Enable standalone-debug by default on FreeBSD

[emaste]

Summary

It was set by default on Darwin in r198655. The same usability issues
with DTrace and LLDB apply to FreeBSD, so set it by default there too.

rdar://problem/15758808
http://llvm.org/pr19676

[• rafael]

Can you add a testcase?

[emaste]

Update existing testcase to cover FreeBSD too

[• rafael]

LGTM

[emaste]

Committed (with the wrong review ID in the commit message, sorry) in r208310
http://llvm.org/viewvc/llvm-project?rev=208310&view=rev

[echristo]

As a note I would suggest that you not do this by default, but rather
have it set for things that can't assume that clang is building debug
info for everything etc or when you're using dtrace.

-eric

lib/Frontend/CompilerInvocation.cpp

static bool ParseCodeGenArgs(CodeGenOptions &Opts, ArgList &Args, InputKind IK,
   Opts.setInlining(Args.hasArg(OPT_fno_inline_functions) ?
                      CodeGenOptions::OnlyAlwaysInlining : Opts.getInlining());
 
   if (Args.hasArg(OPT_gline_tables_only)) {
     Opts.setDebugInfo(CodeGenOptions::DebugLineTablesOnly);
   } else if (Args.hasArg(OPT_g_Flag) || Args.hasArg(OPT_gdwarf_2) ||
              Args.hasArg(OPT_gdwarf_3) || Args.hasArg(OPT_gdwarf_4)) {
     bool Default = false;
-    // Until dtrace (via CTF) can deal with distributed debug info,
-    // Darwin defaults to standalone/full debug info.
-    if (llvm::Triple(TargetOpts.Triple).isOSDarwin())
+    // Until dtrace (via CTF) and LLDB can deal with distributed debug info,
+    // Darwin and FreeBSD default to standalone/full debug info.
+    if (llvm::Triple(TargetOpts.Triple).isOSDarwin() ||
+        llvm::Triple(TargetOpts.Triple).isOSFreeBSD())
       Default = true;
 
     if (Args.hasFlag(OPT_fstandalone_debug, OPT_fno_standalone_debug, Default))
       Opts.setDebugInfo(CodeGenOptions::FullDebugInfo);
     else
       Opts.setDebugInfo(CodeGenOptions::LimitedDebugInfo);
   }
   Opts.DebugColumnInfo = Args.hasArg(OPT_dwarf_column_info);

test/CodeGenCXX/debug-info-vtable-optzn.cpp

 // RUN: %clang_cc1 -emit-llvm -g -triple x86_64-apple-darwin %s -o - | FileCheck %s
+// RUN: %clang_cc1 -emit-llvm -g -triple amd64-unknown-freebsd %s -o - | FileCheck %s
 //
 // This tests that the "emit debug info for a C++ class only in the
 // module that has its vtable" optimization is disabled by default on
-// Darwin.
+// Darwin and FreeBSD.
 //
 // CHECK: [ DW_TAG_member ] [lost]
 class A
 {
   virtual bool f() = 0;
   int lost;
 };
 
 class B : public A
 {
   B *g();
 };
 
 B *B::g() {
   return this;
 }