Finish mathomizing Perl_instr.

fea1d2dd5d210564d4 turned instr into a macro.  It also left the
actual function in util.c while commenting out the prototype
in proto.h (via the m flag in embed.fnc).

A function compiled without a prototype under C++ does not get
declared with extern "C" and thus gets mangled, which breaks the
build with a strict linker (VMS, possibly AIX) because the
expected symbol name is no longer produced.  Without a strict
linker, it just breaks the binary compatibility that was presumably
the nominal reason for leaving the function around in the first
place.

So move the function into mathoms.c and put its prototype in the
extern "C"-guarded section at the top of the same file.

We also have to fake the PERL_ARGS_ASSERT_INSTR macro since its
original declaration in proto.h is commented out but the porting
test t/porting/args_assert.t will take revenge if it doesn't
find the macro being used somewhere.

1 files changed, 20 insertions, 0 deletions

diff --git a/mathoms.c b/mathoms.c
index 3187782a8c..d530cc03e0 100644
--- a/mathoms.c
+++ b/mathoms.c
@@ -107,6 +107,9 @@ PERL_CALLCONV UV Perl_to_utf8_title(pTHX_ const U8 *p, U8* ustrp, STRLEN *lenp);
 PERL_CALLCONV UV Perl_to_utf8_upper(pTHX_ const U8 *p, U8* ustrp, STRLEN *lenp);
 PERL_CALLCONV UV Perl_to_utf8_fold(pTHX_ const U8 *p, U8* ustrp, STRLEN *lenp);
 PERL_CALLCONV SV *Perl_sv_mortalcopy(pTHX_ SV *const oldstr);
+PERL_CALLCONV char*	Perl_instr(const char* big, const char* little)
+			__attribute__warn_unused_result__
+			__attribute__pure__;
 
 /* ref() is now a macro using Perl_doref;
  * this version provided for binary compatibility only.
@@ -1808,6 +1811,23 @@ Perl_pad_compname_type(pTHX_ const PADOFFSET po)
     return PAD_COMPNAME_TYPE(po);
 }
 
+/* now a macro */
+/* return ptr to little string in big string, NULL if not found */
+/* This routine was donated by Corey Satten. */
+
+char *
+Perl_instr(const char *big, const char *little)
+{
+    /* Porting tests require this macro to be used even though it doesn't exist
+     * (except for the commented-out version in proto.h).  So provide a commented-out
+     * "use" of the prototype and supply a real version of what it expanded to.
+    PERL_ARGS_ASSERT_INSTR;
+    */
+    assert(big);
+    assert(little);
+
+    return strstr((char*)big, (char*)little);
+}
 
 END_EXTERN_C