Support powerpc and sparc when building without init_array.

[saugustine]

Summary

Support powerpc and sparc when building without init_array.

[echristo]

Looks ok to me.

[saugustine]

Submitted as 1d891a32cf433e205b5d30697beb265dc0e1f248

[vvereschaka]

Hi Sterling Augustine,

these changes broke the aarch64 toolchain build http://lab.llvm.org:8011/builders/llvm-clang-win-x-aarch64/builds/2108
with those error messages "crtbegin without .init_fini array unimplemented for this architecture".

Would you update the patch and avoid displaying of those error messages for other platforms?

[saugustine]

In D71944#1798505, @vvereschaka wrote:

Would you update the patch and avoid displaying of those error messages for other platforms?

https://reviews.llvm.org/D72005 adds support for aarch64. However, updating this so that no error message is reported seems wrong to me.

Before this patch, those files as they had been compiled are buggy. Using them results in subtly broken binaries, and figuring out what is wrong is quite challenging (ask me how I know!). I suspect your target had been building them, and then ignoring the result. But producing a broken file and hoping that the target doesn't use it seems like a bad idea.

[vvereschaka]

Thank you Sterling, I agree.

Currently we don't run the library tests on the target devices (aarch64) for this builder, but we plan doing that very soon.

compiler-rt/lib/crt/crtbegin.c

#ifndef CRT_HAS_INITFINI_ARRAY
   const size_t n = __CTOR_LIST_END__ - __CTOR_LIST__ - 1;
   for (size_t i = n; i >= 1; i--) __CTOR_LIST__[i]();
 #endif
 }
 
 #ifdef CRT_HAS_INITFINI_ARRAY
 __attribute__((section(".init_array"),
                used)) static void (*__init)(void) = __do_init;
-#else  // CRT_HAS_INITFINI_ARRAY
-#if defined(__i386__) || defined(__x86_64__)
+#elif defined(__i386__) || defined(__x86_64__)
 __asm__(".pushsection .init,\"ax\",@progbits\n\t"
     "call " __USER_LABEL_PREFIX__ "__do_init\n\t"
     ".popsection");
 #elif defined(__arm__)
 __asm__(".pushsection .init,\"ax\",%progbits\n\t"
     "bl " __USER_LABEL_PREFIX__ "__do_init\n\t"
     ".popsection");
-#endif  // CRT_HAS_INITFINI_ARRAY
-#endif
+#elif defined(__powerpc__) || defined(__powerpc64__)
+__asm__(".pushsection .init,\"ax\",@progbits\n\t"
+    "bl " __USER_LABEL_PREFIX__ "__do_init\n\t"
+    "nop\n\t"
+    ".popsection");
+#elif defined(__sparc__)
+__asm__(".pushsection .init,\"ax\",@progbits\n\t"
+    "call " __USER_LABEL_PREFIX__ "__do_init\n\t"
+    ".popsection");
+#else
+#error "crtbegin without .init_fini array unimplemented for this architecture"
+#endif // CRT_HAS_INITFINI_ARRAY
 
 #ifndef CRT_HAS_INITFINI_ARRAY
 static fp __DTOR_LIST__[]
     __attribute__((section(".dtors"), aligned(sizeof(fp)))) = {(fp)-1};
 extern fp __DTOR_LIST_END__[];
 #endif
 
 static void __attribute__((used)) __do_fini() {
#ifdef EH_USE_FRAME_REGISTRY
   if (__deregister_frame_info)
     __deregister_frame_info(__EH_FRAME_LIST__);
 #endif
 }
 
 #ifdef CRT_HAS_INITFINI_ARRAY
 __attribute__((section(".fini_array"),
                used)) static void (*__fini)(void) = __do_fini;
-#else  // CRT_HAS_INITFINI_ARRAY
-#if defined(__i386__) || defined(__x86_64__)
+#elif defined(__i386__) || defined(__x86_64__)
 __asm__(".pushsection .fini,\"ax\",@progbits\n\t"
     "call " __USER_LABEL_PREFIX__ "__do_fini\n\t"
     ".popsection");
 #elif defined(__arm__)
 __asm__(".pushsection .fini,\"ax\",%progbits\n\t"
     "bl " __USER_LABEL_PREFIX__ "__do_fini\n\t"
     ".popsection");
-#endif
+#elif defined(__powerpc__) || defined(__powerpc64__)
+__asm__(".pushsection .fini,\"ax\",@progbits\n\t"
+    "bl " __USER_LABEL_PREFIX__ "__do_fini\n\t"
+    "nop\n\t"
+    ".popsection");
+#elif defined(__sparc__)
+__asm__(".pushsection .fini,\"ax\",@progbits\n\t"
+    "call " __USER_LABEL_PREFIX__ "__do_fini\n\t"
+    ".popsection");
+#else
+#error "crtbegin without .init_fini array unimplemented for this architecture"
 #endif  // CRT_HAS_INIT_FINI_ARRAY