Fix -use-nullptr problems with assert()

If a cast expression (NullToPointer) is detected in a function-like macro
parameter, we should use the spelling location instead of the expansion
location. Using SourceManager::getFileLoc() fixes this problem.

Also added testcases for this bug.

Fixes: PR15279
Author: Tareq A Siraj <tareq.a.siraj@intel.com>
Reviewer: klimek
llvm-svn: 175399

2 files changed, 33 insertions, 4 deletions

diff --git a/clang-tools-extra/cpp11-migrate/UseNullptr/NullptrActions.cpp b/clang-tools-extra/cpp11-migrate/UseNullptr/NullptrActions.cpp
index 54ea3e8a0ad..22cdbc65e87 100644
--- a/clang-tools-extra/cpp11-migrate/UseNullptr/NullptrActions.cpp
+++ b/clang-tools-extra/cpp11-migrate/UseNullptr/NullptrActions.cpp
@@ -57,6 +57,10 @@ public:
       SourceLocation StartLoc = FirstCast->getLocStart();
       SourceLocation EndLoc = FirstCast->getLocEnd();
 
+      // If the start/end location is a macro, get the expansion location.
+      StartLoc = SM.getFileLoc(StartLoc);
+      EndLoc = SM.getFileLoc(EndLoc);
+
       if (SM.getFileID(StartLoc) == SM.getFileID(EndLoc) &&
           SM.isFromMainFile(StartLoc) && SM.isFromMainFile(EndLoc)) {
         CharSourceRange Range(SourceRange(StartLoc, EndLoc), true);
@@ -100,10 +104,9 @@ void NullptrFixer::run(const ast_matchers::MatchFinder::MatchResult &Result) {
     if (SM.getFileID(StartLoc) != SM.getFileID(EndLoc))
       return;
 
-    if (StartLoc.isMacroID())
-      StartLoc = SM.getExpansionLoc(StartLoc);
-    if (EndLoc.isMacroID())
-      EndLoc = SM.getExpansionLoc(EndLoc);
+    // If the start/end location is a macro, get the expansion location.
+    StartLoc = SM.getFileLoc(StartLoc);
+    EndLoc = SM.getFileLoc(EndLoc);
 
     if (!SM.isFromMainFile(StartLoc) || !SM.isFromMainFile(EndLoc))
       return;
diff --git a/clang-tools-extra/test/cpp11-migrate/UseNullptr/basic.cpp b/clang-tools-extra/test/cpp11-migrate/UseNullptr/basic.cpp
index a0d93b13004..c9dc404b8a3 100644
--- a/clang-tools-extra/test/cpp11-migrate/UseNullptr/basic.cpp
+++ b/clang-tools-extra/test/cpp11-migrate/UseNullptr/basic.cpp
@@ -178,3 +178,29 @@ int test_function_return6() {
   return g_null;
   // CHECK: return g_null;
 }
+
+// Test function-like macros where the parameter to the macro (expression)
+// results in a nullptr.
+void __dummy_assert_fail() {}
+
+void test_function_like_macro1() {
+  // This tests that the CastSequenceVisitor is working properly.
+#define my_assert(expr) \
+  ((expr) ? static_cast<void>(expr) : __dummy_assert_fail())
+
+  int *p;
+  my_assert(p != 0);
+  // CHECK: my_assert(p != nullptr);
+#undef my_assert
+}
+
+void test_function_like_macro2() {
+  // This tests that the implicit cast is working properly.
+#define my_macro(expr) \
+  (expr)
+
+  int *p;
+  my_macro(p != 0);
+  // CHECK: my_macro(p != nullptr);
+#undef my_macro
+}