First cut at adding arm64 Linux / Android support to Breakpad.

This is an initial attempt to add Arm64 (aarch64) support to Breakpad for
Linux / Android platforms.  This CL adds the Arm64 data structures, but does
not yet implement the Android getcontext support or CPUFillFromThreadInfo /
CPUFillFromUContext.

BUG=354405,335641
R=mark@chromium.org

Review URL: https://breakpad.appspot.com/1354002

git-svn-id: http://google-breakpad.googlecode.com/svn/trunk@1301 4c0a9323-5329-0410-9bdc-e9ce6186880e

src/common/android/breakpad_getcontext.S

@@ -140,6 +140,10 @@ breakpad_getcontext:
 
   .size breakpad_getcontext, . - breakpad_getcontext
 
+#elif defined(__aarch64__)
+
+ // TODO(rmcilroy): Implement for arm64.
+
 #elif defined(__mips__)
 
 #if _MIPS_SIM != _ABIO32

src/common/android/include/elf.h

@@ -38,7 +38,7 @@ extern "C" {
 #endif  // __cplusplus
 
 // The Android <elf.h> provides BSD-based definitions for the ElfXX_Nhdr
-// types 
+// types
 // always source-compatible with the GLibc/kernel ones. To overcome this
 // issue without modifying a lot of code in Breakpad, use an ugly macro
 // renaming trick with #include_next
@@ -110,9 +110,14 @@ typedef struct {
 
 
 // __WORDSIZE is GLibc-specific and used by Google Breakpad on Linux.
-// All Android platforms are 32-bit for now.
 #ifndef __WORDSIZE
+#if defined(__i386__) ||  defined(__ARM_EABI__) || defined(__mips__)
 #define __WORDSIZE 32
+#elif defined(__x86_64__) || defined(__aarch64__)
+#define __WORDSIZE 64
+#else
+#error "Unsupported Android CPU ABI"
+#endif
 #endif
 
 // The Android headers don't always define this constant.

src/common/android/include/link.h

@@ -34,6 +34,10 @@
    Provide custom version here. */
 #include_next <link.h>
 
+// TODO(rmcilroy): Remove this file once the ndk is updated for other
+// architectures - crbug.com/358831
+#if !defined(__aarch64__) && !defined(__x86_64__)
+
 #ifdef __cplusplus
 extern "C" {
 #endif  // __cplusplus
@@ -61,4 +65,6 @@ struct link_map {
 }  // extern "C"
 #endif  // __cplusplus
 
+#endif  // !defined(__aarch64__) && !defined(__x86_64__)
+
 #endif /* GOOGLE_BREAKPAD_ANDROID_INCLUDE_LINK_H */

src/common/android/include/sys/procfs.h

@@ -44,7 +44,7 @@
 extern "C" {
 #endif  // __cplusplus
 
-#ifdef __x86_64__
+#if defined(__x86_64__) || defined(__aarch64__)
 typedef unsigned long long elf_greg_t;
 #else
 typedef unsigned long  elf_greg_t;
@@ -52,6 +52,8 @@ typedef unsigned long  elf_greg_t;
 
 #ifdef __arm__
 #define ELF_NGREG (sizeof(struct user_regs) / sizeof(elf_greg_t))
+#elif defined(__aarch64__)
+#define ELF_NGREG (sizeof(struct user_pt_regs) / sizeof(elf_greg_t))
 #else
 #define ELF_NGREG (sizeof(struct user_regs_struct) / sizeof(elf_greg_t))
 #endif

src/common/android/include/sys/ucontext.h

@@ -62,6 +62,19 @@ typedef struct ucontext {
   // Other fields are not used by Google Breakpad. Don't define them.
 } ucontext_t;
 
+#elif defined(__aarch64__)
+
+#include <asm/sigcontext.h>
+typedef struct sigcontext mcontext_t;
+
+typedef struct ucontext {
+  unsigned long uc_flags;
+  struct ucontext *uc_link;
+  stack_t uc_stack;
+  sigset_t uc_sigmask;
+  mcontext_t uc_mcontext;
+} ucontext_t;
+
 #elif defined(__i386__)
 
 /* 80-bit floating-point register */

src/common/android/include/sys/user.h

@@ -75,6 +75,11 @@ struct user_vfpregs {
   unsigned long       fpscr;
 };
 
+#elif defined(__aarch64__)
+
+// aarch64 does not have user_regs definitions in <asm/user.h>, instead
+// use the definitions in <asm/ptrace.h>, which we don't need to redefine here.
+
 #elif defined(__i386__)
 
 #define _I386_USER_H 1  // Prevent <asm/user.h> conflicts

src/common/android/ucontext_constants.h

@@ -45,6 +45,11 @@
 #define  MCONTEXT_GREGS_OFFSET     32
 #define  UCONTEXT_SIGMASK_OFFSET   104
 
+#elif defined(__aarch64__)
+
+#define  MCONTEXT_GREGS_OFFSET     56
+#define  UCONTEXT_SIGMASK_OFFSET   40
+
 #elif defined(__i386__)
 
 #define  MCONTEXT_GREGS_OFFSET     20