Start reifying error descriptions

Summary:
This commit sets up the infrastructure to use reified error
descriptions, and moves ReportStackOverflow to the new system.

After we convert all the errors, we'll be able to simplify ScopedInErrorReport
and remove the older debugging mechanism which had some errors partly reified
in some way. We'll be able to maintain the external API.

ScopedInErrorReport will be able to track one of the reified errors at a time.
The purpose of this is so we have its destructor actually print the error and
possibly interface with the debugger (will depend on the platform, of course).

Reviewers: kcc, samsonov, timurrrr

Subscribers: kubabrecka, llvm-commits

Differential Revision: https://reviews.llvm.org/D23672

llvm-svn: 279862

diff --git a/compiler-rt/lib/asan/CMakeLists.txt b/compiler-rt/lib/asan/CMakeLists.txt
index 7325932..49466b2 100644 (file)
--- a/compiler-rt/lib/asan/CMakeLists.txt
+++ b/compiler-rt/lib/asan/CMakeLists.txt
@@ -5,6 +5,7 @@ set(ASAN_SOURCES
   asan_activation.cc
   asan_debugging.cc
   asan_descriptions.cc
+  asan_errors.cc
   asan_fake_stack.cc
   asan_flags.cc
   asan_globals.cc

diff --git a/compiler-rt/lib/asan/asan_errors.cc b/compiler-rt/lib/asan/asan_errors.cc
new file mode 100644 (file)
index 0000000..ea30c1c
--- /dev/null
+++ b/compiler-rt/lib/asan/asan_errors.cc
@@ -0,0 +1,36 @@
+//===-- asan_errors.cc ------------------------------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file is a part of AddressSanitizer, an address sanity checker.
+//
+// ASan implementation for error structures.
+//===----------------------------------------------------------------------===//
+
+#include "asan_errors.h"
+#include "asan_stack.h"
+
+namespace __asan {
+
+void ErrorStackOverflow::Print() {
+  Decorator d;
+  Printf("%s", d.Warning());
+  Report(
+      "ERROR: AddressSanitizer: stack-overflow on address %p"
+      " (pc %p bp %p sp %p T%d)\n",
+      (void *)addr, (void *)pc, (void *)bp, (void *)sp, tid);
+  Printf("%s", d.EndWarning());
+  scariness.Print();
+  BufferedStackTrace stack;
+  GetStackTraceWithPcBpAndContext(&stack, kStackTraceMax, pc, bp, context,
+                                  common_flags()->fast_unwind_on_fatal);
+  stack.Print();
+  ReportErrorSummary("stack-overflow", &stack);
+}
+
+}  // namespace __asan

diff --git a/compiler-rt/lib/asan/asan_errors.h b/compiler-rt/lib/asan/asan_errors.h
new file mode 100644 (file)
index 0000000..a41cb23
--- /dev/null
+++ b/compiler-rt/lib/asan/asan_errors.h
@@ -0,0 +1,78 @@
+//===-- asan_errors.h -------------------------------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file is a part of AddressSanitizer, an address sanity checker.
+//
+// ASan-private header for error structures.
+//===----------------------------------------------------------------------===//
+#ifndef ASAN_ERRORS_H
+#define ASAN_ERRORS_H
+
+#include "asan_descriptions.h"
+#include "asan_scariness_score.h"
+
+namespace __asan {
+
+struct ErrorBase {
+  ScarinessScore scariness;
+};
+
+struct ErrorStackOverflow : ErrorBase {
+  u32 tid;
+  uptr addr, pc, bp, sp;
+  // ErrorStackOverflow never owns the context.
+  void *context;
+  ErrorStackOverflow(const SignalContext &sig, u32 tid_)
+      : tid(tid_),
+        addr(sig.addr),
+        pc(sig.pc),
+        bp(sig.bp),
+        sp(sig.sp),
+        context(sig.context) {
+    scariness.Scare(10, "stack-overflow");
+  }
+  void Print();
+};
+
+enum ErrorKind {
+  kErrorKindInvalid = 0,
+  kErrorKindStackOverflow,
+};
+
+struct ErrorDescription {
+  ErrorKind kind;
+  // We're using a tagged union because it allows us to have a trivially
+  // copiable type and use the same structures as the public interface.
+  //
+  // We can add a wrapper around it to make it "more c++-like", but that would
+  // add a lot of code and the benefit wouldn't be that big.
+  union {
+    ErrorStackOverflow stack_overflow;
+  };
+  ErrorDescription() { internal_memset(this, 0, sizeof(*this)); }
+  ErrorDescription(const ErrorStackOverflow &e)  // NOLINT
+      : kind(kErrorKindStackOverflow),
+        stack_overflow(e) {}
+
+  bool IsValid() { return kind != kErrorKindInvalid; }
+  void Print() {
+    switch (kind) {
+      case kErrorKindStackOverflow:
+        stack_overflow.Print();
+        return;
+      case kErrorKindInvalid:
+        CHECK(0);
+    }
+    CHECK(0);
+  }
+};
+
+}  // namespace __asan
+
+#endif  // ASAN_ERRORS_H

diff --git a/compiler-rt/lib/asan/asan_report.cc b/compiler-rt/lib/asan/asan_report.cc
index 337720e..c8395a5 100644 (file)
--- a/compiler-rt/lib/asan/asan_report.cc
+++ b/compiler-rt/lib/asan/asan_report.cc
@@ -12,6 +12,7 @@
 // This file contains error reporting code.
 //===----------------------------------------------------------------------===//
 
+#include "asan_errors.h"
 #include "asan_flags.h"
 #include "asan_descriptions.h"
 #include "asan_internal.h"
@@ -267,6 +268,8 @@ class ScopedInErrorReport {
   }
 
   ~ScopedInErrorReport() {
+    if (current_error_.IsValid()) current_error_.Print();
+
     // Make sure the current thread is announced.
     DescribeThread(GetCurrentThread());
     // We may want to grab this lock again when printing stats.
@@ -301,6 +304,12 @@ class ScopedInErrorReport {
     }
   }
 
+  void ReportError(const ErrorDescription &description) {
+    // Can only report one error per ScopedInErrorReport.
+    CHECK_EQ(current_error_.kind, kErrorKindInvalid);
+    current_error_ = description;
+  }
+
  private:
   void StartReporting(ReportData *report) {
     if (report) report_data = *report;
@@ -319,26 +328,20 @@ class ScopedInErrorReport {
 
   static StaticSpinMutex lock_;
   static u32 reporting_thread_tid_;
+  // Error currently being reported. This enables the destructor to interact
+  // with the debugger and point it to an error description.
+  static ErrorDescription current_error_;
   bool halt_on_error_;
 };
 
 StaticSpinMutex ScopedInErrorReport::lock_;
 u32 ScopedInErrorReport::reporting_thread_tid_ = kInvalidTid;
+ErrorDescription ScopedInErrorReport::current_error_;
 
 void ReportStackOverflow(const SignalContext &sig) {
   ScopedInErrorReport in_report(/*report*/ nullptr, /*fatal*/ true);
-  Decorator d;
-  Printf("%s", d.Warning());
-  Report(
-      "ERROR: AddressSanitizer: stack-overflow on address %p"
-      " (pc %p bp %p sp %p T%d)\n",
-      (void *)sig.addr, (void *)sig.pc, (void *)sig.bp, (void *)sig.sp,
-      GetCurrentTidOrInvalid());
-  Printf("%s", d.EndWarning());
-  ScarinessScore::PrintSimple(10, "stack-overflow");
-  GET_STACK_TRACE_SIGNAL(sig);
-  stack.Print();
-  ReportErrorSummary("stack-overflow", &stack);
+  ErrorStackOverflow error{sig, GetCurrentTidOrInvalid()};  // NOLINT
+  in_report.ReportError(error);
 }
 
 void ReportDeadlySignal(const char *description, const SignalContext &sig) {