r347205 - [FileManager] getFile(open=true) after getFile(open=false) should open the file.
Nico Weber via cfe-commits
cfe-commits at lists.llvm.org
Wed Jan 23 11:17:23 PST 2019
Here's what I think is a repro:
Nicos-MacBook-Pro:llvm-mono-2 thakis$ cat foo.h
Nicos-MacBook-Pro:llvm-mono-2 thakis$ cat foo2.h
Nicos-MacBook-Pro:llvm-mono-2 thakis$ cat pch.h
#include "foo.h"
Nicos-MacBook-Pro:llvm-mono-2 thakis$ cat pch.cc
Nicos-MacBook-Pro:llvm-mono-2 thakis$ cat client.cc
#include "foo2.h"
#include "foo.h"
#include "foo2.h"
#include "foo.h"
Then just build pch.cc with a pch file, and then use it (you can do this on
any OS; you could also use the gcc style driver if you prefer it).
The following output is with your change reverted, I added
fprintf(stderr, "stat %s %d\n", Filename.str().c_str(), openFile);
right before the call to getStatValue() in getFile, and
if (openFile) fprintf(stderr, "opened %s\n", Filename.str().c_str());
UFE.File = std::move(F);
at the very bottom of that function, and changed getBufferForFile() to have
if (ShouldCloseOpenFile) {
fprintf(stderr, "closing %s\n", Entry->getName().str().c_str());
Entry->closeFile();
}
The output is:
Nicos-MacBook-Pro:llvm-mono-2 thakis$ out/gn/bin/clang-cl /c /Ycpch.h
/FIpch.h pch.cc
stat pch.cc 1
opened pch.cc
closing pch.cc
stat ./pch.h 1
opened ./pch.h
closing ./pch.h
stat ./foo.h 1
opened ./foo.h
closing ./foo.h
stat pch.cc 1
opened pch.cc
stat pch.pch 1
opened pch.pch
closing pch.pch
stat /Users/thakis/src/llvm-mono-2/foo.h 0
stat /Users/thakis/src/llvm-mono-2/pch.h 0
stat /Users/thakis/src/llvm-mono-2/pch.cc 0
closing /Users/thakis/src/llvm-mono-2/pch.cc
stat ./pch.h 1
Nicos-MacBook-Pro:llvm-mono-2 thakis$ out/gn/bin/clang-cl /c /Yupch.h
/FIpch.h client.cc
stat client.cc 1
opened client.cc
stat pch.pch 1
opened pch.pch
closing pch.pch
stat /Users/thakis/src/llvm-mono-2/foo.h 0
stat /Users/thakis/src/llvm-mono-2/pch.h 0
stat /Users/thakis/src/llvm-mono-2/pch.cc 0
closing client.cc
stat ./pch.h 1
stat ./foo2.h 1
opened ./foo2.h
closing ./foo2.h
stat ./foo.h 1
Note how foo.h at the end is stat'd with openFile = 1, but we don't keep
that file handle around.
Now with your patch applied, where put the
if (openFile) fprintf(stderr, "opened %s\n", Filename.str().c_str());
UFE.File = std::move(F);
print in the block you moved up.
Nicos-MacBook-Pro:llvm-mono-2 thakis$ out/gn/bin/clang-cl /c /Ycpch.h
/FIpch.h pch.cc
stat pch.cc 1
opened pch.cc
closing pch.cc
stat ./pch.h 1
opened ./pch.h
closing ./pch.h
stat ./foo.h 1
opened ./foo.h
closing ./foo.h
stat pch.cc 1
opened pch.cc
stat pch.pch 1
opened pch.pch
closing pch.pch
stat /Users/thakis/src/llvm-mono-2/foo.h 0
stat /Users/thakis/src/llvm-mono-2/pch.h 0
stat /Users/thakis/src/llvm-mono-2/pch.cc 0
closing /Users/thakis/src/llvm-mono-2/pch.cc
stat ./pch.h 1
opened ./pch.h
Nicos-MacBook-Pro:llvm-mono-2 thakis$ out/gn/bin/clang-cl /c /Yupch.h
/FIpch.h client.cc
stat client.cc 1
opened client.cc
stat pch.pch 1
opened pch.pch
closing pch.pch
stat /Users/thakis/src/llvm-mono-2/foo.h 0
stat /Users/thakis/src/llvm-mono-2/pch.h 0
stat /Users/thakis/src/llvm-mono-2/pch.cc 0
closing client.cc
stat ./pch.h 1
opened ./pch.h
stat ./foo2.h 1
opened ./foo2.h
closing ./foo2.h
stat ./foo.h 1
opened ./foo.h
closing ./foo.h
Notice how pch.pch gets opened twice but never closed in the version with
your patch. I think this is enough to show that your patch is introducing
assumptions made by clang's PCH code. Even though the issue isn't
understood in detail, this is imho enough to revert and fix and debug
async, unless you're able to fix very quickly.
On Wed, Jan 23, 2019 at 1:23 PM Nico Weber <thakis at chromium.org> wrote:
> The way things worked before your patch is that getFile() calls for
> headers that are loaded from a PCH file hit the early-ish return in
>
> if (UFE.isValid()) { // Already have an entry with this inode, return it.
>
> The first stack I posted (with ReadControlBlock() in it) populates
> this UniqueRealFiles cache, and then getFile() for includes in a pch when
> called from the preprocessor just return "early", at least before the file
> is opened. (Stack for that:
>
> (lldb) bt
> * thread #1, queue = 'com.apple.main-thread', stop reason = breakpoint 3.1
> * frame #0: 0x000000010005a2cf
> clang-cl`clang::FileManager::getFile(this=0x000000011200a190,
> Filename=(Data =
> "../../third_party/blink/renderer/core/layout/api/third_party/skia/include/core/SkPoint3.h/paint/third_party/skia/include/core/SkPoint3.hܲ?\x01",
> Length = 89), openFile=true, CacheFailure=true) at FileManager.cpp:198
> frame #1: 0x0000000102ca1cb2
> clang-cl`clang::HeaderSearch::getFileAndSuggestModule(this=0x000000011282e600,
> FileName=(Data =
> "../../third_party/blink/renderer/core/layout/api/third_party/skia/include/core/SkPoint3.h/paint/third_party/skia/include/core/SkPoint3.hܲ?\x01",
> Length = 89), IncludeLoc=(ID = 4980551), Dir=0x000000011071e500,
> IsSystemHeaderDir=false, RequestingModule=0x0000000000000000,
> SuggestedModule=0x00007fff5fbf9020) at HeaderSearch.cpp:313
> frame #2: 0x0000000102ca37aa
> clang-cl`clang::HeaderSearch::LookupFile(this=0x000000011282e600,
> Filename=(Data = "third_party/skia/include/core/SkPoint3.h", Length = 40),
> IncludeLoc=(ID = 4980551), isAngled=false, FromDir=0x0000000000000000,
> CurDir=0x00007fff5fbf9848, Includers=ArrayRef<std::__1::pair<const
> clang::FileEntry *, const clang::DirectoryEntry *> > @ 0x00007fff5fbf7c78,
> SearchPath=0x00007fff5fbf9438, RelativePath=0x00007fff5fbf9028,
> RequestingModule=0x0000000000000000, SuggestedModule=0x00007fff5fbf9020,
> IsMapped=0x00007fff5fbf9857, SkipCache=false, BuildSystemModule=false) at
> HeaderSearch.cpp:756
> frame #3: 0x0000000102d01898
> clang-cl`clang::Preprocessor::LookupFile(this=0x000000011282f618,
> FilenameLoc=(ID = 4980551), Filename=(Data =
> "third_party/skia/include/core/SkPoint3.h", Length = 40), isAngled=false,
> FromDir=0x0000000000000000, FromFile=0x0000000000000000,
> CurDir=0x00007fff5fbf9848, SearchPath=0x00007fff5fbf9438,
> RelativePath=0x00007fff5fbf9028, SuggestedModule=0x00007fff5fbf9020,
> IsMapped=0x00007fff5fbf9857, SkipCache=false) at PPDirectives.cpp:740
> frame #4: 0x0000000102d033c4
> clang-cl`clang::Preprocessor::HandleIncludeDirective(this=0x000000011282f618,
> HashLoc=(ID = 4980542), IncludeTok=0x000000011180a810,
> LookupFrom=0x0000000000000000, LookupFromFile=0x0000000000000000,
> isImport=false) at PPDirectives.cpp:1773
> frame #5: 0x0000000102d05e3a
> clang-cl`clang::Preprocessor::HandleDirective(this=0x000000011282f618,
> Result=0x000000011180a810) at PPDirectives.cpp:942
> frame #6: 0x0000000102cbff1f
> clang-cl`clang::Lexer::LexTokenInternal(this=0x000000011bc567a0,
> Result=0x000000011180a810, TokAtPhysicalStartOfLine=true) at Lexer.cpp:3931
> frame #7: 0x0000000102cbc1b8
> clang-cl`clang::Lexer::Lex(this=0x000000011bc567a0,
> Result=0x000000011180a810) at Lexer.cpp:3152
> frame #8: 0x0000000102d54dcb
> clang-cl`clang::Preprocessor::Lex(this=0x000000011282f618,
> Result=0x000000011180a810) at Preprocessor.cpp:868
> frame #9: 0x0000000102f235f9
> clang-cl`clang::Parser::ConsumeBrace(this=0x000000011180a800) at
> Parser.h:563
> frame #10: 0x0000000102f2a21a
> clang-cl`clang::BalancedDelimiterTracker::consumeClose(this=0x00007fff5fbfa560)
> at RAIIObjectsForParser.h:429
> frame #11: 0x0000000102e788e5
> clang-cl`clang::Parser::ParseInnerNamespace(this=0x000000011180a800,
> InnerNSs=0x00007fff5fbfa6e0, index=0, InlineLoc=0x00007fff5fbfa7a0,
> attrs=0x00007fff5fbfa6b8, Tracker=0x00007fff5fbfa560) at
> ParseDeclCXX.cpp:250
> frame #12: 0x0000000102e77dd6
> clang-cl`clang::Parser::ParseNamespace(this=0x000000011180a800,
> Context=FileContext, DeclEnd=0x00007fff5fbfaa70, InlineLoc=(ID = 0)) at
> ParseDeclCXX.cpp:223
> frame #13: 0x0000000102e5af29
> clang-cl`clang::Parser::ParseDeclaration(this=0x000000011180a800,
> Context=FileContext, DeclEnd=0x00007fff5fbfaa70, attrs=0x00007fff5fbfac40)
> at ParseDecl.cpp:1714
> frame #14: 0x0000000102f25dc3
> clang-cl`clang::Parser::ParseExternalDeclaration(this=0x000000011180a800,
> attrs=0x00007fff5fbfac40, DS=0x0000000000000000) at Parser.cpp:788
> frame #15: 0x0000000102f24f06
> clang-cl`clang::Parser::ParseTopLevelDecl(this=0x000000011180a800,
> Result=0x00007fff5fbfad78) at Parser.cpp:609
> frame #16: 0x0000000102e4a076
> clang-cl`clang::ParseAST(S=0x00000001118fb600, PrintStats=true,
> SkipFunctionBodies=false) at ParseAST.cpp:156
> frame #17: 0x0000000100add312
> clang-cl`clang::ASTFrontendAction::ExecuteAction(this=0x0000000112007eb0)
> at FrontendAction.cpp:1035
> frame #18: 0x00000001004f6cbd
> clang-cl`clang::CodeGenAction::ExecuteAction(this=0x0000000112007eb0) at
> CodeGenAction.cpp:1047
> frame #19: 0x0000000100adc920
> clang-cl`clang::FrontendAction::Execute(this=0x0000000112007eb0) at
> FrontendAction.cpp:934
> frame #20: 0x0000000100a4ce4e
> clang-cl`clang::CompilerInstance::ExecuteAction(this=0x0000000112005f70,
> Act=0x0000000112007eb0) at CompilerInstance.cpp:954
> frame #21: 0x0000000100b5c25f
> clang-cl`clang::ExecuteCompilerInvocation(Clang=0x0000000112005f70) at
> ExecuteCompilerInvocation.cpp:267
> frame #22: 0x0000000100001ab9 clang-cl`cc1_main(Argv=ArrayRef<const
> char *> @ 0x00007fff5fbfb4c8,
> Argv0="../../../../llvm-mono-2/out/gn/bin/clang-cl",
> MainAddr=0x0000000100028100) at cc1_main.cpp:218
> frame #23: 0x000000010002998f
> clang-cl`ExecuteCC1Tool(argv=ArrayRef<const char *> @ 0x00007fff5fbfba78,
> Tool=(Data = "", Length = 0)) at driver.cpp:309
> frame #24: 0x0000000100028a71 clang-cl`main(argc_=409,
> argv_=0x00007fff5fbfd170) at driver.cpp:381
> frame #25: 0x00007fffb015c235 libdyld.dylib`start + 1
>
> ).
>
>
> After your patch, we open the file before that cache check, and then open
> way more files, and don't the ones from the PCH for some reason. Closing is
> normally happening in through
>
> Preprocessor::HandleIncludeDirective() -> Preprocessor::EnterSourceFile()
> -> SourceManager::getBuffer() -> ContentCache::getBuffer()
> -> FileManager::getBufferForFile(ShouldCloseOpenFile)
>
> but apparently that's not getting called for headers from PCH files.
>
> On Wed, Jan 23, 2019 at 12:38 PM Nico Weber <thakis at chromium.org> wrote:
>
>> Stacks for getFile() from PCH files look like so:
>>
>> (lldb) bt
>> * thread #1, queue = 'com.apple.main-thread', stop reason = breakpoint 1.1
>> * frame #0: 0x000000010005a1fb
>> clang-cl`clang::FileManager::getFile(this=0x00000001106111f0,
>> Filename=(Data =
>> "/Users/thakis/src/chrome/src/out/gnwin/../../third_party/skia/include/core/SkPoint3.h",
>> Length = 85), openFile=false, CacheFailure=true) at FileManager.cpp:187
>> frame #1: 0x0000000103c44b2e
>> clang-cl`clang::ASTReader::getInputFile(this=0x000000011104c200,
>> F=0x000000011104fc00, ID=3, Complain=true) at ASTReader.cpp:2120
>> frame #2: 0x0000000103c5173b
>> clang-cl`clang::ASTReader::ReadControlBlock(this=0x000000011104c200,
>> F=0x000000011104fc00, Loaded=0x00007fff5fbfa130,
>> ImportedBy=0x0000000000000000, ClientLoadCapabilities=0) at
>> ASTReader.cpp:2398
>> frame #3: 0x0000000103c5381b
>> clang-cl`clang::ASTReader::ReadASTCore(this=0x000000011104c200,
>> FileName=(Data =
>> "obj/third_party/blink/renderer/core/layout/layout_cc.pch", Length = 56),
>> Type=MK_PCH, ImportLoc=(ID = 0), ImportedBy=0x0000000000000000,
>> Loaded=0x00007fff5fbfa130, ExpectedSize=0, ExpectedModTime=0,
>> ExpectedSignature=ASTFileSignature @ 0x00007fff5fbf9d58,
>> ClientLoadCapabilities=0) at ASTReader.cpp:4208
>> frame #4: 0x0000000103c5fe95
>> clang-cl`clang::ASTReader::ReadAST(this=0x000000011104c200, FileName=(Data
>> = "obj/third_party/blink/renderer/core/layout/layout_cc.pch", Length = 56),
>> Type=MK_PCH, ImportLoc=(ID = 0), ClientLoadCapabilities=0,
>> Imported=0x0000000000000000) at ASTReader.cpp:3883
>> frame #5: 0x0000000100a49542
>> clang-cl`clang::CompilerInstance::createPCHExternalASTSource(Path=(Data =
>> "obj/third_party/blink/renderer/core/layout/layout_cc.pch", Length = 56),
>> Sysroot=(Data = "/", Length = 1), DisablePCHValidation=false,
>> AllowPCHWithCompilerErrors=false, PP=0x0000000111037e18,
>> Context=0x0000000111042200, PCHContainerRdr=0x000000011060d2b0,
>> Extensions=ArrayRef<std::__1::shared_ptr<clang::ModuleFileExtension> > @
>> 0x00007fff5fbfa430, DependencyFile=0x0000000000000000,
>> DependencyCollectors=ArrayRef<std::__1::shared_ptr<clang::DependencyCollector>
>> > @ 0x00007fff5fbfa448, DeserializationListener=0x0000000000000000,
>> OwnDeserializationListener=false, Preamble=false,
>> UseGlobalModuleIndex=true) at CompilerInstance.cpp:532
>> frame #6: 0x0000000100a4909b
>> clang-cl`clang::CompilerInstance::createPCHExternalASTSource(this=0x000000011060d000,
>> Path=(Data = "obj/third_party/blink/renderer/core/layout/layout_cc.pch",
>> Length = 56), DisablePCHValidation=false, AllowPCHWithCompilerErrors=false,
>> DeserializationListener=0x0000000000000000,
>> OwnDeserializationListener=false) at CompilerInstance.cpp:490
>> frame #7: 0x0000000100ada301
>> clang-cl`clang::FrontendAction::BeginSourceFile(this=0x000000011060eee0,
>> CI=0x000000011060d000, RealInput=0x0000000110614a60) at
>> FrontendAction.cpp:859
>> frame #8: 0x0000000100a4cdf8
>> clang-cl`clang::CompilerInstance::ExecuteAction(this=0x000000011060d000,
>> Act=0x000000011060eee0) at CompilerInstance.cpp:953
>> frame #9: 0x0000000100b5c21f
>> clang-cl`clang::ExecuteCompilerInvocation(Clang=0x000000011060d000) at
>> ExecuteCompilerInvocation.cpp:267
>> frame #10: 0x0000000100001ac9 clang-cl`cc1_main(Argv=ArrayRef<const
>> char *> @ 0x00007fff5fbfb4c8,
>> Argv0="../../../../llvm-mono-2/out/gn/bin/clang-cl",
>> MainAddr=0x0000000100028110) at cc1_main.cpp:218
>> frame #11: 0x000000010002999f
>> clang-cl`ExecuteCC1Tool(argv=ArrayRef<const char *> @ 0x00007fff5fbfba78,
>> Tool=(Data = "", Length = 0)) at driver.cpp:309
>> frame #12: 0x0000000100028a81 clang-cl`main(argc_=409,
>> argv_=0x00007fff5fbfd170) at driver.cpp:381
>> frame #13: 0x00007fffb015c235 libdyld.dylib`start + 1
>>
>> (lldb) bt
>> * thread #1, queue = 'com.apple.main-thread', stop reason = breakpoint 1.1
>> * frame #0: 0x000000010005a1fb
>> clang-cl`clang::FileManager::getFile(this=0x00000001106111f0,
>> Filename=(Data =
>> "/Users/thakis/src/chrome/src/out/gnwin/../../third_party/skia/include/core/SkPoint3.h",
>> Length = 85), openFile=false, CacheFailure=true) at FileManager.cpp:187
>> frame #1: 0x0000000103c476e3
>> clang-cl`clang::serialization::reader::HeaderFileInfoTrait::EqualKey(this=0x00007fff5fbf5f80,
>> Key=0x00007fff5fbf6068)::$_1::operator()(clang::serialization::reader::HeaderFileInfoTrait::internal_key_type
>> const&) const at ASTReader.cpp:1723
>> frame #2: 0x0000000103c4759f
>> clang-cl`clang::serialization::reader::HeaderFileInfoTrait::EqualKey(this=0x0000000113a16c88,
>> a=0x00007fff5fbf6068, b=0x00007fff5fbf6138) at ASTReader.cpp:1726
>> frame #3: 0x0000000103cd5c1e
>> clang-cl`llvm::OnDiskChainedHashTable<clang::serialization::reader::HeaderFileInfoTrait>::find_hashed(this=0x0000000113a16c70,
>> IKey=0x00007fff5fbf6138, KeyHash=986574196, InfoPtr=0x0000000113a16c88) at
>> OnDiskHashTable.h:390
>> frame #4: 0x0000000103cd59b8
>> clang-cl`llvm::OnDiskChainedHashTable<clang::serialization::reader::HeaderFileInfoTrait>::find(this=0x0000000113a16c70,
>> EKey=0x00007fff5fbf6538, InfoPtr=0x0000000000000000) at
>> OnDiskHashTable.h:345
>> frame #5: 0x0000000103cd58b9 clang-cl`(anonymous
>> namespace)::HeaderFileInfoVisitor::operator(this=0x00007fff5fbf6538,
>> M=0x000000011104fc00)(clang::serialization::ModuleFile&) at
>> ASTReader.cpp:5683
>> frame #6: 0x0000000103cd5850 clang-cl`bool llvm::function_ref<bool
>> (clang::serialization::ModuleFile&)>::callback_fn<(anonymous
>> namespace)::HeaderFileInfoVisitor>(callable=140734799766840,
>> params=0x000000011104fc00) at STLExtras.h:125
>> frame #7: 0x0000000103e338cc clang-cl`llvm::function_ref<bool
>> (clang::serialization::ModuleFile&)>::operator(this=0x00007fff5fbf64a0,
>> params=0x000000011104fc00)(clang::serialization::ModuleFile&) const at
>> STLExtras.h:142
>> frame #8: 0x0000000103e33507
>> clang-cl`clang::serialization::ModuleManager::visit(this=0x000000011104c298,
>> Visitor=function_ref<bool (clang::serialization::ModuleFile &)> @
>> 0x00007fff5fbf64a0, ModuleFilesHit=0x0000000000000000)>,
>> llvm::SmallPtrSetImpl<clang::serialization::ModuleFile*>*) at
>> ModuleManager.cpp:411
>> frame #9: 0x0000000103c69ade
>> clang-cl`clang::ASTReader::GetHeaderFileInfo(this=0x000000011104c200,
>> FE=0x0000000113a00030) at ASTReader.cpp:5698
>> frame #10: 0x0000000103c69d03 clang-cl`non-virtual thunk to
>> clang::ASTReader::GetHeaderFileInfo(this=0x000000011104c200,
>> FE=0x0000000113a00030) at ASTReader.cpp:0
>> frame #11: 0x0000000102ca607c
>> clang-cl`clang::HeaderSearch::getExistingFileInfo(this=0x0000000111036e00,
>> FE=0x0000000113a00030, WantExternal=true) const at HeaderSearch.cpp:1140
>> frame #12: 0x0000000102ca6faf
>> clang-cl`clang::HeaderSearch::findModuleForHeader(this=0x0000000111036e00,
>> File=0x0000000113a00030, AllowTextual=true) const at HeaderSearch.cpp:1334
>> frame #13: 0x0000000102ca700a
>> clang-cl`suggestModule(HS=0x0000000111036e00, File=0x0000000113a00030,
>> RequestingModule=0x0000000000000000, SuggestedModule=0x00007fff5fbf9020) at
>> HeaderSearch.cpp:1343
>> frame #14: 0x0000000102ca1dd2
>> clang-cl`clang::HeaderSearch::findUsableModuleForHeader(this=0x0000000111036e00,
>> File=0x0000000113a00030, Root=0x00000001106126d0,
>> RequestingModule=0x0000000000000000, SuggestedModule=0x00007fff5fbf9020,
>> IsSystemHeaderDir=false) at HeaderSearch.cpp:1367
>> frame #15: 0x0000000102ca1cee
>> clang-cl`clang::HeaderSearch::getFileAndSuggestModule(this=0x0000000111036e00,
>> FileName=(Data = "../../third_party/skia/include/core/SkPoint3.h", Length =
>> 46), IncludeLoc=(ID = 4980551), Dir=0x00000001106126d0,
>> IsSystemHeaderDir=false, RequestingModule=0x0000000000000000,
>> SuggestedModule=0x00007fff5fbf9020) at HeaderSearch.cpp:318
>> frame #16: 0x0000000102ca20ad
>> clang-cl`clang::DirectoryLookup::LookupFile(this=0x000000011060f1e0,
>> Filename=0x00007fff5fbf7c20, HS=0x0000000111036e00, IncludeLoc=(ID =
>> 4980551), SearchPath=0x00007fff5fbf9438, RelativePath=0x00007fff5fbf9028,
>> RequestingModule=0x0000000000000000, SuggestedModule=0x00007fff5fbf9020,
>> InUserSpecifiedSystemFramework=0x00007fff5fbf763f,
>> HasBeenMapped=0x00007fff5fbf763e, MappedName=0x00007fff5fbf7640) const at
>> HeaderSearch.cpp:357
>> frame #17: 0x0000000102ca3e15
>> clang-cl`clang::HeaderSearch::LookupFile(this=0x0000000111036e00,
>> Filename=(Data = "third_party/skia/include/core/SkPoint3.h", Length = 40),
>> IncludeLoc=(ID = 4980551), isAngled=false, FromDir=0x0000000000000000,
>> CurDir=0x00007fff5fbf9848, Includers=ArrayRef<std::__1::pair<const
>> clang::FileEntry *, const clang::DirectoryEntry *> > @ 0x00007fff5fbf7c78,
>> SearchPath=0x00007fff5fbf9438, RelativePath=0x00007fff5fbf9028,
>> RequestingModule=0x0000000000000000, SuggestedModule=0x00007fff5fbf9020,
>> IsMapped=0x00007fff5fbf9857, SkipCache=false, BuildSystemModule=false) at
>> HeaderSearch.cpp:854
>> frame #18: 0x0000000102d01858
>> clang-cl`clang::Preprocessor::LookupFile(this=0x0000000111037e18,
>> FilenameLoc=(ID = 4980551), Filename=(Data =
>> "third_party/skia/include/core/SkPoint3.h", Length = 40), isAngled=false,
>> FromDir=0x0000000000000000, FromFile=0x0000000000000000,
>> CurDir=0x00007fff5fbf9848, SearchPath=0x00007fff5fbf9438,
>> RelativePath=0x00007fff5fbf9028, SuggestedModule=0x00007fff5fbf9020,
>> IsMapped=0x00007fff5fbf9857, SkipCache=false) at PPDirectives.cpp:740
>> frame #19: 0x0000000102d03384
>> clang-cl`clang::Preprocessor::HandleIncludeDirective(this=0x0000000111037e18,
>> HashLoc=(ID = 4980542), IncludeTok=0x000000011080ac10,
>> LookupFrom=0x0000000000000000, LookupFromFile=0x0000000000000000,
>> isImport=false) at PPDirectives.cpp:1773
>> frame #20: 0x0000000102d05dfa
>> clang-cl`clang::Preprocessor::HandleDirective(this=0x0000000111037e18,
>> Result=0x000000011080ac10) at PPDirectives.cpp:942
>> frame #21: 0x0000000102cbfedf
>> clang-cl`clang::Lexer::LexTokenInternal(this=0x000000011a6f1430,
>> Result=0x000000011080ac10, TokAtPhysicalStartOfLine=true) at Lexer.cpp:3931
>> frame #22: 0x0000000102cbc178
>> clang-cl`clang::Lexer::Lex(this=0x000000011a6f1430,
>> Result=0x000000011080ac10) at Lexer.cpp:3152
>> frame #23: 0x0000000102d54d8b
>> clang-cl`clang::Preprocessor::Lex(this=0x0000000111037e18,
>> Result=0x000000011080ac10) at Preprocessor.cpp:868
>> frame #24: 0x0000000102f235b9
>> clang-cl`clang::Parser::ConsumeBrace(this=0x000000011080ac00) at
>> Parser.h:563
>> frame #25: 0x0000000102f2a1da
>> clang-cl`clang::BalancedDelimiterTracker::consumeClose(this=0x00007fff5fbfa560)
>> at RAIIObjectsForParser.h:429
>> frame #26: 0x0000000102e788a5
>> clang-cl`clang::Parser::ParseInnerNamespace(this=0x000000011080ac00,
>> InnerNSs=0x00007fff5fbfa6e0, index=0, InlineLoc=0x00007fff5fbfa7a0,
>> attrs=0x00007fff5fbfa6b8, Tracker=0x00007fff5fbfa560) at
>> ParseDeclCXX.cpp:250
>> frame #27: 0x0000000102e77d96
>> clang-cl`clang::Parser::ParseNamespace(this=0x000000011080ac00,
>> Context=FileContext, DeclEnd=0x00007fff5fbfaa70, InlineLoc=(ID = 0)) at
>> ParseDeclCXX.cpp:223
>> frame #28: 0x0000000102e5aee9
>> clang-cl`clang::Parser::ParseDeclaration(this=0x000000011080ac00,
>> Context=FileContext, DeclEnd=0x00007fff5fbfaa70, attrs=0x00007fff5fbfac40)
>> at ParseDecl.cpp:1714
>> frame #29: 0x0000000102f25d83
>> clang-cl`clang::Parser::ParseExternalDeclaration(this=0x000000011080ac00,
>> attrs=0x00007fff5fbfac40, DS=0x0000000000000000) at Parser.cpp:788
>> frame #30: 0x0000000102f24ec6
>> clang-cl`clang::Parser::ParseTopLevelDecl(this=0x000000011080ac00,
>> Result=0x00007fff5fbfad78) at Parser.cpp:609
>> frame #31: 0x0000000102e4a036
>> clang-cl`clang::ParseAST(S=0x00000001108fba00, PrintStats=true,
>> SkipFunctionBodies=false) at ParseAST.cpp:156
>> frame #32: 0x0000000100add2d2
>> clang-cl`clang::ASTFrontendAction::ExecuteAction(this=0x000000011060eee0)
>> at FrontendAction.cpp:1035
>> frame #33: 0x00000001004f6c7d
>> clang-cl`clang::CodeGenAction::ExecuteAction(this=0x000000011060eee0) at
>> CodeGenAction.cpp:1047
>> frame #34: 0x0000000100adc8e0
>> clang-cl`clang::FrontendAction::Execute(this=0x000000011060eee0) at
>> FrontendAction.cpp:934
>> frame #35: 0x0000000100a4ce0e
>> clang-cl`clang::CompilerInstance::ExecuteAction(this=0x000000011060d000,
>> Act=0x000000011060eee0) at CompilerInstance.cpp:954
>> frame #36: 0x0000000100b5c21f
>> clang-cl`clang::ExecuteCompilerInvocation(Clang=0x000000011060d000) at
>> ExecuteCompilerInvocation.cpp:267
>> frame #37: 0x0000000100001ac9 clang-cl`cc1_main(Argv=ArrayRef<const
>> char *> @ 0x00007fff5fbfb4c8,
>> Argv0="../../../../llvm-mono-2/out/gn/bin/clang-cl",
>> MainAddr=0x0000000100028110) at cc1_main.cpp:218
>> frame #38: 0x000000010002999f
>> clang-cl`ExecuteCC1Tool(argv=ArrayRef<const char *> @ 0x00007fff5fbfba78,
>> Tool=(Data = "", Length = 0)) at driver.cpp:309
>> frame #39: 0x0000000100028a81 clang-cl`main(argc_=409,
>> argv_=0x00007fff5fbfd170) at driver.cpp:381
>> frame #40: 0x00007fffb015c235 libdyld.dylib`start + 1
>>
>>
>> For regular includes they look like so:
>>
>> (lldb) bt
>> * thread #1, queue = 'com.apple.main-thread', stop reason = breakpoint 1.1
>> * frame #0: 0x0000000100059d29
>> clang-cl`clang::FileManager::getStatValue(this=0x0000000110611270,
>> Path=(Data =
>> "../../third_party/blink/renderer/platform/scheduler/public/scheduling_lifecycle_state.h",
>> Length = 87), Data=0x00007fff5fbf6640, isFile=true, F=0x00007fff5fbf6680)
>> at FileManager.cpp:465
>> frame #1: 0x000000010005a471
>> clang-cl`clang::FileManager::getFile(this=0x0000000110611270,
>> Filename=(Data =
>> "../../third_party/blink/renderer/platform/scheduler/public/scheduling_lifecycle_state.h",
>> Length = 87), openFile=true, CacheFailure=true) at FileManager.cpp:230
>> frame #2: 0x0000000102ca1ca2
>> clang-cl`clang::HeaderSearch::getFileAndSuggestModule(this=0x0000000111036e00,
>> FileName=(Data =
>> "../../third_party/blink/renderer/platform/scheduler/public/scheduling_lifecycle_state.h",
>> Length = 87), IncludeLoc=(ID = 9004850), Dir=0x0000000110502730,
>> IsSystemHeaderDir=false, RequestingModule=0x0000000000000000,
>> SuggestedModule=0x00007fff5fbf9030) at HeaderSearch.cpp:313
>> frame #3: 0x0000000102ca20dd
>> clang-cl`clang::DirectoryLookup::LookupFile(this=0x0000000110503850,
>> Filename=0x00007fff5fbf7c30, HS=0x0000000111036e00, IncludeLoc=(ID =
>> 9004850), SearchPath=0x00007fff5fbf9448, RelativePath=0x00007fff5fbf9038,
>> RequestingModule=0x0000000000000000, SuggestedModule=0x00007fff5fbf9030,
>> InUserSpecifiedSystemFramework=0x00007fff5fbf764f,
>> HasBeenMapped=0x00007fff5fbf764e, MappedName=0x00007fff5fbf7650) const at
>> HeaderSearch.cpp:357
>> frame #4: 0x0000000102ca3e45
>> clang-cl`clang::HeaderSearch::LookupFile(this=0x0000000111036e00,
>> Filename=(Data =
>> "third_party/blink/renderer/platform/scheduler/public/scheduling_lifecycle_state.h",
>> Length = 81), IncludeLoc=(ID = 9004850), isAngled=false,
>> FromDir=0x0000000000000000, CurDir=0x00007fff5fbf9858,
>> Includers=ArrayRef<std::__1::pair<const clang::FileEntry *, const
>> clang::DirectoryEntry *> > @ 0x00007fff5fbf7c88,
>> SearchPath=0x00007fff5fbf9448, RelativePath=0x00007fff5fbf9038,
>> RequestingModule=0x0000000000000000, SuggestedModule=0x00007fff5fbf9030,
>> IsMapped=0x00007fff5fbf9867, SkipCache=false, BuildSystemModule=false) at
>> HeaderSearch.cpp:854
>> frame #5: 0x0000000102d01888
>> clang-cl`clang::Preprocessor::LookupFile(this=0x0000000111037e18,
>> FilenameLoc=(ID = 9004850), Filename=(Data =
>> "third_party/blink/renderer/platform/scheduler/public/scheduling_lifecycle_state.h",
>> Length = 81), isAngled=false, FromDir=0x0000000000000000,
>> FromFile=0x0000000000000000, CurDir=0x00007fff5fbf9858,
>> SearchPath=0x00007fff5fbf9448, RelativePath=0x00007fff5fbf9038,
>> SuggestedModule=0x00007fff5fbf9030, IsMapped=0x00007fff5fbf9867,
>> SkipCache=false) at PPDirectives.cpp:740
>> frame #6: 0x0000000102d033b4
>> clang-cl`clang::Preprocessor::HandleIncludeDirective(this=0x0000000111037e18,
>> HashLoc=(ID = 9004841), IncludeTok=0x0000000115068810,
>> LookupFrom=0x0000000000000000, LookupFromFile=0x0000000000000000,
>> isImport=false) at PPDirectives.cpp:1773
>> frame #7: 0x0000000102d05e2a
>> clang-cl`clang::Preprocessor::HandleDirective(this=0x0000000111037e18,
>> Result=0x0000000115068810) at PPDirectives.cpp:942
>> frame #8: 0x0000000102cbff0f
>> clang-cl`clang::Lexer::LexTokenInternal(this=0x000000011d98b010,
>> Result=0x0000000115068810, TokAtPhysicalStartOfLine=true) at Lexer.cpp:3931
>> frame #9: 0x0000000102cbc1a8
>> clang-cl`clang::Lexer::Lex(this=0x000000011d98b010,
>> Result=0x0000000115068810) at Lexer.cpp:3152
>> frame #10: 0x0000000102d54dbb
>> clang-cl`clang::Preprocessor::Lex(this=0x0000000111037e18,
>> Result=0x0000000115068810) at Preprocessor.cpp:868
>> frame #11: 0x0000000102f235e9
>> clang-cl`clang::Parser::ConsumeBrace(this=0x0000000115068800) at
>> Parser.h:563
>> frame #12: 0x0000000102f2a20a
>> clang-cl`clang::BalancedDelimiterTracker::consumeClose(this=0x00007fff5fbfa570)
>> at RAIIObjectsForParser.h:429
>> frame #13: 0x0000000102e788d5
>> clang-cl`clang::Parser::ParseInnerNamespace(this=0x0000000115068800,
>> InnerNSs=0x00007fff5fbfa6f0, index=0, InlineLoc=0x00007fff5fbfa7b0,
>> attrs=0x00007fff5fbfa6c8, Tracker=0x00007fff5fbfa570) at
>> ParseDeclCXX.cpp:250
>> frame #14: 0x0000000102e77dc6
>> clang-cl`clang::Parser::ParseNamespace(this=0x0000000115068800,
>> Context=FileContext, DeclEnd=0x00007fff5fbfaa80, InlineLoc=(ID = 0)) at
>> ParseDeclCXX.cpp:223
>> frame #15: 0x0000000102e5af19
>> clang-cl`clang::Parser::ParseDeclaration(this=0x0000000115068800,
>> Context=FileContext, DeclEnd=0x00007fff5fbfaa80, attrs=0x00007fff5fbfac50)
>> at ParseDecl.cpp:1714
>> frame #16: 0x0000000102f25db3
>> clang-cl`clang::Parser::ParseExternalDeclaration(this=0x0000000115068800,
>> attrs=0x00007fff5fbfac50, DS=0x0000000000000000) at Parser.cpp:788
>> frame #17: 0x0000000102f24ef6
>> clang-cl`clang::Parser::ParseTopLevelDecl(this=0x0000000115068800,
>> Result=0x00007fff5fbfad88) at Parser.cpp:609
>> frame #18: 0x0000000102e4a066
>> clang-cl`clang::ParseAST(S=0x0000000115061a00, PrintStats=false,
>> SkipFunctionBodies=false) at ParseAST.cpp:156
>> frame #19: 0x0000000100add302
>> clang-cl`clang::ASTFrontendAction::ExecuteAction(this=0x000000011060ef90)
>> at FrontendAction.cpp:1035
>> frame #20: 0x00000001004f6cad
>> clang-cl`clang::CodeGenAction::ExecuteAction(this=0x000000011060ef90) at
>> CodeGenAction.cpp:1047
>> frame #21: 0x0000000100adc910
>> clang-cl`clang::FrontendAction::Execute(this=0x000000011060ef90) at
>> FrontendAction.cpp:934
>> frame #22: 0x0000000100a4ce3e
>> clang-cl`clang::CompilerInstance::ExecuteAction(this=0x000000011060d050,
>> Act=0x000000011060ef90) at CompilerInstance.cpp:954
>> frame #23: 0x0000000100b5c24f
>> clang-cl`clang::ExecuteCompilerInvocation(Clang=0x000000011060d050) at
>> ExecuteCompilerInvocation.cpp:267
>> frame #24: 0x0000000100001b19 clang-cl`cc1_main(Argv=ArrayRef<const
>> char *> @ 0x00007fff5fbfb4d8,
>> Argv0="../../../../llvm-mono-2/out/gn/bin/clang-cl",
>> MainAddr=0x0000000100028160) at cc1_main.cpp:218
>> frame #25: 0x00000001000299ef
>> clang-cl`ExecuteCC1Tool(argv=ArrayRef<const char *> @ 0x00007fff5fbfba88,
>> Tool=(Data = "", Length = 0)) at driver.cpp:309
>> frame #26: 0x0000000100028ad1 clang-cl`main(argc_=408,
>> argv_=0x00007fff5fbfd188) at driver.cpp:381
>> frame #27: 0x00007fffb015c235 libdyld.dylib`start + 1
>> frame #28: 0x00007fffb015c235 libdyld.dylib`start + 1
>>
>>
>>
>> On Wed, Jan 23, 2019 at 12:10 PM Sam McCall <sammccall at google.com> wrote:
>>
>>> Thanks! given that we don't see an earlier stat, I guess these files
>>> were being treated as virtual (file metadata deserialized from PCH).
>>> Previously despite the open=true these never actually got opened, and that
>>> worked fine.
>>>
>>> I'm away from my computer but will verify later tonight or in the
>>> morning (CET) and try to find a fix. If it's not obvious, we should revert
>>> the patch at least on the release branch.
>>>
>>> A stack trace at the relevant breakpoint might well be useful - can't
>>> remember if there are lots of entry points here.
>>>
>>> Cheers, Sam
>>>
>>> On Wed, Jan 23, 2019, 16:38 Nico Weber <thakis at chromium.org wrote:
>>>
>>>> With your patch reverted locally, at the same breakpoint I instead get
>>>>
>>>> $ lsof -p 95842 | wc -l
>>>> 94
>>>>
>>>> So your patch seems to increase number of open file handles by ~260%.
>>>>
>>>> On Wed, Jan 23, 2019 at 10:27 AM Nico Weber <thakis at chromium.org>
>>>> wrote:
>>>>
>>>>> On Wed, Jan 23, 2019 at 9:54 AM Sam McCall <sammccall at google.com>
>>>>> wrote:
>>>>>
>>>>>> (Email is better than IRC if that's OK - I don't know this code that
>>>>>> well so it takes me a while).
>>>>>>
>>>>>> Thanks, that's definitely interesting and not what I expected. I
>>>>>> thought every call sequence r347205 changed the behavior of would have
>>>>>> resulted in two calls to getStatValue().
>>>>>> I guess the "pch"/"main" output is printed before the corresponding
>>>>>> lines in run.sh?
>>>>>>
>>>>>
>>>>> Correct.
>>>>>
>>>>>
>>>>>> Weird that we don't get any output from building the PCH, but I don't
>>>>>> know well how PCH builds work.
>>>>>>
>>>>>> > It looks like FS->getCurrentWorkingDirectory() is set
>>>>>> yet FileSystemOpts.WorkingDir.empty() is also true. Is that expected?
>>>>>> I think so. The FileManager and the VFS each have their own concept
>>>>>> of working directory, I guess for historical reasons.
>>>>>> Making use of the VFS one but not the FileManager one seems
>>>>>> reasonable.
>>>>>>
>>>>>> So the weirdness is that FileSystemStatCache::get() is returning true
>>>>>> (i.e. file doesn't exist), when the file does exist.
>>>>>> Possibilities:
>>>>>> 1) we're serving this result from the FileSystemStatCache (and maybe
>>>>>> it's being poisoned in a PCH-related way somehow). Except as far as I can
>>>>>> tell, FileSystemStatCache is always null (FileManager::setStateCache has no
>>>>>> callers).
>>>>>> 2) the FS.openFileForRead call failed (ultimately ::open, if FS is
>>>>>> the real FS)
>>>>>> 3) the OwnedFile->status() call failed (ultimately ::fstat)
>>>>>> 4) I'm misreading the code somehow
>>>>>>
>>>>>
>>>>> ::open() fails with errno == 24, EMFILE.
>>>>>
>>>>> This log statement here:
>>>>>
>>>>> diff --git a/clang/lib/Basic/FileSystemStatCache.cpp
>>>>> b/clang/lib/Basic/FileSystemStatCache.cpp
>>>>> index d29ebb750fc..63fc4780237 100644
>>>>> --- a/clang/lib/Basic/FileSystemStatCache.cpp
>>>>> +++ b/clang/lib/Basic/FileSystemStatCache.cpp
>>>>> @@ -70,9 +70,13 @@ bool FileSystemStatCache::get(StringRef Path,
>>>>> FileData &Data, bool isFile,
>>>>> //
>>>>> // Because of this, check to see if the file exists with 'open'.
>>>>> If the
>>>>> // open succeeds, use fstat to get the stat info.
>>>>> - auto OwnedFile = FS.openFileForRead(Path);
>>>>> + llvm::ErrorOr<std::unique_ptr<llvm::vfs::File>> OwnedFile =
>>>>> + FS.openFileForRead(Path);
>>>>>
>>>>> if (!OwnedFile) {
>>>>> +if (Path.endswith("scheduling_lifecycle_state.h")) {
>>>>> +fprintf(stderr, "hmm failed %s\n",
>>>>> OwnedFile.getError().message().c_str());
>>>>> +}
>>>>> // If the open fails, our "stat" fails.
>>>>> R = CacheMissing;
>>>>> } else {
>>>>>
>>>>>
>>>>> causes clang to print "hmm failed Too many open files". That path
>>>>> should maybe check if `OwnedFile.getError().value() == EMFILE &&
>>>>> OwnedFile.getError().category() == std::generic_category()` on mac and
>>>>> abort or diag or something more visible.
>>>>>
>>>>> `ulimit -n` on macOS is pretty small -- do you see how your patch
>>>>> could cause clang to keep more file handles open?
>>>>>
>>>>> Here's how many files clang had open when I had a breakpoint in that
>>>>> error path:
>>>>>
>>>>> $ lsof -p 91890 | wc -l
>>>>> 343
>>>>>
>>>>>
>>>>>
>>>>>>
>>>>>> Could you find out which of these is going on? Either running in a
>>>>>> debugger or adding some similar printfs to FileSystemStatCache::get()
>>>>>> should be doable.
>>>>>> I'm also going to try to work out how the patch could have affected
>>>>>> this, but new vs correct much easier for me to compare than new vs old...
>>>>>>
>>>>>
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