[sanitizer_common][test] Disable FastUnwindTest.* on SPARC

[ro]

Summary

Many of the FastUnwindTest.* tests FAIL on SPARC, both Solaris and Linux. The issue is that the fake stacks used in those tests don't match the requirements of the SPARC unwinder in sanitizer_stacktrace_sparc.cpp which has to look at the register window save area.

I'm disabling the failing tests.

Tested on sparcv9-sun-solaris2.11.

[glaubitz]

Thanks a lot Rainer for taking of all of these issues on SPARC!

[vitalybuka]

compiler-rt/lib/sanitizer_common/tests/sanitizer_stacktrace_test.cpp

72

BufferedStackTrace::UnwindFast does not work on fake stack? Can that be fixed?

[ro]

compiler-rt/lib/sanitizer_common/tests/sanitizer_stacktrace_test.cpp

72

In sanitizer_stacktrace_sparc.cpp you see that SPARC UnwindFast has to peek into the parent frame to get at the window save area. Modelling all this just for the benefit of fake stacks and a couple of testcases seems like total overkill to me.

[vitalybuka]

compiler-rt/lib/sanitizer_common/tests/sanitizer_stacktrace_test.cpp

71

Not very important but I would prefer conditional disable like here

https://github.com/llvm/llvm-project/blob/master/lldb/unittests/tools/lldb-server/tests/ThreadIdsInJstopinfoTest.cpp

[ro]

compiler-rt/lib/sanitizer_common/tests/sanitizer_stacktrace_test.cpp

71

While this would mean touching every single test instead of wrapping the whole block, OTOH it allows to skip just those tests that FAIL much less verbosely than the

#if SANITIZER_CAN_FAST_UNWIND && !defined(__sparc__)

form. I like that.

[ro]

Only disable actually failing tests using the SKIP_ON_* form.

compiler-rt/lib/sanitizer_common/tests/sanitizer_stacktrace_test.cpp

void FastUnwindTest::SetUp() {
   start_pc = PC(0);
 }
 
 void FastUnwindTest::TearDown() {
   size_t ps = GetPageSize();
   UnmapOrDie(mapping, 2 * ps);
 }
 
 #if SANITIZER_CAN_FAST_UNWIND
 
+#ifdef __sparc__
+// Fake stacks don't meet SPARC UnwindFast requirements.
+#define SKIP_ON_SPARC(x) DISABLED_##x
+#else
+#define SKIP_ON_SPARC(x) x
+#endif
+
 void FastUnwindTest::UnwindFast() {
   trace.UnwindFast(start_pc, fake_bp, fake_top, fake_bottom, kStackTraceMax);
 }
 
-TEST_F(FastUnwindTest, Basic) {
+TEST_F(FastUnwindTest, SKIP_ON_SPARC(Basic)) {
   UnwindFast();
   // Should get all on-stack retaddrs and start_pc.
   EXPECT_EQ(6U, trace.size);
   EXPECT_EQ(start_pc, trace.trace[0]);
   for (uptr i = 1; i <= 5; i++) {
     EXPECT_EQ(PC(i*2 - 1), trace.trace[i]);
   }
 }
 
 // From: https://github.com/google/sanitizers/issues/162
-TEST_F(FastUnwindTest, FramePointerLoop) {
+TEST_F(FastUnwindTest, SKIP_ON_SPARC(FramePointerLoop)) {
   // Make one fp point to itself.
   fake_stack[4] = (uhwptr)&fake_stack[4];
   UnwindFast();
   // Should get all on-stack retaddrs up to the 4th slot and start_pc.
   EXPECT_EQ(4U, trace.size);
   EXPECT_EQ(start_pc, trace.trace[0]);
   for (uptr i = 1; i <= 3; i++) {
     EXPECT_EQ(PC(i*2 - 1), trace.trace[i]);
   }
 }
 
-TEST_F(FastUnwindTest, MisalignedFramePointer) {
+TEST_F(FastUnwindTest, SKIP_ON_SPARC(MisalignedFramePointer)) {
   // Make one fp misaligned.
   fake_stack[4] += 3;
   UnwindFast();
   // Should get all on-stack retaddrs up to the 4th slot and start_pc.
   EXPECT_EQ(4U, trace.size);
   EXPECT_EQ(start_pc, trace.trace[0]);
   for (uptr i = 1; i < 4U; i++) {
     EXPECT_EQ(PC(i*2 - 1), trace.trace[i]);
   }
 }
 
 TEST_F(FastUnwindTest, OneFrameStackTrace) {
   trace.Unwind(start_pc, fake_bp, nullptr, true, 1);
   EXPECT_EQ(1U, trace.size);
   EXPECT_EQ(start_pc, trace.trace[0]);
   EXPECT_EQ((uhwptr)&fake_stack[0], trace.top_frame_bp);
 }
 
 TEST_F(FastUnwindTest, ZeroFramesStackTrace) {
   trace.Unwind(start_pc, fake_bp, nullptr, true, 0);
   EXPECT_EQ(0U, trace.size);
   EXPECT_EQ(0U, trace.top_frame_bp);
 }
 
-TEST_F(FastUnwindTest, FPBelowPrevFP) {
+TEST_F(FastUnwindTest, SKIP_ON_SPARC(FPBelowPrevFP)) {
   // The next FP points to unreadable memory inside the stack limits, but below
   // current FP.
   fake_stack[0] = (uhwptr)&fake_stack[-50];
   fake_stack[1] = PC(1);
   UnwindFast();
   EXPECT_EQ(2U, trace.size);
   EXPECT_EQ(PC(0), trace.trace[0]);
   EXPECT_EQ(PC(1), trace.trace[1]);
 }
 
-TEST_F(FastUnwindTest, CloseToZeroFrame) {
+TEST_F(FastUnwindTest, SKIP_ON_SPARC(CloseToZeroFrame)) {
   // Make one pc a NULL pointer.
   fake_stack[5] = 0x0;
   UnwindFast();
   // The stack should be truncated at the NULL pointer (and not include it).
   EXPECT_EQ(3U, trace.size);
   EXPECT_EQ(start_pc, trace.trace[0]);
   for (uptr i = 1; i < 3U; i++) {
     EXPECT_EQ(PC(i*2 - 1), trace.trace[i]);