[CompilerRT] Add support for numerical sanitizer (llvm#94322)

This diff contains the compiler-rt changes / preparations for nsan.

Test plan:

1. cd build/runtimes/runtimes-bins && ninja check-nsan
2. ninja check-all

compiler-rt/cmake/Modules/AllSupportedArchDefs.cmake

@@ -61,6 +61,7 @@ else()
 endif()
 set(ALL_MSAN_SUPPORTED_ARCH ${X86_64} ${MIPS64} ${ARM64} ${PPC64} ${S390X}
     ${LOONGARCH64})
+set(ALL_NSAN_SUPPORTED_ARCH ${X86_64})
 set(ALL_HWASAN_SUPPORTED_ARCH ${X86_64} ${ARM64} ${RISCV64})
 set(ALL_MEMPROF_SUPPORTED_ARCH ${X86_64})
 set(ALL_PROFILE_SUPPORTED_ARCH ${X86} ${X86_64} ${ARM32} ${ARM64} ${PPC32} ${PPC64}

compiler-rt/cmake/config-ix.cmake

@@ -609,6 +609,9 @@ if(APPLE)
   list_intersect(MSAN_SUPPORTED_ARCH
     ALL_MSAN_SUPPORTED_ARCH
     SANITIZER_COMMON_SUPPORTED_ARCH)
+  list_intersect(NSAN_SUPPORTED_ARCH
+    ALL_NSAN_SUPPORTED_ARCH
+    SANITIZER_COMMON_SUPPORTED_ARCH)
   list_intersect(HWASAN_SUPPORTED_ARCH
     ALL_HWASAN_SUPPORTED_ARCH
     SANITIZER_COMMON_SUPPORTED_ARCH)
@@ -678,6 +681,7 @@ else()
   filter_available_targets(SHADOWCALLSTACK_SUPPORTED_ARCH
     ${ALL_SHADOWCALLSTACK_SUPPORTED_ARCH})
   filter_available_targets(GWP_ASAN_SUPPORTED_ARCH ${ALL_GWP_ASAN_SUPPORTED_ARCH})
+  filter_available_targets(NSAN_SUPPORTED_ARCH ${ALL_NSAN_SUPPORTED_ARCH})
   filter_available_targets(ORC_SUPPORTED_ARCH ${ALL_ORC_SUPPORTED_ARCH})
 endif()
 
@@ -712,7 +716,7 @@ if(COMPILER_RT_SUPPORTED_ARCH)
 endif()
 message(STATUS "Compiler-RT supported architectures: ${COMPILER_RT_SUPPORTED_ARCH}")
 
-set(ALL_SANITIZERS asan;dfsan;msan;hwasan;tsan;safestack;cfi;scudo_standalone;ubsan_minimal;gwp_asan;asan_abi)
+set(ALL_SANITIZERS asan;dfsan;msan;hwasan;tsan;safestack;cfi;scudo_standalone;ubsan_minimal;gwp_asan;nsan;asan_abi)
 set(COMPILER_RT_SANITIZERS_TO_BUILD all CACHE STRING
     "sanitizers to build if supported on the target (all;${ALL_SANITIZERS})")
 list_replace(COMPILER_RT_SANITIZERS_TO_BUILD all "${ALL_SANITIZERS}")
@@ -897,4 +901,11 @@ if (GWP_ASAN_SUPPORTED_ARCH AND
 else()
   set(COMPILER_RT_HAS_GWP_ASAN FALSE)
 endif()
+
+if (COMPILER_RT_HAS_SANITIZER_COMMON AND NSAN_SUPPORTED_ARCH AND
+    OS_NAME MATCHES "Linux")
+  set(COMPILER_RT_HAS_NSAN TRUE)
+else()
+  set(COMPILER_RT_HAS_NSAN FALSE)
+endif()
 pythonize_bool(COMPILER_RT_HAS_GWP_ASAN)

compiler-rt/include/sanitizer/nsan_interface.h

@@ -0,0 +1,75 @@
+//===-- sanitizer/nsan_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
+//
+//===----------------------------------------------------------------------===//
+//
+// Public interface for nsan.
+//
+//===----------------------------------------------------------------------===//
+#ifndef SANITIZER_NSAN_INTERFACE_H
+#define SANITIZER_NSAN_INTERFACE_H
+
+#include <sanitizer/common_interface_defs.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/// User-provided default option settings.
+///
+/// You can provide your own implementation of this function to return a string
+/// containing NSan runtime options (for example,
+/// <c>verbosity=1:halt_on_error=0</c>).
+///
+/// \returns Default options string.
+const char *__nsan_default_options(void);
+
+// Dumps nsan shadow data for a block of `size_bytes` bytes of application
+// memory at location `addr`.
+//
+// Each line contains application address, shadow types, then values.
+// Unknown types are shown as `__`, while known values are shown as
+// `f`, `d`, `l` for float, double, and long double respectively. Position is
+// shown as a single hex digit. The shadow value itself appears on the line that
+// contains the first byte of the value.
+// FIXME: Show both shadow and application value.
+//
+// Example: `__nsan_dump_shadow_mem(addr, 32, 8, 0)` might print:
+//
+//  0x0add7359:  __ f0 f1 f2 f3 __ __ __   (42.000)
+//  0x0add7361:  __ d1 d2 d3 d4 d5 d6 d7
+//  0x0add7369:  d8 f0 f1 f2 f3 __ __ f2   (-1.000) (12.5)
+//  0x0add7371:  f3 __ __ __ __ __ __ __
+//
+// This means that there is:
+//   - a shadow double for the float at address 0x0add7360, with value 42;
+//   - a shadow float128 for the double at address 0x0add7362, with value -1;
+//   - a shadow double for the float at address 0x0add736a, with value 12.5;
+// There was also a shadow double for the float at address 0x0add736e, but bytes
+// f0 and f1 were overwritten by one or several stores, so that the shadow value
+// is no longer valid.
+// The argument `reserved` can be any value. Its true value is provided by the
+// instrumentation.
+void __nsan_dump_shadow_mem(const char *addr, size_t size_bytes,
+                            size_t bytes_per_line, size_t reserved);
+
+// Explicitly dumps a value.
+// FIXME: vector versions ?
+void __nsan_dump_float(float value);
+void __nsan_dump_double(double value);
+void __nsan_dump_longdouble(long double value);
+
+// Explicitly checks a value.
+// FIXME: vector versions ?
+void __nsan_check_float(float value);
+void __nsan_check_double(double value);
+void __nsan_check_longdouble(long double value);
+
+#ifdef __cplusplus
+} // extern "C"
+#endif
+
+#endif // SANITIZER_NSAN_INTERFACE_H

compiler-rt/lib/nsan/CMakeLists.txt

@@ -0,0 +1,56 @@
+add_compiler_rt_component(nsan)
+
+include_directories(..)
+
+set(NSAN_SOURCES
+  nsan.cc
+  nsan_flags.cc
+  nsan_interceptors.cc
+  nsan_stats.cc
+  nsan_suppressions.cc
+)
+
+set(NSAN_HEADERS
+  nsan.h
+  nsan_flags.h
+  nsan_flags.inc
+  nsan_platform.h
+  nsan_stats.h
+  nsan_suppressions.h
+)
+
+append_list_if(COMPILER_RT_HAS_FPIC_FLAG -fPIC NSAN_CFLAGS)
+
+set(NSAN_DYNAMIC_LINK_FLAGS ${SANITIZER_COMMON_LINK_FLAGS})
+
+set(NSAN_CFLAGS ${SANITIZER_COMMON_CFLAGS})
+
+if (COMPILER_RT_HAS_NSAN)
+  foreach(arch ${NSAN_SUPPORTED_ARCH})
+    add_compiler_rt_runtime(
+      clang_rt.nsan
+      STATIC
+      ARCHS ${arch}
+      SOURCES ${NSAN_SOURCES}
+              $<TARGET_OBJECTS:RTInterception.${arch}>
+              $<TARGET_OBJECTS:RTSanitizerCommon.${arch}>
+              $<TARGET_OBJECTS:RTSanitizerCommonLibc.${arch}>
+              $<TARGET_OBJECTS:RTSanitizerCommonCoverage.${arch}>
+              $<TARGET_OBJECTS:RTSanitizerCommonSymbolizer.${arch}>
+              $<TARGET_OBJECTS:RTUbsan.${arch}>
+      ADDITIONAL_HEADERS ${NSAN_HEADERS}
+      CFLAGS ${NSAN_CFLAGS}
+      PARENT_TARGET nsan
+    )
+  endforeach()
+
+  add_compiler_rt_object_libraries(RTNsan
+      ARCHS ${NSAN_SUPPORTED_ARCH}
+      SOURCES ${NSAN_SOURCES}
+      ADDITIONAL_HEADERS ${NSAN_HEADERS}
+      CFLAGS ${NSAN_CFLAGS})
+endif()
+
+if(COMPILER_RT_INCLUDE_TESTS)
+  add_subdirectory(tests)
+endif()