Error: The function "strlen" must have a prototype.

avysotsk commented 8 years ago

I'm trying to build BSL on Solaris with Oracle Solaris Studio compilers. I stopped in the build step with the error: $ CC -library=stlport4 -DBDE_BUILD_TARGET_STLPORT -template=no%extdef -xcode=pic32 -m64 -xtarget=generic -DBDE_BUILD_TARGET_EXC -DBDE_BUILD_TARGET_MT -DBDE_BUILD_TARGET_OPT -m64 -xtarget=generic -xthreadvar=dynamic -xannotate=no -features=except -xO3 -DNDEBUG -xbuiltin=%all -D_POSIX_PTHREAD_SEMANTICS -mt -DBSLS_IDENT_OFF -library=no%rwtools7 -xcode=pic32 -DPIC -I/BSL/gcc/new/bde/groups/bdl/bdlb -I/BSL/gcc/new/bde/groups/bdl/bdlf -I/BSL/gcc/new/bde/groups/bdl/bdlscm -I/BSL/gcc/new/bde/groups/bsl/bsls -I/BSL/gcc/new/bde/groups/bsl/bslscm -I/BSL/gcc/new/bde/groups/bsl/bsldoc -I/BSL/gcc/new/bde/groups/bsl/bslmf -I/BSL/gcc/new/bde/groups/bsl/bslma -I/BSL/gcc/new/bde/groups/bsl/bslalg -I/BSL/gcc/new/bde/groups/bsl/bslh -I/BSL/gcc/new/bde/groups/bsl/bsltf -I/BSL/gcc/new/bde/groups/bsl/bslstl -I/BSL/gcc/new/bde/groups/bsl/bsl+bslhdrs -I/BSL/gcc/new/bde/groups/bsl/bsl+stdhdrs -I/BSL/gcc/new/bde/groups/bsl/bslim -I/BSL/gcc/new/bde/groups/bsl/bslmt -I/BSL/gcc/new/bde/groups/bsl/bslx -I/BSL/gcc/new/bde/build/thirdparty/decnumber -I/BSL/gcc/new/bde/thirdparty/decnumber -I/BSL/gcc/new/bde/build/thirdparty/inteldfp/LIBRARY/src -I/BSL/gcc/new/bde/thirdparty/inteldfp/LIBRARY/src groups/bdl/bdlb/bdlb_cstringhash.cpp -c -o /BSL/gcc/new/bde/build/groups/bdl/bdlb/bdlb_cstringhash.cpp.1.o CC: Warning: illegal use of -library option, illegal item ignored: rwtools7 CC: Warning: illegal use of -library option, empty value ignored "/BSL/gcc/new/bde/groups/bdl/bdlb/bdlb_cstringhash.h", line 261: Error: The function "strlen" must have a prototype. 1 Error(s) detected.

I would propose the following fix:

$ git diff groups/bdl/bdlb/bdlb_cstringhash.h
diff --git a/groups/bdl/bdlb/bdlb_cstringhash.h b/groups/bdl/bdlb/bdlb_cstringhash.h
index 578ff15..f2cb435 100644
--- a/groups/bdl/bdlb/bdlb_cstringhash.h
+++ b/groups/bdl/bdlb/bdlb_cstringhash.h
@@ -258,7 +258,7 @@ bsl::size_t bdlb::CStringHash::operator()(const char *argument) const
     BSLS_ASSERT_SAFE(argument);

     bslh::SpookyHashAlgorithm hash;
-    hash(argument, strlen(argument));
+    hash(argument, bsl::strlen(argument));
     return static_cast(hash.computeHash());
 }

avysotsk commented 8 years ago

I see the same issue in file groups/bdl/bdldfp/bdldfp_decimalconvertutil.cpp. Namespace is not explicitly set for function modf on line 476. This results to the similar compilation error. The propose fix is similar:

$ git diff groups/bdl/bdldfp/bdldfp_decimalconvertutil.cpp
diff --git a/groups/bdl/bdldfp/bdldfp_decimalconvertutil.cpp b/groups/bdl/bdldfp/bdldfp_decimalconvertutil.cpp
index d6a1948..7ffc9de 100644
--- a/groups/bdl/bdldfp/bdldfp_decimalconvertutil.cpp
+++ b/groups/bdl/bdldfp/bdldfp_decimalconvertutil.cpp
@@ -473,7 +473,7 @@ Decimal64 DecimalConvertUtil::decimal64FromDouble(double binary)
         // to its integer part.  If it's small enough (using 1e-17, generously
         // below the 1e-16 computed above), skip the verification.
         double dn, r;
-        r = modf(d, &dn);
+        r = bsl::modf(d, &dn);
         if ((dn != 0 && r / dn < 1e-17) || r == 0) {
             return rv;                                                // RETURN
         }

avysotsk commented 8 years ago

When someone uses GNU compilers, then the issue is not seen. That's happened because GNU compiler includes by default system headers like /usr/include/stdlib.h or /usr/include/math.h or /usr/include/string.h. And in these headers one can find explicit point to the std:: namespace. For example,

/*
 * Allow global visibility for symbols defined in
 * C++ "std" namespace in .
 */
#if __cplusplus >= 199711L
..........................................
using std::strlen;

So, it means when in BSL code one writes just "strlen" or "modf", then functions will be taken from std:: namespace. But not from bsl:: namespace. It'll mask the problem.