Bug 761287 - Fix NDKr8 build by including Android sigcontext instead of using our own; r=ehsan

tools/profiler/android-signal-defs.h

@@ -6,14 +6,16 @@
 // Android runs a fairly new Linux kernel, so signal info is there,
 // but the C library doesn't have the structs defined.
 
-struct sigcontext {
-  uint32_t trap_no;
-  uint32_t error_code;
-  uint32_t oldmask;
-  uint32_t gregs[16];
-  uint32_t arm_cpsr;
-  uint32_t fault_address;
-};
+// All NDK platform versions have asm/sigcontext.h for ARM
+// Only NDK >= 6, platform >= 9 have asm/sigcontext.h for x86
+// Only NDK >= 8, platform >= 9 have asm/sigcontext.h for MIPS
+#if defined(__arm__) || defined(__thumb__) || ANDROID_VERSION >= 9
+#include <asm/sigcontext.h>
+#else
+#error use newer NDK or newer platform version (e.g. --with-android-version=9)
+#endif
+
+#ifndef __BIONIC_HAVE_UCONTEXT_T
 typedef uint32_t __sigset_t;
 typedef struct sigcontext mcontext_t;
 typedef struct ucontext {
@@ -23,7 +25,5 @@ typedef struct ucontext {
   mcontext_t uc_mcontext;
   __sigset_t uc_sigmask;
 } ucontext_t;
-enum ArmRegisters {R0 = 0, R1 = 1, R2 = 2, R3 = 3, R4 = 4, R5 = 5,
-                   R6 = 6, R7 = 7, R8 = 8, R9 = 9, R10 = 10,
-                   R11 = 11, R12 = 12, R13 = 13, R14 = 14, R15 = 15};
+#endif
 

tools/profiler/platform-linux.cc

@@ -54,7 +54,7 @@ pid_t gettid()
 static Sampler* sActiveSampler = NULL;
 
 
-#if !defined(__GLIBC__) && (defined(__arm__) || defined(__thumb__))
+#ifdef ANDROID
 #include "android-signal-defs.h"
 #endif
 
@@ -93,7 +93,7 @@ static void ProfilerSignalHandler(int signal, siginfo_t* info, void* context) {
     sample->fp = reinterpret_cast<Address>(mcontext.gregs[REG_RBP]);
 #elif V8_HOST_ARCH_ARM
 // An undefined macro evaluates to 0, so this applies to Android's Bionic also.
-#if (__GLIBC__ < 2 || (__GLIBC__ == 2 && __GLIBC_MINOR__ <= 3))
+#if !defined(ANDROID) && (__GLIBC__ < 2 || (__GLIBC__ == 2 && __GLIBC_MINOR__ <= 3))
     sample->pc = reinterpret_cast<Address>(mcontext.gregs[R15]);
     sample->sp = reinterpret_cast<Address>(mcontext.gregs[R13]);
     sample->fp = reinterpret_cast<Address>(mcontext.gregs[R11]);