[binutils-gdb] gdb: fix variable shadowing error in darwin-nat.c

[gdb-buildbot@sergiodj.net]

*** TEST RESULTS FOR COMMIT ab53f3826242df0f051f9a6fa4b2926687205025 ***

commit ab53f3826242df0f051f9a6fa4b2926687205025
Author:     Simon Marchi <simon.marchi@efficios.com>
AuthorDate: Thu Jan 23 17:44:22 2020 -0500
Commit:     Simon Marchi <simon.marchi@efficios.com>
CommitDate: Thu Jan 23 17:44:22 2020 -0500

    gdb: fix variable shadowing error in darwin-nat.c
    
    We encounter this error when building on macOS with GCC.
    
      CXX    darwin-nat.o
    /src-local/binutils-gdb/gdb/darwin-nat.c: In member function 'ptid_t darwin_nat_target::wait_1(ptid_t, target_waitstatus*)':
    /src-local/binutils-gdb/gdb/darwin-nat.c:1264:18: error: declaration of 'inf' shadows a previous local [-Werror=shadow=compatible-local]
       for (inferior *inf : all_inferiors (this))
                      ^~~
    /src-local/binutils-gdb/gdb/darwin-nat.c:1205:20: note: shadowed declaration is here
       struct inferior *inf;
                        ^~~
    
    Fix it by moving the declaration of `inf` in the specific scopes that
    need it.  I think it's clearer this way anyway, as it shows that it's
    not the same `inf` that is used in these different scopes.
    
    Thanks to Iain Sandoe for reporting this.  I did not see this error at
    first, because I compile with the default system compiler on macOS,
    which is clang.  The compiler flag we try to enable for this is
    `-Wshadow=local`, which is not one recognized by clang.  I checked to
    see if there would a version of the -Wshadow* warnings [1] we could
    enable for clang, that would catch this, but the only one that would is
    `-Wshadow` itself, and this is too invasive for us (which is why we
    enabled just -Wshadow=local in the first place).
    
    [1] https://clang.llvm.org/docs/DiagnosticsReference.html#wshadow
    
    gdb/ChangeLog:
    
            * darwin-nat.c (darwin_nat_target::wait_1): Move `inf`
            declaration to narrower scopes.

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index b1c437bfd2..a37affef5b 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,8 @@
+2020-01-23  Simon Marchi  <simon.marchi@efficios.com>
+
+	* darwin-nat.c (darwin_nat_target::wait_1): Move `inf`
+	declaration to narrower scopes.
+
 2020-01-23  Simon Marchi  <simon.marchi@efficios.com>
 
 	* darwin-nat.h (struct darwin_exception_msg, enum
diff --git a/gdb/darwin-nat.c b/gdb/darwin-nat.c
index 27677d16ea..3bd8d8ce00 100644
--- a/gdb/darwin-nat.c
+++ b/gdb/darwin-nat.c
@@ -1202,7 +1202,6 @@ darwin_nat_target::wait_1 (ptid_t ptid, struct target_waitstatus *status)
   mach_msg_header_t *hdr = &msgin.hdr;
   ptid_t res;
   darwin_thread_t *thread;
-  struct inferior *inf;
 
   inferior_debug
     (2, _("darwin_wait: waiting for a message pid=%d thread=%lx\n"),
@@ -1211,7 +1210,7 @@ darwin_nat_target::wait_1 (ptid_t ptid, struct target_waitstatus *status)
   /* Handle fake stop events at first.  */
   if (darwin_inf_fake_stop != NULL)
     {
-      inf = darwin_inf_fake_stop;
+      inferior *inf = darwin_inf_fake_stop;
       darwin_inf_fake_stop = NULL;
 
       darwin_inferior *priv = get_darwin_inferior (inf);
@@ -1250,6 +1249,7 @@ darwin_nat_target::wait_1 (ptid_t ptid, struct target_waitstatus *status)
       if (darwin_debug_flag > 10)
 	darwin_dump_message (hdr, darwin_debug_flag > 11);
 
+      inferior *inf;
       res = decode_message (hdr, &thread, &inf, status);
       if (res == minus_one_ptid)
 	continue;
@@ -1290,6 +1290,7 @@ darwin_nat_target::wait_1 (ptid_t ptid, struct target_waitstatus *status)
       if (darwin_debug_flag > 10)
 	darwin_dump_message (hdr, darwin_debug_flag > 11);
 
+      inferior *inf;
       ptid2 = decode_message (hdr, &thread, &inf, &status2);
 
       if (inf != NULL && thread != NULL