r237531 - Don't leak TemplateIds when a plugin parses late-parsed templates at TU end.
Nico Weber
nicolasweber at gmx.de
Sat May 16 18:07:16 PDT 2015
Author: nico
Date: Sat May 16 20:07:16 2015
New Revision: 237531
URL: http://llvm.org/viewvc/llvm-project?rev=237531&view=rev
Log:
Don't leak TemplateIds when a plugin parses late-parsed templates at TU end.
In -fdelayed-template-parsing mode, templates that aren't used are not parsed
at all. For some diagnostic plugins, this is a problem since they want to
analyse the contents of the template function body. What has been suggested
on cfe-dev [1] is to explicitly parse interesting templates in
HandleTranslationUnit(); IWYU does this for example [2].
This is workable, but since the delayed parsing doesn't run below a call to
ParseTopLevelDecl(), no DestroyTemplateIdAnnotationsRAIIObj object is on the
stack to clean up TemplateIds that are created during parsing. To fix this,
let ~Parser() clean them up in delayed template parsing mode instead of
leaking (or asserting in +Assert builds).
(r219810, relanded in r220400, fixed the same problem in incremental processing
mode; the review thread of r219810 has a good discussion of the problem.)
To test this, give the PrintFunctionNames plugin a flag to force parsing
of a template and add a test that uses it in -fdelayed-template-parsing mode.
Without the Parser.cpp change, that test asserts.
1: http://lists.cs.uiuc.edu/pipermail/cfe-dev/2014-August/038415.html
2: https://code.google.com/p/include-what-you-use/source/detail?r=566
Added:
cfe/trunk/test/Frontend/plugin-delayed-template.cpp
Modified:
cfe/trunk/examples/PrintFunctionNames/PrintFunctionNames.cpp
cfe/trunk/lib/Parse/Parser.cpp
Modified: cfe/trunk/examples/PrintFunctionNames/PrintFunctionNames.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/examples/PrintFunctionNames/PrintFunctionNames.cpp?rev=237531&r1=237530&r2=237531&view=diff
==============================================================================
--- cfe/trunk/examples/PrintFunctionNames/PrintFunctionNames.cpp (original)
+++ cfe/trunk/examples/PrintFunctionNames/PrintFunctionNames.cpp Sat May 16 20:07:16 2015
@@ -15,14 +15,23 @@
#include "clang/Frontend/FrontendPluginRegistry.h"
#include "clang/AST/AST.h"
#include "clang/AST/ASTConsumer.h"
+#include "clang/AST/RecursiveASTVisitor.h"
#include "clang/Frontend/CompilerInstance.h"
+#include "clang/Sema/Sema.h"
#include "llvm/Support/raw_ostream.h"
using namespace clang;
namespace {
class PrintFunctionsConsumer : public ASTConsumer {
+ CompilerInstance &Instance;
+ std::set<std::string> ParsedTemplates;
+
public:
+ PrintFunctionsConsumer(CompilerInstance &Instance,
+ std::set<std::string> ParsedTemplates)
+ : Instance(Instance), ParsedTemplates(ParsedTemplates) {}
+
bool HandleTopLevelDecl(DeclGroupRef DG) override {
for (DeclGroupRef::iterator i = DG.begin(), e = DG.end(); i != e; ++i) {
const Decl *D = *i;
@@ -32,13 +41,47 @@ public:
return true;
}
+
+ void HandleTranslationUnit(ASTContext& context) override {
+ if (!Instance.getLangOpts().DelayedTemplateParsing)
+ return;
+
+ // This demonstrates how to force instantiation of some templates in
+ // -fdelayed-template-parsing mode. (Note: Doing this unconditionally for
+ // all templates is similar to not using -fdelayed-template-parsig in the
+ // first place.)
+ // The advantage of doing this in HandleTranslationUnit() is that all
+ // codegen (when using -add-plugin) is completely finished and this can't
+ // affect the compiler output.
+ struct Visitor : public RecursiveASTVisitor<Visitor> {
+ const std::set<std::string> &ParsedTemplates;
+ Visitor(const std::set<std::string> &ParsedTemplates)
+ : ParsedTemplates(ParsedTemplates) {}
+ bool VisitFunctionDecl(FunctionDecl *FD) {
+ if (FD->isLateTemplateParsed() &&
+ ParsedTemplates.count(FD->getNameAsString()))
+ LateParsedDecls.insert(FD);
+ return true;
+ }
+
+ std::set<FunctionDecl*> LateParsedDecls;
+ } v(ParsedTemplates);
+ v.TraverseDecl(context.getTranslationUnitDecl());
+ clang::Sema &sema = Instance.getSema();
+ for (const FunctionDecl *FD : v.LateParsedDecls) {
+ clang::LateParsedTemplate* LPT = sema.LateParsedTemplateMap.lookup(FD);
+ sema.LateTemplateParser(sema.OpaqueParser, *LPT);
+ llvm::errs() << "late-parsed-decl: \"" << FD->getNameAsString() << "\"\n";
+ }
+ }
};
class PrintFunctionNamesAction : public PluginASTAction {
+ std::set<std::string> ParsedTemplates;
protected:
std::unique_ptr<ASTConsumer> CreateASTConsumer(CompilerInstance &CI,
llvm::StringRef) override {
- return llvm::make_unique<PrintFunctionsConsumer>();
+ return llvm::make_unique<PrintFunctionsConsumer>(CI, ParsedTemplates);
}
bool ParseArgs(const CompilerInstance &CI,
@@ -47,12 +90,20 @@ protected:
llvm::errs() << "PrintFunctionNames arg = " << args[i] << "\n";
// Example error handling.
+ DiagnosticsEngine &D = CI.getDiagnostics();
if (args[i] == "-an-error") {
- DiagnosticsEngine &D = CI.getDiagnostics();
unsigned DiagID = D.getCustomDiagID(DiagnosticsEngine::Error,
"invalid argument '%0'");
D.Report(DiagID) << args[i];
return false;
+ } else if (args[i] == "-parse-template") {
+ if (i + 1 >= e) {
+ D.Report(D.getCustomDiagID(DiagnosticsEngine::Error,
+ "missing -parse-template argument"));
+ return false;
+ }
+ ++i;
+ ParsedTemplates.insert(args[i]);
}
}
if (!args.empty() && args[0] == "help")
Modified: cfe/trunk/lib/Parse/Parser.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Parse/Parser.cpp?rev=237531&r1=237530&r2=237531&view=diff
==============================================================================
--- cfe/trunk/lib/Parse/Parser.cpp (original)
+++ cfe/trunk/lib/Parse/Parser.cpp Sat May 16 20:07:16 2015
@@ -38,6 +38,26 @@ public:
return false;
}
};
+
+/// \brief RAIIObject to destroy the contents of a SmallVector of
+/// TemplateIdAnnotation pointers and clear the vector.
+class DestroyTemplateIdAnnotationsRAIIObj {
+ SmallVectorImpl<TemplateIdAnnotation *> &Container;
+
+public:
+ DestroyTemplateIdAnnotationsRAIIObj(
+ SmallVectorImpl<TemplateIdAnnotation *> &Container)
+ : Container(Container) {}
+
+ ~DestroyTemplateIdAnnotationsRAIIObj() {
+ for (SmallVectorImpl<TemplateIdAnnotation *>::iterator I =
+ Container.begin(),
+ E = Container.end();
+ I != E; ++I)
+ (*I)->Destroy();
+ Container.clear();
+ }
+};
} // end anonymous namespace
IdentifierInfo *Parser::getSEHExceptKeyword() {
@@ -414,6 +434,15 @@ Parser::~Parser() {
PP.clearCodeCompletionHandler();
+ if (getLangOpts().DelayedTemplateParsing &&
+ !PP.isIncrementalProcessingEnabled() && !TemplateIds.empty()) {
+ // If an ASTConsumer parsed delay-parsed templates in their
+ // HandleTranslationUnit() method, TemplateIds created there were not
+ // guarded by a DestroyTemplateIdAnnotationsRAIIObj object in
+ // ParseTopLevelDecl(). Destroy them here.
+ DestroyTemplateIdAnnotationsRAIIObj CleanupRAII(TemplateIds);
+ }
+
assert(TemplateIds.empty() && "Still alive TemplateIdAnnotations around?");
}
@@ -490,26 +519,6 @@ void Parser::Initialize() {
ConsumeToken();
}
-namespace {
- /// \brief RAIIObject to destroy the contents of a SmallVector of
- /// TemplateIdAnnotation pointers and clear the vector.
- class DestroyTemplateIdAnnotationsRAIIObj {
- SmallVectorImpl<TemplateIdAnnotation *> &Container;
- public:
- DestroyTemplateIdAnnotationsRAIIObj(SmallVectorImpl<TemplateIdAnnotation *>
- &Container)
- : Container(Container) {}
-
- ~DestroyTemplateIdAnnotationsRAIIObj() {
- for (SmallVectorImpl<TemplateIdAnnotation *>::iterator I =
- Container.begin(), E = Container.end();
- I != E; ++I)
- (*I)->Destroy();
- Container.clear();
- }
- };
-}
-
void Parser::LateTemplateParserCleanupCallback(void *P) {
// While this RAII helper doesn't bracket any actual work, the destructor will
// clean up annotations that were created during ActOnEndOfTranslationUnit
Added: cfe/trunk/test/Frontend/plugin-delayed-template.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Frontend/plugin-delayed-template.cpp?rev=237531&view=auto
==============================================================================
--- cfe/trunk/test/Frontend/plugin-delayed-template.cpp (added)
+++ cfe/trunk/test/Frontend/plugin-delayed-template.cpp Sat May 16 20:07:16 2015
@@ -0,0 +1,17 @@
+// RUN: %clang_cc1 -fdelayed-template-parsing -load %llvmshlibdir/PrintFunctionNames%pluginext -plugin print-fns -plugin-arg-print-fns -parse-template -plugin-arg-print-fns ForcedTemplate %s 2>&1 | FileCheck %s
+// REQUIRES: plugins, examples
+
+template <typename T>
+void TemplateDep();
+
+// CHECK: top-level-decl: "ForcedTemplate"
+// The plugin should force parsing of this template, even though it's
+// not used and -fdelayed-template-parsing is specified.
+// CHECK: warning: expression result unused
+// CHECK: late-parsed-decl: "ForcedTemplate"
+template <typename T>
+void ForcedTemplate() {
+ TemplateDep<T>(); // Shouldn't crash.
+
+ ""; // Triggers the warning checked for above.
+}
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