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Casting subclass to parent of three class heirarchy causes crashes #3048

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pow2clk opened this issue Jul 22, 2020 · 8 comments
Open

Casting subclass to parent of three class heirarchy causes crashes #3048

pow2clk opened this issue Jul 22, 2020 · 8 comments
Labels
bug Bug, regression, crash check-in-clang See if this repros in clang as well crash DXC crashing or hitting an assert
Milestone
Dormant

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@pow2clk
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pow2clk commented Jul 22, 2020

The following shader which attempts to cast a variable of type C to its immediate parent, type B while passing an argument crashes DXC. If the only classes are B and C, this works fine. If there is a parent class to B, then it fails. Passing the argument as class C works fine as well.

struct A {
  float4 stuff;
};
struct B : A {
  float4 gimme() {return stuff;}
};
struct C : B {
  void dostuff() {stuff = 0;}
};
float4 f(B thing1) { // THIS IS THE PROBLEM
  return thing1.gimme();
}
float4 main() : SV_Target
{
  C thing2;
  thing2.stuff = float4(1,2,3,4);
  return f(thing2);
}
@pow2clk
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pow2clk commented Jul 22, 2020

A slightly altered shader gives a slightly different crash location that comes a bit earlier.

struct A {
  float4 stuff;
};
struct B : A {
  Texture2D tex;  // THIS IS WHAT'S NEW
  float4 gimme() {return stuff;}
};
struct C : B {
  void dostuff() {stuff = 0;}
};
float4 f(B thing1) { // THIS IS THE PROBLEM
  return thing1.gimme();
}
float4 main() : SV_Target
{
  C thing2;
  thing2.stuff = float4(1,2,3,4);
  return f(thing2);
}

@pow2clk
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pow2clk commented Jul 22, 2020

Both of these crashes are in codegen and seem to stem from the expectation that casts of this sort will be limited to simple types rather than structs.

@pow2clk pow2clk self-assigned this Nov 26, 2020
@damyanp damyanp added bug Bug, regression, crash crash DXC crashing or hitting an assert labels Jul 1, 2024
@llvm-beanz
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Compiler Explorer: https://godbolt.org/z/33nncaE4z

@damyanp damyanp added this to the Dormant milestone Jul 1, 2024
@damyanp damyanp moved this to Triaged in HLSL Triage Jul 1, 2024
@llvm-beanz llvm-beanz added the check-in-clang See if this repros in clang as well label Jul 1, 2024
@llvm-beanz
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Crash callstack:

(lldb) bt
* thread #1, name = 'dxc', stop reason = signal SIGABRT
    frame #0: 0x00007fffe64909fc libc.so.6 at pthread_kill.c:44
    frame #1: 0x00007fffe64909b0 libc.so.6 at pthread_kill.c:78
    frame #2: 0x00007fffe64909b0 libc.so.6 at pthread_kill.c:89
    frame #3: 0x00007fffe643c476 libc.so.6 at raise.c:26
    frame #4: 0x00007fffe64227f3 libc.so.6 at abort.c:79
    frame #5: 0x00007fffe642271b libc.so.6 __assert_fail_base.cold:`__assert_fail_base.cold + 15 at assert.c:92
    frame #6: 0x00007fffe6433e96 libc.so.6 at assert.c:101
    frame #7: 0x00007fffef77e577 libdxcompiler.so llvm::ArrayRef<llvm::Value*>::operator[]:`llvm::ArrayRef<llvm::Value*>::operator[](this=0x00007fffffff19c0, Index=0) const + 135 at ArrayRef.h:197
  * frame #8: 0x00007ffff14b5d19 libdxcompiler.so (anonymous namespace)::CGMSHLSLRuntime::ConvertAndStoreElements:`(anonymous namespace)::CGMSHLSLRuntime::ConvertAndStoreElements(this=0x00005555570bad30, CGF=0x00007fffffff6eb8, SrcVals=ArrayRef<llvm::Value *> @ 0x00007fffffff19c0, SrcQualTys=ArrayRef<clang::QualType> @ 0x00007fffffff19b0, DstPtrs=ArrayRef<llvm::Value *> @ 0x00007fffffff19e0, DstQualTys=ArrayRef<clang::QualType> @ 0x00007fffffff19f0) + 345 at CGHLSLMS.cpp:5752
    frame #9: 0x00007ffff1482768 libdxcompiler.so (anonymous namespace)::CGMSHLSLRuntime::EmitHLSLFlatConversionAggregateCopy:`(anonymous namespace)::CGMSHLSLRuntime::EmitHLSLFlatConversionAggregateCopy(this=0x00005555570bad30, CGF=0x00007fffffff6eb8, SrcPtr=0x000055555711bf28, SrcTy=QualType @ 0x00007fffffff1f68, DestPtr=0x000055555711f878, DestTy=QualType @ 0x00007fffffff1f60) + 4968 at CGHLSLMS.cpp:6050
    frame #10: 0x00007ffff13271a3 libdxcompiler.so (anonymous namespace)::AggExprEmitter::VisitCastExpr:`(anonymous namespace)::AggExprEmitter::VisitCastExpr(this=0x00007fffffff31c0, E=0x0000555557108be0) + 8915 at CGExprAgg.cpp:754
    frame #11: 0x00007ffff131cfa9 libdxcompiler.so clang::StmtVisitorBase<clang::make_ptr, (anonymous namespace)::AggExprEmitter, void>::VisitImplicitCastExpr:`clang::StmtVisitorBase<clang::make_ptr, (anonymous namespace)::AggExprEmitter, void>::VisitImplicitCastExpr(this=0x00007fffffff31c0, S=0x0000555557108be0) + 105 at StmtNodes.inc:399
    frame #12: 0x00007ffff13165da libdxcompiler.so clang::StmtVisitorBase<clang::make_ptr, (anonymous namespace)::AggExprEmitter, void>::Visit:`clang::StmtVisitorBase<clang::make_ptr, (anonymous namespace)::AggExprEmitter, void>::Visit(this=0x00007fffffff31c0, S=0x0000555557108be0) + 7098 at StmtNodes.inc:399
    frame #13: 0x00007ffff13126fc libdxcompiler.so (anonymous namespace)::AggExprEmitter::Visit:`(anonymous namespace)::AggExprEmitter::Visit(this=0x00007fffffff31c0, E=0x0000555557108be0) + 140 at CGExprAgg.cpp:105
    frame #14: 0x00007ffff1311e61 libdxcompiler.so clang::CodeGen::CodeGenFunction::EmitAggExpr:`clang::CodeGen::CodeGenFunction::EmitAggExpr(this=0x00007fffffff6eb8, E=0x0000555557108be0, Slot=AggValueSlot @ 0x00007fffffff3200) + 529 at CGExprAgg.cpp:1505
    frame #15: 0x00007ffff11c311b libdxcompiler.so clang::CodeGen::CodeGenFunction::EmitAnyExpr:`clang::CodeGen::CodeGenFunction::EmitAnyExpr(this=0x00007fffffff6eb8, E=0x0000555557108be0, aggSlot=AggValueSlot @ 0x00007fffffff3300, ignoreResult=false) + 747 at CGExpr.cpp:134
    frame #16: 0x00007ffff11c4309 libdxcompiler.so clang::CodeGen::CodeGenFunction::EmitAnyExprToTemp:`clang::CodeGen::CodeGenFunction::EmitAnyExprToTemp(this=0x00007fffffff6eb8, E=0x0000555557108be0) + 313 at CGExpr.cpp:147
    frame #17: 0x00007ffff147bea0 libdxcompiler.so (anonymous namespace)::CGMSHLSLRuntime::EmitHLSLOutParamConversionInit:`(anonymous namespace)::CGMSHLSLRuntime::EmitHLSLOutParamConversionInit(this=0x00005555570bad30, CGF=0x00007fffffff6eb8, FD=0x00005555571008b8, E=0x0000555557108bb0, castArgList=0x00007fffffff4c78, argList=0x00007fffffff4948, lifetimeCleanupList=0x00007fffffff49a0, TmpArgMap=0x00007fffffff48b8)> const&) + 4128 at CGHLSLMS.cpp:6343
    frame #18: 0x00007ffff11ecb64 libdxcompiler.so clang::CodeGen::CodeGenFunction::EmitCall:`clang::CodeGen::CodeGenFunction::EmitCall(this=0x00007fffffff6eb8, CalleeType=QualType @ 0x00007fffffff5198, Callee=0x000055555711f3e8, E=0x0000555557108bb0, ReturnValue=ReturnValueSlot @ 0x00007fffffff5190, TargetDecl=0x00005555571008b8, Chain=0x0000000000000000) + 4308 at CGExpr.cpp:3960
    frame #19: 0x00007ffff11eba6a libdxcompiler.so clang::CodeGen::CodeGenFunction::EmitCallExpr:`clang::CodeGen::CodeGenFunction::EmitCallExpr(this=0x00007fffffff6eb8, E=0x0000555557108bb0, ReturnValue=ReturnValueSlot @ 0x00007fffffff5448) + 2634 at CGExpr.cpp:3719
    frame #20: 0x00007ffff12261f9 libdxcompiler.so (anonymous namespace)::ScalarExprEmitter::VisitCallExpr:`(anonymous namespace)::ScalarExprEmitter::VisitCallExpr(this=0x00007fffffff5fb0, E=0x0000555557108bb0) + 505 at CGExprScalar.cpp:364
    frame #21: 0x00007ffff121c55e libdxcompiler.so clang::StmtVisitorBase<clang::make_ptr, (anonymous namespace)::ScalarExprEmitter, llvm::Value*>::Visit:`clang::StmtVisitorBase<clang::make_ptr, (anonymous namespace)::ScalarExprEmitter, llvm::Value*>::Visit(this=0x00007fffffff5fb0, S=0x0000555557108bb0) + 6702 at StmtNodes.inc:305
    frame #22: 0x00007ffff120cb9d libdxcompiler.so (anonymous namespace)::ScalarExprEmitter::Visit:`(anonymous namespace)::ScalarExprEmitter::Visit(this=0x00007fffffff5fb0, E=0x0000555557108bb0) + 2877 at CGExprScalar.cpp:230
    frame #23: 0x00007ffff120bf1f libdxcompiler.so clang::CodeGen::CodeGenFunction::EmitScalarExpr:`clang::CodeGen::CodeGenFunction::EmitScalarExpr(this=0x00007fffffff6eb8, E=0x0000555557108bb0, IgnoreResultAssign=false) + 335 at CGExprScalar.cpp:3926
    frame #24: 0x00007ffff133f554 libdxcompiler.so clang::CodeGen::CodeGenFunction::EmitReturnStmt:`clang::CodeGen::CodeGenFunction::EmitReturnStmt(this=0x00007fffffff6eb8, S=0x0000555557108c00) + 2340 at CGStmt.cpp:1164
    frame #25: 0x00007ffff133b8a3 libdxcompiler.so clang::CodeGen::CodeGenFunction::EmitStmt:`clang::CodeGen::CodeGenFunction::EmitStmt(this=0x00007fffffff6eb8, S=0x0000555557108c00) + 1971 at CGStmt.cpp:138
    frame #26: 0x00007ffff1342f1c libdxcompiler.so clang::CodeGen::CodeGenFunction::EmitCompoundStmtWithoutScope:`clang::CodeGen::CodeGenFunction::EmitCompoundStmtWithoutScope(this=0x00007fffffff6eb8, S=0x0000555557108c18, GetLast=false, AggSlot=AggValueSlot @ 0x00007fffffff6700) + 380 at CGStmt.cpp:305
    frame #27: 0x00007ffff117db21 libdxcompiler.so clang::CodeGen::CodeGenFunction::EmitFunctionBody:`clang::CodeGen::CodeGenFunction::EmitFunctionBody(this=0x00007fffffff6eb8, Args=0x00007fffffff6ba0, Body=0x0000555557108c18) + 161 at CodeGenFunction.cpp:811
    frame #28: 0x00007ffff117ec71 libdxcompiler.so clang::CodeGen::CodeGenFunction::GenerateCode:`clang::CodeGen::CodeGenFunction::GenerateCode(this=0x00007fffffff6eb8, GD=GlobalDecl @ 0x00007fffffff6c58, Fn=0x0000555557109f58, FnInfo=0x00005555570fe9f0) + 4065 at CodeGenFunction.cpp:932
    frame #29: 0x00007ffff0f768fb libdxcompiler.so clang::CodeGen::CodeGenModule::EmitGlobalFunctionDefinition:`clang::CodeGen::CodeGenModule::EmitGlobalFunctionDefinition(this=0x00005555570b86d0, GD=GlobalDecl @ 0x00007fffffff7978, GV=0x0000555557109f58) + 3483 at CodeGenModule.cpp:2620
    frame #30: 0x00007ffff0f70157 libdxcompiler.so clang::CodeGen::CodeGenModule::EmitGlobalDefinition:`clang::CodeGen::CodeGenModule::EmitGlobalDefinition(this=0x00005555570b86d0, GD=GlobalDecl @ 0x00007fffffff7b28, GV=0x0000000000000000) + 1463 at CodeGenModule.cpp:1603
    frame #31: 0x00007ffff0f747f5 libdxcompiler.so clang::CodeGen::CodeGenModule::EmitGlobal:`clang::CodeGen::CodeGenModule::EmitGlobal(this=0x00005555570b86d0, GD=GlobalDecl @ 0x00007fffffff7d28) + 1749 at CodeGenModule.cpp:1451
    frame #32: 0x00007ffff0f7aa2e libdxcompiler.so clang::CodeGen::CodeGenModule::EmitTopLevelDecl:`clang::CodeGen::CodeGenModule::EmitTopLevelDecl(this=0x00005555570b86d0, D=0x0000555557108680) + 462 at CodeGenModule.cpp:3392
    frame #33: 0x00007ffff15b69f8 libdxcompiler.so (anonymous namespace)::CodeGeneratorImpl::HandleTopLevelDecl:`(anonymous namespace)::CodeGeneratorImpl::HandleTopLevelDecl(this=0x00005555570b3680, DG=DeclGroupRef @ 0x00007fffffff7f30) + 360 at ModuleBuilder.cpp:134
    frame #34: 0x00007ffff0e85559 libdxcompiler.so clang::BackendConsumer::HandleTopLevelDecl:`clang::BackendConsumer::HandleTopLevelDecl(this=0x00005555570b3580, D=DeclGroupRef @ 0x00007fffffff8018) + 505 at CodeGenAction.cpp:120
    frame #35: 0x00007ffff38b1262 libdxcompiler.so clang::ParseAST:`clang::ParseAST(S=0x00005555570b4240, PrintStats=false, SkipFunctionBodies=false) + 1746 at ParseAST.cpp:148
    frame #36: 0x00007ffff16370e5 libdxcompiler.so clang::ASTFrontendAction::ExecuteAction:`clang::ASTFrontendAction::ExecuteAction(this=0x00007fffffffa1e0) + 725 at FrontendAction.cpp:554
    frame #37: 0x00007ffff0e82393 libdxcompiler.so clang::CodeGenAction::ExecuteAction:`clang::CodeGenAction::ExecuteAction(this=0x00007fffffffa1e0) + 3715 at CodeGenAction.cpp:807
    frame #38: 0x00007ffff16365cf libdxcompiler.so clang::FrontendAction::Execute:`clang::FrontendAction::Execute(this=0x00007fffffffa1e0) + 303 at FrontendAction.cpp:455
    frame #39: 0x00007fffef57d743 libdxcompiler.so DxcCompiler::Compile:`DxcCompiler::Compile(this=0x00005555570738a0, pSource=0x00007fffffffc970, pArguments=0x0000555557074220, argCount=5 0x00000005, pIncludeHandler=0x0000555557073570, riid=0x0000555555b06c40, ppResult=0x00007fffffffbe60) + 22435 at dxcompilerobj.cpp:984
    frame #40: 0x00007fffef569450 libdxcompiler.so hlsl::DxcCompilerAdapter::WrapCompile:`hlsl::DxcCompilerAdapter::WrapCompile(this=0x0000555557073cc0, bPreprocess=NO, pSource=0x0000555557073d70, pSourceName=L"crash.hlsl", pEntryPoint=L"main", pTargetProfile=L"vs_6_0", pArguments=0x0000555557073550, argCount=2 0x00000002, pDefines=0x00007fffffffd7f0, defineCount=0 0x00000000, pIncludeHandler=0x0000555557073570, ppResult=0x00007fffffffd320, ppDebugBlobName=0x0000000000000000, ppDebugBlob=0x0000000000000000) + 4288 at dxcompilerobj.cpp:1845
    frame #41: 0x00007fffef56afa8 libdxcompiler.so hlsl::DxcCompilerAdapter::CompileWithDebug:`hlsl::DxcCompilerAdapter::CompileWithDebug(this=0x0000555557073cc0, pSource=0x0000555557073d70, pSourceName=L"crash.hlsl", pEntryPoint=L"main", pTargetProfile=L"vs_6_0", pArguments=0x0000555557073550, argCount=2 0x00000002, pDefines=0x00007fffffffd7f0, defineCount=0 0x00000000, pIncludeHandler=0x0000555557073570, ppResult=0x00007fffffffd320, ppDebugBlobName=0x0000000000000000, ppDebugBlob=0x0000000000000000) + 360 at dxcompilerobj.cpp:1748
    frame #42: 0x00007fffef5724e8 libdxcompiler.so hlsl::DxcCompilerAdapter::Compile:`hlsl::DxcCompilerAdapter::Compile(this=0x0000555557073cc0, pSource=0x0000555557073d70, pSourceName=L"crash.hlsl", pEntryPoint=L"main", pTargetProfile=L"vs_6_0", pArguments=0x0000555557073550, argCount=2 0x00000002, pDefines=0x00007fffffffd7f0, defineCount=0 0x00000000, pIncludeHandler=0x0000555557073570, ppResult=0x00007fffffffd320) + 184 at dxcompileradapter.h:75
    frame #43: 0x0000555555e15a30 dxc DxcContext::Compile:`DxcContext::Compile(this=0x00007fffffffd650) + 5344 at dxc.cpp:874
    frame #44: 0x0000555555e1bce8 dxc dxc::main:`dxc::main(argc=4 0x00000004, argv_=0x00007fffffffe338) + 2744 at dxc.cpp:1502
    frame #45: 0x0000555555e0ac52 dxc main:`main(argc=4 0x00000004, argv_=0x00007fffffffe338) + 34 at dxcmain.cpp:19
    frame #46: 0x00007fffe6423d90 libc.so.6 __libc_start_call_main:`__libc_start_call_main(main=(dxc`main at dxcmain.cpp:18), argc=4 0x00000004, argv=0x00007fffffffe338) + 128 at libc_start_call_main.h:58
    frame #47: 0x00007fffe6423e40 libc.so.6 __libc_start_main_impl:`__libc_start_main_impl(main=(dxc`main at dxcmain.cpp:18), argc=4 0x00000004, argv=0x00007fffffffe338, init=0x00007ffff7ffd040, fini=<unavailable>, rtld_fini=<unavailable>, stack_end=0x00007fffffffe328) + 128 at libc-start.c:392
    frame #48: 0x0000555555de25e5 dxc _start:`_start + 37

@llvm-beanz
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The crash here is weird, it is crashing codegen-ing a flat conversion, but it should be (and is in the AST) a derived to base conversion.

@llvm-beanz
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Caused by: #2312

Which treats derived-to-base as a flat conversion. That could cause all sorts of things to break.

@devshgraphicsprogramming
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devshgraphicsprogramming commented Jul 5, 2024 •
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btw what happens if you make the f() take an in or inout ?

@llvm-beanz
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Derived to base conversions are disallowed on out and inout parameters: https://godbolt.org/z/P1GP7sYns

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bug Bug, regression, crash check-in-clang See if this repros in clang as well crash DXC crashing or hitting an assert
Projects
HLSL Triage
Status: Triaged
Milestone
Dormant
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@devshgraphicsprogramming @damyanp @llvm-beanz @pow2clk