Driver: Only add extra -L paths on darwin if they exist. Unfortunately, this
means it isn't really possible to write the test case for this code, but this is
the kind of thing that really requires testing against the installed compiler
anyway.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@100935 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Driver/ToolChains.cpp b/lib/Driver/ToolChains.cpp
index 80dea50..1cd8ee1 100644
--- a/lib/Driver/ToolChains.cpp
+++ b/lib/Driver/ToolChains.cpp
@@ -217,6 +217,8 @@
 
 void DarwinGCC::AddLinkSearchPathArgs(const ArgList &Args,
                                       ArgStringList &CmdArgs) const {
+  std::string Tmp;
+
   // FIXME: Derive these correctly.
   if (getArchName() == "x86_64") {
     CmdArgs.push_back(Args.MakeArgString("-L/usr/lib/gcc/" + ToolChainDir +
@@ -227,15 +229,22 @@
   }
   
   CmdArgs.push_back(Args.MakeArgString("-L/usr/lib/" + ToolChainDir));
-  CmdArgs.push_back(Args.MakeArgString("-L" + getDriver().Dir + "/../lib/gcc/" +
-                                       ToolChainDir));
-  CmdArgs.push_back(Args.MakeArgString("-L" + getDriver().Dir + "/../lib/gcc"));
+
+  Tmp = getDriver().Dir + "/../lib/gcc/" + ToolChainDir;
+  if (llvm::sys::Path(Tmp).exists())
+    CmdArgs.push_back(Args.MakeArgString("-L" + Tmp));
+  Tmp = getDriver().Dir + "/../lib/gcc";
+  if (llvm::sys::Path(Tmp).exists())
+    CmdArgs.push_back(Args.MakeArgString("-L" + Tmp));
   CmdArgs.push_back(Args.MakeArgString("-L/usr/lib/gcc/" + ToolChainDir));
   // Intentionally duplicated for (temporary) gcc bug compatibility.
   CmdArgs.push_back(Args.MakeArgString("-L/usr/lib/gcc/" + ToolChainDir));
-  CmdArgs.push_back(Args.MakeArgString("-L" + getDriver().Dir + "/../lib/" +
-                                       ToolChainDir));
-  CmdArgs.push_back(Args.MakeArgString("-L" + getDriver().Dir + "/../lib"));
+  Tmp = getDriver().Dir + "/../lib/" + ToolChainDir;
+  if (llvm::sys::Path(Tmp).exists())
+    CmdArgs.push_back(Args.MakeArgString("-L" + Tmp));
+  Tmp = getDriver().Dir + "/../lib";
+  if (llvm::sys::Path(Tmp).exists())
+    CmdArgs.push_back(Args.MakeArgString("-L" + Tmp));
   CmdArgs.push_back(Args.MakeArgString("-L/usr/lib/gcc/" + ToolChainDir +
                                        "/../../../" + ToolChainDir));
   CmdArgs.push_back(Args.MakeArgString("-L/usr/lib/gcc/" + ToolChainDir +
diff --git a/test/Driver/darwin-ld.c b/test/Driver/darwin-ld.c
index deeb568..c6b8a20 100644
--- a/test/Driver/darwin-ld.c
+++ b/test/Driver/darwin-ld.c
@@ -33,7 +33,7 @@
 // Note that at conception, this exactly matches gcc.
 
 // RUN: %clang -ccc-host-triple i386-apple-darwin9 -### -A ARG0 -F ARG1 -L ARG2 -Mach -T ARG4 -X -Z -all_load -allowable_client ARG8 -bind_at_load -compatibility_version ARG11 -current_version ARG12 -d -dead_strip -dylib_file ARG14 -dylinker -dylinker_install_name ARG16 -dynamic -dynamiclib -e ARG19 -exported_symbols_list ARG20 -fexceptions -flat_namespace -fnested-functions -fopenmp -force_cpusubtype_ALL -fpie -fprofile-arcs -headerpad_max_install_names -image_base ARG29 -init ARG30 -install_name ARG31 -m ARG33 -miphoneos-version-min=2.0 -mmacosx-version-min=10.3.2 -multi_module -multiply_defined ARG37 -multiply_defined_unused ARG38 -no_dead_strip_inits_and_terms -nodefaultlibs -nofixprebinding -nomultidefs -noprebind -noseglinkedit -nostartfiles -nostdlib -pagezero_size ARG54 -pg -prebind -prebind_all_twolevel_modules -preload -r -read_only_relocs ARG55 -s -sectalign ARG57_0 ARG57_1 ARG57_2 -sectcreate ARG58_0 ARG58_1 ARG58_2 -sectobjectsymbols ARG59_0 ARG59_1 -sectorder ARG60_0 ARG60_1 ARG60_2 -seg1addr ARG61 -seg_addr_table ARG62 -seg_addr_table_filename ARG63 -segaddr ARG64_0 ARG64_1 -segcreate ARG65_0 ARG65_1 ARG65_2 -seglinkedit -segprot ARG67_0 ARG67_1 ARG67_2 -segs_read_FOO -segs_read_only_addr ARG69 -segs_read_write_addr ARG70 -shared-libgcc -single_module -static -static-libgcc -sub_library ARG77 -sub_umbrella ARG78 -t -twolevel_namespace -twolevel_namespace_hints -u ARG82 -umbrella ARG83 -undefined ARG84 -unexported_symbols_list ARG85 -w -weak_reference_mismatches ARG87 -whatsloaded -whyload -y -filelist FOO -l FOO 2> %t.log
-// RUN: grep '".*ld.*" "-static" "-dylib" "-dylib_compatibility_version" "ARG11" "-dylib_current_version" "ARG12" "-arch" "i386" "-dylib_install_name" "ARG31" "-all_load" "-allowable_client" "ARG8" "-bind_at_load" "-dead_strip" "-no_dead_strip_inits_and_terms" "-dylib_file" "ARG14" "-dynamic" "-exported_symbols_list" "ARG20" "-flat_namespace" "-headerpad_max_install_names" "-image_base" "ARG29" "-init" "ARG30" "-macosx_version_min" "10.3.2" "-iphoneos_version_min" "2.0" "-nomultidefs" "-multi_module" "-single_module" "-multiply_defined" "ARG37" "-multiply_defined_unused" "ARG38" "-pie" "-prebind" "-noprebind" "-nofixprebinding" "-prebind_all_twolevel_modules" "-read_only_relocs" "ARG55" "-sectcreate" "ARG58_0" "ARG58_1" "ARG58_2" "-sectorder" "ARG60_0" "ARG60_1" "ARG60_2" "-seg1addr" "ARG61" "-segprot" "ARG67_0" "ARG67_1" "ARG67_2" "-segaddr" "ARG64_0" "ARG64_1" "-segs_read_only_addr" "ARG69" "-segs_read_write_addr" "ARG70" "-seg_addr_table" "ARG62" "-seg_addr_table_filename" "ARG63" "-sub_library" "ARG77" "-sub_umbrella" "ARG78" "-twolevel_namespace" "-twolevel_namespace_hints" "-umbrella" "ARG83" "-undefined" "ARG84" "-unexported_symbols_list" "ARG85" "-weak_reference_mismatches" "ARG87" "-X" "-y" "-w" "-pagezero_size" "ARG54" "-segs_read_FOO" "-seglinkedit" "-noseglinkedit" "-sectalign" "ARG57_0" "ARG57_1" "ARG57_2" "-sectobjectsymbols" "ARG59_0" "ARG59_1" "-segcreate" "ARG65_0" "ARG65_1" "ARG65_2" "-whyload" "-whatsloaded" "-dylinker_install_name" "ARG16" "-dylinker" "-Mach" "-d" "-s" "-t" "-Z" "-u" "ARG82" "-undefined" "ARG84" "-A" "ARG0" "-e" "ARG19" "-m" "ARG33" "-r" "-o" "a.out" "-L" "ARG2" "-lgomp" "-L/usr/lib/i686-apple-darwin10/4.2.1" "-L.*/../lib/gcc/.*" "-L.*/lib/gcc" "-L/usr/lib/gcc/i686-apple-darwin10/4.2.1" "-L/usr/lib/gcc/i686-apple-darwin10/4.2.1" "-L.*/../lib/.*" "-L.*/../lib" "-L/usr/lib/gcc/i686-apple-darwin10/4.2.1/../../../i686-apple-darwin10/4.2.1" "-L/usr/lib/gcc/i686-apple-darwin10/4.2.1/../../.." "-filelist" "FOO" "-lFOO" "-lgcov" "-allow_stack_execute" "-T" "ARG4" "-F" "ARG1"' %t.log
+// RUN: grep '".*ld.*" "-static" "-dylib" "-dylib_compatibility_version" "ARG11" "-dylib_current_version" "ARG12" "-arch" "i386" "-dylib_install_name" "ARG31" "-all_load" "-allowable_client" "ARG8" "-bind_at_load" "-dead_strip" "-no_dead_strip_inits_and_terms" "-dylib_file" "ARG14" "-dynamic" "-exported_symbols_list" "ARG20" "-flat_namespace" "-headerpad_max_install_names" "-image_base" "ARG29" "-init" "ARG30" "-macosx_version_min" "10.3.2" "-iphoneos_version_min" "2.0" "-nomultidefs" "-multi_module" "-single_module" "-multiply_defined" "ARG37" "-multiply_defined_unused" "ARG38" "-pie" "-prebind" "-noprebind" "-nofixprebinding" "-prebind_all_twolevel_modules" "-read_only_relocs" "ARG55" "-sectcreate" "ARG58_0" "ARG58_1" "ARG58_2" "-sectorder" "ARG60_0" "ARG60_1" "ARG60_2" "-seg1addr" "ARG61" "-segprot" "ARG67_0" "ARG67_1" "ARG67_2" "-segaddr" "ARG64_0" "ARG64_1" "-segs_read_only_addr" "ARG69" "-segs_read_write_addr" "ARG70" "-seg_addr_table" "ARG62" "-seg_addr_table_filename" "ARG63" "-sub_library" "ARG77" "-sub_umbrella" "ARG78" "-twolevel_namespace" "-twolevel_namespace_hints" "-umbrella" "ARG83" "-undefined" "ARG84" "-unexported_symbols_list" "ARG85" "-weak_reference_mismatches" "ARG87" "-X" "-y" "-w" "-pagezero_size" "ARG54" "-segs_read_FOO" "-seglinkedit" "-noseglinkedit" "-sectalign" "ARG57_0" "ARG57_1" "ARG57_2" "-sectobjectsymbols" "ARG59_0" "ARG59_1" "-segcreate" "ARG65_0" "ARG65_1" "ARG65_2" "-whyload" "-whatsloaded" "-dylinker_install_name" "ARG16" "-dylinker" "-Mach" "-d" "-s" "-t" "-Z" "-u" "ARG82" "-undefined" "ARG84" "-A" "ARG0" "-e" "ARG19" "-m" "ARG33" "-r" "-o" "a.out" "-L" "ARG2" "-lgomp" "-L/usr/lib/i686-apple-darwin10/4.2.1".* "-L/usr/lib/gcc/i686-apple-darwin10/4.2.1" "-L/usr/lib/gcc/i686-apple-darwin10/4.2.1".* "-L/usr/lib/gcc/i686-apple-darwin10/4.2.1/../../../i686-apple-darwin10/4.2.1" "-L/usr/lib/gcc/i686-apple-darwin10/4.2.1/../../.." "-filelist" "FOO" "-lFOO" "-lgcov" "-allow_stack_execute" "-T" "ARG4" "-F" "ARG1"' %t.log
 
 // Don't run dsymutil on a fat build of an executable.
 // RUN: %clang -ccc-host-triple i386-apple-darwin9 -### -arch i386 -arch x86_64 -g %s 2> %t.log