Eric_Wing
November 15, 2016, 9:31pm
1
Hi, I have encountered an internal Swift compiler assertion/bug when
The assertion is:
It seems to be related to calling a bridged C function with a C struct
I posted on the swift-arm group. hpux735 said this is deeper into the
I filed the bug here:
opened 07:58PM - 20 Sep 16 UTC
closed 12:45AM - 24 Jan 18 UTC
bug
Compiler
arm
compiler crash
3.0Regression
armv7
| | |
|------------------|-----------------|…
|Previous ID | SR-2706 |
|Radar | None |
|Original Reporter | ewmailing (JIRA User) |
|Type | Bug |
|Status | Closed |
|Resolution | Duplicate |
Attachment: [Download](https://user-images.githubusercontent.com/2727770/164961611-f17e1d47-367e-4c17-87e8-33edf57104c9.gz)
<details>
<summary>Environment</summary>
Raspberry Pi 2 (32-bit armv7) running Raspbian Jessie
Built Swift 3 from source. (A bunch of components failed to build, but the Swift compiler got built.)
I've tested this code on Mac, iOS, Linux x86_64, and Android. The code compiles and works for all these other platforms. So this bug seems to be arm specific. (iOS and Android use x86_64 platforms to cross-compile, whereas I am directly compiling on the arm device to generate arm binaries which is the big difference there.)
</details>
<details>
<summary>Additional Detail from JIRA</summary>
| | |
|------------------|-----------------|
|Votes | 1 |
|Component/s | Compiler |
|Labels | Bug, 3.0Regression, CompilerCrash, arm, armv7 |
|Assignee | @compnerd |
|Priority | Medium |
md5: 8f2abfe8f8520f432ecc0169bea57a0a
</details>
**Issue Description:**
I'm trying to use Swift 3 on a Raspberry Pi 2 (armv7). On code that used to compile in Swift 2.3, and code that currently compiles correctly on Swift 3 for Mac/Xcode 8, Linux x86_64, and for Android, I'm getting a compiler assertion failure and stack dump.
=======
``` java
swift: /home/pi/Source/SWIFT/swift/lib/IRGen/GenCall.cpp:1886: void swift::irgen::CallEmission::setArgs(swift::irgen::Explosion &, swift::irgen::WitnessMetadata *): Assertion `LastArgWritten >= adjustedArg.size()' failed.
Stack dump:
0. Program arguments: /home/pi/swift3/usr/bin/swift -frontend -c -DBLURRR_PLATFORM_LINUX -DBLURRR_PLATFORM_LINUX=1 -DBLURRR_PLATFORM_RASPBERRY_PI -DBLURRR_PLATFORM_RASPBERRY_PI=1 -DBLURRR_PLATFORM_RASPBIAN -DBLURRR_PLATFORM_RASPBIAN=1 -I/home/pi/Source/Blurrr/Release/BlurrrSDKRaspberryPi/Libraries/SDK/Raspbian/C/include/BlurrrCore -I/home/pi/Source/Blurrr/Release/BlurrrSDKRaspberryPi/Libraries/SDK/Raspbian/C/include/ALmixer -I/home/pi/Source/Blurrr/Release/BlurrrSDKRaspberryPi/Libraries/SDK/Raspbian/C/include/AL -I/home/pi/Source/Blurrr/Release/BlurrrSDKRaspberryPi/Libraries/SDK/Raspbian/C/include/chipmunk -I/home/pi/Source/Blurrr/Release/BlurrrSDKRaspberryPi/Libraries/SDK/Raspbian/C/include/SDL_ttf -I/home/pi/Source/Blurrr/Release/BlurrrSDKRaspberryPi/Libraries/SDK/Raspbian/C/include/SDL_image -I/home/pi/Source/Blurrr/Release/BlurrrSDKRaspberryPi/Libraries/SDK/Raspbian/C/include/SDL2 -I/home/pi/Source/Blurrr/Examples/flappyblurrrswift/source -target armv7-unknown-linux-gnueabihf -primary-file /home/pi/Source/Blurrr/Examples/flappyblurrrswift/source/BlurrrMain.swift /home/pi/Source/Blurrr/Examples/flappyblurrrswift/source/main.swift /home/pi/Source/Blurrr/Examples/flappyblurrrswift/source/BlurrrMain.swift -import-objc-header /home/pi/Source/Blurrr/Examples/flappyblurrrswift/source/MySwiftBridgingHeader.h -emit-module -module-name FlappyBlurrrSwift -o CMakeFiles/FlappyBlurrrSwift.dir/source/BlurrrMain.swift.o
1. While emitting IR SIL function @_TF17FlappyBlurrrSwift27Flappy_UpdateGroundPositionFTVs6UInt329base_timeS0_12current_timeS0__T_ for 'Flappy_UpdateGroundPosition' at /home/pi/Source/Blurrr/Examples/flappyblurrrswift/source/BlurrrMain.swift:1137:1
CMakeFiles/FlappyBlurrrSwift.dir/build.make:78: recipe for target 'CMakeFiles/FlappyBlurrrSwift.dir/source/BlurrrMain.swift.o' failed
make[2]: *** [CMakeFiles/FlappyBlurrrSwift.dir/source/BlurrrMain.swift.o] Aborted
CMakeFiles/Makefile2:102: recipe for target 'CMakeFiles/FlappyBlurrrSwift.dir/all' failed
make[1]: *** [CMakeFiles/FlappyBlurrrSwift.dir/all] Error 2
Makefile:149: recipe for target 'all' failed
make: *** [all] Error 2
```
\_\_\_\_\_\_
I think Swift is having trouble with C-bindings. As far as I can tell, the compiler is breaking with stuff related to a type called cpVect defined as:
``` java
typedef struct cpVect{cpFloat x,y;} cpVect;
```
My code typically used a convenience function provided by the library defined as:
``` java
/// Convenience constructor for cpVect structs.
static inline cpVect cpv(const cpFloat x, const cpFloat y)
{
cpVect v = {x, y};
return v;
}
```
The simple pattern that seems to trigger this seems to come down to:
``` java
let pos_vec = cpv(0.0, 0.0);
cpBodySetPosition(body, pos_vec); // also tried explicit nil for body to try to suggest that it is the cpVect causing the problem
```
~~I'm attaching my slightly modified file trying to isolate the problem. It is line 1178 that trips up the compiler. (But if I comment this out, there are other instances of the code that trigger this.)~~
~~The full source code is in BlurrrMain.swift which can be found here.~~
~~bitbucket.org/blurrr/flappyblurrrswift/src~~
~~The project has a bunch of dependencies. I'm developing a cross-platform SDK that makes this easy to build. I'm happy to give you access to the SDK if it helps you debug this.~~
\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_
# Update:
# \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_
I have new/additional information for this bug.
I have created a minimal, reproducible test case that can demonstrate this bug. It seems to be related to using a bridged C struct and function in Swift.
So in Swift, I have a simple function like which will cause the compiler to hit the assertion failure:
``` java
func BlurrrMain() -> Int32
{
let body_vec: fakeVect = fakeVect(x:1.1, y:2.2);
fakeSetPosition(body_vec);
return 0;
}
```
In C, I have a header like so:
``` java
#ifndef MYCTYPES_H
#define MYCTYPES_H
struct fakeVect
{
float x;
float y;
};
typedef struct fakeVect fakeVect;
void fakeSetPosition(fakeVect vec);
#endif
```
I make sure to include this header in my bridging header.
Compiling this on Pi is sufficient enough to trigger the Swift compiler assertion.
I know this code builds and works for Mac, iOS, Linux x86_64, and Android. I’m only having this problem with the Pi.
As a reminder, the assertion says:
``` java
swift: /home/pi/Source/SWIFT3ARM/build-swift/swift/lib/IRGen/GenCall.cpp:1864: void swift::irgen::CallEmission::setArgs(swift::irgen::Explosion &, swift::irgen::WitnessMetadata *): Assertion `LastArgWritten >= adjustedArg.size()' failed.
```
In this case, LastArgWritten is 2 and adustedArg.size() is 3
I am attaching a reproducible project called SwiftArmCompileBug.tar.gz.
There is a build.sh script to help build it, but if you want to jump directly to the failing part, the command is the 3rd one which is:
``` java
swift -frontend -c -target armv7-unknown-linux-gnueabihf -primary-file BlurrrMain.swift main.swift BlurrrMain.swift -import-objc-header MySwiftBridgingHeader.h -emit-module -module-name MyBlurrrProject -o BlurrrMain.swift.o
```
It also contains the simple reproducible test case with a build.sh script.
Thanks,