Implement built-in macro '__has_warning', which allows one to query if a warning flag is valid. Fixes <rdar://problem/10263428>.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@141802 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Lex/PPMacroExpansion.cpp b/lib/Lex/PPMacroExpansion.cpp
index 5bdebf9..486ffbe 100644
--- a/lib/Lex/PPMacroExpansion.cpp
+++ b/lib/Lex/PPMacroExpansion.cpp
@@ -21,6 +21,7 @@
#include "clang/Lex/LexDiagnostic.h"
#include "clang/Lex/CodeCompletionHandler.h"
#include "clang/Lex/ExternalPreprocessorSource.h"
+#include "clang/Lex/LiteralSupport.h"
#include "llvm/ADT/StringSwitch.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/Config/config.h"
@@ -92,6 +93,7 @@
Ident__has_attribute = RegisterBuiltinMacro(*this, "__has_attribute");
Ident__has_include = RegisterBuiltinMacro(*this, "__has_include");
Ident__has_include_next = RegisterBuiltinMacro(*this, "__has_include_next");
+ Ident__has_warning = RegisterBuiltinMacro(*this, "__has_warning");
// Microsoft Extensions.
if (Features.MicrosoftExt)
@@ -1016,6 +1018,73 @@
Value = EvaluateHasIncludeNext(Tok, II, *this);
OS << (int)Value;
Tok.setKind(tok::numeric_constant);
+ } else if (II == Ident__has_warning) {
+ // The argument should be a parenthesized string literal.
+ // The argument to these builtins should be a parenthesized identifier.
+ SourceLocation StartLoc = Tok.getLocation();
+ bool IsValid = false;
+ bool Value = false;
+ // Read the '('.
+ Lex(Tok);
+ do {
+ if (Tok.is(tok::l_paren)) {
+ // Read the string.
+ Lex(Tok);
+
+ // We need at least one string literal.
+ if (!Tok.is(tok::string_literal)) {
+ StartLoc = Tok.getLocation();
+ IsValid = false;
+ // Eat tokens until ')'.
+ do Lex(Tok); while (!(Tok.is(tok::r_paren) || Tok.is(tok::eod)));
+ break;
+ }
+
+ // String concatenation allows multiple strings, which can even come
+ // from macro expansion.
+ SmallVector<Token, 4> StrToks;
+ while (Tok.is(tok::string_literal)) {
+ StrToks.push_back(Tok);
+ LexUnexpandedToken(Tok);
+ }
+
+ // Is the end a ')'?
+ if (!(IsValid = Tok.is(tok::r_paren)))
+ break;
+
+ // Concatenate and parse the strings.
+ StringLiteralParser Literal(&StrToks[0], StrToks.size(), *this);
+ assert(Literal.isAscii() && "Didn't allow wide strings in");
+ if (Literal.hadError)
+ break;
+ if (Literal.Pascal) {
+ Diag(Tok, diag::warn_pragma_diagnostic_invalid);
+ break;
+ }
+
+ StringRef WarningName(Literal.GetString());
+
+ if (WarningName.size() < 3 || WarningName[0] != '-' ||
+ WarningName[1] != 'W') {
+ Diag(StrToks[0].getLocation(), diag::warn_has_warning_invalid_option);
+ break;
+ }
+
+ // Finally, check if the warning flags maps to a diagnostic group.
+ // We construct a SmallVector here to talk to getDiagnosticIDs().
+ // Although we don't use the result, this isn't a hot path, and not
+ // worth special casing.
+ llvm::SmallVector<diag::kind, 10> Diags;
+ Value = !getDiagnostics().getDiagnosticIDs()->
+ getDiagnosticsInGroup(WarningName.substr(2), Diags);
+ }
+ } while (false);
+
+ if (!IsValid)
+ Diag(StartLoc, diag::err_warning_check_malformed);
+
+ OS << (int)Value;
+ Tok.setKind(tok::numeric_constant);
} else {
llvm_unreachable("Unknown identifier!");
}