[cfe-commits] r110187 - in /cfe/trunk: include/clang/Frontend/ASTUnit.h lib/Frontend/ASTUnit.cpp
Douglas Gregor
dgregor at apple.com
Tue Aug 3 22:53:38 PDT 2010
Author: dgregor
Date: Wed Aug 4 00:53:38 2010
New Revision: 110187
URL: http://llvm.org/viewvc/llvm-project?rev=110187&view=rev
Log:
When we try (but fail) to build a precompiled preamble, wait for a
short "cooling off" period (defaulting to 5 reparses) before trying to
build a precompiled preamble again. Previously, if we failed to build
the precompiled preamble at any time, we just gave up the whole
charade any never tried again.
Modified:
cfe/trunk/include/clang/Frontend/ASTUnit.h
cfe/trunk/lib/Frontend/ASTUnit.cpp
Modified: cfe/trunk/include/clang/Frontend/ASTUnit.h
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Frontend/ASTUnit.h?rev=110187&r1=110186&r2=110187&view=diff
==============================================================================
--- cfe/trunk/include/clang/Frontend/ASTUnit.h (original)
+++ cfe/trunk/include/clang/Frontend/ASTUnit.h Wed Aug 4 00:53:38 2010
@@ -122,6 +122,17 @@
static const unsigned int CheckLocked = 28573289;
static const unsigned int CheckUnlocked = 9803453;
+ /// \brief Counter that determines when we want to try building a
+ /// precompiled preamble.
+ ///
+ /// If zero, we will never build a precompiled preamble. Otherwise,
+ /// it's treated as a counter that decrements each time we reparse
+ /// without the benefit of a precompiled preamble. When it hits 1,
+ /// we'll attempt to rebuild the precompiled header. This way, if
+ /// building the precompiled preamble fails, we won't try again for
+ /// some number of calls.
+ unsigned PreambleRebuildCounter;
+
/// \brief The file in which the precompiled preamble is stored.
std::string PreambleFile;
Modified: cfe/trunk/lib/Frontend/ASTUnit.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Frontend/ASTUnit.cpp?rev=110187&r1=110186&r2=110187&view=diff
==============================================================================
--- cfe/trunk/lib/Frontend/ASTUnit.cpp (original)
+++ cfe/trunk/lib/Frontend/ASTUnit.cpp Wed Aug 4 00:53:38 2010
@@ -40,9 +40,16 @@
#include <sys/stat.h>
using namespace clang;
+/// \brief After failing to build a precompiled preamble (due to
+/// errors in the source that occurs in the preamble), the number of
+/// reparses during which we'll skip even trying to precompile the
+/// preamble.
+const unsigned DefaultPreambleRebuildInterval = 5;
+
ASTUnit::ASTUnit(bool _MainFileIsAST)
: CaptureDiagnostics(false), MainFileIsAST(_MainFileIsAST),
- ConcurrencyCheckValue(CheckUnlocked), SavedMainFileBuffer(0) {
+ ConcurrencyCheckValue(CheckUnlocked), PreambleRebuildCounter(0),
+ SavedMainFileBuffer(0) {
}
ASTUnit::~ASTUnit() {
@@ -685,7 +692,9 @@
}
if (CreatedPreambleBuffer)
delete NewPreamble.first;
-
+
+ // The next time we actually see a preamble, precompile it.
+ PreambleRebuildCounter = 1;
return 0;
}
@@ -784,8 +793,17 @@
// We can't reuse the previously-computed preamble. Build a new one.
Preamble.clear();
llvm::sys::Path(PreambleFile).eraseFromDisk();
+ PreambleRebuildCounter = 1;
}
-
+
+ // If the preamble rebuild counter > 1, it's because we previously
+ // failed to build a preamble and we're not yet ready to try
+ // again. Decrement the counter and return a failure.
+ if (PreambleRebuildCounter > 1) {
+ --PreambleRebuildCounter;
+ return 0;
+ }
+
// We did not previously compute a preamble, or it can't be reused anyway.
llvm::Timer *PreambleTimer = 0;
if (TimerGroup.get()) {
@@ -850,7 +868,7 @@
delete NewPreamble.first;
if (PreambleTimer)
PreambleTimer->stopTimer();
-
+ PreambleRebuildCounter = DefaultPreambleRebuildInterval;
return 0;
}
@@ -895,6 +913,7 @@
delete NewPreamble.first;
if (PreambleTimer)
PreambleTimer->stopTimer();
+ PreambleRebuildCounter = DefaultPreambleRebuildInterval;
return 0;
}
@@ -915,6 +934,7 @@
if (PreambleTimer)
PreambleTimer->stopTimer();
TopLevelDeclsInPreamble.clear();
+ PreambleRebuildCounter = DefaultPreambleRebuildInterval;
return 0;
}
@@ -944,6 +964,7 @@
if (PreambleTimer)
PreambleTimer->stopTimer();
+ PreambleRebuildCounter = 1;
return CreatePaddedMainFileBuffer(NewPreamble.first,
CreatedPreambleBuffer,
PreambleReservedSize,
@@ -1003,8 +1024,10 @@
llvm::MemoryBuffer *OverrideMainBuffer = 0;
// FIXME: When C++ PCH is ready, allow use of it for a precompiled preamble.
- if (PrecompilePreamble && !CI->getLangOpts().CPlusPlus)
+ if (PrecompilePreamble && !CI->getLangOpts().CPlusPlus) {
+ AST->PreambleRebuildCounter = 1;
OverrideMainBuffer = AST->BuildPrecompiledPreamble();
+ }
llvm::Timer *ParsingTimer = 0;
if (AST->TimerGroup.get()) {
@@ -1110,10 +1133,10 @@
Invocation->getPreprocessorOpts().addRemappedFile(RemappedFiles[I].first,
RemappedFiles[I].second);
- // If we have a preamble file lying around, build or reuse the precompiled
- // preamble.
+ // If we have a preamble file lying around, or if we might try to
+ // build a precompiled preamble, do so now.
llvm::MemoryBuffer *OverrideMainBuffer = 0;
- if (!PreambleFile.empty())
+ if (!PreambleFile.empty() || PreambleRebuildCounter > 0)
OverrideMainBuffer = BuildPrecompiledPreamble();
// Clear out the diagnostics state.
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