From 9ade6a9a747c49383ac747bd8ffaa6a0beaef71c Mon Sep 17 00:00:00 2001
From: Chandler Carruth <chandlerc@gmail.com>
Date: Wed, 5 Aug 2015 17:07:33 +0000
Subject: [PATCH] Fix a tiny bug in -no-canonical-prefixes that somehow we have
 never noticed until now.

The code for setting up the driver's InstalledDir didn't respect
-no-canonical-prefixes. Because of this, there are a few places in the
driver where we would unexpectedly form absolute paths, notably when
searching for and finding GCC installations to use, etc. The fix is
straightforward, and I've added this path to '-v' both so we can test it
sanely and so that it will be substantially more obvious the next time
someone has to debug something here.

Note that there is another bug that we don't actually *canonicalize* the
installed directory! I don't really want to fix that because I don't
have a realistic way to test the usage of this mode. I suspect that
folks using the shared module cache would care about getting this right
though, and so they might want to address it. I've left the appropriate
FIXMEs so that it is clear what to change, and I've updated the test
code to make it clear what is happening here.

llvm-svn: 244065
---
 clang/lib/Driver/Driver.cpp               |  3 +++
 clang/test/Driver/no-canonical-prefixes.c | 22 ++++++++++++++--------
 clang/tools/driver/driver.cpp             | 10 +++++++---
 3 files changed, 24 insertions(+), 11 deletions(-)

diff --git a/clang/lib/Driver/Driver.cpp b/clang/lib/Driver/Driver.cpp
index a39f7fc..548baf3 100644
--- a/clang/lib/Driver/Driver.cpp
+++ b/clang/lib/Driver/Driver.cpp
@@ -762,6 +762,9 @@ void Driver::PrintVersion(const Compilation &C, raw_ostream &OS) const {
   } else
     OS << "Thread model: " << TC.getThreadModel();
   OS << '\n';
+
+  // Print out the install directory.
+  OS << "InstalledDir: " << InstalledDir << '\n';
 }
 
 /// PrintDiagnosticCategories - Implement the --print-diagnostic-categories
diff --git a/clang/test/Driver/no-canonical-prefixes.c b/clang/test/Driver/no-canonical-prefixes.c
index b617cd4..7bc76be 100644
--- a/clang/test/Driver/no-canonical-prefixes.c
+++ b/clang/test/Driver/no-canonical-prefixes.c
@@ -1,11 +1,17 @@
 // Due to ln -sf:
 // REQUIRES: shell
-// RUN: mkdir -p %t
-// RUN: cd %t
+// RUN: mkdir -p %t.real
+// RUN: cd %t.real
 // RUN: ln -sf %clang test-clang
-// RUN: ./test-clang -v -S %s 2>&1 | FileCheck %s
-// RUN: ./test-clang -v -S %s -no-canonical-prefixes 2>&1 | FileCheck --check-prefix=NCP %s
-
-
-// CHECK: /clang{{.*}}" -cc1
-// NCP: test-clang" -cc1
+// RUN: cd ..
+// RUN: ln -sf %t.real %t.fake
+// RUN: cd %t.fake
+// RUN: ./test-clang -v -S %s 2>&1 | FileCheck --check-prefix=CANONICAL %s
+// RUN: ./test-clang -v -S %s -no-canonical-prefixes 2>&1 | FileCheck --check-prefix=NON-CANONICAL %s
+//
+// FIXME: This should really be '.real'.
+// CANONICAL: InstalledDir: {{.*}}.fake
+// CANONICAL: {{[/|\\]*}}clang{{.*}}" -cc1
+//
+// NON-CANONICAL: InstalledDir: .{{$}}
+// NON-CANONICAL: test-clang" -cc1
diff --git a/clang/tools/driver/driver.cpp b/clang/tools/driver/driver.cpp
index d6817a8..40c5a61 100644
--- a/clang/tools/driver/driver.cpp
+++ b/clang/tools/driver/driver.cpp
@@ -344,7 +344,7 @@ CreateAndPopulateDiagOpts(ArrayRef<const char *> argv) {
 }
 
 static void SetInstallDir(SmallVectorImpl<const char *> &argv,
-                          Driver &TheDriver) {
+                          Driver &TheDriver, bool CanonicalPrefixes) {
   // Attempt to find the original path used to invoke the driver, to determine
   // the installed path. We do this manually, because we want to support that
   // path being a symlink.
@@ -355,7 +355,11 @@ static void SetInstallDir(SmallVectorImpl<const char *> &argv,
     if (llvm::ErrorOr<std::string> Tmp = llvm::sys::findProgramByName(
             llvm::sys::path::filename(InstalledPath.str())))
       InstalledPath = *Tmp;
-  llvm::sys::fs::make_absolute(InstalledPath);
+
+  // FIXME: We don't actually canonicalize this, we just make it absolute.
+  if (CanonicalPrefixes)
+    llvm::sys::fs::make_absolute(InstalledPath);
+
   InstalledPath = llvm::sys::path::parent_path(InstalledPath);
   if (llvm::sys::fs::exists(InstalledPath.c_str()))
     TheDriver.setInstalledDir(InstalledPath);
@@ -473,7 +477,7 @@ int main(int argc_, const char **argv_) {
   ProcessWarningOptions(Diags, *DiagOpts, /*ReportDiags=*/false);
 
   Driver TheDriver(Path, llvm::sys::getDefaultTargetTriple(), Diags);
-  SetInstallDir(argv, TheDriver);
+  SetInstallDir(argv, TheDriver, CanonicalPrefixes);
 
   llvm::InitializeAllTargets();
   insertArgsFromProgramName(ProgName, DS, argv, SavedStrings);
-- 
2.7.4