From 89be6ed38a376e9076768d56d6fa9712fcb0657e Mon Sep 17 00:00:00 2001
From: Kostya Serebryany <kcc@google.com>
Date: Fri, 27 Dec 2013 08:11:08 +0000
Subject: [PATCH] Bury leaked pointers in a global array to silence a leak
detector in --disable-free mode
Summary:
This is an alternative to http://llvm-reviews.chandlerc.com/D2475
suggested by Chandler.
Reviewers: chandlerc, rnk, dblaikie
CC: cfe-commits, earthdok
Differential Revision: http://llvm-reviews.chandlerc.com/D2478
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@198073 91177308-0d34-0410-b5e6-96231b3b80d8
---
include/clang/Frontend/CompilerInstance.h | 5 +++++
include/clang/Frontend/Utils.h | 5 +++++
lib/CodeGen/BackendUtil.cpp | 3 ++-
lib/Frontend/CompilerInvocation.cpp | 16 ++++++++++++++++
lib/Frontend/FrontendAction.cpp | 5 +++--
lib/FrontendTool/ExecuteCompilerInvocation.cpp | 3 ++-
tools/driver/cc1_main.cpp | 3 ++-
7 files changed, 35 insertions(+), 5 deletions(-)
diff --git a/include/clang/Frontend/CompilerInstance.h b/include/clang/Frontend/CompilerInstance.h
index ad752acf782..fa20ae48e4f 100644
--- a/include/clang/Frontend/CompilerInstance.h
+++ b/include/clang/Frontend/CompilerInstance.h
@@ -13,6 +13,7 @@
#include "clang/Basic/Diagnostic.h"
#include "clang/Basic/SourceManager.h"
#include "clang/Frontend/CompilerInvocation.h"
+#include "clang/Frontend/Utils.h"
#include "clang/Lex/ModuleLoader.h"
#include "llvm/ADT/ArrayRef.h"
#include "llvm/ADT/DenseMap.h"
@@ -325,6 +326,7 @@ public:
}
void resetAndLeakFileManager() {
+ BuryPointer(FileMgr.getPtr());
FileMgr.resetWithoutRelease();
}
@@ -344,6 +346,7 @@ public:
}
void resetAndLeakSourceManager() {
+ BuryPointer(SourceMgr.getPtr());
SourceMgr.resetWithoutRelease();
}
@@ -363,6 +366,7 @@ public:
}
void resetAndLeakPreprocessor() {
+ BuryPointer(PP.getPtr());
PP.resetWithoutRelease();
}
@@ -381,6 +385,7 @@ public:
}
void resetAndLeakASTContext() {
+ BuryPointer(Context.getPtr());
Context.resetWithoutRelease();
}
diff --git a/include/clang/Frontend/Utils.h b/include/clang/Frontend/Utils.h
index dff56c3a8a4..db52d5cf0dd 100644
--- a/include/clang/Frontend/Utils.h
+++ b/include/clang/Frontend/Utils.h
@@ -123,6 +123,11 @@ inline int getLastArgIntValue(const llvm::opt::ArgList &Args,
return getLastArgIntValue(Args, Id, Default, &Diags);
}
+// When Clang->getFrontendOpts().DisableFree is set we don't delete some of the
+// global objects, but we don't want LeakDetectors to complain, so we bury them
+// in a globally visible array.
+void BuryPointer(const void *Ptr);
+
} // end namespace clang
#endif
diff --git a/lib/CodeGen/BackendUtil.cpp b/lib/CodeGen/BackendUtil.cpp
index f302ef7b37c..55970cdf842 100644
--- a/lib/CodeGen/BackendUtil.cpp
+++ b/lib/CodeGen/BackendUtil.cpp
@@ -13,6 +13,7 @@
#include "clang/Basic/TargetOptions.h"
#include "clang/Frontend/CodeGenOptions.h"
#include "clang/Frontend/FrontendDiagnostic.h"
+#include "clang/Frontend/Utils.h"
#include "llvm/Analysis/Verifier.h"
#include "llvm/Assembly/PrintModulePass.h"
#include "llvm/Bitcode/ReaderWriter.h"
@@ -117,7 +118,7 @@ public:
delete PerModulePasses;
delete PerFunctionPasses;
if (CodeGenOpts.DisableFree)
- TM.take();
+ BuryPointer(TM.take());
}
llvm::OwningPtr<TargetMachine> TM;
diff --git a/lib/Frontend/CompilerInvocation.cpp b/lib/Frontend/CompilerInvocation.cpp
index 71e6b74d38b..78a88f65f6b 100644
--- a/lib/Frontend/CompilerInvocation.cpp
+++ b/lib/Frontend/CompilerInvocation.cpp
@@ -28,6 +28,7 @@
#include "llvm/Option/ArgList.h"
#include "llvm/Option/OptTable.h"
#include "llvm/Option/Option.h"
+#include "llvm/Support/Atomic.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/FileSystem.h"
#include "llvm/Support/Host.h"
@@ -1827,4 +1828,19 @@ int getLastArgIntValue(const ArgList &Args, OptSpecifier Id, int Default,
}
return Res;
}
+
+void BuryPointer(const void *Ptr) {
+ // This function may be called only a small fixed amount of times per each
+ // invocation, otherwise we do actually have a leak which we want to report.
+ // If this function is called more than kGraveYardMaxSize times, the pointers
+ // will not be properly buried and a leak detector will report a leak, which
+ // is what we want in such case.
+ static const size_t kGraveYardMaxSize = 16;
+ static const void *GraveYard[kGraveYardMaxSize];
+ static llvm::sys::cas_flag GraveYardSize;
+ llvm::sys::cas_flag Idx = llvm::sys::AtomicIncrement(&GraveYardSize) - 1;
+ if (Idx >= kGraveYardMaxSize)
+ return;
+ GraveYard[Idx] = Ptr;
+}
}
diff --git a/lib/Frontend/FrontendAction.cpp b/lib/Frontend/FrontendAction.cpp
index 49d01f9d372..31889f1fff8 100644
--- a/lib/Frontend/FrontendAction.cpp
+++ b/lib/Frontend/FrontendAction.cpp
@@ -17,6 +17,7 @@
#include "clang/Frontend/FrontendDiagnostic.h"
#include "clang/Frontend/FrontendPluginRegistry.h"
#include "clang/Frontend/LayoutOverrideSource.h"
+#include "clang/Frontend/Utils.h"
#include "clang/Frontend/MultiplexConsumer.h"
#include "clang/Lex/HeaderSearch.h"
#include "clang/Lex/Preprocessor.h"
@@ -403,9 +404,9 @@ void FrontendAction::EndSourceFile() {
//
// FIXME: There is more per-file stuff we could just drop here?
if (CI.getFrontendOpts().DisableFree) {
- CI.takeASTConsumer();
+ BuryPointer(CI.takeASTConsumer());
if (!isCurrentFileAST()) {
- CI.takeSema();
+ BuryPointer(CI.takeSema());
CI.resetAndLeakASTContext();
}
} else {
diff --git a/lib/FrontendTool/ExecuteCompilerInvocation.cpp b/lib/FrontendTool/ExecuteCompilerInvocation.cpp
index e22f9ba0523..e14fb2340e6 100644
--- a/lib/FrontendTool/ExecuteCompilerInvocation.cpp
+++ b/lib/FrontendTool/ExecuteCompilerInvocation.cpp
@@ -21,6 +21,7 @@
#include "clang/Frontend/FrontendActions.h"
#include "clang/Frontend/FrontendDiagnostic.h"
#include "clang/Frontend/FrontendPluginRegistry.h"
+#include "clang/Frontend/Utils.h"
#include "clang/Rewrite/Frontend/FrontendActions.h"
#include "clang/StaticAnalyzer/Frontend/FrontendActions.h"
#include "llvm/Option/OptTable.h"
@@ -236,6 +237,6 @@ bool clang::ExecuteCompilerInvocation(CompilerInstance *Clang) {
return false;
bool Success = Clang->ExecuteAction(*Act);
if (Clang->getFrontendOpts().DisableFree)
- Act.take();
+ BuryPointer(Act.take());
return Success;
}
diff --git a/tools/driver/cc1_main.cpp b/tools/driver/cc1_main.cpp
index 5b3b5ad6500..28ada6944e8 100644
--- a/tools/driver/cc1_main.cpp
+++ b/tools/driver/cc1_main.cpp
@@ -21,6 +21,7 @@
#include "clang/Frontend/FrontendDiagnostic.h"
#include "clang/Frontend/TextDiagnosticBuffer.h"
#include "clang/Frontend/TextDiagnosticPrinter.h"
+#include "clang/Frontend/Utils.h"
#include "clang/FrontendTool/Utils.h"
#include "llvm/ADT/Statistic.h"
#include "llvm/LinkAllPasses.h"
@@ -112,7 +113,7 @@ int cc1_main(const char **ArgBegin, const char **ArgEnd,
if (Clang->getFrontendOpts().DisableFree) {
if (llvm::AreStatisticsEnabled() || Clang->getFrontendOpts().ShowStats)
llvm::PrintStatistics();
- Clang.take();
+ BuryPointer(Clang.take());
return !Success;
}
--
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