Merge ~dirk.zimoch/epics-base:dynamicVxWorksVmeFunctionBinding into ~epics-core/epics-base/+git/epics-base:7.0

[Dirk Zimoch]

Use dynamic binding for vxWorks BSP functions because some BSPs don't provide them.

[Andrew Johnson (anj)]

Why not just replace the #if lines with if (...) { and leave the bodies of the functions untouched? That would make it easier for reviewers to confirm that you aren't changing the logic at all. As it is we have to understand both the original logic and what you've replaced it with and convince ourselves that their behavior will be the same, but using run-time detection instead of compile-time. Modern compilers should generate the same code for both versions so human readability is more important than conciseness.

I know that some people don't like having multiple return statements in a function; personally I disagree with that position, especially in simple cases like these where there are no resources that need releasing.

[Dirk Zimoch (dirk.zimoch)]

New version as suggested.

[Andrew Johnson (anj)]

Thanks.

review: Approve

[mdavidsaver (mdavidsaver)]

Should this change be made in devLib2 as well?

https://github.com/epics-modules/devlib2/blob/master/vmeApp/os/vxWorks/devLibVMEOSD.c

[Dirk Zimoch (dirk.zimoch)]

The problem here was that not every vxWorks system has a VME bus and thus loading EPICS base failed with unresolved symbols. This applies to each library/module that has vxWorks support for VME mixed with code for other useful stuff. At the moment if you want the other stuff you must have VME. So yes, that may apply to devLib2 as well.

However so far I only had one such system, that is an old CompactRIO fom NI. And on that system I do not use devLib2. So I have not noticed a problem.

diff --git a/modules/libcom/src/osi/os/vxWorks/devLibVMEOSD.c b/modules/libcom/src/osi/os/vxWorks/devLibVMEOSD.c
index 82bec60..93d30fc 100644
--- a/modules/libcom/src/osi/os/vxWorks/devLibVMEOSD.c
+++ b/modules/libcom/src/osi/os/vxWorks/devLibVMEOSD.c
@@ -110,7 +110,21 @@ static long vxDevWriteProbe (unsigned wordSize, volatile void *ptr, const void *
 
 static void *devA24Malloc(size_t size);
 static void devA24Free(void *pBlock);
-static long devInit(void) { return 0;}
+
+/* We don't know which functions are implemented in the BSP */
+static int (*sysIntEnableFunc)(int) = NULL;
+static int (*sysIntDisableFunc)(int) = NULL;
+static int (*sysIntEnablePICFunc)(int) = NULL;
+static int (*sysIntDisablePICFunc)(int) = NULL;
+
+static long devInit(void)
+{
+    sysIntEnableFunc = epicsFindSymbol ("sysIntEnable");
+    sysIntDisableFunc = epicsFindSymbol ("sysIntDisable");
+    sysIntDisablePICFunc = epicsFindSymbol ("sysIntDisablePIC");
+    sysIntEnablePICFunc = epicsFindSymbol ("sysIntEnablePIC");
+    return 0;
+}
 
 static long vxDevConnectInterruptVME (
     unsigned vectorNumber,
@@ -214,16 +228,16 @@ static long vxDevDisconnectInterruptVME (
  */
 static long vxDevEnableInterruptLevelVME (unsigned level)
 {
-#   if CPU_FAMILY != I80X86 
+    if (sysIntEnableFunc) {
         int s;
-        s = sysIntEnable (level);
+        s = sysIntEnableFunc (level);
         if (s!=OK) {
             return S_dev_intEnFail;
         }
         return 0;
-#   else
+    } else {
         return S_dev_intEnFail;
-#   endif
+    }
 }
 
 /*
@@ -231,16 +245,16 @@ static long vxDevEnableInterruptLevelVME (unsigned level)
  */
 long devEnableInterruptLevelISA (unsigned level)
 {
-#   if CPU_FAMILY == I80X86
+    if (sysIntEnablePICFunc) {
         int s;
-        s = sysIntEnablePIC (level);
+        s = sysIntEnablePICFunc (level);
         if (s!=OK) {
             return S_dev_intEnFail;
         }
         return 0;
-#   else
+    } else {
         return S_dev_intEnFail;
-#   endif
+    }
 }
 
 /*
@@ -248,15 +262,15 @@ long devEnableInterruptLevelISA (unsigned level)
  */
 long devDisableInterruptLevelISA (unsigned level)
 {
-#   if CPU_FAMILY == I80X86
+    if (sysIntDisablePICFunc) {
         int s;
-        s = sysIntDisablePIC (level);
+        s = sysIntDisablePICFunc (level);
         if (s!=OK) {
             return S_dev_intEnFail;
         }
-#   else
+    } else {
         return S_dev_intEnFail;
-#   endif
+    }
 
     return 0;
 }
@@ -266,16 +280,16 @@ long devDisableInterruptLevelISA (unsigned level)
  */
 static long vxDevDisableInterruptLevelVME (unsigned level)
 {
-#   if CPU_FAMILY != I80X86
+    if (sysIntDisableFunc) {
         int s;
-        s = sysIntDisable (level);
+        s = sysIntDisableFunc (level);
         if (s!=OK) {
             return S_dev_intDissFail;
         }
         return 0;
-#   else
+    } else {
         return S_dev_intEnFail;
-#   endif
+    }
 }
 
 /*