Fix temporary directory computation on linux (pr25147)

Summary:
On linux, the environment variables for temp directories that lldb checks for are generally not
defined, and the temp directory computation failed. This caused expression evaluation to fall
back to creating "/tmp/lldb-*.expr" debugging files instead of the usual
"$TMP/lldb/pid/lldb-*.expr". Crucially, these files were not cleaned up on lldb exit, which
caused clutter in the /tmp folder, especially on long-running machines (e.g. builtbots). This
commit fixes lldb to use llvm::sys::path::system_temp_directory, which does the same environment
variable dance, but (!) also falls back to the P_tmpdir macro, which is how the temp directory is
defined on linux.

Since the linux temp path computation now succeeds, I needed to also modify Android path
computation to check for actual directory existence, rather then checking whether the operation
failed.

Reviewers: clayborg, tberghammer

Subscribers: tberghammer, lldb-commits, danalbert, srhines, emaste

Differential Revision: http://reviews.llvm.org/D13772

llvm-svn: 250502

1 files changed, 4 insertions, 13 deletions

diff --git a/lldb/source/Host/common/HostInfoBase.cpp b/lldb/source/Host/common/HostInfoBase.cpp
index 3cb00a875e2..0f4324f83dd 100644
--- a/lldb/source/Host/common/HostInfoBase.cpp
+++ b/lldb/source/Host/common/HostInfoBase.cpp
@@ -20,6 +20,7 @@
 #include "llvm/ADT/Triple.h"
 #include "llvm/ADT/StringExtras.h"
 #include "llvm/Support/Host.h"
+#include "llvm/Support/Path.h"
 #include "llvm/Support/raw_ostream.h"
 
 #include <thread>
@@ -344,19 +345,9 @@ HostInfoBase::ComputeProcessTempFileDirectory(FileSpec &file_spec)
 bool
 HostInfoBase::ComputeTempFileBaseDirectory(FileSpec &file_spec)
 {
-    file_spec.Clear();
-
-    const char *tmpdir_cstr = getenv("TMPDIR");
-    if (tmpdir_cstr == nullptr)
-    {
-        tmpdir_cstr = getenv("TMP");
-        if (tmpdir_cstr == nullptr)
-            tmpdir_cstr = getenv("TEMP");
-    }
-    if (!tmpdir_cstr)
-        return false;
-
-    file_spec = FileSpec(tmpdir_cstr, false);
+    llvm::SmallVector<char, 16> tmpdir;
+    llvm::sys::path::system_temp_directory(/*ErasedOnReboot*/ true, tmpdir);
+    file_spec = FileSpec(std::string(tmpdir.data(), tmpdir.size()), true);
     return true;
 }