Use getauxval() if available.

src/sampler.cc

 // Copyright 2013 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/sampler.h"
 
 #if V8_OS_POSIX && !V8_OS_CYGWIN
 
 #define USE_SIGNALS
 
@@ skipping 356 matching lines @@
 #if V8_OS_LINUX
 #if V8_HOST_ARCH_IA32
   state.pc = reinterpret_cast<Address>(mcontext.gregs[REG_EIP]);
   state.sp = reinterpret_cast<Address>(mcontext.gregs[REG_ESP]);
   state.fp = reinterpret_cast<Address>(mcontext.gregs[REG_EBP]);
 #elif V8_HOST_ARCH_X64
   state.pc = reinterpret_cast<Address>(mcontext.gregs[REG_RIP]);
   state.sp = reinterpret_cast<Address>(mcontext.gregs[REG_RSP]);
   state.fp = reinterpret_cast<Address>(mcontext.gregs[REG_RBP]);
 #elif V8_HOST_ARCH_ARM
-#if defined(__GLIBC__) && !defined(__UCLIBC__) && \
-    (__GLIBC__ < 2 || (__GLIBC__ == 2 && __GLIBC_MINOR__ <= 3))
+#if V8_LIBC_GLIBC && !V8_GLIBC_PREREQ(2, 4)
   // Old GLibc ARM versions used a gregs[] array to access the register
   // values from mcontext_t.
   state.pc = reinterpret_cast<Address>(mcontext.gregs[R15]);
   state.sp = reinterpret_cast<Address>(mcontext.gregs[R13]);
   state.fp = reinterpret_cast<Address>(mcontext.gregs[R11]);
 #else
   state.pc = reinterpret_cast<Address>(mcontext.arm_pc);
   state.sp = reinterpret_cast<Address>(mcontext.arm_sp);
   state.fp = reinterpret_cast<Address>(mcontext.arm_fp);
-#endif  // defined(__GLIBC__) && !defined(__UCLIBC__) &&
-        // (__GLIBC__ < 2 || (__GLIBC__ == 2 && __GLIBC_MINOR__ <= 3))
+#endif  // V8_LIBC_GLIBC && !V8_GLIBC_PREREQ(2, 4)
 #elif V8_HOST_ARCH_ARM64
   state.pc = reinterpret_cast<Address>(mcontext.pc);
   state.sp = reinterpret_cast<Address>(mcontext.sp);
   // FP is an alias for x29.
   state.fp = reinterpret_cast<Address>(mcontext.regs[29]);
 #elif V8_HOST_ARCH_MIPS
   state.pc = reinterpret_cast<Address>(mcontext.pc);
   state.sp = reinterpret_cast<Address>(mcontext.gregs[29]);
   state.fp = reinterpret_cast<Address>(mcontext.gregs[30]);
 #elif V8_HOST_ARCH_MIPS64
@@ skipping 357 matching lines @@
 #endif  // USE_SIMULATOR
     SampleStack(state);
   }
   ResumeThread(profiled_thread);
 }
 
 #endif  // USE_SIGNALS
 
 
 } }  // namespace v8::internal