* i386-prologue.exp: Add testcase for jump instruction as first

instruction of the real code.
* i386-prologue.c (jump_at_beginning): New function.

2 files changed, 31 insertions, 0 deletions

diff --git a/gdb/testsuite/gdb.arch/i386-prologue.c b/gdb/testsuite/gdb.arch/i386-prologue.c
index 4c92a9c..33fc1db 100644
--- a/gdb/testsuite/gdb.arch/i386-prologue.c
+++ b/gdb/testsuite/gdb.arch/i386-prologue.c
@@ -1,11 +1,13 @@
 void gdb1253 (void);
 void gdb1338 (void);
+void jump_at_beginning (void);
 
 int
 main (void)
 {
   gdb1253 ();
   gdb1338 ();
+  jump_at_beginning ();
   return 0;
 }
 
@@ -35,3 +37,19 @@ asm(".text\n"
     "    popl  %esi\n"
     "    popl  %edi\n"
     "    ret\n");
+
+/* The purpose of this function is to verify that, during prologue
+   skip, GDB does not follow a jump at the beginnning of the "real"
+   code.  */
+
+asm(".text\n"
+    "    .align 8\n"
+    "jump_at_beginning:\n"
+    "    pushl %ebp\n"
+    "    movl  %esp,%ebp\n"
+    "    jmp   .gdbjump\n"
+    "    nop\n"
+    ".gdbjump:\n"
+    "    movl  %ebp,%esp\n"
+    "    popl  %ebp\n"
+    "    ret\n");
diff --git a/gdb/testsuite/gdb.arch/i386-prologue.exp b/gdb/testsuite/gdb.arch/i386-prologue.exp
index f1c1e72..ea04b53 100644
--- a/gdb/testsuite/gdb.arch/i386-prologue.exp
+++ b/gdb/testsuite/gdb.arch/i386-prologue.exp
@@ -76,3 +76,16 @@ gdb_test "backtrace 10" \
 gdb_test "info frame" \
 	".*Saved registers:.*ebx at.*esi at.*edi at.*eip at.*" \
 	"saved registers in gdb1338"
+
+# Testcase jump_at_beginning.
+gdb_test_multiple "break jump_at_beginning" \
+	"set breakpoint in jump_at_beginning" {
+    -re "Breakpoint \[0-9\]* at ($hex).*$gdb_prompt $" {
+	gdb_test "x/i $expect_out(1,string)" \
+		".*<jump_at_beginning.*>:.*jmp.*" \
+		"check jump_at_beginning prologue end"
+    }
+    default {
+        fail "set breakpoint in jump_at_beginning"
+    }
+}