use of clock_gettime() blocks build of xray on macOS 10.11 and less

[kencu]

Bugzilla Link	38959
Version	unspecified
OS	MacOS X
CC	@devnexen

Extended Description

clock_gettime() was added in macOS 10.12.

https://stackoverflow.com/questions/5167269/clock-gettime-alternative-in-mac-os-x

clock_gettime() is used in several instances in the xray runtime library, and CLOCK_REALTIME is used but undefined on 10.11 and earlier, and so the build fails on systems without this function and definition.

A possible replacement function is used in MacPorts for a similar failure in other software:

https://github.com/macports/macports-ports/blob/master/graphics/cogl/files/patch-clock_gettime.diff

Another clock_gettime() replacement function with an MIT license is noted here https://gist.github.com/alfwatt/3588c5aa1f7a1ef7a3bb

[kencu]

On macOS 10.9, I tried adding the MacPorts replacement function in

compiler-rt/lib/xray/xray_fdr_logging.cc
compiler-rt/lib/xray/xray_basic_logging.cc

like this:

--- xray_fdr_logging.cc.orig 2018-09-15 11:21:18.000000000 -0700
+++ xray_fdr_logging.cc 2018-09-15 11:21:53.000000000 -0700
@@ -22,7 +22,29 @@
#include <pthread.h>
#include <sys/syscall.h>
#include <sys/time.h>
-#include <time.h>
+
+#if APPLE && ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED < 101200

• #include <mach/mach_time.h>
• #ifndef CLOCK_REALTIME
• #define CLOCK_REALTIME 0
• #define CLOCK_MONOTONIC 0
• #endif
  +static int
  +clock_gettime(int clk_id, struct timespec *t){
• mach_timebase_info_data_t timebase;
• mach_timebase_info(&timebase);
• uint64_t time;
• time = mach_absolute_time();
• double nseconds = ((double)time * (double)timebase.numer)/((double)timebase.denom);
• double seconds = ((double)time * (double)timebase.numer)/((double)timebase.denom * 1e9);
• t->tv_sec = seconds;
• t->tv_nsec = nseconds;
• return 0;
  +}
  +#else
• #include <time.h>
  +#endif

#include <unistd.h>

#include "sanitizer_common/sanitizer_allocator_internal.h"

but:

[ 37%] Building CXX object projects/compiler-rt/lib/xray/CMakeFiles/RTXrayFDR.osx.dir/xray_fdr_logging.cc.o
cd /opt/local/var/macports/build/_opt_myports_lang_llvm-7.0/clang-7.0/work/build/projects/compiler-rt/lib/xray && /opt/local/bin/clang++-mp-5.0 -DMAP_ANONYMOUS=MAP_ANON -DXRAY_HAS_EXCEPTIONS=1 -D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -D__STDC_LIMIT_MACROS -I/opt/local/var/macports/build/_opt_myports_lang_llvm-7.0/clang-7.0/work/build/projects/compiler-rt/lib/xray -I/opt/local/var/macports/build/_opt_myports_lang_llvm-7.0/clang-7.0/work/llvm-7.0.0rc2.src/projects/compiler-rt/lib/xray -I//opt/local/include/libxml2 -I/opt/local/var/macports/build/_opt_myports_lang_llvm-7.0/clang-7.0/work/build/include -I/opt/local/var/macports/build/_opt_myports_lang_llvm-7.0/clang-7.0/work/llvm-7.0.0rc2.src/include -I/opt/local/var/macports/build/_opt_myports_lang_llvm-7.0/clang-7.0/work/llvm-7.0.0rc2.src/projects/compiler-rt/lib/xray/.. -I/opt/local/var/macports/build/_opt_myports_lang_llvm-7.0/clang-7.0/work/llvm-7.0.0rc2.src/projects/compiler-rt/lib/xray/../../include -pipe -Os -std=c++11 -stdlib=libc++ -fPIC -fvisibility-inlines-hidden -Werror=date-time -Werror=unguarded-availability-new -std=c++11 -Wall -Wextra -Wno-unused-parameter -Wwrite-strings -Wcast-qual -Wmissing-field-initializers -pedantic -Wno-long-long -Wcovered-switch-default -Wnon-virtual-dtor -Wdelete-non-virtual-dtor -Wstring-conversion -Wall -std=c++11 -Wno-unused-parameter -DNDEBUG -arch x86_64 -arch x86_64h -pipe -Os -std=c++11 -stdlib=libc++ -fPIC -fvisibility-inlines-hidden -Werror=date-time -Werror=unguarded-availability-new -std=c++11 -Wall -Wextra -Wno-unused-parameter -Wwrite-strings -Wcast-qual -Wmissing-field-initializers -pedantic -Wno-long-long -Wcovered-switch-default -Wnon-virtual-dtor -Wdelete-non-virtual-dtor -Wstring-conversion -Wall -std=c++11 -Wno-unused-parameter -stdlib=libc++ -mmacosx-version-min=10.9 -isysroot /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.10.sdk -fPIC -fno-builtin -fno-exceptions -funwind-tables -fno-stack-protector -fno-sanitize=safe-stack -fvisibility=hidden -fno-lto -O3 -gline-tables-only -Wno-gnu -Wno-variadic-macros -Wno-c99-extensions -Wno-non-virtual-dtor -fno-rtti -o CMakeFiles/RTXrayFDR.osx.dir/xray_fdr_logging.cc.o -c /opt/local/var/macports/build/_opt_myports_lang_llvm-7.0/clang-7.0/work/llvm-7.0.0rc2.src/projects/compiler-rt/lib/xray/xray_fdr_logging.cc
/opt/local/var/macports/build/_opt_myports_lang_llvm-7.0/clang-7.0/work/llvm-7.0.0rc2.src/projects/compiler-rt/lib/xray/xray_fdr_logging.cc:221:13: error: variable has incomplete type 'void'
static void setupNewBuffer(int (*wall_clock_reader)(
^
/opt/local/var/macports/build/_opt_myports_lang_llvm-7.0/clang-7.0/work/llvm-7.0.0rc2.src/projects/compiler-rt/lib/xray/xray_fdr_logging.cc:221:34: error: use of undeclared identifier 'wall_clock_reader'
static void setupNewBuffer(int (*wall_clock_reader)(
^
/opt/local/var/macports/build/_opt_myports_lang_llvm-7.0/clang-7.0/work/llvm-7.0.0rc2.src/projects/compiler-rt/lib/xray/xray_fdr_logging.cc:222:5: error: use of undeclared identifier 'clockid_t'
clockid_t, struct timespec *)) XRAY_NEVER_INSTRUMENT {
^
/opt/local/var/macports/build/_opt_myports_lang_llvm-7.0/clang-7.0/work/llvm-7.0.0rc2.src/projects/compiler-rt/lib/xray/xray_fdr_logging.cc:222:16: error: expected expression
clockid_t, struct timespec *)) XRAY_NEVER_INSTRUMENT {
^
/opt/local/var/macports/build/_opt_myports_lang_llvm-7.0/clang-7.0/work/llvm-7.0.0rc2.src/projects/compiler-rt/lib/xray/xray_fdr_logging.cc:222:35: error: expected ';' after top level declarator
clockid_t, struct timespec *)) XRAY_NEVER_INSTRUMENT {
^
;
/opt/local/var/macports/build/_opt_myports_lang_llvm-7.0/clang-7.0/work/llvm-7.0.0rc2.src/projects/compiler-rt/lib/xray/xray_fdr_logging.cc:373:3: error: use of undeclared identifier 'decrementExtents'
decrementExtents(FunctionRecSize);
^
/opt/local/var/macports/build/_opt_myports_lang_llvm-7.0/clang-7.0/work/llvm-7.0.0rc2.src/projects/compiler-rt/lib/xray/xray_fdr_logging.cc:428:5: error: use of undeclared identifier 'decrementExtents'
decrementExtents(2 * FunctionRecSize);
^
/opt/local/var/macports/build/_opt_myports_lang_llvm-7.0/clang-7.0/work/llvm-7.0.0rc2.src/projects/compiler-rt/lib/xray/xray_fdr_logging.cc:444:52: error: C++ requires a type specifier for all declarations
int (*wall_clock_reader)(clockid_t,
^
/opt/local/var/macports/build/_opt_myports_lang_llvm-7.0/clang-7.0/work/llvm-7.0.0rc2.src/projects/compiler-rt/lib/xray/xray_fdr_logging.cc:461:5: error: use of undeclared identifier 'writeNewCPUIdMetadata'
writeNewCPUIdMetadata(CPU, TSC);
^
/opt/local/var/macports/build/_opt_myports_lang_llvm-7.0/clang-7.0/work/llvm-7.0.0rc2.src/projects/compiler-rt/lib/xray/xray_fdr_logging.cc:468:51: error: C++ requires a type specifier for all declarations
int (*wall_clock_reader)(clockid_t, struct timespec *))
^
/opt/local/var/macports/build/_opt_myports_lang_llvm-7.0/clang-7.0/work/llvm-7.0.0rc2.src/projects/compiler-rt/lib/xray/xray_fdr_logging.cc:508:5: error: use of undeclared identifier 'writeNewCPUIdMetadata'
writeNewCPUIdMetadata(CPU, TSC);
^
/opt/local/var/macports/build/_opt_myports_lang_llvm-7.0/clang-7.0/work/llvm-7.0.0rc2.src/projects/compiler-rt/lib/xray/xray_fdr_logging.cc:515:5: error: use of undeclared identifier 'writeNewCPUIdMetadata'
writeNewCPUIdMetadata(CPU, TSC);
^
/opt/local/var/macports/build/_opt_myports_lang_llvm-7.0/clang-7.0/work/llvm-7.0.0rc2.src/projects/compiler-rt/lib/xray/xray_fdr_logging.cc:543:5: error: use of undeclared identifier 'writeNewCPUIdMetadata'
writeNewCPUIdMetadata(CPU, TSC);
^
/opt/local/var/macports/build/_opt_myports_lang_llvm-7.0/clang-7.0/work/llvm-7.0.0rc2.src/projects/compiler-rt/lib/xray/xray_fdr_logging.cc:553:3: error: use of undeclared identifier 'writeTSCWrapMetadata'
writeTSCWrapMetadata(TSC);
^
/opt/local/var/macports/build/_opt_myports_lang_llvm-7.0/clang-7.0/work/llvm-7.0.0rc2.src/projects/compiler-rt/lib/xray/xray_fdr_logging.cc:578:58: error: C++ requires a type specifier for all declarations
int (*wall_clock_reader)(clockid_t,
^
/opt/local/var/macports/build/_opt_myports_lang_llvm-7.0/clang-7.0/work/llvm-7.0.0rc2.src/projects/compiler-rt/lib/xray/xray_fdr_logging.cc:682:3: error: use of undeclared identifier 'writeFunctionRecord'
writeFunctionRecord(FuncId, RecordTSCDelta, Entry);
^
/opt/local/var/macports/build/_opt_myports_lang_llvm-7.0/clang-7.0/work/llvm-7.0.0rc2.src/projects/compiler-rt/lib/xray/xray_fdr_logging.cc:684:5: error: use of undeclared identifier 'writeCallArgumentMetadata'
writeCallArgumentMetadata(Arg1);
^
/opt/local/var/macports/build/_opt_myports_lang_llvm-7.0/clang-7.0/work/llvm-7.0.0rc2.src/projects/compiler-rt/lib/xray/xray_fdr_logging.cc:1030:3: error: use of undeclared identifier 'incrementExtents'
incrementExtents(MetadataRecSize + EventSize);
^
/opt/local/var/macports/build/_opt_myports_lang_llvm-7.0/clang-7.0/work/llvm-7.0.0rc2.src/projects/compiler-rt/lib/xray/xray_fdr_logging.cc:1081:3: error: use of undeclared identifier 'incrementExtents'
incrementExtents(MetadataRecSize + EventSize);
^
fatal error: too many errors emitted, stopping now [-ferror-limit=]
20 errors generated.

[llvmbot]

We still need time.h to be included because that defines the various other types needed in xray_fdr_logging.cc -- also, this would be better as a code review through Phabricator though (reviews.llvm.org) on the top-of-trunk.

There's also a concern that using code just copy-pasted from another project with a potentially conflicting license with the compiler-rt project is problematic.

Perhaps it's better if we consolidate the implementation of the clock-reading functionality somewhere and have the platform-specific bits be isolated to a single file. Then we can determine at build time which version of a function should be called hidden behind an XRay-runtime specific abstraction.

I personally don't have time to go chase this down myself, but if you're interested please send patches to me and/or devnexen@.