Refactor print_pc()

Split print_pc() into arch-independent print_instruction_pointer()
and arch-specific get_instruction_pointer().

* print_instruction_pointer.c: New file.
* Makefile.am (strace_SOURCES): Add it.
* defs.h (print_pc): Remove.
(get_instruction_pointer, print_instruction_pointer): New prototypes.
* syscall.c (print_pc): Remove.
(get_instruction_pointer): New function.
* strace.c (printleader): Replace print_pc with
print_instruction_pointer.

Makefile.am

@@ -248,6 +248,7 @@ strace_SOURCES =	\
 	print_group_req.c \
 	print_fields.h	\
 	print_ifindex.c	\
+	print_instruction_pointer.c \
 	print_mac.c	\
 	print_mq_attr.c	\
 	print_msgbuf.c	\

defs.h

@@ -441,7 +441,9 @@ extern int read_int_from_file(struct tcb *, const char *, int *);
 
 extern void set_sortby(const char *);
 extern void set_overhead(int);
-extern void print_pc(struct tcb *);
+
+extern bool get_instruction_pointer(struct tcb *, kernel_ulong_t *);
+extern void print_instruction_pointer(struct tcb *);
 
 extern int syscall_entering_decode(struct tcb *);
 extern int syscall_entering_trace(struct tcb *, unsigned int *);

print_instruction_pointer.c

@@ -0,0 +1,44 @@
+/*
+ * Copyright (c) 1999-2018 The strace developers.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "defs.h"
+
+void
+print_instruction_pointer(struct tcb *tcp)
+{
+	kernel_ulong_t ip;
+
+	if (get_instruction_pointer(tcp, &ip)) {
+		tprintf(current_wordsize == 4
+			? "[%08" PRI_klx "] "
+			: "[%016" PRI_klx "] ", ip);
+	} else {
+		tprints(current_wordsize == 4
+			? "[????????] "
+			: "[????????????????] ");
+	}
+}

strace.c

@@ -692,7 +692,7 @@ printleader(struct tcb *tcp)
 	}
 
 	if (iflag)
-		print_pc(tcp);
+		print_instruction_pointer(tcp);
 }
 
 void

syscall.c

@@ -998,27 +998,6 @@ restore_cleared_syserror(struct tcb *tcp)
 # include "arch_getrval2.c"
 #endif
 
-void
-print_pc(struct tcb *tcp)
-{
-#if defined ARCH_PC_REG
-# define ARCH_GET_PC 0
-#elif defined ARCH_PC_PEEK_ADDR
-	kernel_ulong_t pc;
-# define ARCH_PC_REG pc
-# define ARCH_GET_PC upeek(tcp, ARCH_PC_PEEK_ADDR, &pc)
-#else
-# error Neither ARCH_PC_REG nor ARCH_PC_PEEK_ADDR is defined
-#endif
-	if (get_regs(tcp) < 0 || ARCH_GET_PC)
-		tprints(current_wordsize == 4 ? "[????????] "
-					      : "[????????????????] ");
-	else
-		tprintf(current_wordsize == 4
-			? "[%08" PRI_klx "] " : "[%016" PRI_klx "] ",
-			(kernel_ulong_t) ARCH_PC_REG);
-}
-
 #include "getregs_old.h"
 
 #undef ptrace_getregset_or_getregs
@@ -1199,6 +1178,23 @@ free_sysent_buf(void *ptr)
 	free(ptr);
 }
 
+bool
+get_instruction_pointer(struct tcb *tcp, kernel_ulong_t *ip)
+{
+#if defined ARCH_PC_REG
+	if (get_regs(tcp) < 0)
+		return false;
+	*ip = (kernel_ulong_t) ARCH_PC_REG;
+	return true;
+#elif defined ARCH_PC_PEEK_ADDR
+	if (upeek(tcp, ARCH_PC_PEEK_ADDR, ip) < 0)
+		return false;
+	return true;
+#else
+# error Neither ARCH_PC_REG nor ARCH_PC_PEEK_ADDR is defined
+#endif
+}
+
 /*
  * Returns:
  * 0: "ignore this ptrace stop", syscall_entering_decode() should return a "bail