factor token concatenation avoidance logic out of
PrintPreprocessedOutput into its own file. No functionality change.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@64418 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Lex/TokenConcatenation.cpp b/lib/Lex/TokenConcatenation.cpp
new file mode 100644
index 0000000..549fb8d
--- /dev/null
+++ b/lib/Lex/TokenConcatenation.cpp
@@ -0,0 +1,205 @@
+//===--- TokenConcatenation.cpp - Token Concatenation Avoidance -----------===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements the TokenConcatenation class.
+//
+//===----------------------------------------------------------------------===//
+
+#include "clang/Lex/TokenConcatenation.h"
+#include "clang/Lex/Preprocessor.h"
+using namespace clang;
+
+
+/// StartsWithL - Return true if the spelling of this token starts with 'L'.
+bool TokenConcatenation::StartsWithL(const Token &Tok) const {
+ if (!Tok.needsCleaning()) {
+ SourceManager &SM = PP.getSourceManager();
+ return *SM.getCharacterData(SM.getSpellingLoc(Tok.getLocation())) == 'L';
+ }
+
+ if (Tok.getLength() < 256) {
+ char Buffer[256];
+ const char *TokPtr = Buffer;
+ PP.getSpelling(Tok, TokPtr);
+ return TokPtr[0] == 'L';
+ }
+
+ return PP.getSpelling(Tok)[0] == 'L';
+}
+
+/// IsIdentifierL - Return true if the spelling of this token is literally
+/// 'L'.
+bool TokenConcatenation::IsIdentifierL(const Token &Tok) const {
+ if (!Tok.needsCleaning()) {
+ if (Tok.getLength() != 1)
+ return false;
+ SourceManager &SM = PP.getSourceManager();
+ return *SM.getCharacterData(SM.getSpellingLoc(Tok.getLocation())) == 'L';
+ }
+
+ if (Tok.getLength() < 256) {
+ char Buffer[256];
+ const char *TokPtr = Buffer;
+ if (PP.getSpelling(Tok, TokPtr) != 1)
+ return false;
+ return TokPtr[0] == 'L';
+ }
+
+ return PP.getSpelling(Tok) == "L";
+}
+
+TokenConcatenation::TokenConcatenation(Preprocessor &pp) : PP(pp) {
+ memset(TokenInfo, 0, sizeof(TokenInfo));
+
+ // These tokens have custom code in AvoidConcat.
+ TokenInfo[tok::identifier ] |= aci_custom;
+ TokenInfo[tok::numeric_constant] |= aci_custom_firstchar;
+ TokenInfo[tok::period ] |= aci_custom_firstchar;
+ TokenInfo[tok::amp ] |= aci_custom_firstchar;
+ TokenInfo[tok::plus ] |= aci_custom_firstchar;
+ TokenInfo[tok::minus ] |= aci_custom_firstchar;
+ TokenInfo[tok::slash ] |= aci_custom_firstchar;
+ TokenInfo[tok::less ] |= aci_custom_firstchar;
+ TokenInfo[tok::greater ] |= aci_custom_firstchar;
+ TokenInfo[tok::pipe ] |= aci_custom_firstchar;
+ TokenInfo[tok::percent ] |= aci_custom_firstchar;
+ TokenInfo[tok::colon ] |= aci_custom_firstchar;
+ TokenInfo[tok::hash ] |= aci_custom_firstchar;
+ TokenInfo[tok::arrow ] |= aci_custom_firstchar;
+
+ // These tokens change behavior if followed by an '='.
+ TokenInfo[tok::amp ] |= aci_avoid_equal; // &=
+ TokenInfo[tok::plus ] |= aci_avoid_equal; // +=
+ TokenInfo[tok::minus ] |= aci_avoid_equal; // -=
+ TokenInfo[tok::slash ] |= aci_avoid_equal; // /=
+ TokenInfo[tok::less ] |= aci_avoid_equal; // <=
+ TokenInfo[tok::greater ] |= aci_avoid_equal; // >=
+ TokenInfo[tok::pipe ] |= aci_avoid_equal; // |=
+ TokenInfo[tok::percent ] |= aci_avoid_equal; // %=
+ TokenInfo[tok::star ] |= aci_avoid_equal; // *=
+ TokenInfo[tok::exclaim ] |= aci_avoid_equal; // !=
+ TokenInfo[tok::lessless ] |= aci_avoid_equal; // <<=
+ TokenInfo[tok::greaterequal] |= aci_avoid_equal; // >>=
+ TokenInfo[tok::caret ] |= aci_avoid_equal; // ^=
+ TokenInfo[tok::equal ] |= aci_avoid_equal; // ==
+}
+
+/// AvoidConcat - If printing PrevTok immediately followed by Tok would cause
+/// the two individual tokens to be lexed as a single token, return true
+/// (which causes a space to be printed between them). This allows the output
+/// of -E mode to be lexed to the same token stream as lexing the input
+/// directly would.
+///
+/// This code must conservatively return true if it doesn't want to be 100%
+/// accurate. This will cause the output to include extra space characters,
+/// but the resulting output won't have incorrect concatenations going on.
+/// Examples include "..", which we print with a space between, because we
+/// don't want to track enough to tell "x.." from "...".
+bool TokenConcatenation::AvoidConcat(const Token &PrevTok,
+ const Token &Tok) const {
+ char Buffer[256];
+
+ tok::TokenKind PrevKind = PrevTok.getKind();
+ if (PrevTok.getIdentifierInfo()) // Language keyword or named operator.
+ PrevKind = tok::identifier;
+
+ // Look up information on when we should avoid concatenation with prevtok.
+ unsigned ConcatInfo = TokenInfo[PrevKind];
+
+ // If prevtok never causes a problem for anything after it, return quickly.
+ if (ConcatInfo == 0) return false;
+
+ if (ConcatInfo & aci_avoid_equal) {
+ // If the next token is '=' or '==', avoid concatenation.
+ if (Tok.is(tok::equal) || Tok.is(tok::equalequal))
+ return true;
+ ConcatInfo &= ~aci_avoid_equal;
+ }
+
+ if (ConcatInfo == 0) return false;
+
+ // Basic algorithm: we look at the first character of the second token, and
+ // determine whether it, if appended to the first token, would form (or
+ // would contribute) to a larger token if concatenated.
+ char FirstChar = 0;
+ if (ConcatInfo & aci_custom) {
+ // If the token does not need to know the first character, don't get it.
+ } else if (IdentifierInfo *II = Tok.getIdentifierInfo()) {
+ // Avoid spelling identifiers, the most common form of token.
+ FirstChar = II->getName()[0];
+ } else if (!Tok.needsCleaning()) {
+ if (Tok.isLiteral() && Tok.getLiteralData()) {
+ FirstChar = *Tok.getLiteralData();
+ } else {
+ SourceManager &SrcMgr = PP.getSourceManager();
+ FirstChar =
+ *SrcMgr.getCharacterData(SrcMgr.getSpellingLoc(Tok.getLocation()));
+ }
+ } else if (Tok.getLength() < 256) {
+ const char *TokPtr = Buffer;
+ PP.getSpelling(Tok, TokPtr);
+ FirstChar = TokPtr[0];
+ } else {
+ FirstChar = PP.getSpelling(Tok)[0];
+ }
+
+ switch (PrevKind) {
+ default: assert(0 && "InitAvoidConcatTokenInfo built wrong");
+ case tok::identifier: // id+id or id+number or id+L"foo".
+ if (Tok.is(tok::numeric_constant) || Tok.getIdentifierInfo() ||
+ Tok.is(tok::wide_string_literal) /* ||
+ Tok.is(tok::wide_char_literal)*/)
+ return true;
+
+ // If this isn't identifier + string, we're done.
+ if (Tok.isNot(tok::char_constant) && Tok.isNot(tok::string_literal))
+ return false;
+
+ // FIXME: need a wide_char_constant!
+
+ // If the string was a wide string L"foo" or wide char L'f', it would
+ // concat with the previous identifier into fooL"bar". Avoid this.
+ if (StartsWithL(Tok))
+ return true;
+
+ // Otherwise, this is a narrow character or string. If the *identifier*
+ // is a literal 'L', avoid pasting L "foo" -> L"foo".
+ return IsIdentifierL(PrevTok);
+ case tok::numeric_constant:
+ return isalnum(FirstChar) || Tok.is(tok::numeric_constant) ||
+ FirstChar == '+' || FirstChar == '-' || FirstChar == '.';
+ case tok::period: // ..., .*, .1234
+ return FirstChar == '.' || isdigit(FirstChar) ||
+ (FirstChar == '*' && PP.getLangOptions().CPlusPlus);
+ case tok::amp: // &&
+ return FirstChar == '&';
+ case tok::plus: // ++
+ return FirstChar == '+';
+ case tok::minus: // --, ->, ->*
+ return FirstChar == '-' || FirstChar == '>';
+ case tok::slash: //, /*, //
+ return FirstChar == '*' || FirstChar == '/';
+ case tok::less: // <<, <<=, <:, <%
+ return FirstChar == '<' || FirstChar == ':' || FirstChar == '%';
+ case tok::greater: // >>, >>=
+ return FirstChar == '>';
+ case tok::pipe: // ||
+ return FirstChar == '|';
+ case tok::percent: // %>, %:
+ return (FirstChar == '>' || FirstChar == ':') &&
+ PP.getLangOptions().Digraphs;
+ case tok::colon: // ::, :>
+ return (FirstChar == ':' && PP.getLangOptions().CPlusPlus) ||
+ (FirstChar == '>' && PP.getLangOptions().Digraphs);
+ case tok::hash: // ##, #@, %:%:
+ return FirstChar == '#' || FirstChar == '@' || FirstChar == '%';
+ case tok::arrow: // ->*
+ return FirstChar == '*';
+ }
+}