r228013 - Make the default module cache user-specific

[Ben Langmuir]

Author: benlangmuir
Date: Tue Feb  3 13:28:37 2015
New Revision: 228013

URL: http://llvm.org/viewvc/llvm-project?rev=228013&view=rev
Log:
Make the default module cache user-specific

Appends the username to the first component (after the temp dir) of the
module cache path.  If the username contains a character that shouldn't
go into a path (for now conservatively allow [a-zA-Z0-9_]), we fallback
to the user id.

Added:
    cfe/trunk/test/Driver/modules-cache-path.m
Modified:
    cfe/trunk/lib/Driver/Tools.cpp

Modified: cfe/trunk/lib/Driver/Tools.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Driver/Tools.cpp?rev=228013&r1=228012&r2=228013&view=diff
==============================================================================
--- cfe/trunk/lib/Driver/Tools.cpp (original)
+++ cfe/trunk/lib/Driver/Tools.cpp Tue Feb  3 13:28:37 2015
@@ -40,6 +40,10 @@
 #include "llvm/Support/Program.h"
 #include "llvm/Support/raw_ostream.h"
 
+#ifdef LLVM_ON_UNIX
+#include <unistd.h> // For getuid().
+#endif
+
 using namespace clang::driver;
 using namespace clang::driver::tools;
 using namespace clang;
@@ -2456,6 +2460,38 @@ static void claimNoWarnArgs(const ArgLis
   Args.ClaimAllArgs(options::OPT_fno_lto);
 }
 
+static void appendUserToPath(SmallVectorImpl<char> &Result) {
+#ifdef LLVM_ON_UNIX
+  const char *Username = getenv("LOGNAME");
+#else
+  const char *Username = getenv("USERNAME");
+#endif
+  if (Username) {
+    // Validate that LoginName can be used in a path, and get its length.
+    size_t Len = 0;
+    for (const char *P = Username; *P; ++P, ++Len) {
+      if (!isalnum(*P) && *P != '_') {
+        Username = nullptr;
+        break;
+      }
+    }
+
+    if (Username && Len > 0) {
+      Result.append(Username, Username + Len);
+      return;
+    }
+  }
+
+  // Fallback to user id.
+#ifdef LLVM_ON_UNIX
+  std::string UID = llvm::utostr(getuid());
+#else
+  // FIXME: Windows seems to have an 'SID' that might work.
+  std::string UID = "9999";
+#endif
+  Result.append(UID.begin(), UID.end());
+}
+
 void Clang::ConstructJob(Compilation &C, const JobAction &JA,
                          const InputInfo &Output,
                          const InputInfoList &Inputs,
@@ -3878,7 +3914,8 @@ void Clang::ConstructJob(Compilation &C,
       // No module path was provided: use the default.
       llvm::sys::path::system_temp_directory(/*erasedOnReboot=*/false,
                                              ModuleCachePath);
-      llvm::sys::path::append(ModuleCachePath, "org.llvm.clang");
+      llvm::sys::path::append(ModuleCachePath, "org.llvm.clang.");
+      appendUserToPath(ModuleCachePath);
       llvm::sys::path::append(ModuleCachePath, "ModuleCache");
     }
     const char Arg[] = "-fmodules-cache-path=";

Added: cfe/trunk/test/Driver/modules-cache-path.m
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Driver/modules-cache-path.m?rev=228013&view=auto
==============================================================================
--- cfe/trunk/test/Driver/modules-cache-path.m (added)
+++ cfe/trunk/test/Driver/modules-cache-path.m Tue Feb  3 13:28:37 2015
@@ -0,0 +1,5 @@
+// RUN: env USERNAME=asdf LOGNAME=asdf %clang -fmodules -### %s 2>&1 | FileCheck %s -check-prefix=CHECK-SET
+// CHECK-SET: -fmodules-cache-path={{.*}}org.llvm.clang.asdf{{[/\\]+}}ModuleCache
+
+// RUN: %clang -fmodules -### %s 2>&1 | FileCheck %s -check-prefix=CHECK-DEFAULT
+// CHECK-DEFAULT: -fmodules-cache-path={{.*}}org.llvm.clang.{{[A-Za-z0-9_]*[/\\]+}}ModuleCache