Commit 7c36d206 authored by Brad King's avatar Brad King

cmListFileBacktrace: Refactor storage to provide efficient value semantics

Since commit v3.4.0-rc1~321^2~2 (Genex: Store a backtrace, not a pointer
to one, 2015-07-08) we treat cmListFileBacktrace instances as
lightweight values.  This was true at the time only because the
backtrace information was kept in the cmState snapshot hierarchy.
However, that forced us to accumulate a lot of otherwise short-lived
snapshots just to have the backtrace fields available for reference by
cmListFileBacktrace instances.  Recent refactoring made backtrace
instances independent of the snapshot hierarchy to avoid accumulating
short-lived snapshots.  This came at the cost of making backtrace values
heavy again, leading to lots of string coying and slower execution.

Fix this by refactoring cmListFileBacktrace to provide value semantics
with efficient shared storage underneath.  Teach cmMakefile to maintain
its call stack using an instance of cmListFileBacktrace.  This approach
allows the current backtrace to be efficiently saved whenever it is
needed.

Also teach cmListFileBacktrace the notion of a file-level scope.  This
is useful for messages about the whole file (e.g. during parsing) that
are not specific to any line within it.  Push the CMakeLists.txt scope
for each directory and never pop it.  This ensures that we always have
some context information and simplifies cmMakefile::IssueMessage.
Push/pop a file-level scope as each included file is processed.  This
supersedes cmParseFileScope and improves diagnostic message context
information in a few places.  Fix the corresponding test cases to expect
the improved output.
parent 1f6bd8a9
......@@ -398,73 +398,172 @@ bool cmListFileParser::AddArgument(cmListFileLexer_Token* token,
}
}
cmListFileBacktrace::cmListFileBacktrace(cmState::Snapshot snapshot,
cmCommandContext const& cc)
: Snapshot(snapshot)
struct cmListFileBacktrace::Entry: public cmListFileContext
{
if (!this->Snapshot.IsValid())
Entry(cmListFileContext const& lfc, Entry* up):
cmListFileContext(lfc), Up(up), RefCount(0)
{
return;
if (this->Up)
{
this->Up->Ref();
}
}
// Record the entire call stack now so that the `Snapshot` we
// save for later refers to a long-lived scope. This avoids
// having to keep short-lived scopes around just to extract
// their backtrace information later.
cmListFileContext lfc =
cmListFileContext::FromCommandContext(
cc, this->Snapshot.GetExecutionListFile());
this->push_back(lfc);
cmState::Snapshot parent = this->Snapshot.GetCallStackParent();
while (parent.IsValid())
~Entry()
{
if (this->Up)
{
this->Up->Unref();
}
}
void Ref()
{
++this->RefCount;
}
void Unref()
{
lfc.Name = this->Snapshot.GetEntryPointCommand();
lfc.Line = this->Snapshot.GetEntryPointLine();
lfc.FilePath = parent.GetExecutionListFile();
if (lfc.FilePath.empty())
if (--this->RefCount == 0)
{
break;
delete this;
}
this->push_back(lfc);
}
Entry* Up;
unsigned int RefCount;
};
this->Snapshot = parent;
parent = parent.GetCallStackParent();
cmListFileBacktrace::cmListFileBacktrace(cmState::Snapshot bottom,
Entry* up,
cmListFileContext const& lfc):
Bottom(bottom), Cur(new Entry(lfc, up))
{
assert(this->Bottom.IsValid());
this->Cur->Ref();
}
cmListFileBacktrace::cmListFileBacktrace(cmState::Snapshot bottom, Entry* cur):
Bottom(bottom), Cur(cur)
{
if (this->Cur)
{
assert(this->Bottom.IsValid());
this->Cur->Ref();
}
}
cmListFileBacktrace::cmListFileBacktrace(): Bottom(), Cur(0)
{
}
cmListFileBacktrace::cmListFileBacktrace(cmState::Snapshot snapshot):
Bottom(snapshot.GetCallStackBottom()), Cur(0)
{
}
cmListFileBacktrace::cmListFileBacktrace(cmListFileBacktrace const& r):
Bottom(r.Bottom), Cur(r.Cur)
{
if (this->Cur)
{
assert(this->Bottom.IsValid());
this->Cur->Ref();
}
}
this->Snapshot = this->Snapshot.GetCallStackBottom();
cmListFileBacktrace&
cmListFileBacktrace::operator=(cmListFileBacktrace const& r)
{
cmListFileBacktrace tmp(r);
std::swap(this->Cur, tmp.Cur);
std::swap(this->Bottom, tmp.Bottom);
return *this;
}
cmListFileBacktrace::~cmListFileBacktrace()
{
if (this->Cur)
{
this->Cur->Unref();
}
}
cmListFileBacktrace
cmListFileBacktrace::Push(std::string const& file) const
{
// We are entering a file-level scope but have not yet reached
// any specific line or command invocation within it. This context
// is useful to print when it is at the top but otherwise can be
// skipped during call stack printing.
cmListFileContext lfc;
lfc.FilePath = file;
return cmListFileBacktrace(this->Bottom, this->Cur, lfc);
}
cmListFileBacktrace
cmListFileBacktrace::Push(cmListFileContext const& lfc) const
{
return cmListFileBacktrace(this->Bottom, this->Cur, lfc);
}
cmListFileBacktrace cmListFileBacktrace::Pop() const
{
assert(this->Cur);
return cmListFileBacktrace(this->Bottom, this->Cur->Up);
}
cmListFileContext const& cmListFileBacktrace::Top() const
{
if (this->Cur)
{
return *this->Cur;
}
else
{
static cmListFileContext const empty;
return empty;
}
}
void cmListFileBacktrace::PrintTitle(std::ostream& out) const
{
if (this->empty())
if (!this->Cur)
{
return;
}
cmOutputConverter converter(this->Snapshot);
cmListFileContext lfc = this->front();
lfc.FilePath = converter.Convert(lfc.FilePath, cmOutputConverter::HOME);
cmOutputConverter converter(this->Bottom);
cmListFileContext lfc = *this->Cur;
if (!this->Bottom.GetState()->GetIsInTryCompile())
{
lfc.FilePath = converter.Convert(lfc.FilePath, cmOutputConverter::HOME);
}
out << (lfc.Line ? " at " : " in ") << lfc;
}
void cmListFileBacktrace::PrintCallStack(std::ostream& out) const
{
if (this->size() <= 1)
if (!this->Cur || !this->Cur->Up)
{
return;
}
out << "Call Stack (most recent call first):\n";
cmOutputConverter converter(this->Snapshot);
for (const_iterator i = this->begin() + 1; i != this->end(); ++i)
bool first = true;
cmOutputConverter converter(this->Bottom);
for (Entry* i = this->Cur->Up; i; i = i->Up)
{
if (i->Name.empty())
{
// Skip this whole-file scope. When we get here we already will
// have printed a more-specific context within the file.
continue;
}
if (first)
{
first = false;
out << "Call Stack (most recent call first):\n";
}
cmListFileContext lfc = *i;
lfc.FilePath = converter.Convert(lfc.FilePath, cmOutputConverter::HOME);
if (!this->Bottom.GetState()->GetIsInTryCompile())
{
lfc.FilePath = converter.Convert(lfc.FilePath, cmOutputConverter::HOME);
}
out << " " << lfc << "\n";
}
}
......
......@@ -87,17 +87,53 @@ struct cmListFileFunction: public cmCommandContext
std::vector<cmListFileArgument> Arguments;
};
class cmListFileBacktrace: private std::vector<cmListFileContext>
// Represent a backtrace (call stack). Provide value semantics
// but use efficient reference-counting underneath to avoid copies.
class cmListFileBacktrace
{
public:
cmListFileBacktrace(cmState::Snapshot snapshot = cmState::Snapshot(),
cmCommandContext const& cc = cmCommandContext());
~cmListFileBacktrace();
void PrintTitle(std::ostream& out) const;
void PrintCallStack(std::ostream& out) const;
private:
cmState::Snapshot Snapshot;
public:
// Default-constructed backtrace may not be used until after
// set via assignment from a backtrace constructed with a
// valid snapshot.
cmListFileBacktrace();
// Construct an empty backtrace whose bottom sits in the directory
// indicated by the given valid snapshot.
cmListFileBacktrace(cmState::Snapshot snapshot);
// Backtraces may be copied and assigned as values.
cmListFileBacktrace(cmListFileBacktrace const& r);
cmListFileBacktrace& operator=(cmListFileBacktrace const& r);
~cmListFileBacktrace();
// Get a backtrace with the given file scope added to the top.
// May not be called until after construction with a valid snapshot.
cmListFileBacktrace Push(std::string const& file) const;
// Get a backtrace with the given call context added to the top.
// May not be called until after construction with a valid snapshot.
cmListFileBacktrace Push(cmListFileContext const& lfc) const;
// Get a backtrace with the top level removed.
// May not be called until after a matching Push.
cmListFileBacktrace Pop() const;
// Get the context at the top of the backtrace.
// Returns an empty context if the backtrace is empty.
cmListFileContext const& Top() const;
// Print the top of the backtrace.
void PrintTitle(std::ostream& out) const;
// Print the call stack below the top of the backtrace.
void PrintCallStack(std::ostream& out) const;
private:
struct Entry;
cmState::Snapshot Bottom;
Entry* Cur;
cmListFileBacktrace(cmState::Snapshot bottom, Entry* up,
cmListFileContext const& lfc);
cmListFileBacktrace(cmState::Snapshot bottom, Entry* cur);
};
struct cmListFile
......
......@@ -46,7 +46,8 @@
cmMakefile::cmMakefile(cmGlobalGenerator* globalGenerator,
cmState::Snapshot const& snapshot)
: GlobalGenerator(globalGenerator),
StateSnapshot(snapshot)
StateSnapshot(snapshot),
Backtrace(snapshot)
{
this->IsSourceFileTryCompile = false;
......@@ -115,24 +116,8 @@ void cmMakefile::IssueMessage(cmake::MessageType t,
{
this->ExecutionStatusStack.back()->SetNestedError(true);
}
this->GetCMakeInstance()->IssueMessage(t, text, this->GetBacktrace(),
force);
}
else
{
cmListFileContext lfc;
// We are not currently executing a command. Add whatever context
// information we have.
lfc.FilePath = this->GetExecutionFilePath();
if(!this->GetCMakeInstance()->GetIsInTryCompile())
{
cmOutputConverter converter(this->StateSnapshot);
lfc.FilePath = converter.Convert(lfc.FilePath, cmOutputConverter::HOME);
}
lfc.Line = 0;
this->GetCMakeInstance()->IssueMessage(t, text, lfc, force);
}
this->GetCMakeInstance()->IssueMessage(t, text, this->GetBacktrace(), force);
}
cmStringRange cmMakefile::GetIncludeDirectoriesEntries() const
......@@ -170,29 +155,28 @@ cmBacktraceRange cmMakefile::GetCompileDefinitionsBacktraces() const
//----------------------------------------------------------------------------
cmListFileBacktrace cmMakefile::GetBacktrace() const
{
cmListFileBacktrace backtrace;
if (!this->ContextStack.empty())
{
backtrace = cmListFileBacktrace(this->StateSnapshot,
*this->ContextStack.back());
}
return backtrace;
return this->Backtrace;
}
//----------------------------------------------------------------------------
cmListFileBacktrace
cmMakefile::GetBacktrace(cmCommandContext const& cc) const
cmListFileBacktrace cmMakefile::GetBacktrace(cmCommandContext const& cc) const
{
cmState::Snapshot snp = this->StateSnapshot;
return cmListFileBacktrace(snp, cc);
cmListFileContext lfc;
lfc.Name = cc.Name;
lfc.Line = cc.Line;
lfc.FilePath = this->StateSnapshot.GetExecutionListFile();
return this->Backtrace.Push(lfc);
}
//----------------------------------------------------------------------------
cmListFileContext cmMakefile::GetExecutionContext() const
{
return cmListFileContext::FromCommandContext(
*this->ContextStack.back(),
this->StateSnapshot.GetExecutionListFile());
cmListFileContext const& cur = this->Backtrace.Top();
cmListFileContext lfc;
lfc.Name = cur.Name;
lfc.Line = cur.Line;
lfc.FilePath = this->StateSnapshot.GetExecutionListFile();
return lfc;
}
//----------------------------------------------------------------------------
......@@ -226,17 +210,20 @@ void cmMakefile::PrintCommandTrace(const cmListFileFunction& lff) const
class cmMakefileCall
{
public:
cmMakefileCall(cmMakefile* mf, const cmCommandContext& lfc,
cmMakefileCall(cmMakefile* mf, cmCommandContext const& cc,
cmExecutionStatus& status): Makefile(mf)
{
this->Makefile->ContextStack.push_back(&lfc);
cmListFileContext const& lfc =
cmListFileContext::FromCommandContext(
cc, this->Makefile->StateSnapshot.GetExecutionListFile());
this->Makefile->Backtrace = this->Makefile->Backtrace.Push(lfc);
this->Makefile->ExecutionStatusStack.push_back(&status);
}
~cmMakefileCall()
{
this->Makefile->ExecutionStatusStack.pop_back();
this->Makefile->ContextStack.pop_back();
this->Makefile->Backtrace = this->Makefile->Backtrace.Pop();
}
private:
cmMakefile* Makefile;
......@@ -350,13 +337,14 @@ cmMakefile::IncludeScope::IncludeScope(cmMakefile* mf,
Makefile(mf), NoPolicyScope(noPolicyScope),
CheckCMP0011(false), ReportError(true)
{
this->Makefile->Backtrace =
this->Makefile->Backtrace.Push(filenametoread);
this->Makefile->PushFunctionBlockerBarrier();
this->Makefile->StateSnapshot =
this->Makefile->GetState()->CreateIncludeFileSnapshot(
this->Makefile->StateSnapshot,
this->Makefile->ContextStack.back()->Name,
this->Makefile->ContextStack.back()->Line,
filenametoread);
if(!this->NoPolicyScope)
{
......@@ -416,6 +404,8 @@ cmMakefile::IncludeScope::~IncludeScope()
this->Makefile->PopSnapshot(this->ReportError);
this->Makefile->PopFunctionBlockerBarrier(this->ReportError);
this->Makefile->Backtrace = this->Makefile->Backtrace.Pop();
}
//----------------------------------------------------------------------------
......@@ -458,25 +448,6 @@ void cmMakefile::IncludeScope::EnforceCMP0011()
}
}
class cmParseFileScope
{
public:
cmParseFileScope(cmMakefile* mf)
: Makefile(mf)
{
this->Makefile->ContextStack.push_back(&this->Context);
}
~cmParseFileScope()
{
this->Makefile->ContextStack.pop_back();
}
private:
cmMakefile* Makefile;
cmCommandContext Context;
};
bool cmMakefile::ReadDependentFile(const char* filename, bool noPolicyScope)
{
this->AddDefinition("CMAKE_PARENT_LIST_FILE",
......@@ -488,13 +459,10 @@ bool cmMakefile::ReadDependentFile(const char* filename, bool noPolicyScope)
IncludeScope incScope(this, filenametoread, noPolicyScope);
cmListFile listFile;
{
cmParseFileScope pfs(this);
if (!listFile.ParseFile(filenametoread.c_str(), false, this))
{
return false;
}
}
this->ReadListFile(listFile, filenametoread);
if(cmSystemTools::GetFatalErrorOccured())
......@@ -510,16 +478,12 @@ public:
ListFileScope(cmMakefile* mf, std::string const& filenametoread)
: Makefile(mf), ReportError(true)
{
long line = 0;
std::string name;
if (!this->Makefile->ContextStack.empty())
{
line = this->Makefile->ContextStack.back()->Line;
name = this->Makefile->ContextStack.back()->Name;
}
this->Makefile->Backtrace =
this->Makefile->Backtrace.Push(filenametoread);
this->Makefile->StateSnapshot =
this->Makefile->GetState()->CreateInlineListFileSnapshot(
this->Makefile->StateSnapshot, name, line, filenametoread);
this->Makefile->StateSnapshot, filenametoread);
assert(this->Makefile->StateSnapshot.IsValid());
this->Makefile->PushFunctionBlockerBarrier();
......@@ -529,6 +493,7 @@ public:
{
this->Makefile->PopSnapshot(this->ReportError);
this->Makefile->PopFunctionBlockerBarrier(this->ReportError);
this->Makefile->Backtrace = this->Makefile->Backtrace.Pop();
}
void Quiet() { this->ReportError = false; }
......@@ -546,13 +511,10 @@ bool cmMakefile::ReadListFile(const char* filename)
ListFileScope scope(this, filenametoread);
cmListFile listFile;
{
cmParseFileScope pfs(this);
if (!listFile.ParseFile(filenametoread.c_str(), false, this))
{
return false;
}
}
this->ReadListFile(listFile, filenametoread);
if(cmSystemTools::GetFatalErrorOccured())
......@@ -1525,9 +1487,7 @@ void cmMakefile::PushFunctionScope(std::string const& fileName,
{
this->StateSnapshot =
this->GetState()->CreateFunctionCallSnapshot(
this->StateSnapshot,
this->ContextStack.back()->Name, this->ContextStack.back()->Line,
fileName);
this->StateSnapshot, fileName);
assert(this->StateSnapshot.IsValid());
this->PushLoopBlockBarrier();
......@@ -1563,9 +1523,7 @@ void cmMakefile::PushMacroScope(std::string const& fileName,
{
this->StateSnapshot =
this->GetState()->CreateMacroCallSnapshot(
this->StateSnapshot,
this->ContextStack.back()->Name, this->ContextStack.back()->Line,
fileName);
this->StateSnapshot, fileName);
assert(this->StateSnapshot.IsValid());
this->PushFunctionBlockerBarrier();
......@@ -1633,6 +1591,15 @@ private:
//----------------------------------------------------------------------------
void cmMakefile::Configure()
{
std::string currentStart =
this->StateSnapshot.GetDirectory().GetCurrentSource();
currentStart += "/CMakeLists.txt";
// Add the bottom of all backtraces within this directory.
// We will never pop this scope because it should be available
// for messages during the generate step too.
this->Backtrace = this->Backtrace.Push(currentStart);
BuildsystemFileScope scope(this);
// make sure the CMakeFiles dir is there
......@@ -1640,20 +1607,14 @@ void cmMakefile::Configure()
filesDir += cmake::GetCMakeFilesDirectory();
cmSystemTools::MakeDirectory(filesDir.c_str());
std::string currentStart =
this->StateSnapshot.GetDirectory().GetCurrentSource();
currentStart += "/CMakeLists.txt";
assert(cmSystemTools::FileExists(currentStart.c_str(), true));
this->AddDefinition("CMAKE_PARENT_LIST_FILE", currentStart.c_str());
cmListFile listFile;
{
cmParseFileScope pfs(this);
if (!listFile.ParseFile(currentStart.c_str(), this->IsRootMakefile(), this))
{
return;
}
}
this->ReadListFile(listFile, currentStart);
if(cmSystemTools::GetFatalErrorOccured())
{
......@@ -1740,9 +1701,7 @@ void cmMakefile::AddSubDirectory(const std::string& srcPath,
}
cmState::Snapshot newSnapshot = this->GetState()
->CreateBuildsystemDirectorySnapshot(this->StateSnapshot,
this->ContextStack.back()->Name,
this->ContextStack.back()->Line);
->CreateBuildsystemDirectorySnapshot(this->StateSnapshot);
newSnapshot.GetDirectory().SetCurrentSource(srcPath);
newSnapshot.GetDirectory().SetCurrentBinary(binPath);
......@@ -4128,17 +4087,8 @@ std::string cmMakefile::FormatListFileStack() const
void cmMakefile::PushScope()
{
std::string commandName;
long line = 0;
if (!this->ContextStack.empty())
{
commandName = this->ContextStack.back()->Name;
line = this->ContextStack.back()->Line;
}
this->StateSnapshot = this->GetState()->CreateVariableScopeSnapshot(
this->StateSnapshot,
commandName,
line);
this->StateSnapshot);
this->PushLoopBlockBarrier();
#if defined(CMAKE_BUILD_WITH_CMAKE)
......
......@@ -835,6 +835,7 @@ private:
cmMakefile& operator=(const cmMakefile& mf);
cmState::Snapshot StateSnapshot;
cmListFileBacktrace Backtrace;
void ReadListFile(cmListFile const& listFile,
const std::string& filenametoread);
......@@ -862,7 +863,6 @@ private:
std::vector<cmGeneratorExpressionEvaluationFile*> EvaluationFiles;
std::vector<cmCommandContext const*> ContextStack;
std::vector<cmExecutionStatus*> ExecutionStatusStack;
friend class cmMakefileCall;
friend class cmParseFileScope;
......
......@@ -845,14 +845,10 @@ cmState::Snapshot cmState::CreateBaseSnapshot()
}
cmState::Snapshot
cmState::CreateBuildsystemDirectorySnapshot(Snapshot originSnapshot,
std::string const& entryPointCommand,
long entryPointLine)
cmState::CreateBuildsystemDirectorySnapshot(Snapshot originSnapshot)
{
assert(originSnapshot.IsValid());
PositionType pos = this->SnapshotData.Push(originSnapshot.Position);
pos->EntryPointLine = entryPointLine;
pos->EntryPointCommand = entryPointCommand;
pos->DirectoryParent = originSnapshot.Position;
pos->ScopeParent = originSnapshot.Position;
pos->SnapshotType = BuildsystemDirectoryType;
......@@ -886,15 +882,11 @@ cmState::CreateBuildsystemDirectorySnapshot(Snapshot originSnapshot,
cmState::Snapshot
cmState::CreateFunctionCallSnapshot(cmState::Snapshot originSnapshot,
std::string const& entryPointCommand,
long entryPointLine,
std::string const& fileName)
{
PositionType pos = this->SnapshotData.Push(originSnapshot.Position,
*originSnapshot.Position);
pos->ScopeParent = originSnapshot.Position;
pos->EntryPointLine = entryPointLine;
pos->EntryPointCommand = entryPointCommand;
pos->SnapshotType = FunctionCallType;
pos->Keep = false;
pos->ExecutionListFile = this->ExecutionListFiles.Push(
......@@ -912,14 +904,10 @@ cmState::CreateFunctionCallSnapshot(cmState::Snapshot originSnapshot,
cmState::Snapshot
cmState::CreateMacroCallSnapshot(cmState::Snapshot originSnapshot,
std::string const& entryPointCommand,
long entryPointLine,
std::string const& fileName)
{
PositionType pos = this->SnapshotData.Push(originSnapshot.Position,
*originSnapshot.Position);
pos->EntryPointLine = entryPointLine;
pos->EntryPointCommand = entryPointCommand;
pos->SnapshotType = MacroCallType;
pos->Keep = false;
pos->ExecutionListFile = this->ExecutionListFiles.Push(
......@@ -932,14 +920,10 @@ cmState::CreateMacroCallSnapshot(cmState::Snapshot originSnapshot,
cmState::Snapshot
cmState::CreateIncludeFileSnapshot(cmState::Snapshot originSnapshot,
const std::string& entryPointCommand,
long entryPointLine,
const std::string& fileName)
{
PositionType pos = this->SnapshotData.Push(originSnapshot.Position,