r200787 - Fix whitespace handling in empty macro expansions

[Justin Bogner]

Author: bogner
Date: Tue Feb  4 13:18:35 2014
New Revision: 200787

URL: http://llvm.org/viewvc/llvm-project?rev=200787&view=rev
Log:
Fix whitespace handling in empty macro expansions

When a macro expansion does not result in any tokens, and the macro name
is preceded by whitespace, the whitespace should be passed to the first
token that follows the macro expansion. Similarly when a macro expansion
ends with a placemarker token, and that placemarker token is preceded by
whitespace. This worked already for top-level macro expansions, but is
now extended to also work for nested macro expansions.

Patch by Harald van Dijk!

Modified:
    cfe/trunk/lib/Lex/TokenLexer.cpp
    cfe/trunk/test/Preprocessor/macro_space.c

Modified: cfe/trunk/lib/Lex/TokenLexer.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Lex/TokenLexer.cpp?rev=200787&r1=200786&r2=200787&view=diff
==============================================================================
--- cfe/trunk/lib/Lex/TokenLexer.cpp (original)
+++ cfe/trunk/lib/Lex/TokenLexer.cpp Tue Feb  4 13:18:35 2014
@@ -477,9 +477,13 @@ bool TokenLexer::Lex(Token &Tok) {
   if (isFirstToken) {
     Tok.setFlagValue(Token::StartOfLine , AtStartOfLine);
     Tok.setFlagValue(Token::LeadingSpace, HasLeadingSpace);
-    AtStartOfLine = false;
-    HasLeadingSpace = false;
+  } else {
+    // If this is not the first token, we may still need to pass through
+    // leading whitespace if we've expanded a macro.
+    if (HasLeadingSpace) Tok.setFlag(Token::LeadingSpace);
   }
+  AtStartOfLine = false;
+  HasLeadingSpace = false;
 
   // Handle recursive expansion!
   if (!Tok.isAnnotation() && Tok.getIdentifierInfo() != 0) {

Modified: cfe/trunk/test/Preprocessor/macro_space.c
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Preprocessor/macro_space.c?rev=200787&r1=200786&r2=200787&view=diff
==============================================================================
--- cfe/trunk/test/Preprocessor/macro_space.c (original)
+++ cfe/trunk/test/Preprocessor/macro_space.c Tue Feb  4 13:18:35 2014
@@ -1,6 +1,36 @@
 // RUN: %clang_cc1 -E %s | FileCheck --strict-whitespace %s
 
-#define XX
-! XX,
+#define FOO1()
+#define FOO2(x)x
+#define FOO3(x) x
+#define FOO4(x)x x
+#define FOO5(x) x x
+#define FOO6(x) [x]
+#define FOO7(x) [ x]
+#define FOO8(x) [x ]
 
-// CHECK: {{^}}! ,{{$}}
+#define TEST(FOO,x) FOO <FOO()> < FOO()> <FOO ()> <FOO( )> <FOO() > <FOO()x> <FOO() x> < FOO()x>
+
+TEST(FOO1,)
+// CHECK: FOO1 <> < > <> <> < > <> < > < >
+
+TEST(FOO2,)
+// CHECK: FOO2 <> < > <> <> < > <> < > < >
+
+TEST(FOO3,)
+// CHECK: FOO3 <> < > <> <> < > <> < > < >
+
+TEST(FOO4,)
+// CHECK: FOO4 < > < > < > < > < > < > < > < >
+
+TEST(FOO5,)
+// CHECK: FOO5 < > < > < > < > < > < > < > < >
+
+TEST(FOO6,)
+// CHECK: FOO6 <[]> < []> <[]> <[]> <[] > <[]> <[] > < []>
+
+TEST(FOO7,)
+// CHECK: FOO7 <[ ]> < [ ]> <[ ]> <[ ]> <[ ] > <[ ]> <[ ] > < [ ]>
+
+TEST(FOO8,)
+// CHECK: FOO8 <[ ]> < [ ]> <[ ]> <[ ]> <[ ] > <[ ]> <[ ] > < [ ]>