Assertion failure building code that uses blocks (qsort_b_test.c)

[bsdjhb]

While merging in an upstream change from FreeBSD to add a test for qsort_b(3), I get the following crash:

Assertion failed: ((2 * CGM.getIntSize()).isMultipleOf(CGM.getPointerAlign())), function initializeForBlockHeader, file /home/john/work/cheri/git/llvm-project/clang/lib/CodeGen/CGBlocks.cpp, line 500.
 #0 0x000000000381b8f7 llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) (/home/john/work/cheri/output/sdk/bin/clang+0x381b8f7)
 #1 0x000000000381bcd8 __assert (/home/john/work/cheri/output/sdk/bin/clang+0x381bcd8)
 #2 0x0000000003b352cb computeBlockInfo(clang::CodeGen::CodeGenModule&, clang::CodeGen::CodeGenFunction*, clang::CodeGen::CGBlockInfo&) CGBlocks.cpp:0:0
 #3 0x0000000003b33a80 clang::CodeGen::CodeGenFunction::EmitBlockLiteral(clang::BlockExpr const*) (/home/john/work/cheri/output/sdk/bin/clang+0x3b33a80)
 #4 0x0000000003b6e28b clang::CodeGen::CodeGenFunction::EmitScalarExpr(clang::Expr const*, bool) (/home/john/work/cheri/output/sdk/bin/clang+0x3b6e28b)
 #5 0x0000000003b453f8 clang::CodeGen::CodeGenFunction::EmitAnyExpr(clang::Expr const*, clang::CodeGen::AggValueSlot, bool) (/home/john/work/cheri/output/sdk/bin/clang+0x3b453f8)
 #6 0x0000000003b45e5b clang::CodeGen::CodeGenFunction::EmitAnyExprToTemp(clang::Expr const*) (/home/john/work/cheri/output/sdk/bin/clang+0x3b45e5b)
 #7 0x0000000003b231bc clang::CodeGen::CodeGenFunction::EmitCallArg(clang::CodeGen::CallArgList&, clang::Expr const*, clang::QualType) (/home/john/work/cheri/output/sdk/bin/clang+0x3b231bc)
 #8 0x0000000003b21ee6 clang::CodeGen::CodeGenFunction::EmitCallArgs(clang::CodeGen::CallArgList&, clang::CodeGen::CodeGenFunction::PrototypeWrapper, llvm::iterator_range<clang::Stmt::CastIterator<clang::Expr, clang::Expr const* const, clang::Stmt const* const> >, clang::CodeGen::CodeGenFunction::AbstractCallee, unsigned int, clang::CodeGen::CodeGenFunction::EvaluationOrder) (/home/john/work/cheri/output/sdk/bin/clang+0x3b21ee6)
 #9 0x0000000003b68200 clang::CodeGen::CodeGenFunction::EmitCall(clang::QualType, clang::CodeGen::CGCallee const&, clang::CallExpr const*, clang::CodeGen::ReturnValueSlot, llvm::Value*) (/home/john/work/cheri/output/sdk/bin/clang+0x3b68200)
#10 0x0000000003b67233 clang::CodeGen::CodeGenFunction::EmitCallExpr(clang::CallExpr const*, clang::CodeGen::ReturnValueSlot) (/home/john/work/cheri/output/sdk/bin/clang+0x3b67233)
#11 0x0000000003b7ec33 (anonymous namespace)::ScalarExprEmitter::VisitCallExpr(clang::CallExpr const*) CGExprScalar.cpp:0:0
#12 0x0000000003b6e28b clang::CodeGen::CodeGenFunction::EmitScalarExpr(clang::Expr const*, bool) (/home/john/work/cheri/output/sdk/bin/clang+0x3b6e28b)
#13 0x0000000003b453f8 clang::CodeGen::CodeGenFunction::EmitAnyExpr(clang::Expr const*, clang::CodeGen::AggValueSlot, bool) (/home/john/work/cheri/output/sdk/bin/clang+0x3b453f8)
#14 0x0000000003b45399 clang::CodeGen::CodeGenFunction::EmitIgnoredExpr(clang::Expr const*) (/home/john/work/cheri/output/sdk/bin/clang+0x3b45399)
#15 0x0000000003ba9082 clang::CodeGen::CodeGenFunction::EmitStmt(clang::Stmt const*, llvm::ArrayRef<clang::Attr const*>) (/home/john/work/cheri/output/sdk/bin/clang+0x3ba9082)
#16 0x0000000003ba9c01 clang::CodeGen::CodeGenFunction::EmitSimpleStmt(clang::Stmt const*, llvm::ArrayRef<clang::Attr const*>) (/home/john/work/cheri/output/sdk/bin/clang+0x3ba9c01)
#17 0x0000000003ba8f94 clang::CodeGen::CodeGenFunction::EmitStmt(clang::Stmt const*, llvm::ArrayRef<clang::Attr const*>) (/home/john/work/cheri/output/sdk/bin/clang+0x3ba8f94)
#18 0x0000000003bac913 clang::CodeGen::CodeGenFunction::EmitForStmt(clang::ForStmt const&, llvm::ArrayRef<clang::Attr const*>) (/home/john/work/cheri/output/sdk/bin/clang+0x3bac913)
#19 0x0000000003bb59b0 clang::CodeGen::CodeGenFunction::EmitCompoundStmtWithoutScope(clang::CompoundStmt const&, bool, clang::CodeGen::AggValueSlot) (/home/john/work/cheri/output/sdk/bin/clang+0x3bb59b0)
#20 0x0000000003b9ac88 clang::CodeGen::CodeGenFunction::GenerateCode(clang::GlobalDecl, llvm::Function*, clang::CodeGen::CGFunctionInfo const&) (/home/john/work/cheri/output/sdk/bin/clang+0x3b9ac88)
#21 0x0000000003ab88d2 clang::CodeGen::CodeGenModule::EmitGlobalFunctionDefinition(clang::GlobalDecl, llvm::GlobalValue*) (/home/john/work/cheri/output/sdk/bin/clang+0x3ab88d2)
#22 0x0000000003ab10cf clang::CodeGen::CodeGenModule::EmitGlobalDefinition(clang::GlobalDecl, llvm::GlobalValue*) (/home/john/work/cheri/output/sdk/bin/clang+0x3ab10cf)
#23 0x0000000003aa4333 clang::CodeGen::CodeGenModule::EmitDeferred() (/home/john/work/cheri/output/sdk/bin/clang+0x3aa4333)
#24 0x0000000003aa4363 clang::CodeGen::CodeGenModule::EmitDeferred() (/home/john/work/cheri/output/sdk/bin/clang+0x3aa4363)
#25 0x0000000003aa4363 clang::CodeGen::CodeGenModule::EmitDeferred() (/home/john/work/cheri/output/sdk/bin/clang+0x3aa4363)
#26 0x0000000003aa290c clang::CodeGen::CodeGenModule::Release() (/home/john/work/cheri/output/sdk/bin/clang+0x3aa290c)
#27 0x0000000004375354 (anonymous namespace)::CodeGeneratorImpl::HandleTranslationUnit(clang::ASTContext&) ModuleBuilder.cpp:0:0
#28 0x0000000004372a89 clang::BackendConsumer::HandleTranslationUnit(clang::ASTContext&) CodeGenAction.cpp:0:0
#29 0x0000000004b5cae4 clang::ParseAST(clang::Sema&, bool, bool) (/home/john/work/cheri/output/sdk/bin/clang+0x4b5cae4)
#30 0x00000000042a4083 clang::FrontendAction::Execute() (/home/john/work/cheri/output/sdk/bin/clang+0x42a4083)
#31 0x000000000422689f clang::CompilerInstance::ExecuteAction(clang::FrontendAction&) (/home/john/work/cheri/output/sdk/bin/clang+0x422689f)
#32 0x000000000436c37a clang::ExecuteCompilerInvocation(clang::CompilerInstance*) (/home/john/work/cheri/output/sdk/bin/clang+0x436c37a)
#33 0x0000000001fe485a cc1_main(llvm::ArrayRef<char const*>, char const*, void*) (/home/john/work/cheri/output/sdk/bin/clang+0x1fe485a)
#34 0x0000000001fe2147 ExecuteCC1Tool(llvm::SmallVectorImpl<char const*>&) driver.cpp:0:0
#35 0x00000000040e7b17 void llvm::function_ref<void ()>::callback_fn<clang::driver::CC1Command::Execute(llvm::ArrayRef<llvm::Optional<llvm::StringRef> >, std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> >*, bool*) const::$_1>(long) Job.cpp:0:0
#36 0x0000000003791130 llvm::CrashRecoveryContext::RunSafely(llvm::function_ref<void ()>) (/home/john/work/cheri/output/sdk/bin/clang+0x3791130)
#37 0x00000000040e762b clang::driver::CC1Command::Execute(llvm::ArrayRef<llvm::Optional<llvm::StringRef> >, std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> >*, bool*) const (/home/john/work/cheri/output/sdk/bin/clang+0x40e762b)
#38 0x00000000040b7665 clang::driver::Compilation::ExecuteCommand(clang::driver::Command const&, clang::driver::Command const*&) const (/home/john/work/cheri/output/sdk/bin/clang+0x40b7665)
#39 0x00000000040b7a99 clang::driver::Compilation::ExecuteJobs(clang::driver::JobList const&, llvm::SmallVectorImpl<std::__1::pair<int, clang::driver::Command const*> >&) const (/home/john/work/cheri/output/sdk/bin/clang+0x40b7a99)
#40 0x00000000040cc17c clang::driver::Driver::ExecuteCompilation(clang::driver::Compilation&, llvm::SmallVectorImpl<std::__1::pair<int, clang::driver::Command const*> >&) (/home/john/work/cheri/output/sdk/bin/clang+0x40cc17c)
PLEASE submit a bug report to https://github.com/CTSRD-CHERI/llvm-project/issues and include the crash backtrace, preprocessed source, and associated run script.
If you built clang from source, please provide a reduced test case by running:
        $LLVM_BUILD_DIR/bin/creduce_crash_testcase.py <reproducer>.sh
Stack dump:
0.      Program arguments: /home/john/work/cheri/output/sdk/bin/clang -target riscv64-unknown-freebsd14.0 --sysroot=/usr/obj/cheri/cheribsd-riscv64-purecap-build/usr/home/john/work/cheri/git/cheribsd/riscv.riscv64c/tmp -B/usr/obj/cheri/cheribsd-riscv64-purecap-build/usr/home/john/work/cheri/git/cheribsd/riscv.riscv64c/tmp/usr/bin -O2 -pipe -fno-common -march=rv64imafdcxcheri -mabi=l64pc128d -D__LP64__=1 -D__HAVE_FENV -D__HAVE_LONG_DOUBLE -I/usr/home/john/work/cheri/git/cheribsd/lib/libc/tests/stdlib -fPIE -mno-relax -g -gz=zlib -MD -MF.depend.qsort_b_test.qsort_b_test.o -MTqsort_b_test.o -std=gnu99 -Wno-format-zero-length -nobuiltininc -idirafter /usr/home/john/work/cheri/output/sdk/lib/clang/13.0.0/include -Werror=implicit-function-declaration -Wsystem-headers -Werror -Wall -Wno-format-y2k -Wno-uninitialized -Wno-pointer-sign -Wno-error=pass-failed -Wno-empty-body -Wno-string-plus-int -Wno-unused-const-variable -Wno-error=unused-but-set-variable -Wno-tautological-compare -Wno-unused-value -Wno-parentheses-equality -Wno-unused-function -Wno-enum-conversion -Wno-unused-local-typedef -Wno-address-of-packed-member -Wno-switch -Wno-switch-enum -Wno-knr-promoted-parameter -Qunused-arguments -fblocks -c /usr/home/john/work/cheri/git/cheribsd/lib/libc/tests/stdlib/qsort_b_test.c -o qsort_b_test.o
1.      <eof> parser at end of file
2.      Per-file LLVM IR generation
3.      /usr/home/john/work/cheri/git/cheribsd/lib/libc/tests/stdlib/qsort_b_test.c:38:1 <Spelling=<scratch space>:57:1>: Generating code for declaration 'atfu_qsort_b_test_body'
4.      /usr/home/john/work/cheri/git/cheribsd/lib/libc/tests/stdlib/qsort_b_test.c:44:33: LLVM IR generation of compound statement ('{}')

I will see if I can get a smaller test case.

[bsdjhb]

void atfu_qsort_b_test_body() {
  ^{
  };
}

[bsdjhb]

The sh file:

# Crash reproducer for clang version 13.0.0 ([email protected]:CTSRD-CHERI/llvm-project.git f06202e95b8ba0ca0655ab5753f0fff070007e1f)
# Driver args: "--target=riscv64-unknown-freebsd14.0" "--sysroot=/usr/obj/cheri/cheribsd-riscv64-purecap-build/usr/home/john/work/cheri/git/cheribsd/riscv.riscv64c/tmp" "-B" "/usr/obj/cheri/cheribsd-riscv64-purecap-build/usr/home/john/work/cheri/git/cheribsd/riscv.riscv64c/tmp/usr/bin" "-O2" "-pipe" "-fno-common" "-march=rv64imafdcxcheri" "-mabi=l64pc128d" "-D" "__LP64__=1" "-D" "__HAVE_FENV" "-D" "__HAVE_LONG_DOUBLE" "-I" "/usr/home/john/work/cheri/git/cheribsd/lib/libc/tests/stdlib" "-fPIE" "-mno-relax" "-g" "-gz=zlib" "-MD" "-MF" ".depend.qsort_b_test.qsort_b_test.o" "-MT" "qsort_b_test.o" "-std=gnu99" "-Wno-format-zero-length" "-nobuiltininc" "-idirafter" "/usr/home/john/work/cheri/output/sdk/lib/clang/13.0.0/include" "-Werror=implicit-function-declaration" "-Wsystem-headers" "-Werror" "-Wall" "-Wno-format-y2k" "-Wno-uninitialized" "-Wno-pointer-sign" "-Wno-error=pass-failed" "-Wno-empty-body" "-Wno-string-plus-int" "-Wno-unused-const-variable" "-Wno-error=unused-but-set-variable" "-Wno-tautological-compare" "-Wno-unused-value" "-Wno-parentheses-equality" "-Wno-unused-function" "-Wno-enum-conversion" "-Wno-unused-local-typedef" "-Wno-address-of-packed-member" "-Wno-switch" "-Wno-switch-enum" "-Wno-knr-promoted-parameter" "-Qunused-arguments" "-fblocks" "-c" "/usr/home/john/work/cheri/git/cheribsd/lib/libc/tests/stdlib/qsort_b_test.c" "-o" "qsort_b_test.o"
# Original command:  "/usr/home/john/work/cheri/output/sdk/bin/clang-13" "-cc1" "-triple" "riscv64-unknown-freebsd14.0" "-emit-obj" "--mrelax-relocations" "-disable-free" "-main-file-name" "qsort_b_test.c" "-mrelocation-model" "pic" "-pic-level" "2" "-pic-is-pie" "-mframe-pointer=none" "-ffp-contract=on" "-fno-rounding-math" "-mconstructor-aliases" "-munwind-tables" "-target-feature" "+m" "-target-feature" "+a" "-target-feature" "+f" "-target-feature" "+d" "-target-feature" "+c" "-target-feature" "+xcheri" "-target-feature" "-relax" "-target-feature" "+cap-mode" "-target-feature" "-xcheri-rvc" "-target-feature" "-save-restore" "-target-abi" "l64pc128d" "-msmall-data-limit" "8" "-debug-info-kind=standalone" "-dwarf-version=4" "-debugger-tuning=gdb" "--compress-debug-sections=zlib" "-fcoverage-compilation-dir=/usr/obj/cheri/cheribsd-riscv64-purecap-build/usr/home/john/work/cheri/git/cheribsd/riscv.riscv64c/lib/libc/tests/stdlib" "-nobuiltininc" "-resource-dir" "/usr/home/john/work/cheri/output/sdk/lib/clang/13.0.0" "-dependency-file" ".depend.qsort_b_test.qsort_b_test.o" "-MT" "qsort_b_test.o" "-sys-header-deps" "-idirafter" "/usr/home/john/work/cheri/output/sdk/lib/clang/13.0.0/include" "-D" "__LP64__=1" "-D" "__HAVE_FENV" "-D" "__HAVE_LONG_DOUBLE" "-I" "/usr/home/john/work/cheri/git/cheribsd/lib/libc/tests/stdlib" "-isysroot" "/usr/obj/cheri/cheribsd-riscv64-purecap-build/usr/home/john/work/cheri/git/cheribsd/riscv.riscv64c/tmp" "-O2" "-Wno-format-zero-length" "-Werror=implicit-function-declaration" "-Wsystem-headers" "-Werror" "-Wall" "-Wno-format-y2k" "-Wno-uninitialized" "-Wno-pointer-sign" "-Wno-error=pass-failed" "-Wno-empty-body" "-Wno-string-plus-int" "-Wno-unused-const-variable" "-Wno-error=unused-but-set-variable" "-Wno-tautological-compare" "-Wno-unused-value" "-Wno-parentheses-equality" "-Wno-unused-function" "-Wno-enum-conversion" "-Wno-unused-local-typedef" "-Wno-address-of-packed-member" "-Wno-switch" "-Wno-switch-enum" "-Wno-knr-promoted-parameter" "-std=gnu99" "-fdebug-compilation-dir=/usr/obj/cheri/cheribsd-riscv64-purecap-build/usr/home/john/work/cheri/git/cheribsd/riscv.riscv64c/lib/libc/tests/stdlib" "-ferror-limit" "19" "-fblocks" "-fno-signed-char" "-fgnuc-version=4.2.1" "-fcolor-diagnostics" "-vectorize-loops" "-vectorize-slp" "-faddrsig" "-D__GCC_HAVE_DWARF2_CFI_ASM=1" "-o" "qsort_b_test.o" "-x" "c" "/usr/home/john/work/cheri/git/cheribsd/lib/libc/tests/stdlib/qsort_b_test.c"
 "/usr/home/john/work/cheri/output/sdk/bin/clang-13" "-cc1" "-triple" "riscv64-unknown-freebsd14.0" "-emit-obj" "--mrelax-relocations" "-disable-free" "-main-file-name" "qsort_b_test.c" "-mrelocation-model" "pic" "-pic-level" "2" "-pic-is-pie" "-mframe-pointer=none" "-ffp-contract=on" "-fno-rounding-math" "-mconstructor-aliases" "-munwind-tables" "-target-feature" "+m" "-target-feature" "+a" "-target-feature" "+f" "-target-feature" "+d" "-target-feature" "+c" "-target-feature" "+xcheri" "-target-feature" "-relax" "-target-feature" "+cap-mode" "-target-feature" "-xcheri-rvc" "-target-feature" "-save-restore" "-target-abi" "l64pc128d" "-msmall-data-limit" "8" "-debug-info-kind=standalone" "-dwarf-version=4" "-debugger-tuning=gdb" "--compress-debug-sections=zlib" "-fcoverage-compilation-dir=/usr/obj/cheri/cheribsd-riscv64-purecap-build/usr/home/john/work/cheri/git/cheribsd/riscv.riscv64c/lib/libc/tests/stdlib" "-nobuiltininc" "-sys-header-deps" "-D" "__LP64__=1" "-D" "__HAVE_FENV" "-D" "__HAVE_LONG_DOUBLE" "-O2" "-Wno-format-zero-length" "-Werror=implicit-function-declaration" "-Wsystem-headers" "-Werror" "-Wall" "-Wno-format-y2k" "-Wno-uninitialized" "-Wno-pointer-sign" "-Wno-error=pass-failed" "-Wno-empty-body" "-Wno-string-plus-int" "-Wno-unused-const-variable" "-Wno-error=unused-but-set-variable" "-Wno-tautological-compare" "-Wno-unused-value" "-Wno-parentheses-equality" "-Wno-unused-function" "-Wno-enum-conversion" "-Wno-unused-local-typedef" "-Wno-address-of-packed-member" "-Wno-switch" "-Wno-switch-enum" "-Wno-knr-promoted-parameter" "-std=gnu99" "-fdebug-compilation-dir=/usr/obj/cheri/cheribsd-riscv64-purecap-build/usr/home/john/work/cheri/git/cheribsd/riscv.riscv64c/lib/libc/tests/stdlib" "-ferror-limit" "19" "-fblocks" "-fno-signed-char" "-fgnuc-version=4.2.1" "-fcolor-diagnostics" "-vectorize-loops" "-vectorize-slp" "-faddrsig" "-D__GCC_HAVE_DWARF2_CFI_ASM=1" "-x" "c" "qsort_b_test-c48a10.c"