 --- src/shims/time.rs | 18 ++- tests/pass-dep/libc/libc-time.rs | 196 ++++++++++++++++++++++++++++--- 2 files changed, 194 insertions(+), 20 deletions(-) diff --git a/src/shims/time.rs b/src/shims/time.rs index 6436823b0f..11557d51c8 100644 --- a/src/shims/time.rs +++ b/src/shims/time.rs @@ -5,6 +5,8 @@ use std::time::{Duration, SystemTime}; use chrono::{DateTime, Datelike, Offset, Timelike, Utc}; use chrono_tz::Tz; +use rustc_abi::Align; +use rustc_ast::ast::Mutability; use crate::*; @@ -180,6 +182,7 @@ pub trait EvalContextExt<'tcx>: crate::MiriInterpCxExt<'tcx> { if !matches!(&*this.tcx.sess.target.os, "solaris" | "illumos") { // tm_zone represents the timezone value in the form of: +0730, +08, -0730 or -08. // This may not be consistent with libc::localtime_r's result. + let offset_in_seconds = dt.offset().fix().local_minus_utc(); let tm_gmtoff = offset_in_seconds; let mut tm_zone = String::new(); @@ -195,11 +198,18 @@ pub trait EvalContextExt<'tcx>: crate::MiriInterpCxExt<'tcx> { write!(tm_zone, "{:02}", offset_min).unwrap(); } - // FIXME: String de-duplication is needed so that we only allocate this string only once - // even when there are multiple calls to this function. - let tm_zone_ptr = this - .alloc_os_str_as_c_str(&OsString::from(tm_zone), MiriMemoryKind::Machine.into())?; + // Add null terminator for C string compatibility. + tm_zone.push('\0'); + + // Deduplicate and allocate the string. + let tm_zone_ptr = this.allocate_bytes( + tm_zone.as_bytes(), + Align::ONE, + MiriMemoryKind::Machine.into(), + Mutability::Not, + )?; + // Write the timezone pointer and offset into the result structure. this.write_pointer(tm_zone_ptr, &this.project_field_named(&result, "tm_zone")?)?; this.write_int_fields_named(&[("tm_gmtoff", tm_gmtoff.into())], &result)?; } diff --git a/tests/pass-dep/libc/libc-time.rs b/tests/pass-dep/libc/libc-time.rs index 84dbd8ad76..06af1e8c85 100644 --- a/tests/pass-dep/libc/libc-time.rs +++ b/tests/pass-dep/libc/libc-time.rs @@ -5,7 +5,14 @@ use std::{env, mem, ptr}; fn main() { test_clocks(); test_posix_gettimeofday(); - test_localtime_r(); + test_localtime_r_gmt(); + test_localtime_r_pst(); + test_localtime_r_epoch(); + // Architecture-specific tests. + #[cfg(target_pointer_width = "32")] + test_localtime_r_future_32b(); + #[cfg(target_pointer_width = "64")] + test_localtime_r_future_64b(); } /// Tests whether clock support exists at all @@ -46,14 +53,9 @@ fn test_posix_gettimeofday() { assert_eq!(is_error, -1); } -fn test_localtime_r() { - // Set timezone to GMT. - let key = "TZ"; - env::set_var(key, "GMT"); - - const TIME_SINCE_EPOCH: libc::time_t = 1712475836; - let custom_time_ptr = &TIME_SINCE_EPOCH; - let mut tm = libc::tm { +// Helper function to create an empty tm struct. +fn create_empty_tm() -> libc::tm { + libc::tm { tm_sec: 0, tm_min: 0, tm_hour: 0, @@ -77,7 +79,17 @@ fn test_localtime_r() { target_os = "android" ))] tm_zone: std::ptr::null_mut::(), - }; + } +} + +// Original GMT test +fn test_localtime_r_gmt() { + // Set timezone to GMT. + let key = "TZ"; + env::set_var(key, "GMT"); + const TIME_SINCE_EPOCH: libc::time_t = 1712475836; // 2024-04-07 07:43:56 GMT + let custom_time_ptr = &TIME_SINCE_EPOCH; + let mut tm = create_empty_tm(); let res = unsafe { libc::localtime_r(custom_time_ptr, &mut tm) }; assert_eq!(tm.tm_sec, 56); @@ -95,20 +107,172 @@ fn test_localtime_r() { target_os = "freebsd", target_os = "android" ))] - assert_eq!(tm.tm_gmtoff, 0); + { + assert_eq!(tm.tm_gmtoff, 0); + unsafe { + assert_eq!(std::ffi::CStr::from_ptr(tm.tm_zone).to_str().unwrap(), "+00"); + } + } + + // The returned value is the pointer passed in. + assert!(ptr::eq(res, &mut tm)); + + // Remove timezone setting. + env::remove_var(key); +} + +// PST timezone test (testing different timezone handling). +fn test_localtime_r_pst() { + let key = "TZ"; + env::set_var(key, "PST8PDT"); + const TIME_SINCE_EPOCH: libc::time_t = 1712475836;// 2024-04-07 07:43:56 GMT + let custom_time_ptr = &TIME_SINCE_EPOCH; + let mut tm = create_empty_tm(); + + let res = unsafe { libc::localtime_r(custom_time_ptr, &mut tm) }; + + assert_eq!(tm.tm_sec, 56); + assert_eq!(tm.tm_min, 43); + assert_eq!(tm.tm_hour, 0); // 7 - 7 = 0 (PDT offset) + assert_eq!(tm.tm_mday, 7); + assert_eq!(tm.tm_mon, 3); + assert_eq!(tm.tm_year, 124); + assert_eq!(tm.tm_wday, 0); + assert_eq!(tm.tm_yday, 97); + assert_eq!(tm.tm_isdst, -1); // DST information unavailable + #[cfg(any( target_os = "linux", target_os = "macos", target_os = "freebsd", target_os = "android" ))] - unsafe { - assert_eq!(std::ffi::CStr::from_ptr(tm.tm_zone).to_str().unwrap(), "+00") - }; + { + assert_eq!(tm.tm_gmtoff, -7 * 3600); // -7 hours in seconds + unsafe { + assert_eq!(std::ffi::CStr::from_ptr(tm.tm_zone).to_str().unwrap(), "-07"); + } + } - // The returned value is the pointer passed in. assert!(ptr::eq(res, &mut tm)); + env::remove_var(key); +} - // Remove timezone setting. +// Unix epoch test (edge case testing). +fn test_localtime_r_epoch() { + let key = "TZ"; + env::set_var(key, "GMT"); + const TIME_SINCE_EPOCH: libc::time_t = 0; // 1970-01-01 00:00:00 + let custom_time_ptr = &TIME_SINCE_EPOCH; + let mut tm = create_empty_tm(); + + let res = unsafe { libc::localtime_r(custom_time_ptr, &mut tm) }; + + assert_eq!(tm.tm_sec, 0); + assert_eq!(tm.tm_min, 0); + assert_eq!(tm.tm_hour, 0); + assert_eq!(tm.tm_mday, 1); + assert_eq!(tm.tm_mon, 0); + assert_eq!(tm.tm_year, 70); + assert_eq!(tm.tm_wday, 4); // Thursday + assert_eq!(tm.tm_yday, 0); + assert_eq!(tm.tm_isdst, -1); + + #[cfg(any( + target_os = "linux", + target_os = "macos", + target_os = "freebsd", + target_os = "android" + ))] + { + assert_eq!(tm.tm_gmtoff, 0); + unsafe { + assert_eq!(std::ffi::CStr::from_ptr(tm.tm_zone).to_str().unwrap(), "+00"); + } + } + + assert!(ptr::eq(res, &mut tm)); + env::remove_var(key); +} + +// Future date test (testing large values). +#[cfg(target_pointer_width = "64")] +fn test_localtime_r_future_64b() { + let key = "TZ"; + env::set_var(key, "GMT"); + + // Using 2050-01-01 00:00:00 for 64-bit systems + // value that's safe for 64-bit time_t + const TIME_SINCE_EPOCH: libc::time_t = 2524608000; + let custom_time_ptr = &TIME_SINCE_EPOCH; + let mut tm = create_empty_tm(); + + let res = unsafe { libc::localtime_r(custom_time_ptr, &mut tm) }; + + assert_eq!(tm.tm_sec, 0); + assert_eq!(tm.tm_min, 0); + assert_eq!(tm.tm_hour, 0); + assert_eq!(tm.tm_mday, 1); + assert_eq!(tm.tm_mon, 0); + assert_eq!(tm.tm_year, 150); // 2050 - 1900 + assert_eq!(tm.tm_wday, 6); // Saturday + assert_eq!(tm.tm_yday, 0); + assert_eq!(tm.tm_isdst, -1); + + #[cfg(any( + target_os = "linux", + target_os = "macos", + target_os = "freebsd", + target_os = "android" + ))] + { + assert_eq!(tm.tm_gmtoff, 0); + unsafe { + assert_eq!(std::ffi::CStr::from_ptr(tm.tm_zone).to_str().unwrap(), "+00"); + } + } + + assert!(ptr::eq(res, &mut tm)); + env::remove_var(key); +} + +#[cfg(target_pointer_width = "32")] +fn test_localtime_r_future_32b() { + let key = "TZ"; + env::set_var(key, "GMT"); + + // Using 2030-01-01 00:00:00 for 32-bit systems + // Safe value within i32 range + const TIME_SINCE_EPOCH: libc::time_t = 1893456000; + let custom_time_ptr = &TIME_SINCE_EPOCH; + let mut tm = create_empty_tm(); + + let res = unsafe { libc::localtime_r(custom_time_ptr, &mut tm) }; + + // Verify 2030-01-01 00:00:00 + assert_eq!(tm.tm_sec, 0); + assert_eq!(tm.tm_min, 0); + assert_eq!(tm.tm_hour, 0); + assert_eq!(tm.tm_mday, 1); + assert_eq!(tm.tm_mon, 0); + assert_eq!(tm.tm_year, 130); // 2030 - 1900 + assert_eq!(tm.tm_wday, 2); // Tuesday + assert_eq!(tm.tm_yday, 0); + assert_eq!(tm.tm_isdst, -1); + + #[cfg(any( + target_os = "linux", + target_os = "macos", + target_os = "freebsd", + target_os = "android" + ))] + { + assert_eq!(tm.tm_gmtoff, 0); + unsafe { + assert_eq!(std::ffi::CStr::from_ptr(tm.tm_zone).to_str().unwrap(), "+00"); + } + } + + assert!(ptr::eq(res, &mut tm)); env::remove_var(key); }