[MemProf] Memory profiling runtime support

See RFC for background:
http://lists.llvm.org/pipermail/llvm-dev/2020-June/142744.html

Follow on companion to the clang/llvm instrumentation support in D85948
and committed earlier.

This patch adds the compiler-rt runtime support for the memory
profiling.

Note that much of this support was cloned from asan (and then greatly
simplified and renamed). For example the interactions with the
sanitizer_common allocators, error handling, interception, etc.

The bulk of the memory profiling specific code can be found in the
MemInfoBlock, MemInfoBlockCache, and related classes defined and used
in memprof_allocator.cpp.

For now, the memory profile is dumped to text (stderr by default, but
honors the sanitizer_common log_path flag). It is dumped in either a
default verbose format, or an optional terse format.

This patch also adds a set of tests for the core functionality.

Differential Revision: https://reviews.llvm.org/D87120

2 files changed, 61 insertions, 0 deletions

diff --git a/compiler-rt/include/CMakeLists.txt b/compiler-rt/include/CMakeLists.txt
index d47d7ba..de4cf36 100644
--- a/compiler-rt/include/CMakeLists.txt
+++ b/compiler-rt/include/CMakeLists.txt
@@ -5,6 +5,7 @@ if (COMPILER_RT_BUILD_SANITIZERS)
     sanitizer/common_interface_defs.h
     sanitizer/coverage_interface.h
     sanitizer/dfsan_interface.h
+    sanitizer/memprof_interface.h
     sanitizer/hwasan_interface.h
     sanitizer/linux_syscall_hooks.h
     sanitizer/lsan_interface.h
diff --git a/compiler-rt/include/sanitizer/memprof_interface.h b/compiler-rt/include/sanitizer/memprof_interface.h
new file mode 100644
index 0000000..a721260
--- /dev/null
+++ b/compiler-rt/include/sanitizer/memprof_interface.h
@@ -0,0 +1,60 @@
+//===-- sanitizer/memprof_interface.h --------------------------*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// This file is a part of MemProfiler (MemProf).
+//
+// Public interface header.
+//===----------------------------------------------------------------------===//
+#ifndef SANITIZER_MEMPROF_INTERFACE_H
+#define SANITIZER_MEMPROF_INTERFACE_H
+
+#include <sanitizer/common_interface_defs.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+/// Records access to a memory region (<c>[addr, addr+size)</c>).
+///
+/// This memory must be previously allocated by your program.
+///
+/// \param addr Start of memory region.
+/// \param size Size of memory region.
+void __memprof_record_access_range(void const volatile *addr, size_t size);
+
+/// Records access to a memory address <c><i>addr</i></c>.
+///
+/// This memory must be previously allocated by your program.
+///
+/// \param addr Accessed memory address
+void __memprof_record_access(void const volatile *addr);
+
+/// User-provided callback on MemProf errors.
+///
+/// You can provide a function that would be called immediately when MemProf
+/// detects an error. This is useful in cases when MemProf detects an error but
+/// your program crashes before the MemProf report is printed.
+void __memprof_on_error(void);
+
+/// Prints accumulated statistics to <c>stderr</c> (useful for calling from the
+/// debugger).
+void __memprof_print_accumulated_stats(void);
+
+/// User-provided default option settings.
+///
+/// You can provide your own implementation of this function to return a string
+/// containing MemProf runtime options (for example,
+/// <c>verbosity=1:print_stats=1</c>).
+///
+/// \returns Default options string.
+const char *__memprof_default_options(void);
+
+#ifdef __cplusplus
+} // extern "C"
+#endif
+
+#endif // SANITIZER_MEMPROF_INTERFACE_H