[test-suite] Add a simple test for class member functions in a custom section

[daltenty]

Summary

Since there were some problems with the result of these cases, leading to invalid assembly/object code on some platforms.
Fixed by https://reviews.llvm.org/D147184.

[hubert.reinterpretcast]

SingleSource/Regression/C++/custom_section_members.cpp

2

Minor nit: grammar.

13

clang-format not happy in pre-merge checks.

[hubert.reinterpretcast]

SingleSource/Regression/C++/custom_section_members.cpp

12

The second function is more likely to be misaligned and should also be called. In particular, since there was also a change recently on AIX to use integrated-as by default, nothing in the test as-is detects the misaligned branch/misaligned instruction that occurs without the fix for this issue.

[daltenty]

SingleSource/Regression/C++/custom_section_members.cpp

12

In particular, since there was also a change recently on AIX to use integrated-as by default, nothing in the test as-is detects the misaligned branch/misaligned instruction that occurs without the fix for this issue.

Yep, I think that's a limitation unfortunately since we rely on the assembler for the diagnostic. When looking at the original issue, I noticed some other Power assemblers (i.e. GNU as) would not diagnose this case either, but instead just silently correct the alignment.

[daltenty]

Address comments

[hubert.reinterpretcast]

LGTM; thanks!

[steven_wu]

This break all the Darwin Bots. MachO section names need to be __SEGMENT,__SECTION.

SingleSource/Regression/C++/custom_section_members.cpp

+// Test that we can compile a simple class with members in a custom section.
+
+struct A {
+  static int foo() __attribute__((section("section")));
+  static void bar() __attribute__((section("section")));
+};
+
+int A::foo() { return 0; }
+void A::bar() {}
+
+int main() {
+  A::bar();
+  return A::foo();
+}

SingleSource/Regression/C++/custom_section_members.reference_output

+exit 0