add epicsLoadTest

modules/libcom/test/Makefile

@@ -260,6 +260,16 @@ iocshTest_SRCS += iocshTest.cpp
 TESTS += iocshTest
 TESTFILES += $(wildcard ../iocshTest*.cmd)
 
+TESTPROD_HOST += epicsLoadTest
+epicsLoadTest_SRCS += epicsLoadTest.cpp
+# test linked against static libCom?
+epicsLoadTest_CPPFLAGS_STATIC_YES = -DLINKING_STATIC
+epicsLoadTest_CPPFLAGS += $(epicsLoadTest_CPPFLAGS_STATIC_$(STATIC_BUILD))
+# are dynamic libraries built?
+epicsLoadTest_CPPFLAGS_SHARED_YES = -DBUILDING_SHARED_LIBRARIES
+epicsLoadTest_CPPFLAGS += $(epicsLoadTest_CPPFLAGS_SHARED_$(SHARED_LIBRARIES))
+TESTS += epicsLoadTest
+
 # The testHarness runs all the test programs in a known working order.
 testHarness_SRCS += epicsRunLibComTests.c
 

modules/libcom/test/epicsLoadTest.cpp

@@ -0,0 +1,91 @@
+/*************************************************************************\
+* Copyright (c) 2020 Michael Davidsaver
+* EPICS BASE is distributed subject to a Software License Agreement found
+* in file LICENSE that is included with this distribution.
+\*************************************************************************/
+
+#include <sstream>
+
+#include <stdlib.h>
+
+#include "epicsUnitTest.h"
+#include "testMain.h"
+
+#include "envDefs.h"
+#include "epicsFindSymbol.h"
+#include "epicsThread.h"
+
+namespace {
+
+// lookup a symbol from libCom
+// which this executable is linked against (maybe statically)
+// Doesn't work for static builds on windows
+void loadCom()
+{
+    testDiag("Lookup symbol from Com");
+
+#if defined (_WIN32) && defined(LINKING_STATIC)
+    testTodoBegin("windows static build");
+#endif
+
+    void* ptr = epicsFindSymbol("epicsThreadGetCPUs");
+    testOk(ptr==(void*)&epicsThreadGetCPUs,
+           "%p == %p (epicsThreadGetCPUs) : %s",
+           ptr, (void*)&epicsThreadGetCPUs,
+           epicsLoadError());
+
+    testTodoEnd();
+}
+
+void loadCA()
+{
+    testDiag("Load and lookup symbol from libca");
+
+    std::string libname;
+    {
+        std::ostringstream strm;
+        // running in eg. modules/libcom/test/O.linux-x86_64-debug
+#ifdef _WIN32
+        strm<<"..\\..\\..\\..\\bin\\"<<envGetConfigParamPtr(&EPICS_BUILD_TARGET_ARCH)<<"\\ca.dll";
+#else
+        strm<<"../../../../lib/"<<envGetConfigParamPtr(&EPICS_BUILD_TARGET_ARCH)<<"/";
+#  ifdef __APPLE__
+        strm<<"libca.dylib";
+#  else
+        strm<<"libca.so";
+#  endif
+#endif
+        libname = strm.str();
+    }
+    testDiag("Loading %s", libname.c_str());
+
+    void *ptr = epicsLoadLibrary(libname.c_str());
+    testOk(!!ptr, "Loaded %p : %s", ptr, epicsLoadError());
+
+    ptr = epicsFindSymbol("ca_context_create");
+    testOk(!!ptr, "ca_context_create %p : %s", ptr, epicsLoadError());
+}
+
+} // namespace
+
+MAIN(epicsLoadTest)
+{
+    testPlan(3);
+
+    // reference to ensure linkage when linking statically,
+    // and actually use the result to make extra doubly sure that
+    // this call isn't optimized out by eg. an LTO pass.
+    testDiag("# of CPUs %d", epicsThreadGetCPUs());
+
+#if defined(__rtems__) || defined(vxWorks)
+    testSkip(3, "Target does not implement epicsFindSymbol()");
+#else
+    loadCom();
+#  if defined(BUILDING_SHARED_LIBRARIES)
+    loadCA();
+#  else
+    testSkip(2, "Shared libraries not built");
+#  endif
+#endif
+    return testDone();
+}