[clang] ea8e71c - [clang][HeaderInsert] Do not treat defines with values as header guards

[Kadir Cetinkaya via cfe-commits]

Author: Kadir Cetinkaya
Date: 2020-08-11T16:02:11+02:00
New Revision: ea8e71c3da56f76ae2ab2f9ee7afc6444408ffab

URL: https://github.com/llvm/llvm-project/commit/ea8e71c3da56f76ae2ab2f9ee7afc6444408ffab
DIFF: https://github.com/llvm/llvm-project/commit/ea8e71c3da56f76ae2ab2f9ee7afc6444408ffab.diff

LOG: [clang][HeaderInsert] Do not treat defines with values as header guards

This was resulting in inserting headers at bogus locations, see
https://github.com/ycm-core/YouCompleteMe/issues/3736 for an example.

Differential Revision: https://reviews.llvm.org/D85590

Added: 
    

Modified: 
    clang/lib/Tooling/Inclusions/HeaderIncludes.cpp
    clang/unittests/Tooling/HeaderIncludesTest.cpp

Removed: 
    


################################################################################
diff  --git a/clang/lib/Tooling/Inclusions/HeaderIncludes.cpp b/clang/lib/Tooling/Inclusions/HeaderIncludes.cpp
index 681fcc5c762a..b65d7f0c1a39 100644
--- a/clang/lib/Tooling/Inclusions/HeaderIncludes.cpp
+++ b/clang/lib/Tooling/Inclusions/HeaderIncludes.cpp
@@ -100,7 +100,8 @@ unsigned getOffsetAfterHeaderGuardsAndComments(StringRef FileName,
           [](const SourceManager &SM, Lexer &Lex, Token Tok) -> unsigned {
             if (checkAndConsumeDirectiveWithName(Lex, "ifndef", Tok)) {
               skipComments(Lex, Tok);
-              if (checkAndConsumeDirectiveWithName(Lex, "define", Tok))
+              if (checkAndConsumeDirectiveWithName(Lex, "define", Tok) &&
+                  Tok.isAtStartOfLine())
                 return SM.getFileOffset(Tok.getLocation());
             }
             return 0;

diff  --git a/clang/unittests/Tooling/HeaderIncludesTest.cpp b/clang/unittests/Tooling/HeaderIncludesTest.cpp
index 9f86d2e913a8..d38104fe40ec 100644
--- a/clang/unittests/Tooling/HeaderIncludesTest.cpp
+++ b/clang/unittests/Tooling/HeaderIncludesTest.cpp
@@ -347,6 +347,18 @@ TEST_F(HeaderIncludesTest, FakeHeaderGuard) {
   EXPECT_EQ(Expected, insert(Code, "<vector>"));
 }
 
+TEST_F(HeaderIncludesTest, FakeHeaderGuardIfnDef) {
+  std::string Code = "#ifndef A_H\n"
+                     "#define A_H 1\n"
+                     "#endif";
+  std::string Expected = "#include \"b.h\"\n"
+                         "#ifndef A_H\n"
+                         "#define A_H 1\n"
+                         "#endif";
+
+  EXPECT_EQ(Expected, insert(Code, "\"b.h\""));
+}
+
 TEST_F(HeaderIncludesTest, HeaderGuardWithComment) {
   std::string Code = "// comment \n"
                      "#ifndef X // comment\n"