[llvm] 24239e2 - Add new hidden option -print-on-crash that prints out IR that caused opt pipeline to crash
Arthur Eubanks via llvm-commits
llvm-commits at lists.llvm.org
Mon May 23 15:39:28 PDT 2022
Author: Jamie Schmeiser
Date: 2022-05-23T15:38:38-07:00
New Revision: 24239e246c78c48dabdc042e5c40f40b2a28947b
URL: https://github.com/llvm/llvm-project/commit/24239e246c78c48dabdc042e5c40f40b2a28947b
DIFF: https://github.com/llvm/llvm-project/commit/24239e246c78c48dabdc042e5c40f40b2a28947b.diff
LOG: Add new hidden option -print-on-crash that prints out IR that caused opt pipeline to crash
A new hidden option -print-on-crash that prints the IR as it was upon entering
the last pass when there is a crash.
The IR is saved in its print form before each pass is started and a
signal handler is registered. If the compilation crashes, the signal
handler will print the saved IR to dbgs(). This option
can be modified using -print-module-scope to get the IR for the complete
module. Note that this option only works with the new pass manager.
Reviewed By: yrouban
Differential Revision: https://reviews.llvm.org/D86657
Added:
llvm/test/Other/print-on-crash.ll
Modified:
llvm/include/llvm/Passes/StandardInstrumentations.h
llvm/lib/Passes/PassBuilder.cpp
llvm/lib/Passes/PassRegistry.def
llvm/lib/Passes/StandardInstrumentations.cpp
Removed:
################################################################################
diff --git a/llvm/include/llvm/Passes/StandardInstrumentations.h b/llvm/include/llvm/Passes/StandardInstrumentations.h
index 4438bdb00717c..32ecc9ec5fb00 100644
--- a/llvm/include/llvm/Passes/StandardInstrumentations.h
+++ b/llvm/include/llvm/Passes/StandardInstrumentations.h
@@ -480,6 +480,25 @@ class DotCfgChangeReporter : public ChangeReporter<IRDataT<DCData>> {
std::unique_ptr<raw_fd_ostream> HTML;
};
+// Print IR on crash.
+class PrintCrashIRInstrumentation {
+public:
+ PrintCrashIRInstrumentation()
+ : SavedIR("*** Dump of IR Before Last Pass Unknown ***") {}
+ ~PrintCrashIRInstrumentation();
+ void registerCallbacks(PassInstrumentationCallbacks &PIC);
+ void reportCrashIR();
+
+protected:
+ std::string SavedIR;
+
+private:
+ // The crash reporter that will report on a crash.
+ static PrintCrashIRInstrumentation *CrashReporter;
+ // Crash handler registered when print-on-crash is specified.
+ static void SignalHandler(void *);
+};
+
/// This class provides an interface to register all the standard pass
/// instrumentations and manages their state (if any).
class StandardInstrumentations {
@@ -493,6 +512,7 @@ class StandardInstrumentations {
PseudoProbeVerifier PseudoProbeVerification;
InLineChangePrinter PrintChangedDiff;
DotCfgChangeReporter WebsiteChangeReporter;
+ PrintCrashIRInstrumentation PrintCrashIR;
VerifyInstrumentation Verify;
bool VerifyEach;
diff --git a/llvm/lib/Passes/PassBuilder.cpp b/llvm/lib/Passes/PassBuilder.cpp
index 52feab025f128..42fde3752724e 100644
--- a/llvm/lib/Passes/PassBuilder.cpp
+++ b/llvm/lib/Passes/PassBuilder.cpp
@@ -375,6 +375,17 @@ bool shouldPopulateClassToPassNames() {
!printAfterPasses().empty();
}
+// A pass for testing -print-on-crash.
+// DO NOT USE THIS EXCEPT FOR TESTING!
+class TriggerCrashPass : public PassInfoMixin<TriggerCrashPass> {
+public:
+ PreservedAnalyses run(Module &, ModuleAnalysisManager &) {
+ abort();
+ return PreservedAnalyses::all();
+ }
+ static StringRef name() { return "TriggerCrashPass"; }
+};
+
} // namespace
PassBuilder::PassBuilder(TargetMachine *TM, PipelineTuningOptions PTO,
diff --git a/llvm/lib/Passes/PassRegistry.def b/llvm/lib/Passes/PassRegistry.def
index bb839c7cee6ff..aa43c96cb1fe1 100644
--- a/llvm/lib/Passes/PassRegistry.def
+++ b/llvm/lib/Passes/PassRegistry.def
@@ -114,6 +114,7 @@ MODULE_PASS("strip-debug-declare", StripDebugDeclarePass())
MODULE_PASS("strip-nondebug", StripNonDebugSymbolsPass())
MODULE_PASS("strip-nonlinetable-debuginfo", StripNonLineTableDebugInfoPass())
MODULE_PASS("synthetic-counts-propagation", SyntheticCountsPropagation())
+MODULE_PASS("trigger-crash", TriggerCrashPass())
MODULE_PASS("verify", VerifierPass())
MODULE_PASS("view-callgraph", CallGraphViewerPass())
MODULE_PASS("wholeprogramdevirt", WholeProgramDevirtPass())
diff --git a/llvm/lib/Passes/StandardInstrumentations.cpp b/llvm/lib/Passes/StandardInstrumentations.cpp
index 83c8239bc9b36..4cd2a1ad51e36 100644
--- a/llvm/lib/Passes/StandardInstrumentations.cpp
+++ b/llvm/lib/Passes/StandardInstrumentations.cpp
@@ -28,12 +28,14 @@
#include "llvm/IR/PrintPasses.h"
#include "llvm/IR/Verifier.h"
#include "llvm/Support/CommandLine.h"
+#include "llvm/Support/CrashRecoveryContext.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/FormatVariadic.h"
#include "llvm/Support/GraphWriter.h"
#include "llvm/Support/MemoryBuffer.h"
#include "llvm/Support/Program.h"
#include "llvm/Support/Regex.h"
+#include "llvm/Support/Signals.h"
#include "llvm/Support/raw_ostream.h"
#include <unordered_map>
#include <unordered_set>
@@ -165,6 +167,12 @@ static cl::opt<std::string> DotCfgDir(
cl::desc("Generate dot files into specified directory for changed IRs"),
cl::Hidden, cl::init("./"));
+// An option to print the IR that was being processed when a pass crashes.
+static cl::opt<bool>
+ PrintCrashIR("print-on-crash",
+ cl::desc("Print the last form of the IR before crash"),
+ cl::init(false), cl::Hidden);
+
namespace {
// Perform a system based
diff between \p Before and \p After, using
@@ -2115,6 +2123,51 @@ StandardInstrumentations::StandardInstrumentations(
ChangePrinter::PrintChangedDotCfgVerbose),
Verify(DebugLogging), VerifyEach(VerifyEach) {}
+PrintCrashIRInstrumentation *PrintCrashIRInstrumentation::CrashReporter =
+ nullptr;
+
+void PrintCrashIRInstrumentation::reportCrashIR() { dbgs() << SavedIR; }
+
+void PrintCrashIRInstrumentation::SignalHandler(void *) {
+ // Called by signal handlers so do not lock here
+ // Is the PrintCrashIRInstrumentation still alive?
+ if (!CrashReporter)
+ return;
+
+ assert(PrintCrashIR && "Did not expect to get here without option set.");
+ CrashReporter->reportCrashIR();
+}
+
+PrintCrashIRInstrumentation::~PrintCrashIRInstrumentation() {
+ if (!CrashReporter)
+ return;
+
+ assert(PrintCrashIR && "Did not expect to get here without option set.");
+ CrashReporter = nullptr;
+}
+
+void PrintCrashIRInstrumentation::registerCallbacks(
+ PassInstrumentationCallbacks &PIC) {
+ if (!PrintCrashIR || CrashReporter)
+ return;
+
+ sys::AddSignalHandler(SignalHandler, nullptr);
+ CrashReporter = this;
+
+ PIC.registerBeforeNonSkippedPassCallback([this](StringRef PassID, Any IR) {
+ SavedIR.clear();
+ raw_string_ostream OS(SavedIR);
+ OS << formatv("*** Dump of {0}IR Before Last Pass {1}",
+ llvm::forcePrintModuleIR() ? "Module " : "", PassID);
+ if (!isInteresting(IR, PassID)) {
+ OS << " Filtered Out ***\n";
+ return;
+ }
+ OS << " Started ***\n";
+ unwrapAndPrint(OS, IR);
+ });
+}
+
void StandardInstrumentations::registerCallbacks(
PassInstrumentationCallbacks &PIC, FunctionAnalysisManager *FAM) {
PrintIR.registerCallbacks(PIC);
@@ -2130,6 +2183,7 @@ void StandardInstrumentations::registerCallbacks(
Verify.registerCallbacks(PIC);
PrintChangedDiff.registerCallbacks(PIC);
WebsiteChangeReporter.registerCallbacks(PIC);
+ PrintCrashIR.registerCallbacks(PIC);
}
template class ChangeReporter<std::string>;
diff --git a/llvm/test/Other/print-on-crash.ll b/llvm/test/Other/print-on-crash.ll
new file mode 100644
index 0000000000000..640ddb2b34ab5
--- /dev/null
+++ b/llvm/test/Other/print-on-crash.ll
@@ -0,0 +1,30 @@
+; A test that the hidden option -print-on-crash properly sets a signal handler
+; which gets called when a pass crashes. The trigger-crash pass asserts.
+
+; RUN: not --crash opt -print-on-crash -passes=trigger-crash < %s 2>&1 | FileCheck %s --check-prefix=CHECK_SIMPLE
+
+; A test that the signal handler set by the hidden option -print-on-crash
+; is not called when no pass crashes.
+
+; RUN: opt -print-on-crash -passes="default<O2>" < %s 2>&1 | FileCheck %s --check-prefix=CHECK_NO_CRASH
+
+; RUN: not --crash opt -print-on-crash -print-module-scope -passes=trigger-crash < %s 2>&1 | FileCheck %s --check-prefix=CHECK_MODULE
+
+; RUN: not --crash opt -print-on-crash -print-module-scope -passes=trigger-crash -filter-passes=TriggerCrashPass < %s 2>&1 | FileCheck %s --check-prefix=CHECK_MODULE
+
+; RUN: not --crash opt -print-on-crash -print-module-scope -passes=trigger-crash -filter-passes=blah < %s 2>&1 | FileCheck %s --check-prefix=CHECK_FILTERED
+
+; CHECK_SIMPLE: *** Dump of IR Before Last Pass {{.*}} Started ***
+; CHECK_SIMPLE: @main
+; CHECK_SIMPLE: entry:
+; CHECK_NO_CRASH-NOT: *** Dump of IR
+; CHECK_MODULE: *** Dump of Module IR Before Last Pass {{.*}} Started ***
+; CHECK_MODULE: ; ModuleID = {{.*}}
+; CHECK_FILTERED: *** Dump of Module IR Before Last Pass {{.*}} Filtered Out ***
+
+define i32 @main() {
+entry:
+ %retval = alloca i32, align 4
+ store i32 0, i32* %retval, align 4
+ ret i32 0
+}
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