ICE with extern C functions receiving/returning structs by value with f32/f64 members on x86_64

[SiegeLord]

Structs that contain f32/f64 and have a total size of <= 128 bytes produce an out of bounds error at src/librustc/middle/trans/cabi_x86_64.rs:259 . Tested with incoming at a9247e0.

Here is a collection of structs that produce an ICE and some that don't. I haven't tested whether the ones that do compile produce correct code.

// rust: task failed at 'index out of bounds: the len is 1 but the index is 1', /home/siege/src/rust2/src/librustc/middle/trans/cabi_x86_64.rs:259
struct f64_1
{
    a : f64,
}

// rust: task failed at 'index out of bounds: the len is 2 but the index is 2', /home/siege/src/rust2/src/librustc/middle/trans/cabi_x86_64.rs:259
struct f64_2
{
    a : f64,
    b : f64
}

// No ICE
struct f64_3
{
    a : f64,
    b : f64,
    c : f64
}

// No ICE
struct f64_4
{
    a : f64,
    b : f64,
    c : f64,
    d : f64
}

// No ICE
struct f64_5
{
    a : f64,
    b : f64,
    c : f64,
    d : f64,
    e : f64
}

// rust: task failed at 'index out of bounds: the len is 1 but the index is 1', /home/siege/src/rust2/src/librustc/middle/trans/cabi_x86_64.rs:259
struct f32_1
{
    a : f32
}

// rust: task failed at 'index out of bounds: the len is 1 but the index is 1', /home/siege/src/rust2/src/librustc/middle/trans/cabi_x86_64.rs:259
struct f32_2
{
    a : f32,
    b : f32
}

// rust: task failed at 'index out of bounds: the len is 2 but the index is 2', /home/siege/src/rust2/src/librustc/middle/trans/cabi_x86_64.rs:259
struct f32_3
{
    a : f32,
    b : f32,
    c : f32
}

// rust: task failed at 'index out of bounds: the len is 2 but the index is 2', /home/siege/src/rust2/src/librustc/middle/trans/cabi_x86_64.rs:259
struct f32_4
{
    a : f32,
    b : f32,
    c : f32,
    d : f32,
}

// No ICE
struct f32_5
{
    a : f32,
    b : f32,
    c : f32,
    d : f32,
    e : f32,
}

type T = f32_1;

extern "C"
{
    fn test1(a : T);
    fn test2() -> T;
}

fn main()
{
}

Here's a representative backtrace, if it's useful:

/usr/local/bin/../lib/librustrt.so(_ZN9rust_task13begin_failureEPKcS1_m+0x4b)[0x7fcb85a20c8b]
/usr/local/bin/../lib/librustrt.so(+0x2aa79)[0x7fcb85a31a79]
/usr/local/bin/../lib/librustrt.so(upcall_fail+0x1a8)[0x7fcb85a22a78]
/usr/local/bin/../lib/libcore-c3ca5d77d81b46c1-0.7-pre.so(+0x10911b)[0x7fcb875f611b]
/usr/local/bin/../lib/libcore-c3ca5d77d81b46c1-0.7-pre.so(+0x4f15e)[0x7fcb8753c15e]
/usr/local/bin/../lib/libcore-c3ca5d77d81b46c1-0.7-pre.so(_ZN8unstable4lang17fail_bounds_check16_6fb13a2fe60974b6_07preE+0x23a)[0x7fcb875454da]
/usr/local/bin/../lib/librustc-c84825241471686d-0.7-pre.so(+0x305e2d)[0x7fcb85f68e2d]
/usr/local/bin/../lib/librustc-c84825241471686d-0.7-pre.so(+0x3066f4)[0x7fcb85f696f4]
/usr/local/bin/../lib/librustc-c84825241471686d-0.7-pre.so(_ZN6middle5trans11cabi_x86_6414__extensions__10meth_3501512compute_info17_63f5244ae590c1b66_07preE+0x11e)[0x7fcb85f698fe]
/usr/local/bin/../lib/librustc-c84825241471686d-0.7-pre.so(+0x309fea)[0x7fcb85f6cfea]
/usr/local/bin/../lib/librustc-c84825241471686d-0.7-pre.so(+0x30b52d)[0x7fcb85f6e52d]
/usr/local/bin/../lib/librustc-c84825241471686d-0.7-pre.so(+0x30b210)[0x7fcb85f6e210]
/usr/local/bin/../lib/librustc-c84825241471686d-0.7-pre.so(_ZN6middle5trans7foreign17trans_foreign_mod17_f7e97aff939386996_07preE+0x11e)[0x7fcb85ee75ee]
/usr/local/bin/../lib/librustc-c84825241471686d-0.7-pre.so(_ZN6middle5trans4base10trans_item17_e83b64764568c7be6_07preE+0x499)[0x7fcb85d7b909]
/usr/local/bin/../lib/librustc-c84825241471686d-0.7-pre.so(_ZN6middle5trans4base9trans_mod17_d740d055c716f9476_07preE+0xa3)[0x7fcb85ee73d3]
/usr/local/bin/../lib/librustc-c84825241471686d-0.7-pre.so(_ZN6middle5trans4base11trans_crate15_4f38ab124cab2e6_07preE+0x13c4)[0x7fcb85f073e4]
/usr/local/bin/../lib/librustc-c84825241471686d-0.7-pre.so(+0x8ddce4)[0x7fcb86540ce4]
/usr/local/bin/../lib/librustc-c84825241471686d-0.7-pre.so(+0x89b8b0)[0x7fcb864fe8b0]
/usr/local/bin/../lib/librustc-c84825241471686d-0.7-pre.so(_ZN6driver6driver12compile_rest15_58068714615f2b6_07preE+0x336a)[0x7fcb864fb90a]
/usr/local/bin/../lib/librustc-c84825241471686d-0.7-pre.so(+0x8ddce4)[0x7fcb86540ce4]
/usr/local/bin/../lib/librustc-c84825241471686d-0.7-pre.so(_ZN6driver6driver12compile_upto17_3ccd839185751c4f6_07preE+0x108)[0x7fcb864feac8]
/usr/local/bin/../lib/librustc-c84825241471686d-0.7-pre.so(_ZN6driver6driver13compile_input17_7bc345e59d22cba06_07preE+0xca)[0x7fcb864fef0a]
/usr/local/bin/../lib/librustc-c84825241471686d-0.7-pre.so(_ZN12run_compiler16_aa88c3dc13843746_07preE+0x20a0)[0x7fcb86531720]
/usr/local/bin/../lib/librustc-c84825241471686d-0.7-pre.so(+0x8db691)[0x7fcb8653e691]
/usr/local/bin/../lib/librustc-c84825241471686d-0.7-pre.so(+0x8d7bba)[0x7fcb8653abba]
/usr/local/bin/../lib/librustc-c84825241471686d-0.7-pre.so(+0x8ddce4)[0x7fcb86540ce4]
/usr/local/bin/../lib/libcore-c3ca5d77d81b46c1-0.7-pre.so(+0xd0fbf)[0x7fcb875bdfbf]
/usr/local/bin/../lib/libcore-c3ca5d77d81b46c1-0.7-pre.so(+0x152264)[0x7fcb8763f264]
/usr/local/bin/../lib/librustrt.so(_Z18task_start_wrapperP10spawn_args+0x24)[0x7fcb85a214d4]

[jdm]

Could you run rustc under gdb, set a breakpoint in rust_task_fail and paste the backtrace here?

[SiegeLord]

Sure, here it is. I'm not sure how to compile rustc so I get the line numbers, so there are very few of those present.

#0  rust_task_fail (task=0x7fffec208970, expr=0x7fffe473b4d0 "index out of bounds: the len is 1 but the index is 1", 
    file=0x7ffff6923c20 <str34878> "/home/siege/src/rust2/src/librustc/middle/trans/cabi_x86_64.rs", line=259)
    at /home/siege/src/rust2/src/rt/rust_task.cpp:86
#1  0x00007ffff5e0bb69 in __morestack () from /usr/local/bin/../lib/librustrt.so
#2  0x00007ffff5dfcb68 in call_on_c_stack (fn_ptr=0x7ffff5dfc4a0 <upcall_s_fail(s_fail_args*)>, args=0x7fffe420fe90, this=0x7fffec208970)
    at /home/siege/src/rust2/src/rt/rust_task.h:470
#3  call_upcall_on_c_stack (fn_ptr=0x7ffff5dfc4a0 <upcall_s_fail(s_fail_args*)>, args=0x7fffe420fe90, task=<optimized out>)
    at /home/siege/src/rust2/src/rt/rust_upcall.cpp:45
#4  upcall_fail (expr=<optimized out>, file=0x7ffff6923c20 <str34878> "/home/siege/src/rust2/src/librustc/middle/trans/cabi_x86_64.rs", 
    line=259) at /home/siege/src/rust2/src/rt/rust_upcall.cpp:128
#5  0x00007ffff79d011b in sys::begin_unwind_::_9873ff47b9982218::_07pre () from /usr/local/bin/../lib/libcore-c3ca5d77d81b46c1-0.7-pre.so
#6  0x00007ffff791615e in unstable::lang::fail_::_9873ff47b9982218::_07pre ()
   from /usr/local/bin/../lib/libcore-c3ca5d77d81b46c1-0.7-pre.so
#7  0x00007ffff791f4da in unstable::lang::fail_bounds_check::_6fb13a2fe60974b::_07pre ()
   from /usr/local/bin/../lib/libcore-c3ca5d77d81b46c1-0.7-pre.so
#8  0x00007ffff6342c7d in middle::trans::cabi_x86_64::x86_64_tys::x86_64_ty::_cba3ba6a69dd212b::_07pre ()
   from /usr/local/bin/../lib/librustc-c84825241471686d-0.7-pre.so
#9  0x00007ffff6343544 in middle::trans::cabi_x86_64::x86_64_tys::anon::expr_fn_34991 ()
   from /usr/local/bin/../lib/librustc-c84825241471686d-0.7-pre.so
#10 0x00007ffff634374e in middle::trans::cabi_x86_64::__extensions__::meth_35015::compute_info::_63f5244ae590c1b6::_07pre ()
   from /usr/local/bin/../lib/librustc-c84825241471686d-0.7-pre.so
#11 0x00007ffff6346e3a in middle::trans::foreign::shim_types::_4ddc0485e8ab7a0::_07pre ()
   from /usr/local/bin/../lib/librustc-c84825241471686d-0.7-pre.so
#12 0x00007ffff634837d in middle::trans::foreign::trans_foreign_mod::build_foreign_fn::_cadbd7f24e409e5f::_07pre ()
   from /usr/local/bin/../lib/librustc-c84825241471686d-0.7-pre.so
#13 0x00007ffff6348060 in middle::trans::foreign::trans_foreign_mod::anon::expr_fn_35155 ()
   from /usr/local/bin/../lib/librustc-c84825241471686d-0.7-pre.so
#14 0x00007ffff62c146e in middle::trans::foreign::trans_foreign_mod::_f7e97aff93938699::_07pre ()
   from /usr/local/bin/../lib/librustc-c84825241471686d-0.7-pre.so
#15 0x00007ffff6155909 in middle::trans::base::trans_item::_e83b64764568c7be::_07pre ()
   from /usr/local/bin/../lib/librustc-c84825241471686d-0.7-pre.so
#16 0x00007ffff62c1253 in middle::trans::base::trans_mod::_d740d055c716f947::_07pre ()
   from /usr/local/bin/../lib/librustc-c84825241471686d-0.7-pre.so
#17 0x00007ffff62e1264 in middle::trans::base::trans_crate::_4f38ab124cab2e::_07pre ()
   from /usr/local/bin/../lib/librustc-c84825241471686d-0.7-pre.so
#18 0x00007ffff691ade4 in __morestack () from /usr/local/bin/../lib/librustc-c84825241471686d-0.7-pre.so
#19 0x00007ffff68d8c10 in driver::driver::compile_rest::anon::expr_fn_81655 ()
   from /usr/local/bin/../lib/librustc-c84825241471686d-0.7-pre.so
#20 0x00007ffff68d5c6a in driver::driver::compile_rest::_58068714615f2b::_07pre ()
   from /usr/local/bin/../lib/librustc-c84825241471686d-0.7-pre.so
#21 0x00007ffff691ade4 in __morestack () from /usr/local/bin/../lib/librustc-c84825241471686d-0.7-pre.so
#22 0x00007ffff68d8e28 in driver::driver::compile_upto::_3ccd839185751c4f::_07pre ()
   from /usr/local/bin/../lib/librustc-c84825241471686d-0.7-pre.so
#23 0x00007ffff68d926a in driver::driver::compile_input::_7bc345e59d22cba0::_07pre ()
   from /usr/local/bin/../lib/librustc-c84825241471686d-0.7-pre.so
#24 0x00007ffff690b820 in run_compiler::_aa88c3dc1384374::_07pre () from /usr/local/bin/../lib/librustc-c84825241471686d-0.7-pre.so
#25 0x00007ffff6918791 in monitor::anon::expr_fn_83847 () from /usr/local/bin/../lib/librustc-c84825241471686d-0.7-pre.so
#26 0x00007ffff6914cba in task::__extensions__::try_83368::anon::expr_fn_83631 ()
   from /usr/local/bin/../lib/librustc-c84825241471686d-0.7-pre.so
#27 0x00007ffff691ade4 in __morestack () from /usr/local/bin/../lib/librustc-c84825241471686d-0.7-pre.so
#28 0x00007ffff7997fbf in task::spawn::spawn_raw::make_child_wrapper::anon::expr_fn_12061 ()
   from /usr/local/bin/../lib/libcore-c3ca5d77d81b46c1-0.7-pre.so
#29 0x00007ffff7a19264 in __morestack () from /usr/local/bin/../lib/libcore-c3ca5d77d81b46c1-0.7-pre.so
#30 0x00007ffff5dfb5c4 in task_start_wrapper (a=0x7fffec2097b0) at /home/siege/src/rust2/src/rt/rust_task.cpp:162
#31 0x0000000000000000 in ?? ()

[yichoi]

at efd1438, no ICE but produce below messages

[jet@~/rust_latest/build] rustc test4.rs
error: linking with `cc` failed with code 1
note: cc arguments: -L/usr/local/lib/rustc/x86_64-unknown-linux-gnu/lib -m64 -o test4 test4.o -L/usr/local/lib/rustc/x86_64-unknown-linux-gnu/lib -lstd-6c65cf4b443341b1-0.7-pre -lrustrt -lrt -lpthread -lrt -ldl -lm -lmorestack -lrustrt -Wl,-rpath,$ORIGIN/../../../../usr/local/lib/rustc/x86_64-unknown-linux-gnu/lib -Wl,-rpath,/usr/local/lib/rustc/x86_64-unknown-linux-gnu/lib
note: test4.o: In function `test1__c_stack_shim':
test4.rc:(.text+0xb2): undefined reference to `test1'
test4.o: In function `test2__c_stack_shim':
test4.rc:(.text+0x16a): undefined reference to `test2'
collect2: error: ld returned 1 exit status

[jdm]

Sounds like it's no longer valid, in that case.

[SiegeLord]

It doesn't ICE, but it does generate wrong code. I submitted a new issue: #7415