Smoke me/fix caller issues

MANIFEST

@@ -5639,6 +5639,10 @@ t/lib/feature/nonesuch		Tests for enabling/disabling nonexistent feature
 t/lib/feature/removed		Tests for enabling/disabling removed feature
 t/lib/feature/say		Tests for enabling/disabling say feature
 t/lib/feature/switch		Tests for enabling/disabling switch feature
+t/lib/GH_15109/Apack.pm		test Module for caller.t
+t/lib/GH_15109/Bpack.pm		test Module for caller.t
+t/lib/GH_15109/Cpack.pm		test Module for caller.t
+t/lib/GH_15109/Foo.pm		test Module for caller.t
 t/lib/h2ph.h			Test header file for h2ph
 t/lib/h2ph.pht			Generated output from h2ph.h by h2ph, for comparison
 t/lib/locale/latin1		Part of locale.t in Latin 1

op.c

@@ -11742,10 +11742,31 @@ S_process_special_blocks(pTHX_ I32 floor, const char *const fullname,
             (void)CvGV(cv);
 	    if (floor) LEAVE_SCOPE(floor);
 	    ENTER;
+
+            SAVEVPTR(PL_curcop);
+            if (PL_curcop == &PL_compiling) {
+                /* Avoid pushing the "global" &PL_compiling onto the
+                 * context stack. For example, a stack trace inside
+                 * nested use's would show all calls coming from whoever
+                 * most recently updated PL_compiling.cop_file and
+                 * cop_line.  So instead, temporarily set PL_curcop to a
+                 * private copy of &PL_compiling. PL_curcop will soon be
+                 * set to point back to &PL_compiling anyway but only
+                 * after the temp value has been pushed onto the context
+                 * stack as blk_oldcop.
+                 * This is slightly hacky, but necessary. Note also
+                 * that in the brief window before PL_curcop is set back
+                 * to PL_compiling, IN_PERL_COMPILETIME/IN_PERL_RUNTIME
+                 * will give the wrong answer.
+                 */
+                PL_curcop = (COP*)newSTATEOP(PL_compiling.op_flags, NULL, NULL);
+                CopLINE_set(PL_curcop, CopLINE(&PL_compiling));
+                SAVEFREEOP(PL_curcop);
+            }
+
             PUSHSTACKi(PERLSI_REQUIRE);
 	    SAVECOPFILE(&PL_compiling);
 	    SAVECOPLINE(&PL_compiling);
-	    SAVEVPTR(PL_curcop);
 
 	    DEBUG_x( dump_sub(gv) );
 	    Perl_av_create_and_push(aTHX_ &PL_beginav, MUTABLE_SV(cv));

pod/perlvar.pod

@@ -1879,6 +1879,10 @@ It has the same scoping as the C<$^H> and C<%^H> variables.  The exact
 values are considered internal to the L<warnings> pragma and may change
 between versions of Perl.
 
+Each time a statement completes being compiled, the current value of
+C<${^WARNING_BITS}> is stored with that statement, and can later be
+retrieved via C<(caller($level))[9]>.
+
 This variable was added in Perl v5.6.0.
 
 =item $OS_ERROR
@@ -2175,6 +2179,10 @@ This variable contains compile-time hints for the Perl interpreter.  At the
 end of compilation of a BLOCK the value of this variable is restored to the
 value when the interpreter started to compile the BLOCK.
 
+Each time a statement completes being compiled, the current value of
+C<$^H> is stored with that statement, and can later be retrieved via
+C<(caller($level))[8]>.
+
 When perl begins to parse any block construct that provides a lexical scope
 (e.g., eval body, required file, subroutine body, loop body, or conditional
 block), the existing value of C<$^H> is saved, but its value is left unchanged.
@@ -2223,6 +2231,10 @@ L<perlpragma>.   All the entries are stringified when accessed at
 runtime, so only simple values can be accommodated.  This means no
 pointers to objects, for example.
 
+Each time a statement completes being compiled, the current value of
+C<%^H> is stored with that statement, and can later be retrieved via
+C<(caller($level))[10]>.
+
 When putting items into C<%^H>, in order to avoid conflicting with other
 users of the hash there is a convention regarding which keys to use.
 A module should use only keys that begin with the module's name (the

t/lib/GH_15109/Apack.pm

@@ -0,0 +1,4 @@
+# for use by caller.t for GH #15109
+package Apack;
+use Bpack;
+1;

t/lib/GH_15109/Bpack.pm

@@ -0,0 +1,4 @@
+# for use by caller.t for GH #15109
+package Bpack;
+use Cpack;
+1;

t/lib/GH_15109/Cpack.pm

@@ -0,0 +1,11 @@
+# for use by caller.t for GH #15109
+package Cpack;
+
+
+my $i = 0;
+
+while (my ($package, $file, $line) = caller($i++)) {
+    push @Cpack::callers, "$file:$line";
+}
+
+1;

t/lib/GH_15109/Foo.pm

@@ -0,0 +1,9 @@
+# for use by caller.t for GH #15109
+
+package Foo;
+
+sub import {
+    use warnings; # restore default warnings
+    () = caller(1); # this used to cause valgrind errors
+}
+1;

t/op/caller.t

@@ -5,7 +5,7 @@ BEGIN {
     chdir 't' if -d 't';
     require './test.pl';
     set_up_inc('../lib');
-    plan( tests => 97 ); # some tests are run in a BEGIN block
+    plan( tests => 111 ); # some tests are run in a BEGIN block
 }
 
 my @c;
@@ -335,16 +335,45 @@ $::testing_caller = 1;
 
 do './op/caller.pl' or die $@;
 
+# GH #15109
+# See that callers within a nested series of 'use's gets the right
+# filenames.
+{
+    local @INC = 'lib/GH_15109/';
+    # Apack use's Bpack which use's Cpack which populates @Cpack::caller
+    # with the file:N of all the callers
+    eval 'use Apack; 1';
+    is($@, "", "GH #15109 - eval");
+    is (scalar(@Cpack::callers), 10, "GH #15109 - callers count");
+    like($Cpack::callers[$_], qr{GH_15109/Bpack.pm:3}, "GH #15109 level $_") for 0..2;
+    like($Cpack::callers[$_], qr{GH_15109/Apack.pm:3}, "GH #15109 level $_") for 3..5;
+    like($Cpack::callers[$_], qr{\(eval \d+\):1}, "GH #15109 level $_") for 6..8;
+    like($Cpack::callers[$_], qr{caller\.t}, "GH #15109 level $_") for 9;
+
+    # GH #15109 followup - the original fix wasn't saving cop_warnings
+    # correctly and this code used to crash or fail valgrind
+
+    my $w = 0;
+    local $SIG{__WARN__} = sub { $w++ };
+    eval q{
+        use warnings;
+        no warnings 'numeric'; # ensure custom cop_warnings
+        use Foo;      # this used to mess up warnings flags
+        BEGIN { my $x = "foo" + 1; } # potential "numeric" warning
+    };
+    is ($@, "", "GH #15109 - eval okay");
+    is ($w, 0, "GH #15109 - warnings restored");
+}
+
 {
     package RT129239;
     BEGIN {
         my ($pkg, $file, $line) = caller;
         ::is $file, 'virtually/op/caller.t', "BEGIN block sees correct caller filename";
         ::is $line, 12345,                   "BEGIN block sees correct caller line";
-        TODO: {
-            local $::TODO = "BEGIN blocks have wrong caller package [perl #129239]";
-            ::is $pkg, 'RT129239',               "BEGIN block sees correct caller package";
-        }
+        ::is $pkg, 'RT129239',               "BEGIN block sees correct caller package";
 #line 12345 "virtually/op/caller.t"
     }
+
 }
+