Fix -Wnull-conversion for long macros.

Move the function to get a macro name from DiagnosticRenderer.cpp to Lexer.cpp
so that other files can use it.  Lexer now has two functions to get the
immediate macro name, the newly added one is better for diagnostic purposes.
Make -Wnull-conversion use this function for better NULL macro detection.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@258778 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/include/clang/Lex/Lexer.h b/include/clang/Lex/Lexer.h
index 12565d0b14b6384f0356ac82694b583c8f626844..830c25a2e4d29fc6fcead442fe7b9e35ace03f3e 100644 (file)
--- a/include/clang/Lex/Lexer.h
+++ b/include/clang/Lex/Lexer.h
@@ -410,6 +410,26 @@ public:
                                          const SourceManager &SM,
                                          const LangOptions &LangOpts);
 
+  /// \brief Retrieve the name of the immediate macro expansion.
+  ///
+  /// This routine starts from a source location, and finds the name of the
+  /// macro responsible for its immediate expansion. It looks through any
+  /// intervening macro argument expansions to compute this. It returns a
+  /// StringRef which refers to the SourceManager-owned buffer of the source
+  /// where that macro name is spelled. Thus, the result shouldn't out-live
+  /// that SourceManager.
+  ///
+  /// This differs from Lexer::getImmediateMacroName in that any macro argument
+  /// location will result in the topmost function macro that accepted it.
+  /// e.g.
+  /// \code
+  ///   MAC1( MAC2(foo) )
+  /// \endcode
+  /// for location of 'foo' token, this function will return "MAC1" while
+  /// Lexer::getImmediateMacroName will return "MAC2".
+  static StringRef getImmediateMacroNameForDiagnostics(
+      SourceLocation Loc, const SourceManager &SM, const LangOptions &LangOpts);
+
   /// \brief Compute the preamble of the given file.
   ///
   /// The preamble of a file contains the initial comments, include directives,

diff --git a/lib/Frontend/DiagnosticRenderer.cpp b/lib/Frontend/DiagnosticRenderer.cpp
index caf1f0dce99ffce4a719c537f2e1d185e476cd6f..302067a2fb05d29a74eb256d7a6481e0ebdcdfad 100644 (file)
--- a/lib/Frontend/DiagnosticRenderer.cpp
+++ b/lib/Frontend/DiagnosticRenderer.cpp
@@ -23,48 +23,6 @@
 #include <algorithm>
 using namespace clang;
 
-/// \brief Retrieve the name of the immediate macro expansion.
-///
-/// This routine starts from a source location, and finds the name of the macro
-/// responsible for its immediate expansion. It looks through any intervening
-/// macro argument expansions to compute this. It returns a StringRef which
-/// refers to the SourceManager-owned buffer of the source where that macro
-/// name is spelled. Thus, the result shouldn't out-live that SourceManager.
-///
-/// This differs from Lexer::getImmediateMacroName in that any macro argument
-/// location will result in the topmost function macro that accepted it.
-/// e.g.
-/// \code
-///   MAC1( MAC2(foo) )
-/// \endcode
-/// for location of 'foo' token, this function will return "MAC1" while
-/// Lexer::getImmediateMacroName will return "MAC2".
-static StringRef getImmediateMacroName(SourceLocation Loc,
-                                       const SourceManager &SM,
-                                       const LangOptions &LangOpts) {
-   assert(Loc.isMacroID() && "Only reasonble to call this on macros");
-   // Walk past macro argument expanions.
-   while (SM.isMacroArgExpansion(Loc))
-     Loc = SM.getImmediateExpansionRange(Loc).first;
-
-   // If the macro's spelling has no FileID, then it's actually a token paste
-   // or stringization (or similar) and not a macro at all.
-   if (!SM.getFileEntryForID(SM.getFileID(SM.getSpellingLoc(Loc))))
-     return StringRef();
-
-   // Find the spelling location of the start of the non-argument expansion
-   // range. This is where the macro name was spelled in order to begin
-   // expanding this macro.
-   Loc = SM.getSpellingLoc(SM.getImmediateExpansionRange(Loc).first);
-
-   // Dig out the buffer where the macro name was spelled and the extents of the
-   // name so that we can render it into the expansion note.
-   std::pair<FileID, unsigned> ExpansionInfo = SM.getDecomposedLoc(Loc);
-   unsigned MacroTokenLength = Lexer::MeasureTokenLength(Loc, SM, LangOpts);
-   StringRef ExpansionBuffer = SM.getBufferData(ExpansionInfo.first);
-   return ExpansionBuffer.substr(ExpansionInfo.second, MacroTokenLength);
-}
-
 DiagnosticRenderer::DiagnosticRenderer(const LangOptions &LangOpts,
                                        DiagnosticOptions *DiagOpts)
   : LangOpts(LangOpts), DiagOpts(DiagOpts), LastLevel() {}
@@ -474,7 +432,8 @@ void DiagnosticRenderer::emitSingleMacroExpansion(
 
   SmallString<100> MessageStorage;
   llvm::raw_svector_ostream Message(MessageStorage);
-  StringRef MacroName = getImmediateMacroName(Loc, SM, LangOpts);
+  StringRef MacroName =
+      Lexer::getImmediateMacroNameForDiagnostics(Loc, SM, LangOpts);
   if (MacroName.empty())
     Message << "expanded from here";
   else

diff --git a/lib/Lex/Lexer.cpp b/lib/Lex/Lexer.cpp
index 27b0feb4827054f0c0de3402b2f43f03875de446..88e7b247806c70d9f3b76aadbb3d1554306271b1 100644 (file)
--- a/lib/Lex/Lexer.cpp
+++ b/lib/Lex/Lexer.cpp
@@ -1000,6 +1000,31 @@ StringRef Lexer::getImmediateMacroName(SourceLocation Loc,
   return ExpansionBuffer.substr(ExpansionInfo.second, MacroTokenLength);
 }
 
+StringRef Lexer::getImmediateMacroNameForDiagnostics(
+    SourceLocation Loc, const SourceManager &SM, const LangOptions &LangOpts) {
+  assert(Loc.isMacroID() && "Only reasonble to call this on macros");
+  // Walk past macro argument expanions.
+  while (SM.isMacroArgExpansion(Loc))
+    Loc = SM.getImmediateExpansionRange(Loc).first;
+
+  // If the macro's spelling has no FileID, then it's actually a token paste
+  // or stringization (or similar) and not a macro at all.
+  if (!SM.getFileEntryForID(SM.getFileID(SM.getSpellingLoc(Loc))))
+    return StringRef();
+
+  // Find the spelling location of the start of the non-argument expansion
+  // range. This is where the macro name was spelled in order to begin
+  // expanding this macro.
+  Loc = SM.getSpellingLoc(SM.getImmediateExpansionRange(Loc).first);
+
+  // Dig out the buffer where the macro name was spelled and the extents of the
+  // name so that we can render it into the expansion note.
+  std::pair<FileID, unsigned> ExpansionInfo = SM.getDecomposedLoc(Loc);
+  unsigned MacroTokenLength = Lexer::MeasureTokenLength(Loc, SM, LangOpts);
+  StringRef ExpansionBuffer = SM.getBufferData(ExpansionInfo.first);
+  return ExpansionBuffer.substr(ExpansionInfo.second, MacroTokenLength);
+}
+
 bool Lexer::isIdentifierBodyChar(char c, const LangOptions &LangOpts) {
   return isIdentifierBody(c, LangOpts.DollarIdents);
 }

diff --git a/lib/Sema/SemaChecking.cpp b/lib/Sema/SemaChecking.cpp
index c8c4d3331b1e55e2bd93359dd06bad97cfee787c..58ae3acf49876e374710df511eddbfa76c32db11 100644 (file)
--- a/lib/Sema/SemaChecking.cpp
+++ b/lib/Sema/SemaChecking.cpp
@@ -7068,8 +7068,8 @@ static void DiagnoseNullConversion(Sema &S, Expr *E, QualType T,
   // __null is usually wrapped in a macro.  Go up a macro if that is the case.
   if (NullKind == Expr::NPCK_GNUNull) {
     if (Loc.isMacroID()) {
-      StringRef MacroName =
-          Lexer::getImmediateMacroName(Loc, S.SourceMgr, S.getLangOpts());
+      StringRef MacroName = Lexer::getImmediateMacroNameForDiagnostics(
+          Loc, S.SourceMgr, S.getLangOpts());
       if (MacroName == "NULL")
         Loc = S.SourceMgr.getImmediateExpansionRange(Loc).first;
     }

diff --git a/test/SemaCXX/conversion.cpp b/test/SemaCXX/conversion.cpp
index 4c4089c6aae773840122e33d755fabe0c5331246..eea8ac2af8a5bc8aa8a4a41bb568b24697593e63 100644 (file)
--- a/test/SemaCXX/conversion.cpp
+++ b/test/SemaCXX/conversion.cpp
@@ -228,3 +228,31 @@ namespace test10 {
     assert(test2(x));
   }
 }
+
+namespace test11 {
+
+#define assert11(expr) ((expr) ? 0 : 0)
+
+// The whitespace in macro run1 are important to trigger the macro being split
+// over multiple SLocEntry's.
+#define run1() (dostuff() ? \
+    NULL                                   : NULL)
+#define run2() (dostuff() ? NULL : NULL)
+int dostuff ();
+
+void test(const char * content_type) {
+  assert11(run1());
+  assert11(run2());
+}
+
+}
+
+namespace test12 {
+
+#define x return NULL;
+
+bool run() {
+  x  // expected-warning{{}}
+}
+
+}