From cb7fd3caeee52fe94461b717294c4db4056853e3 Mon Sep 17 00:00:00 2001

From: Serge Guelton <sguelton@redhat.com>

Date: Fri, 1 Feb 2019 06:11:44 +0000

Subject: [PATCH 1/3] Fix isInSystemMacro to handle pasted macros

Token pasted by the preprocessor (through ##) have a Spelling pointing to scratch buffer.

As a result they are not recognized at system macro, even though the pasting happened in

a system macro. Fix that by looking into the parent macro if the original lookup finds a

scratch buffer.

Differential Revision: https://reviews.llvm.org/D55782

This effectively fixes https://bugs.llvm.org/show_bug.cgi?id=35268,

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@352838 91177308-0d34-0410-b5e6-96231b3b80d8

---

 include/clang/Basic/SourceManager.h      | 18 +++++++++++++++++-

 test/Misc/no-warn-in-system-macro.c      | 13 +++++++++++++

 test/Misc/no-warn-in-system-macro.c.inc  |  9 +++++++++

 test/Misc/warn-in-system-macro-def.c     | 21 +++++++++++++++++++++

 test/Misc/warn-in-system-macro-def.c.inc |  4 ++++

 5 files changed, 64 insertions(+), 1 deletion(-)

 create mode 100644 test/Misc/no-warn-in-system-macro.c

 create mode 100644 test/Misc/no-warn-in-system-macro.c.inc

 create mode 100644 test/Misc/warn-in-system-macro-def.c

 create mode 100644 test/Misc/warn-in-system-macro-def.c.inc

diff --git a/include/clang/Basic/SourceManager.h b/include/clang/Basic/SourceManager.h

index dcc4a37e23..c6b92f9000 100644

--- a/include/clang/Basic/SourceManager.h

+++ b/include/clang/Basic/SourceManager.h

@@ -1441,6 +1441,12 @@ public:

     return Filename.equals("<command line>");

   }

+  /// Returns whether \p Loc is located in a <scratch space> file.

+  bool isWrittenInScratchSpace(SourceLocation Loc) const {

+    StringRef Filename(getPresumedLoc(Loc).getFilename());

+    return Filename.equals("<scratch space>");

+  }

+

   /// Returns if a SourceLocation is in a system header.

   bool isInSystemHeader(SourceLocation Loc) const {

     return isSystem(getFileCharacteristic(Loc));

@@ -1453,7 +1459,17 @@ public:

   /// Returns whether \p Loc is expanded from a macro in a system header.

   bool isInSystemMacro(SourceLocation loc) const {

-    return loc.isMacroID() && isInSystemHeader(getSpellingLoc(loc));

+    if(!loc.isMacroID())

+      return false;

+

+    // This happens when the macro is the result of a paste, in that case

+    // its spelling is the scratch memory, so we take the parent context.

+    if (isWrittenInScratchSpace(getSpellingLoc(loc))) {

+      return isInSystemHeader(getSpellingLoc(getImmediateMacroCallerLoc(loc)));

+    }

+    else {

+      return isInSystemHeader(getSpellingLoc(loc));

+    }

   }

   /// The size of the SLocEntry that \p FID represents.

diff --git a/test/Misc/no-warn-in-system-macro.c b/test/Misc/no-warn-in-system-macro.c

new file mode 100644

index 0000000000..a319b14c9c

--- /dev/null

+++ b/test/Misc/no-warn-in-system-macro.c

@@ -0,0 +1,13 @@

+// RUN: %clang_cc1 -isystem %S -Wdouble-promotion -fsyntax-only %s  2>&1 | FileCheck -allow-empty %s

+// CHECK-NOT: warning:

+

+#include <no-warn-in-system-macro.c.inc>

+

+int main(void)

+{

+	double foo = 1.0;

+

+	if (isnan(foo))

+		return 1;

+	return 0;

+}

diff --git a/test/Misc/no-warn-in-system-macro.c.inc b/test/Misc/no-warn-in-system-macro.c.inc

new file mode 100644

index 0000000000..3cbe7dfc16

--- /dev/null

+++ b/test/Misc/no-warn-in-system-macro.c.inc

@@ -0,0 +1,9 @@

+extern int __isnanf(float f);

+extern int __isnan(double f);

+extern int __isnanl(long double f);

+#define isnan(x) \

+	(sizeof (x) == sizeof (float)                \

+	? __isnanf (x)                    \

+	: sizeof (x) == sizeof (double)               \

+	? __isnan (x) : __isnanl (x))

+

diff --git a/test/Misc/warn-in-system-macro-def.c b/test/Misc/warn-in-system-macro-def.c

new file mode 100644

index 0000000000..b295130702

--- /dev/null

+++ b/test/Misc/warn-in-system-macro-def.c

@@ -0,0 +1,21 @@

+// RUN: %clang_cc1 -isystem %S -Wdouble-promotion -fsyntax-only %s  2>&1 | FileCheck -allow-empty %s

+// CHECK: warning:

+// CHECK: expanded from macro 'ISNAN'

+// CHECK: expanded from macro 'isnan'

+

+#include <warn-in-system-macro-def.c.inc>

+

+#define isnan(x) \

+	(sizeof (x) == sizeof (float)                \

+	? __isnanf (x)                    \

+	: sizeof (x) == sizeof (double)               \

+	? __isnan (x) : __isnanl (x))

+

+int main(void)

+{

+	double foo = 1.0;

+

+	if (ISNAN(foo))

+		return 1;

+	return 0;

+}

diff --git a/test/Misc/warn-in-system-macro-def.c.inc b/test/Misc/warn-in-system-macro-def.c.inc

new file mode 100644

index 0000000000..5c7e60275a

--- /dev/null

+++ b/test/Misc/warn-in-system-macro-def.c.inc

@@ -0,0 +1,4 @@

+extern int __isnanf(float f);

+extern int __isnan(double f);

+extern int __isnanl(long double f);

+#define ISNAN isnan

-- 

2.20.1