[sanitizers] Make it possible to XFAIL on the effective target, not just the default.

[dsanders]

Summary

The triple is not the right thing to XFAIL on since LIT only sees the default
triple and not the effective triple chosen by any -target option in the RUN
directives. This discrepancy is shown in the table below:

Default Triple   | Options                           | XFAIL  | LIT's expected result | Desired expectation
=================+===================================+========+=======================+====================
mips-linux-gnu   | -target mips-linux-gnu            |        | Pass                  | Pass  
mips-linux-gnu   | -target mips64-linux-gnu -mabi=64 |        | Pass                  | Pass  
mips-linux-gnu   | -target mips-linux-gnu            | mips   | Fail                  | Fail  
mips-linux-gnu   | -target mips64-linux-gnu -mabi=64 | mips   | Fail                  | Fail/Pass* (debatable**)
mips-linux-gnu   | -target mips-linux-gnu            | mips-  | Fail                  | Fail  
mips-linux-gnu   | -target mips64-linux-gnu -mabi=64 | mips-  | Fail                  | Pass* 
mips-linux-gnu   | -target mips-linux-gnu            | mips64 | Pass                  | Pass  
mips-linux-gnu   | -target mips64-linux-gnu -mabi=64 | mips64 | Pass                  | Fail* 
mips64-linux-gnu | -target mips-linux-gnu            |        | Pass                  | Pass  
mips64-linux-gnu | -target mips64-linux-gnu -mabi=64 |        | Pass                  | Pass  
mips64-linux-gnu | -target mips-linux-gnu            | mips   | Fail                  | Fail* 
mips64-linux-gnu | -target mips64-linux-gnu -mabi=64 | mips   | Fail                  | Fail/Pass (debatable**)
mips64-linux-gnu | -target mips-linux-gnu            | mips-  | Pass                  | Fail* 
mips64-linux-gnu | -target mips64-linux-gnu -mabi=64 | mips-  | Pass                  | Pass  
mips64-linux-gnu | -target mips-linux-gnu            | mips64 | Fail                  | Pass* 
mips64-linux-gnu | -target mips64-linux-gnu -mabi=64 | mips64 | Fail                  | Fail  
x64_64-linux-gnu | -target i386-linux-gnu            |        | Pass                  | Pass
x64_64-linux-gnu | -target x86_64-linux-gnu          |        | Pass                  | Pass
x64_64-linux-gnu | -target i386-linux-gnu            | i386   | Pass                  | Fail*
x64_64-linux-gnu | -target x86_64-linux-gnu          | i386   | Pass                  | Pass
x64_64-linux-gnu | -target i386-linux-gnu            | x86_64 | Fail                  | Pass
x64_64-linux-gnu | -target x86_64-linux-gnu          | x86_64 | Fail                  | Fail*
* These all differ from LIT's current behaviour.
** People's expectations vary depending on whether they know that LIT does a
 substring match on the default triple or think it's an exact match on an
 architecture.

This patch adds "target-is-${target_arch}" to the available features list and
updates the mips XFAIL's to use them. XFAIL'ing on these features will
correctly account for the target being tested. Making the table:

Options                           | XFAIL            | LIT's expected result
==================================+==================+======================
-target mips-linux-gnu            |                  | Pass
-target mips64-linux-gnu -mabi=64 |                  | Pass
-target mips-linux-gnu            | target-is-mips   | Fail
-target mips64-linux-gnu -mabi=64 | target-is-mips   | Pass
-target mips-linux-gnu            | target-is-mips64 | Pass
-target mips64-linux-gnu -mabi=64 | target-is-mips64 | Fail
-target i386-linux-gnu            |                  | Pass
-target x86_64-linux-gnu          |                  | Pass
-target i386-linux-gnu            | target-is-i386   | Fail
-target x86_64-linux-gnu          | target-is-i386   | Pass
-target i386-linux-gnu            | target-is-x86_64 | Pass
-target x86_64-linux-gnu          | target-is-x86_64 | Fail

[dsanders]

ping

[dsanders]

ping

[probinson]

No documentation of the target-is-xxx feature. This really matters because the difference between 'mips64' and 'target-is-mips64' seems to be very subtle and even somewhat magical.

[dsanders]

Added documentation of target-is-${arch} and the quirks that make it necessary.
There's no place for such documentation yet so I've created a new file to go
along with TestingGuide.rst from the llvm project.

Also, there's broken cross reference to the llvm document at the moment.
Phabricator won't let me add the necessary anchor to llvm/docs/TestingGuide.rst
in this review but I'll add it in the commit.

[probinson]

That is a really clear description, thanks! LGTM.

test/asan/TestCases/Linux/local_alias.cc

 // Test that mixing instrumented and non-instrumented code doesn't lead to crash.
 // Build two modules (one is instrumented, another is not) that have globals
 // with same names. Check, that ASan doesn't crash with CHECK failure or
 // false positive global-buffer-overflow due to sanitized library poisons
 // globals from non-sanitized one.
 //
 // FIXME: https://github.com/google/sanitizers/issues/316
 // XFAIL: android
-// XFAIL: mips64
+// XFAIL: target-is-mips64
 //
 // RUN: %clangxx_asan -DBUILD_INSTRUMENTED_DSO=1 -fPIC -shared -mllvm -asan-use-private-alias %s -o %t-INSTRUMENTED-SO.so
 // RUN: %clangxx -DBUILD_UNINSTRUMENTED_DSO=1 -fPIC -shared %s -o %t-UNINSTRUMENTED-SO.so
 // RUN: %clangxx %s -c -mllvm -asan-use-private-alias -o %t.o
 // RUN: %clangxx_asan %t.o %t-UNINSTRUMENTED-SO.so %t-INSTRUMENTED-SO.so -o %t-EXE
 // RUN: %env_asan_opts=use_odr_indicator=true %run %t-EXE
 
 #if defined (BUILD_INSTRUMENTED_DSO)

test/asan/TestCases/Linux/odr-violation.cc

 // FIXME: https://code.google.com/p/address-sanitizer/issues/detail?id=316
 // XFAIL: android
-// XFAIL: mips64
+// XFAIL: target-is-mips64
 //
 // We use fast_unwind_on_malloc=0 to have full unwinding even w/o frame
 // pointers. This setting is not on by default because it's too expensive.
 //
 // Different size: detect a bug if detect_odr_violation>=1
 // RUN: %clangxx_asan -DBUILD_SO=1 -fPIC -shared %s -o %t-ODR-SO.so
 // RUN: %clangxx_asan %s %t-ODR-SO.so -Wl,-R. -o %t-ODR-EXE
 // RUN: %env_asan_opts=fast_unwind_on_malloc=0:detect_odr_violation=1 not %run %t-ODR-EXE 2>&1 | FileCheck %s

test/lit.common.configured.in

 set_default("compiler_id", "@COMPILER_RT_TEST_COMPILER_ID@")
 set_default("python_executable", "@PYTHON_EXECUTABLE@")
 set_default("compiler_rt_debug", @COMPILER_RT_DEBUG_PYBOOL@)
 set_default("compiler_rt_libdir", "@COMPILER_RT_LIBRARY_OUTPUT_DIR@")
 set_default("emulator", "@COMPILER_RT_EMULATOR@")
 set_default("sanitizer_can_use_cxxabi", @SANITIZER_CAN_USE_CXXABI_PYBOOL@)
 set_default("has_lld", @COMPILER_RT_HAS_LLD_SOURCES_PYBOOL@)
 set_default("can_symbolize", @CAN_SYMBOLIZE@)
+config.available_features.add('target-is-%s' % config.target_arch)
 
 # LLVM tools dir can be passed in lit parameters, so try to
 # apply substitution.
 try:
   config.llvm_tools_dir = config.llvm_tools_dir % lit_config.params
 except KeyError as e:
   key, = e.args
   lit_config.fatal("unable to find %r parameter, use '--param=%s=VALUE'" % (key, key))
 
 # Setup attributes common for all compiler-rt projects.
 lit_config.load_config(config, "@COMPILER_RT_SOURCE_DIR@/test/lit.common.cfg")

test/tsan/ignore_lib4.cc

 // RUN: %clangxx_tsan -O1 %s -DLIB -fPIC -shared -o %T/libignore_lib4.so
 // RUN: %clangxx_tsan -O1 %s -o %t
 // RUN: echo "called_from_lib:libignore_lib4.so" > %t.supp
 // RUN: %env_tsan_opts=suppressions='%t.supp' %run %t 2>&1 | FileCheck %s
 
 // Longjmp assembly has not been implemented for mips64 yet
-// XFAIL: mips64
+// XFAIL: target-is-mips64
 // powerpc64 big endian bots failed with "FileCheck error: '-' is empty" due
 // to a segmentation fault.
 // UNSUPPORTED: powerpc64-unknown-linux-gnu
 // aarch64 bots failed with "called_from_lib suppression 'libignore_lib4.so'
 //                           is matched against 2 libraries".
 // UNSUPPORTED: aarch64
 
 // Test longjmp in ignored lib.

test/tsan/longjmp.cc

 // RUN: %clang_tsan -O1 %s -o %t && %run %t 2>&1 | FileCheck %s
 
 // Longjmp assembly has not been implemented for mips64 yet
-// XFAIL: mips64
+// XFAIL: target-is-mips64
 
 #include <stdio.h>
 #include <stdlib.h>
 #include <setjmp.h>
 
 int foo(jmp_buf env) {
   longjmp(env, 42);
 }

test/tsan/longjmp2.cc

 // RUN: %clang_tsan -O1 %s -o %t && %run %t 2>&1 | FileCheck %s
 
 // Longjmp assembly has not been implemented for mips64 yet
-// XFAIL: mips64
+// XFAIL: target-is-mips64
 
 #include <stdio.h>
 #include <stdlib.h>
 #include <setjmp.h>
 
 int foo(sigjmp_buf env) {
   printf("env=%p\n", env);
   siglongjmp(env, 42);

test/tsan/longjmp3.cc

 // RUN: %clang_tsan -O1 %s -o %t && %deflake %run %t 2>&1 | FileCheck %s
 
 // Longjmp assembly has not been implemented for mips64 yet
-// XFAIL: mips64
+// XFAIL: target-is-mips64
 
 #include <pthread.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <setjmp.h>
 
 void bar(jmp_buf env) {
   volatile int x = 42;

test/tsan/longjmp4.cc

 // RUN: %clang_tsan -O1 %s -o %t && %deflake %run %t 2>&1 | FileCheck %s
 
 // Longjmp assembly has not been implemented for mips64 yet
-// XFAIL: mips64
+// XFAIL: target-is-mips64
 
 #include <pthread.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <setjmp.h>
 #include <string.h>
 
 void bar(jmp_buf env) {

test/tsan/map32bit.cc

 // RUN: %clangxx_tsan -O1 %s -o %t && %deflake %run %t 2>&1 | FileCheck %s
 #include "test.h"
 #include <stdint.h>
 #include <errno.h>
 #include <sys/mman.h>
 
 // Test for issue:
 // https://github.com/google/sanitizers/issues/412
 
 // MAP_32BIT flag for mmap is supported only for x86_64.
-// XFAIL: mips64
+// XFAIL: target-is-mips64
 // XFAIL: aarch64
 // XFAIL: powerpc64
 
 // MAP_32BIT doesn't exist on OS X.
 // UNSUPPORTED: darwin
 
 void *Thread(void *ptr) {
   *(int*)ptr = 42;

test/tsan/signal_longjmp.cc

 // RUN: %clang_tsan -O1 %s -o %t && %run %t 2>&1 | FileCheck %s
 
 // Test case for longjumping out of signal handler:
 // https://github.com/google/sanitizers/issues/482
 
 // Longjmp assembly has not been implemented for mips64 yet
-// XFAIL: mips64
+// XFAIL: target-is-mips64
 // This test fails on powerpc64 BE (VMA=44), a segmentation fault
 // error happens at the second assignment
 // "((volatile int *volatile)mem)[1] = 1".
 // XFAIL: powerpc64-unknown-linux-gnu
 
 #include <setjmp.h>
 #include <signal.h>
 #include <stdlib.h>