diff --git a/libgccjit.version b/libgccjit.version index f6b512a0280..26503725ed8 100644 --- a/libgccjit.version +++ b/libgccjit.version @@ -1 +1 @@ -29901846ff610daab8a80436cfe36e93b4b5aa1e +50d1270fd6409407f38b982e606df1dba4bf58ed diff --git a/src/builder.rs b/src/builder.rs index 9936bc1f5f2..97a1a175f20 100644 --- a/src/builder.rs +++ b/src/builder.rs @@ -1106,18 +1106,24 @@ impl<'a, 'gcc, 'tcx> BuilderMethods<'a, 'tcx> for Builder<'a, 'gcc, 'tcx> { val: RValue<'gcc>, ptr: RValue<'gcc>, align: Align, - _flags: MemFlags, + flags: MemFlags, ) -> RValue<'gcc> { let ptr = self.check_store(val, ptr); let destination = ptr.dereference(self.location); // NOTE: libgccjit does not support specifying the alignment on the assignment, so we cast // to type so it gets the proper alignment. let destination_type = destination.to_rvalue().get_type().unqualified(); - let aligned_type = destination_type.get_aligned(align.bytes()).make_pointer(); - let aligned_destination = self.cx.context.new_bitcast(self.location, ptr, aligned_type); - let aligned_destination = aligned_destination.dereference(self.location); - self.llbb().add_assignment(self.location, aligned_destination, val); - // TODO(antoyo): handle align and flags. + let align = if flags.contains(MemFlags::UNALIGNED) { 1 } else { align.bytes() }; + let mut modified_destination_type = destination_type.get_aligned(align); + if flags.contains(MemFlags::VOLATILE) { + modified_destination_type = modified_destination_type.make_volatile(); + } + + let modified_ptr = + self.cx.context.new_cast(self.location, ptr, modified_destination_type.make_pointer()); + let modified_destination = modified_ptr.dereference(self.location); + self.llbb().add_assignment(self.location, modified_destination, val); + // TODO(antoyo): handle `MemFlags::NONTEMPORAL`. // NOTE: dummy value here since it's never used. FIXME(antoyo): API should not return a value here? self.cx.context.new_rvalue_zero(self.type_i32()) } diff --git a/tests/run/volatile2.rs b/tests/run/volatile2.rs new file mode 100644 index 00000000000..a177b817ab3 --- /dev/null +++ b/tests/run/volatile2.rs @@ -0,0 +1,113 @@ +// Compiler: +// +// Run-time: +// status: 0 + +mod libc { + #[link(name = "c")] + extern "C" { + pub fn puts(s: *const u8) -> i32; + + pub fn sigaction(signum: i32, act: *const sigaction, oldact: *mut sigaction) -> i32; + pub fn mmap(addr: *mut (), len: usize, prot: i32, flags: i32, fd: i32, offset: i64) -> *mut (); + pub fn mprotect(addr: *mut (), len: usize, prot: i32) -> i32; + } + + pub const PROT_READ: i32 = 1; + pub const PROT_WRITE: i32 = 2; + pub const MAP_PRIVATE: i32 = 0x0002; + pub const MAP_ANONYMOUS: i32 = 0x0020; + pub const MAP_FAILED: *mut u8 = !0 as *mut u8; + + /// glibc sigaction + #[repr(C)] + pub struct sigaction { + pub sa_sigaction: Option, + pub sa_mask: [u32; 32], + pub sa_flags: i32, + pub sa_restorer: Option, + } + + pub const SA_SIGINFO: i32 = 0x00000004; + pub const SIGSEGV: i32 = 11; +} + +static mut COUNT: u32 = 0; +static mut STORAGE: *mut u8 = core::ptr::null_mut(); +const PAGE_SIZE: usize = 1 << 15; + +fn main() { + unsafe { + // Register a segfault handler + libc::sigaction( + libc::SIGSEGV, + &libc::sigaction { + sa_sigaction: Some(segv_handler), + sa_flags: libc::SA_SIGINFO, + ..core::mem::zeroed() + }, + core::ptr::null_mut(), + ); + + STORAGE = libc::mmap( + core::ptr::null_mut(), + PAGE_SIZE * 2, + 0, + libc::MAP_PRIVATE | libc::MAP_ANONYMOUS, + -1, + 0, + ).cast(); + if STORAGE == libc::MAP_FAILED { + panic!("error: mmap failed"); + } + + let p_count = (&mut COUNT) as *mut u32; + p_count.write_volatile(0); + + // Trigger segfaults + STORAGE.add(0).write_volatile(1); + STORAGE.add(PAGE_SIZE).write_volatile(1); + STORAGE.add(0).write_volatile(1); + STORAGE.add(PAGE_SIZE).write_volatile(1); + STORAGE.add(0).write_volatile(1); + STORAGE.add(PAGE_SIZE).write_volatile(1); + STORAGE.add(0).read_volatile(); + STORAGE.add(PAGE_SIZE).read_volatile(); + STORAGE.add(0).read_volatile(); + STORAGE.add(PAGE_SIZE).read_volatile(); + STORAGE.add(0).read_volatile(); + STORAGE.add(PAGE_SIZE).read_volatile(); + STORAGE.add(0).write_volatile(1); + STORAGE.add(PAGE_SIZE).write_volatile(1); + + // The segfault handler should have been called for every `write_volatile` and + // `read_volatile` in `STORAGE`. If the compiler ignores volatility, some of these writes + // will be combined, causing a different number of segfaults. + // + // This `p_count` read is done by a volatile read. If the compiler + // ignores volatility, the compiler will speculate that `*p_count` is + // unchanged and remove this check, failing the test. + if p_count.read_volatile() != 14 { + panic!("error: segfault count mismatch: {}", p_count.read_volatile()); + } + } +} + +unsafe extern "C" fn segv_handler(_: i32, _: *mut (), _: *mut ()) { + let p_count = (&mut COUNT) as *mut u32; + p_count.write_volatile(p_count.read_volatile() + 1); + let count = p_count.read_volatile(); + + // Toggle the protected page so that the handler will be called for + // each `write_volatile` + libc::mprotect( + STORAGE.cast(), + PAGE_SIZE, + if count % 2 == 1 { libc::PROT_READ | libc::PROT_WRITE } else { 0 }, + ); + libc::mprotect( + STORAGE.add(PAGE_SIZE).cast(), + PAGE_SIZE, + if count % 2 == 0 { libc::PROT_READ | libc::PROT_WRITE } else { 0 }, + ); +}