Suppress elided variadic macro argument extension diagnostic for macros using
the related comma pasting extension.
In certain cases, we used to get two diagnostics for what is essentially one
extension. This change suppresses the first diagnostic in certain cases
where we know we're going to print the second diagnostic. The
diagnostic is redundant, and it can't be suppressed in the definition
of the macro because it points at the use of the macro, so we want to
avoid printing it if possible.
The implementation works by detecting constructs which look like comma
pasting at the time of the definition of the macro; this information
is then used when the macro is used. (We can't actually detect
whether we're using the comma pasting extension until the macro is
actually used, but we can detecting constructs which will be comma
pasting if the varargs argument is elided.)
<rdar://problem/12292192>
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@167907 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/include/clang/Lex/MacroInfo.h b/include/clang/Lex/MacroInfo.h
index aba77d5..aeedd73 100644
--- a/include/clang/Lex/MacroInfo.h
+++ b/include/clang/Lex/MacroInfo.h
@@ -76,6 +76,9 @@
/// it has not yet been redefined or undefined.
bool IsBuiltinMacro : 1;
+ /// \brief Whether this macro contains the sequence ", ## __VA_ARGS__"
+ bool HasCommaPasting : 1;
+
/// \brief True if this macro was loaded from an AST file.
bool IsFromAST : 1;
@@ -253,6 +256,9 @@
/// __LINE__, which requires processing before expansion.
bool isBuiltinMacro() const { return IsBuiltinMacro; }
+ bool hasCommaPasting() const { return HasCommaPasting; }
+ void setHasCommaPasting() { HasCommaPasting = true; }
+
/// isFromAST - Return true if this macro was loaded from an AST file.
bool isFromAST() const { return IsFromAST; }
diff --git a/lib/Lex/MacroInfo.cpp b/lib/Lex/MacroInfo.cpp
index 904f04e..d1875c7 100644
--- a/lib/Lex/MacroInfo.cpp
+++ b/lib/Lex/MacroInfo.cpp
@@ -25,6 +25,7 @@
IsC99Varargs(false),
IsGNUVarargs(false),
IsBuiltinMacro(false),
+ HasCommaPasting(false),
IsFromAST(false),
ChangedAfterLoad(false),
IsDisabled(false),
@@ -50,6 +51,7 @@
IsC99Varargs(MI.IsC99Varargs),
IsGNUVarargs(MI.IsGNUVarargs),
IsBuiltinMacro(MI.IsBuiltinMacro),
+ HasCommaPasting(MI.HasCommaPasting),
IsFromAST(MI.IsFromAST),
ChangedAfterLoad(MI.ChangedAfterLoad),
IsDisabled(MI.IsDisabled),
diff --git a/lib/Lex/PPDirectives.cpp b/lib/Lex/PPDirectives.cpp
index b7c1846..50b161a 100644
--- a/lib/Lex/PPDirectives.cpp
+++ b/lib/Lex/PPDirectives.cpp
@@ -1809,7 +1809,7 @@
while (Tok.isNot(tok::eod)) {
LastTok = Tok;
- if (Tok.isNot(tok::hash)) {
+ if (Tok.isNot(tok::hash) && Tok.isNot(tok::hashhash)) {
MI->AddTokenToBody(Tok);
// Get the next token of the macro.
@@ -1817,6 +1817,35 @@
continue;
}
+ if (Tok.is(tok::hashhash)) {
+
+ // If we see token pasting, check if it looks like the gcc comma
+ // pasting extension. We'll use this information to suppress
+ // diagnostics later on.
+
+ // Get the next token of the macro.
+ LexUnexpandedToken(Tok);
+
+ if (Tok.is(tok::eod)) {
+ MI->AddTokenToBody(LastTok);
+ break;
+ }
+
+ unsigned NumTokens = MI->getNumTokens();
+ if (NumTokens && Tok.getIdentifierInfo() == Ident__VA_ARGS__ &&
+ MI->getReplacementToken(NumTokens-1).is(tok::comma))
+ MI->setHasCommaPasting();
+
+ // Things look ok, add the '##' and param name tokens to the macro.
+ MI->AddTokenToBody(LastTok);
+ MI->AddTokenToBody(Tok);
+ LastTok = Tok;
+
+ // Get the next token of the macro.
+ LexUnexpandedToken(Tok);
+ continue;
+ }
+
// Get the next token of the macro.
LexUnexpandedToken(Tok);
diff --git a/lib/Lex/PPMacroExpansion.cpp b/lib/Lex/PPMacroExpansion.cpp
index eee4342..de98d50 100644
--- a/lib/Lex/PPMacroExpansion.cpp
+++ b/lib/Lex/PPMacroExpansion.cpp
@@ -619,9 +619,14 @@
// Varargs where the named vararg parameter is missing: OK as extension.
// #define A(x, ...)
// A("blah")
- Diag(Tok, diag::ext_missing_varargs_arg);
- Diag(MI->getDefinitionLoc(), diag::note_macro_here)
- << MacroName.getIdentifierInfo();
+ //
+ // If the macro contains the comma pasting extension, the diagnostic
+ // is suppressed; we know we'll get another diagnostic later.
+ if (!MI->hasCommaPasting()) {
+ Diag(Tok, diag::ext_missing_varargs_arg);
+ Diag(MI->getDefinitionLoc(), diag::note_macro_here)
+ << MacroName.getIdentifierInfo();
+ }
// Remember this occurred, allowing us to elide the comma when used for
// cases like:
diff --git a/lib/Serialization/ASTReader.cpp b/lib/Serialization/ASTReader.cpp
index deba302..f64962e 100644
--- a/lib/Serialization/ASTReader.cpp
+++ b/lib/Serialization/ASTReader.cpp
@@ -1141,6 +1141,7 @@
// Decode function-like macro info.
bool isC99VarArgs = Record[NextIndex++];
bool isGNUVarArgs = Record[NextIndex++];
+ bool hasCommaPasting = Record[NextIndex++];
MacroArgs.clear();
unsigned NumArgs = Record[NextIndex++];
for (unsigned i = 0; i != NumArgs; ++i)
@@ -1150,6 +1151,7 @@
MI->setIsFunctionLike();
if (isC99VarArgs) MI->setIsC99Varargs();
if (isGNUVarArgs) MI->setIsGNUVarargs();
+ if (hasCommaPasting) MI->setHasCommaPasting();
MI->setArgumentList(MacroArgs.data(), MacroArgs.size(),
PP.getPreprocessorAllocator());
}
diff --git a/lib/Serialization/ASTWriter.cpp b/lib/Serialization/ASTWriter.cpp
index a2e8b71..a34244d 100644
--- a/lib/Serialization/ASTWriter.cpp
+++ b/lib/Serialization/ASTWriter.cpp
@@ -1855,6 +1855,7 @@
Record.push_back(MI->isC99Varargs());
Record.push_back(MI->isGNUVarargs());
+ Record.push_back(MI->hasCommaPasting());
Record.push_back(MI->getNumArgs());
for (MacroInfo::arg_iterator I = MI->arg_begin(), E = MI->arg_end();
I != E; ++I)
diff --git a/test/Preprocessor/macro_fn.c b/test/Preprocessor/macro_fn.c
index f93d52c..8ac9ed9 100644
--- a/test/Preprocessor/macro_fn.c
+++ b/test/Preprocessor/macro_fn.c
@@ -44,3 +44,9 @@
#define E() (i == 0)
#if E
#endif
+
+
+/* <rdar://problem/12292192> */
+#define NSAssert(condition, desc, ...) /* expected-warning {{variadic macros are a C99 feature}} */ \
+ SomeComplicatedStuff((desc), ##__VA_ARGS__) /* expected-warning {{token pasting of ',' and __VA_ARGS__ is a GNU extension}} */
+NSAssert(somecond, somedesc)