New common function "startswith"

This commit introduces a new inline common function "startswith"
which takes two string arguments and returns nonzero if the first
string starts with the second.  It also updates the 295 places
where this logic was written out longhand to use the new function.

gdb/ChangeLog:

	* common/common-utils.h (startswith): New inline function.
	All places where this logic was used updated to use the above.

1 files changed, 11 insertions, 17 deletions

diff --git a/gdb/arm-tdep.c b/gdb/arm-tdep.c
index d7cd6e5..630a207 100644
--- a/gdb/arm-tdep.c
+++ b/gdb/arm-tdep.c
@@ -484,15 +484,15 @@ skip_prologue_function (struct gdbarch *gdbarch, CORE_ADDR pc, int is_thumb)
       /* On soft-float targets, __truncdfsf2 is called to convert promoted
 	 arguments to their argument types in non-prototyped
 	 functions.  */
-      if (strncmp (name, "__truncdfsf2", strlen ("__truncdfsf2")) == 0)
+      if (startswith (name, "__truncdfsf2"))
 	return 1;
-      if (strncmp (name, "__aeabi_d2f", strlen ("__aeabi_d2f")) == 0)
+      if (startswith (name, "__aeabi_d2f"))
 	return 1;
 
       /* Internal functions related to thread-local storage.  */
-      if (strncmp (name, "__tls_get_addr", strlen ("__tls_get_addr")) == 0)
+      if (startswith (name, "__tls_get_addr"))
 	return 1;
-      if (strncmp (name, "__aeabi_read_tp", strlen ("__aeabi_read_tp")) == 0)
+      if (startswith (name, "__aeabi_read_tp"))
 	return 1;
     }
   else
@@ -1314,9 +1314,7 @@ arm_skip_stack_protector(CORE_ADDR pc, struct gdbarch *gdbarch)
   /* ADDR must correspond to a symbol whose name is __stack_chk_guard.
      Otherwise, this sequence cannot be for stack protector.  */
   if (stack_chk_guard.minsym == NULL
-      || strncmp (MSYMBOL_LINKAGE_NAME (stack_chk_guard.minsym),
-		  "__stack_chk_guard",
-		  strlen ("__stack_chk_guard")) != 0)
+      || !startswith (MSYMBOL_LINKAGE_NAME (stack_chk_guard.minsym), "__stack_chk_guard"))
    return pc;
 
   if (is_thumb)
@@ -1413,10 +1411,8 @@ arm_skip_prologue (struct gdbarch *gdbarch, CORE_ADDR pc)
       if (post_prologue_pc
 	  && (cust == NULL
 	      || COMPUNIT_PRODUCER (cust) == NULL
-	      || strncmp (COMPUNIT_PRODUCER (cust), "GNU ",
-			  sizeof ("GNU ") - 1) == 0
-	      || strncmp (COMPUNIT_PRODUCER (cust), "clang ",
-			  sizeof ("clang ") - 1) == 0))
+	      || startswith (COMPUNIT_PRODUCER (cust), "GNU ")
+	      || startswith (COMPUNIT_PRODUCER (cust), "clang ")))
 	return post_prologue_pc;
 
       if (post_prologue_pc != 0)
@@ -9315,8 +9311,8 @@ arm_skip_stub (struct frame_info *frame, CORE_ADDR pc)
      _call_via_xx, where x is the register name.  The possible names
      are r0-r9, sl, fp, ip, sp, and lr.  ARM RealView has similar
      functions, named __ARM_call_via_r[0-7].  */
-  if (strncmp (name, "_call_via_", 10) == 0
-      || strncmp (name, "__ARM_call_via_", strlen ("__ARM_call_via_")) == 0)
+  if (startswith (name, "_call_via_")
+      || startswith (name, "__ARM_call_via_"))
     {
       /* Use the name suffix to determine which register contains the
          target PC.  */
@@ -9338,11 +9334,9 @@ arm_skip_stub (struct frame_info *frame, CORE_ADDR pc)
   namelen = strlen (name);
   if (name[0] == '_' && name[1] == '_'
       && ((namelen > 2 + strlen ("_from_thumb")
-	   && strncmp (name + namelen - strlen ("_from_thumb"), "_from_thumb",
-		       strlen ("_from_thumb")) == 0)
+	   && startswith (name + namelen - strlen ("_from_thumb"), "_from_thumb"))
 	  || (namelen > 2 + strlen ("_from_arm")
-	      && strncmp (name + namelen - strlen ("_from_arm"), "_from_arm",
-			  strlen ("_from_arm")) == 0)))
+	      && startswith (name + namelen - strlen ("_from_arm"), "_from_arm"))))
     {
       char *target_name;
       int target_len = namelen - 2;