Don't truncate the target triple when initializing clang

[zturner]

Summary

Don't truncate the target triple when initializing clang.

Target triples support an optional 4th component, the environment. Clang on Windows uses this 4th component to make various decisions when looking for header file includes, so truncating it leads to crashes on Windows when performing simple expression evaluation.

[tfiala]

Yep I'm planning on looking at this later today.

[tfiala]

Looking at this now.

[tfiala]

I'm going to look into why that was truncated in the first place. My guess is at least one other system depends on it not including the environment portion of the triple. We might need to conditionalize it but I'll at least test it as is on Linux and MacOSX.

[tfiala]

It looks like that code came in with r164563:

svn log -r 164563

r164563 | spyffe | 2012-09-24 15:25:51 -0700 (Mon, 24 Sep 2012) | 10 lines

Brought LLDB top-of-tree into sync with LLVM/Clang
top-of-tree. Removed all local patches and llvm.zip.

The intent is that fron now on top-of-tree will
always build against LLVM/Clang top-of-tree, and
that problems building will be resolved as they
occur. Stable release branches of LLDB can be
constructed as needed and linked to specific release
branches of LLVM/Clang.

[tfiala]

LGTM - here's how I tested:

Linux x86_64:
(lldb) file /path/to/exe
(lldb) b main.cpp:10
(lldb) run
... at breakpoint ...
(lldb) expr 5*3
// prints result as expected

Same result for MacOSX 10.9.3 with x86_64 MacOS executable.

Let's ping the Apple folks and see if there is some kind of simulator/device that might choke on that, though, before you check this in.

[zturner]

+Greg and Jim, as one of them would probably know.

[zturner]

Closed by commit rL211968 (authored by @zturner).

lldb/trunk/source/Expression/ClangExpressionParser.cpp

ClangExpressionParser::ClangExpressionParser (ExecutionContextScope *exe_scope,
     // TODO: figure out what to really do when we don't have a valid target.
     // Sometimes this will be ok to just use the host target triple (when we
     // evaluate say "2+3", but other expressions like breakpoint conditions
     // and other things that _are_ target specific really shouldn't just be
     // using the host triple. This needs to be fixed in a better way.
     if (target_sp && target_sp->GetArchitecture().IsValid())
     {
         std::string triple = target_sp->GetArchitecture().GetTriple().str();
-        
-        int dash_count = 0;
-        for (size_t i = 0; i < triple.size(); ++i)
-        {
-            if (triple[i] == '-')
-                dash_count++;
-            if (dash_count == 3)
-            {
-                triple.resize(i);
-                break;
-            }
-        }
-        
         m_compiler->getTargetOpts().Triple = triple;
     }
     else
     {
         m_compiler->getTargetOpts().Triple = llvm::sys::getDefaultTargetTriple();
     }
     
     if (target_sp->GetArchitecture().GetMachine() == llvm::Triple::x86 ||