Contribution of PowerPC port (continuation of 422063005) - AIX Common1

src/base/logging.h

Index: src/base/logging.h
diff --git a/src/base/logging.h b/src/base/logging.h
index e73fac46adc1b771ee44da70143d81cbb8ceae61..d228eb0bf4df9500d881311acabbbf71cd641808 100644
--- a/src/base/logging.h
+++ b/src/base/logging.h
@@ -76,6 +76,23 @@ inline void CheckEqualsHelper(const char* file, int line,
 }
 
 
+// 32-bit AIX defines intptr_t as long int.
+#if V8_OS_AIX && V8_HOST_ARCH_32_BIT

[Sven Panne, 2015/01/27 11:47:05]

Can we turn this into something less fragile (e.g. compile-time tests regarding
int sizes)? Why do we need this at all? Is intptr_t different from int *and*
int64_t? If yes, what is it?

As a side note, we should really get rid of this CheckEqualsHelper nonsense, we
tripped over this several times already.

[michael_dawson, 2015/01/29 00:08:29]

 intptr_t - defined as long
 int64_t is not the same as long

On AIX 64 bit:
 intptr_t - defined as long
 int64_t - defined as long

I read this description:
  int64_t is guaranteed by the C99 standard to be exactly 64 
  long which is at least 32

So in the case of AIX 32 we are missing the case for intptr_t which is not an
int or an int64_t

I'm probably missing the point but, I'm not sure how a compile-time check would
work as we the type used by the caller needs to match the type in the function
definition and I assume we don't want to change the callers.  

I tried defining a new helper with type long, which seemed to work for AIX 32
(since intptr_t was a long), but on 64 bit the compile failed because the helper
with using the int64_t conflicted.  

[Sven Panne, 2015/01/29 09:54:33]

The whole Check(Non)EqualsHelper approach in v8 is fundamentally broken: The
expected value and the actual value have to be of the same type, and this gives
endless headaches with C++'s integral promotion rules when you mix different
sizes/signedness. We should really just use Chrome's approach where this is
handled via templates with 2 type arguments, there is no other sane way.
Benedikt just told me that he wants to give it try, but this shouldn't block
this CL: I propose to leave your code here as it is in the CL, we can clean this
up later when we have a sane framework.

+// Helper function used by the CHECK_EQ function when given intptr_t
+// arguments.  Should not be called directly.
+inline void CheckEqualsHelper(const char* file, int line,
+                              const char* expected_source, intptr_t expected,
+                              const char* value_source, intptr_t value) {
+  if (expected != value) {
+    V8_Fatal(file, line,
+             "CHECK_EQ(%s, %s) failed\n#"
+             "   Expected: 0x%lx\n#   Found: 0x%lx",
+             expected_source, value_source, expected, value);
+  }
+}
+#endif
+
+
 // Helper function used by the CHECK_NE function when given int
 // arguments.  Should not be called directly.
 inline void CheckNonEqualsHelper(const char* file,