Use getProcessTriple inside HostInfoBase::ComputeHostArchitectureSupport instead of getDefaultTargetTriple

[ovyalov]

Summary

Make lldb (lldb-server or debugserver) to get architecture information using getProcessTriple instead of getDefaultTargetTriple.
It seems getProcessTriple produces more accurate results - when cross-compiling for Android x86 (LLVM_TARGET_ARCH=X86) getDefaultTargetTriple yields 'x86_64--linux-android' whereas getProcessTriple() returns a valid 'i386--linux-android' which is compatible with inferiors' architecture.

[zturner]

Maybe I'm confusing what you're trying to do, but HostInfoBase::GetArchitecture() is supposed to return the triple of the host, by definition. If you want something that is compatible with a remote, you need a different function, maybe in Platform?

[zturner]

I think i get it, when you said inferior it made me think you were trying
to return the triple of the remote.

Anyway, this change looks correct to me, getProcessTriple() returns
LLVM_HOST_TRIPLE which is defined as "The triple of the process that LLVM
will run in", which matches what GetArchitecture should return

[ovyalov]

In D7893#130145, @zturner wrote:

I think i get it, when you said inferior it made me think you were trying
to return the triple of the remote.

Sorry for confusion - I mentioned inferior here as rather a test case that allowed me to verify this change works properly on Android.

Anyway, this change looks correct to me, getProcessTriple() returns
LLVM_HOST_TRIPLE which is defined as "The triple of the process that LLVM
will run in", which matches what GetArchitecture should return

[clayborg]

Looks good.

[ovyalov]

AFFECTED FILES

/lldb/trunk/source/Host/common/HostInfoBase.cpp

USERS

ovyalov (Author)

http://reviews.llvm.org/rL230674

source/Host/common/HostInfoBase.cpp

 {
     // TODO(zturner): Figure out how to compute the user plugins directory for all platforms.
     return false;
 }
 
 void
 HostInfoBase::ComputeHostArchitectureSupport(ArchSpec &arch_32, ArchSpec &arch_64)
 {
-    llvm::Triple triple(llvm::sys::getDefaultTargetTriple());
+    llvm::Triple triple(llvm::sys::getProcessTriple());
 
     arch_32.Clear();
     arch_64.Clear();
 
     switch (triple.getArch())
     {
         default:
             arch_32.SetTriple(triple);