git: 2390e2073f12 - stable/13 - Apply clang fix for assertion failure building putty 0.77 on i386
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Date: Mon, 30 May 2022 18:30:33 UTC
The branch stable/13 has been updated by dim: URL: https://cgit.FreeBSD.org/src/commit/?id=2390e2073f12af55d083d98fc124fa8638524e62 commit 2390e2073f12af55d083d98fc124fa8638524e62 Author: Dimitry Andric <dim@FreeBSD.org> AuthorDate: 2022-05-28 21:26:37 +0000 Commit: Dimitry Andric <dim@FreeBSD.org> CommitDate: 2022-05-30 18:28:39 +0000 Apply clang fix for assertion failure building putty 0.77 on i386 Merge commit 45084eab5e63 from llvm git (by Arthur Eubanks): [clang] Fix some clang->llvm type cache invalidation issues Take the following as an example struct z { z (*p)(); }; z f(); When we attempt to get the LLVM type of f, we recurse into z. z itself has a function pointer with the same type as f. Given the recursion, Clang simply treats z::p as a pointer to an empty struct `{}*`. The LLVM type of f is as expected. So we have two different potential LLVM types for a given Clang type. If we store one of those into the cache, when we access the cache with a different context (e.g. we are/aren't recursing on z) we may get an incorrect result. There is some attempt to clear the cache in these cases, but it doesn't seem to handle all cases. This change makes it so we only use the cache when we are not in any sort of function context, i.e. `noRecordsBeingLaidOut() && FunctionsBeingProcessed.empty()`, which are the cases where we may decide to choose a different LLVM type for a given Clang type. LLVM types for builtin types are never recursive so they're always ok. This allows us to clear the type cache less often (as seen with the removal of one of the calls to `TypeCache.clear()`). We still need to clear it when we use a placeholder type then replace it later with the final type and other dependent types need to be recalculated. I've added a check that the cached type matches what we compute. It triggered in this test case without the fix. It's currently not check-clang clean so it's not on by default for something like expensive checks builds. This change uncovered another issue where the LLVM types for an argument and its local temporary don't match. For example in type-cache-3, when expanding z::dc's argument into a temporary alloca, we ConvertType() the type of z::p which is `void ({}*)*`, which doesn't match the alloca GEP type of `{}*`. No noticeable compile time changes: https://llvm-compile-time-tracker.com/compare.php?from=3918dd6b8acf8c5886b9921138312d1c638b2937&to=50bdec9836ed40e38ece0657f3058e730adffc4c&stat=instructions Fixes #53465. Reviewed By: rnk Differential Revision: https://reviews.llvm.org/D118744 PR: 264318 Reported by: mandree MFC after: 3 days (cherry picked from commit 6a5eebc190ab98de98ed7977cbdee3218758376e) --- contrib/llvm-project/clang/lib/CodeGen/CGBuilder.h | 5 ++- contrib/llvm-project/clang/lib/CodeGen/CGCall.cpp | 18 ++++++-- .../clang/lib/CodeGen/CodeGenTypes.cpp | 52 ++++++++++++++++++---- 3 files changed, 60 insertions(+), 15 deletions(-) diff --git a/contrib/llvm-project/clang/lib/CodeGen/CGBuilder.h b/contrib/llvm-project/clang/lib/CodeGen/CGBuilder.h index 4fad44a105cd..9331c03b1838 100644 --- a/contrib/llvm-project/clang/lib/CodeGen/CGBuilder.h +++ b/contrib/llvm-project/clang/lib/CodeGen/CGBuilder.h @@ -9,10 +9,11 @@ #ifndef LLVM_CLANG_LIB_CODEGEN_CGBUILDER_H #define LLVM_CLANG_LIB_CODEGEN_CGBUILDER_H -#include "llvm/IR/DataLayout.h" -#include "llvm/IR/IRBuilder.h" #include "Address.h" #include "CodeGenTypeCache.h" +#include "llvm/IR/DataLayout.h" +#include "llvm/IR/IRBuilder.h" +#include "llvm/IR/Type.h" namespace clang { namespace CodeGen { diff --git a/contrib/llvm-project/clang/lib/CodeGen/CGCall.cpp b/contrib/llvm-project/clang/lib/CodeGen/CGCall.cpp index 47a4ed35be85..638b4e0897ec 100644 --- a/contrib/llvm-project/clang/lib/CodeGen/CGCall.cpp +++ b/contrib/llvm-project/clang/lib/CodeGen/CGCall.cpp @@ -38,6 +38,7 @@ #include "llvm/IR/InlineAsm.h" #include "llvm/IR/IntrinsicInst.h" #include "llvm/IR/Intrinsics.h" +#include "llvm/IR/Type.h" #include "llvm/Transforms/Utils/Local.h" using namespace clang; using namespace CodeGen; @@ -1056,10 +1057,19 @@ void CodeGenFunction::ExpandTypeFromArgs(QualType Ty, LValue LV, // Call EmitStoreOfScalar except when the lvalue is a bitfield to emit a // primitive store. assert(isa<NoExpansion>(Exp.get())); - if (LV.isBitField()) - EmitStoreThroughLValue(RValue::get(&*AI++), LV); - else - EmitStoreOfScalar(&*AI++, LV); + llvm::Value *Arg = &*AI++; + if (LV.isBitField()) { + EmitStoreThroughLValue(RValue::get(Arg), LV); + } else { + // TODO: currently there are some places are inconsistent in what LLVM + // pointer type they use (see D118744). Once clang uses opaque pointers + // all LLVM pointer types will be the same and we can remove this check. + if (Arg->getType()->isPointerTy()) { + Address Addr = LV.getAddress(*this); + Arg = Builder.CreateBitCast(Arg, Addr.getElementType()); + } + EmitStoreOfScalar(Arg, LV); + } } } diff --git a/contrib/llvm-project/clang/lib/CodeGen/CodeGenTypes.cpp b/contrib/llvm-project/clang/lib/CodeGen/CodeGenTypes.cpp index 9cb42941cb96..5b1551ea0355 100644 --- a/contrib/llvm-project/clang/lib/CodeGen/CodeGenTypes.cpp +++ b/contrib/llvm-project/clang/lib/CodeGen/CodeGenTypes.cpp @@ -25,9 +25,20 @@ #include "llvm/IR/DataLayout.h" #include "llvm/IR/DerivedTypes.h" #include "llvm/IR/Module.h" + using namespace clang; using namespace CodeGen; +#ifndef NDEBUG +#include "llvm/Support/CommandLine.h" +// TODO: turn on by default when defined(EXPENSIVE_CHECKS) once check-clang is +// -verify-type-cache clean. +static llvm::cl::opt<bool> VerifyTypeCache( + "verify-type-cache", + llvm::cl::desc("Verify that the type cache matches the computed type"), + llvm::cl::init(false), llvm::cl::Hidden); +#endif + CodeGenTypes::CodeGenTypes(CodeGenModule &cgm) : CGM(cgm), Context(cgm.getContext()), TheModule(cgm.getModule()), Target(cgm.getTarget()), TheCXXABI(cgm.getCXXABI()), @@ -382,9 +393,6 @@ llvm::Type *CodeGenTypes::ConvertFunctionTypeInternal(QualType QFT) { RecordsBeingLaidOut.erase(Ty); - if (SkippedLayout) - TypeCache.clear(); - if (RecordsBeingLaidOut.empty()) while (!DeferredRecords.empty()) ConvertRecordDeclType(DeferredRecords.pop_back_val()); @@ -415,11 +423,29 @@ llvm::Type *CodeGenTypes::ConvertType(QualType T) { if (const RecordType *RT = dyn_cast<RecordType>(Ty)) return ConvertRecordDeclType(RT->getDecl()); - // See if type is already cached. - llvm::DenseMap<const Type *, llvm::Type *>::iterator TCI = TypeCache.find(Ty); - // If type is found in map then use it. Otherwise, convert type T. - if (TCI != TypeCache.end()) - return TCI->second; + // The LLVM type we return for a given Clang type may not always be the same, + // most notably when dealing with recursive structs. We mark these potential + // cases with ShouldUseCache below. Builtin types cannot be recursive. + // TODO: when clang uses LLVM opaque pointers we won't be able to represent + // recursive types with LLVM types, making this logic much simpler. + llvm::Type *CachedType = nullptr; + bool ShouldUseCache = + Ty->isBuiltinType() || + (noRecordsBeingLaidOut() && FunctionsBeingProcessed.empty()); + if (ShouldUseCache) { + llvm::DenseMap<const Type *, llvm::Type *>::iterator TCI = + TypeCache.find(Ty); + if (TCI != TypeCache.end()) + CachedType = TCI->second; + if (CachedType) { +#ifndef NDEBUG + if (!VerifyTypeCache) + return CachedType; +#else + return CachedType; +#endif + } + } // If we don't have it in the cache, convert it now. llvm::Type *ResultType = nullptr; @@ -794,7 +820,15 @@ llvm::Type *CodeGenTypes::ConvertType(QualType T) { assert(ResultType && "Didn't convert a type?"); - TypeCache[Ty] = ResultType; +#ifndef NDEBUG + if (CachedType) { + assert(CachedType == ResultType && + "Cached type doesn't match computed type"); + } +#endif + + if (ShouldUseCache) + TypeCache[Ty] = ResultType; return ResultType; }