[Support] Fix recursive response file expansion guard

Response file expansion limits the amount of expansion to prevent
potential infinite recursion. However, the current logic assumes that
any argument beginning with @ is a response file, which is not true for
e.g. `-Xlinker -rpath -Xlinker @executable_path/../lib` on Darwin.
Having too many of these non-response file arguments beginning with @
prevents actual response files from being expanded. Instead, limit based
on the number of successful response file expansions, which should still
prevent infinite recursion but also avoid false positives.

Differential Revision: https://reviews.llvm.org/D60631

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@358452 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Support/CommandLine.cpp b/lib/Support/CommandLine.cpp
index 98d06f65c79894549695529c215f21c0f38ac6cd..0050002ff054dfa58dec51a18270bad3bf30bf46 100644 (file)
--- a/lib/Support/CommandLine.cpp
+++ b/lib/Support/CommandLine.cpp
@@ -1040,7 +1040,7 @@ static bool ExpandResponseFile(StringRef FName, StringSaver &Saver,
 bool cl::ExpandResponseFiles(StringSaver &Saver, TokenizerCallback Tokenizer,
                              SmallVectorImpl<const char *> &Argv,
                              bool MarkEOLs, bool RelativeNames) {
-  unsigned RspFiles = 0;
+  unsigned ExpandedRspFiles = 0;
   bool AllExpanded = true;
 
   // Don't cache Argv.size() because it can change.
@@ -1058,14 +1058,16 @@ bool cl::ExpandResponseFiles(StringSaver &Saver, TokenizerCallback Tokenizer,
 
     // If we have too many response files, leave some unexpanded.  This avoids
     // crashing on self-referential response files.
-    if (RspFiles++ > 20)
+    if (ExpandedRspFiles > 20)
       return false;
 
     // Replace this response file argument with the tokenization of its
     // contents.  Nested response files are expanded in subsequent iterations.
     SmallVector<const char *, 0> ExpandedArgv;
-    if (!ExpandResponseFile(Arg + 1, Saver, Tokenizer, ExpandedArgv,
-                            MarkEOLs, RelativeNames)) {
+    if (ExpandResponseFile(Arg + 1, Saver, Tokenizer, ExpandedArgv, MarkEOLs,
+                           RelativeNames)) {
+      ++ExpandedRspFiles;
+    } else {
       // We couldn't read this file, so we leave it in the argument stream and
       // move on.
       AllExpanded = false;

diff --git a/unittests/Support/CommandLineTest.cpp b/unittests/Support/CommandLineTest.cpp
index 782a8169ec0bfc21a6d90d2bd707f125e9613361..99db7e2d86cdf3aab24aa7b00737c4389b0ebc8b 100644 (file)
--- a/unittests/Support/CommandLineTest.cpp
+++ b/unittests/Support/CommandLineTest.cpp
@@ -813,6 +813,43 @@ TEST(CommandLineTest, RecursiveResponseFiles) {
     EXPECT_STREQ(Argv[i], ResponseFileRef.c_str());
 }
 
+TEST(CommandLineTest, ResponseFilesAtArguments) {
+  SmallString<128> TestDir;
+  std::error_code EC = sys::fs::createUniqueDirectory("unittest", TestDir);
+  EXPECT_TRUE(!EC);
+
+  SmallString<128> ResponseFilePath;
+  sys::path::append(ResponseFilePath, TestDir, "test.rsp");
+
+  std::ofstream ResponseFile(ResponseFilePath.c_str());
+  EXPECT_TRUE(ResponseFile.is_open());
+  ResponseFile << "-foo" << "\n";
+  ResponseFile << "-bar" << "\n";
+  ResponseFile.close();
+
+  // Ensure we expand rsp files after lots of non-rsp arguments starting with @.
+  constexpr size_t NON_RSP_AT_ARGS = 64;
+  llvm::SmallVector<const char *, 4> Argv = {"test/test"};
+  Argv.append(NON_RSP_AT_ARGS, "@non_rsp_at_arg");
+  std::string ResponseFileRef = std::string("@") + ResponseFilePath.c_str();
+  Argv.push_back(ResponseFileRef.c_str());
+
+  llvm::BumpPtrAllocator A;
+  llvm::StringSaver Saver(A);
+  bool Res = llvm::cl::ExpandResponseFiles(
+      Saver, llvm::cl::TokenizeGNUCommandLine, Argv, false, false);
+  EXPECT_FALSE(Res);
+
+  // ASSERT instead of EXPECT to prevent potential out-of-bounds access.
+  ASSERT_EQ(Argv.size(), 1 + NON_RSP_AT_ARGS + 2);
+  size_t i = 0;
+  EXPECT_STREQ(Argv[i++], "test/test");
+  for (; i < 1 + NON_RSP_AT_ARGS; ++i)
+    EXPECT_STREQ(Argv[i], "@non_rsp_at_arg");
+  EXPECT_STREQ(Argv[i++], "-foo");
+  EXPECT_STREQ(Argv[i++], "-bar");
+}
+
 TEST(CommandLineTest, SetDefautValue) {
   cl::ResetCommandLineParser();