| #include "preprocessor.h" |
| #include "characters.h" |
| #include "idioms.h" |
| #include "message.h" |
| #include "prescan.h" |
| #include <algorithm> |
| #include <cinttypes> |
| #include <cstddef> |
| #include <ctime> |
| #include <map> |
| #include <memory> |
| #include <optional> |
| #include <set> |
| #include <sstream> |
| #include <utility> |
| |
| namespace Fortran { |
| namespace parser { |
| |
| Definition::Definition( |
| const TokenSequence &repl, std::size_t firstToken, std::size_t tokens) |
| : replacement_{Tokenize({}, repl, firstToken, tokens)} {} |
| |
| Definition::Definition(const std::vector<std::string> &argNames, |
| const TokenSequence &repl, std::size_t firstToken, std::size_t tokens, |
| bool isVariadic) |
| : isFunctionLike_{true}, |
| argumentCount_(argNames.size()), isVariadic_{isVariadic}, |
| replacement_{Tokenize(argNames, repl, firstToken, tokens)} {} |
| |
| Definition::Definition(const std::string &predefined, AllSources &sources) |
| : isPredefined_{true}, replacement_{predefined, |
| sources.AddCompilerInsertion(predefined).start()} { |
| } |
| |
| bool Definition::set_isDisabled(bool disable) { |
| bool was{isDisabled_}; |
| isDisabled_ = disable; |
| return was; |
| } |
| |
| static bool IsLegalIdentifierStart(const CharBlock &cpl) { |
| return cpl.size() > 0 && IsLegalIdentifierStart(cpl[0]); |
| } |
| |
| TokenSequence Definition::Tokenize(const std::vector<std::string> &argNames, |
| const TokenSequence &token, std::size_t firstToken, std::size_t tokens) { |
| std::map<std::string, std::string> args; |
| char argIndex{'A'}; |
| for (const std::string &arg : argNames) { |
| CHECK(args.find(arg) == args.end()); |
| args[arg] = "~"s + argIndex++; |
| } |
| TokenSequence result; |
| for (std::size_t j{0}; j < tokens; ++j) { |
| CharBlock tok{token.TokenAt(firstToken + j)}; |
| if (IsLegalIdentifierStart(tok)) { |
| auto it = args.find(tok.ToString()); |
| if (it != args.end()) { |
| result.Put(it->second, token.GetTokenProvenance(j)); |
| continue; |
| } |
| } |
| result.Put(token, firstToken + j, 1); |
| } |
| return result; |
| } |
| |
| static std::size_t AfterLastNonBlank(const TokenSequence &tokens) { |
| for (std::size_t j{tokens.SizeInTokens()}; j > 0; --j) { |
| if (!tokens.TokenAt(j - 1).IsBlank()) { |
| return j; |
| } |
| } |
| return 0; |
| } |
| |
| static TokenSequence Stringify( |
| const TokenSequence &tokens, AllSources &allSources) { |
| TokenSequence result; |
| Provenance quoteProvenance{allSources.CompilerInsertionProvenance('"')}; |
| result.PutNextTokenChar('"', quoteProvenance); |
| for (std::size_t j{0}; j < tokens.SizeInTokens(); ++j) { |
| const CharBlock &token{tokens.TokenAt(j)}; |
| std::size_t bytes{token.size()}; |
| for (std::size_t k{0}; k < bytes; ++k) { |
| char ch{token[k]}; |
| Provenance from{tokens.GetTokenProvenance(j, k)}; |
| if (ch == '"' || ch == '\\') { |
| result.PutNextTokenChar(ch, from); |
| } |
| result.PutNextTokenChar(ch, from); |
| } |
| } |
| result.PutNextTokenChar('"', quoteProvenance); |
| result.CloseToken(); |
| return result; |
| } |
| |
| TokenSequence Definition::Apply( |
| const std::vector<TokenSequence> &args, AllSources &allSources) { |
| TokenSequence result; |
| bool pasting{false}; |
| bool skipping{false}; |
| int parenthesesNesting{0}; |
| std::size_t tokens{replacement_.SizeInTokens()}; |
| for (std::size_t j{0}; j < tokens; ++j) { |
| const CharBlock &token{replacement_.TokenAt(j)}; |
| std::size_t bytes{token.size()}; |
| if (skipping) { |
| if (bytes == 1) { |
| if (token[0] == '(') { |
| ++parenthesesNesting; |
| } else if (token[0] == ')') { |
| skipping = --parenthesesNesting > 0; |
| } |
| } |
| continue; |
| } |
| if (bytes == 2 && token[0] == '~') { |
| std::size_t index = token[1] - 'A'; |
| if (index >= args.size()) { |
| continue; |
| } |
| std::size_t afterLastNonBlank{AfterLastNonBlank(result)}; |
| if (afterLastNonBlank > 0 && |
| result.TokenAt(afterLastNonBlank - 1).ToString() == "#") { |
| // stringifying |
| while (result.SizeInTokens() >= afterLastNonBlank) { |
| result.pop_back(); |
| } |
| result.Put(Stringify(args[index], allSources)); |
| } else { |
| std::size_t argTokens{args[index].SizeInTokens()}; |
| for (std::size_t k{0}; k < argTokens; ++k) { |
| if (!pasting || !args[index].TokenAt(k).IsBlank()) { |
| result.Put(args[index], k); |
| pasting = false; |
| } |
| } |
| } |
| } else if (bytes == 2 && token[0] == '#' && token[1] == '#') { |
| // Token pasting operator in body (not expanded argument); discard any |
| // immediately preceding white space, then reopen the last token. |
| while (!result.empty() && |
| result.TokenAt(result.SizeInTokens() - 1).IsBlank()) { |
| result.pop_back(); |
| } |
| if (!result.empty()) { |
| result.ReopenLastToken(); |
| pasting = true; |
| } |
| } else if (pasting && token.IsBlank()) { |
| // Delete whitespace immediately following ## in the body. |
| } else if (bytes == 11 && isVariadic_ && |
| token.ToString() == "__VA_ARGs__") { |
| Provenance commaProvenance{allSources.CompilerInsertionProvenance(',')}; |
| for (std::size_t k{argumentCount_}; k < args.size(); ++k) { |
| if (k > argumentCount_) { |
| result.Put(","s, commaProvenance); |
| } |
| result.Put(args[k]); |
| } |
| } else if (bytes == 10 && isVariadic_ && token.ToString() == "__VA_OPT__" && |
| j + 2 < tokens && replacement_.TokenAt(j + 1).ToString() == "(" && |
| parenthesesNesting == 0) { |
| parenthesesNesting = 1; |
| skipping = args.size() == argumentCount_; |
| ++j; |
| } else { |
| if (bytes == 1 && parenthesesNesting > 0 && token[0] == '(') { |
| ++parenthesesNesting; |
| } else if (bytes == 1 && parenthesesNesting > 0 && token[0] == ')') { |
| if (--parenthesesNesting == 0) { |
| skipping = false; |
| continue; |
| } |
| } |
| result.Put(replacement_, j); |
| } |
| } |
| return result; |
| } |
| |
| static std::string FormatTime(const std::time_t &now, const char *format) { |
| char buffer[16]; |
| return {buffer, |
| std::strftime(buffer, sizeof buffer, format, std::localtime(&now))}; |
| } |
| |
| Preprocessor::Preprocessor(AllSources &allSources) : allSources_{allSources} { |
| // Capture current local date & time once now to avoid having the values |
| // of __DATE__ or __TIME__ change during compilation. |
| std::time_t now; |
| std::time(&now); |
| definitions_.emplace(SaveTokenAsName("__DATE__"s), // e.g., "Jun 16 1904" |
| Definition{FormatTime(now, "\"%h %e %Y\""), allSources}); |
| definitions_.emplace(SaveTokenAsName("__TIME__"s), // e.g., "23:59:60" |
| Definition{FormatTime(now, "\"%T\""), allSources}); |
| // The values of these predefined macros depend on their invocation sites. |
| definitions_.emplace( |
| SaveTokenAsName("__FILE__"s), Definition{"__FILE__"s, allSources}); |
| definitions_.emplace( |
| SaveTokenAsName("__LINE__"s), Definition{"__LINE__"s, allSources}); |
| } |
| |
| void Preprocessor::Define(std::string macro, std::string value) { |
| definitions_.emplace(SaveTokenAsName(macro), Definition{value, allSources_}); |
| } |
| |
| void Preprocessor::Undefine(std::string macro) { definitions_.erase(macro); } |
| |
| std::optional<TokenSequence> Preprocessor::MacroReplacement( |
| const TokenSequence &input, const Prescanner &prescanner) { |
| // Do quick scan for any use of a defined name. |
| std::size_t tokens{input.SizeInTokens()}; |
| std::size_t j; |
| for (j = 0; j < tokens; ++j) { |
| CharBlock token{input.TokenAt(j)}; |
| if (!token.empty() && IsLegalIdentifierStart(token[0]) && |
| IsNameDefined(token)) { |
| break; |
| } |
| } |
| if (j == tokens) { |
| return {}; // input contains nothing that would be replaced |
| } |
| TokenSequence result{input, 0, j}; |
| for (; j < tokens; ++j) { |
| const CharBlock &token{input.TokenAt(j)}; |
| if (token.IsBlank() || !IsLegalIdentifierStart(token[0])) { |
| result.Put(input, j); |
| continue; |
| } |
| auto it = definitions_.find(token); |
| if (it == definitions_.end()) { |
| result.Put(input, j); |
| continue; |
| } |
| Definition &def{it->second}; |
| if (def.isDisabled()) { |
| result.Put(input, j); |
| continue; |
| } |
| if (!def.isFunctionLike()) { |
| if (def.isPredefined()) { |
| std::string name{def.replacement().TokenAt(0).ToString()}; |
| std::string repl; |
| if (name == "__FILE__") { |
| repl = "\""s + |
| allSources_.GetPath(prescanner.GetCurrentProvenance()) + '"'; |
| } else if (name == "__LINE__") { |
| std::stringstream ss; |
| ss << allSources_.GetLineNumber(prescanner.GetCurrentProvenance()); |
| repl = ss.str(); |
| } |
| if (!repl.empty()) { |
| ProvenanceRange insert{allSources_.AddCompilerInsertion(repl)}; |
| ProvenanceRange call{allSources_.AddMacroCall( |
| insert, input.GetTokenProvenanceRange(j), repl)}; |
| result.Put(repl, call.start()); |
| continue; |
| } |
| } |
| def.set_isDisabled(true); |
| TokenSequence replaced{ReplaceMacros(def.replacement(), prescanner)}; |
| def.set_isDisabled(false); |
| if (!replaced.empty()) { |
| ProvenanceRange from{def.replacement().GetProvenanceRange()}; |
| ProvenanceRange use{input.GetTokenProvenanceRange(j)}; |
| ProvenanceRange newRange{ |
| allSources_.AddMacroCall(from, use, replaced.ToString())}; |
| result.Put(replaced, newRange); |
| } |
| continue; |
| } |
| // Possible function-like macro call. Skip spaces and newlines to see |
| // whether '(' is next. |
| std::size_t k{j}; |
| bool leftParen{false}; |
| while (++k < tokens) { |
| const CharBlock &lookAhead{input.TokenAt(k)}; |
| if (!lookAhead.IsBlank() && lookAhead[0] != '\n') { |
| leftParen = lookAhead[0] == '(' && lookAhead.size() == 1; |
| break; |
| } |
| } |
| if (!leftParen) { |
| result.Put(input, j); |
| continue; |
| } |
| std::vector<std::size_t> argStart{++k}; |
| for (int nesting{0}; k < tokens; ++k) { |
| CharBlock token{input.TokenAt(k)}; |
| if (token.size() == 1) { |
| char ch{token[0]}; |
| if (ch == '(') { |
| ++nesting; |
| } else if (ch == ')') { |
| if (nesting == 0) { |
| break; |
| } |
| --nesting; |
| } else if (ch == ',' && nesting == 0) { |
| argStart.push_back(k + 1); |
| } |
| } |
| } |
| if (k >= tokens || argStart.size() < def.argumentCount() || |
| (argStart.size() > def.argumentCount() && !def.isVariadic())) { |
| result.Put(input, j); |
| continue; |
| } |
| std::vector<TokenSequence> args; |
| for (std::size_t n{0}; n < argStart.size(); ++n) { |
| std::size_t at{argStart[n]}; |
| std::size_t count{ |
| (n + 1 == argStart.size() ? k : argStart[n + 1] - 1) - at}; |
| args.emplace_back(TokenSequence(input, at, count)); |
| } |
| def.set_isDisabled(true); |
| TokenSequence replaced{ |
| ReplaceMacros(def.Apply(args, allSources_), prescanner)}; |
| def.set_isDisabled(false); |
| if (!replaced.empty()) { |
| ProvenanceRange from{def.replacement().GetProvenanceRange()}; |
| ProvenanceRange use{input.GetIntervalProvenanceRange(j, k - j)}; |
| ProvenanceRange newRange{ |
| allSources_.AddMacroCall(from, use, replaced.ToString())}; |
| result.Put(replaced, newRange); |
| } |
| j = k; // advance to the terminal ')' |
| } |
| return {result}; |
| } |
| |
| TokenSequence Preprocessor::ReplaceMacros( |
| const TokenSequence &tokens, const Prescanner &prescanner) { |
| if (std::optional<TokenSequence> repl{MacroReplacement(tokens, prescanner)}) { |
| return std::move(*repl); |
| } |
| return tokens; |
| } |
| |
| static std::size_t SkipBlanks( |
| const TokenSequence &tokens, std::size_t at, std::size_t lastToken) { |
| for (; at < lastToken; ++at) { |
| if (!tokens.TokenAt(at).IsBlank()) { |
| break; |
| } |
| } |
| return std::min(at, lastToken); |
| } |
| |
| static TokenSequence StripBlanks( |
| const TokenSequence &token, std::size_t first, std::size_t tokens) { |
| TokenSequence noBlanks; |
| for (std::size_t j{SkipBlanks(token, first, tokens)}; j < tokens; |
| j = SkipBlanks(token, j + 1, tokens)) { |
| noBlanks.Put(token, j); |
| } |
| return noBlanks; |
| } |
| |
| void Preprocessor::Directive(const TokenSequence &dir, Prescanner *prescanner) { |
| std::size_t tokens{dir.SizeInTokens()}; |
| std::size_t j{SkipBlanks(dir, 0, tokens)}; |
| if (j == tokens) { |
| return; |
| } |
| if (dir.TokenAt(j).ToString() != "#") { |
| prescanner->Error("missing '#'"_en_US, dir.GetTokenProvenance(j)); |
| return; |
| } |
| j = SkipBlanks(dir, j + 1, tokens); |
| if (j == tokens) { |
| return; |
| } |
| if (IsDecimalDigit(dir.TokenAt(j)[0]) || dir.TokenAt(j)[0] == '"') { |
| return; // TODO: treat as #line |
| } |
| std::size_t dirOffset{j}; |
| std::string dirName{ToLowerCaseLetters(dir.TokenAt(dirOffset).ToString())}; |
| j = SkipBlanks(dir, j + 1, tokens); |
| CharBlock nameToken; |
| if (j < tokens && IsLegalIdentifierStart(dir.TokenAt(j)[0])) { |
| nameToken = dir.TokenAt(j); |
| } |
| if (dirName == "line") { |
| // TODO: implement #line |
| } else if (dirName == "define") { |
| if (nameToken.empty()) { |
| prescanner->Error("#define: missing or invalid name"_en_US, |
| dir.GetTokenProvenance(j < tokens ? j : tokens - 1)); |
| return; |
| } |
| nameToken = SaveTokenAsName(nameToken); |
| definitions_.erase(nameToken); |
| if (++j < tokens && dir.TokenAt(j).size() == 1 && |
| dir.TokenAt(j)[0] == '(') { |
| j = SkipBlanks(dir, j + 1, tokens); |
| std::vector<std::string> argName; |
| bool isVariadic{false}; |
| if (dir.TokenAt(j).ToString() != ")") { |
| while (true) { |
| std::string an{dir.TokenAt(j).ToString()}; |
| if (an == "...") { |
| isVariadic = true; |
| } else { |
| if (an.empty() || !IsLegalIdentifierStart(an[0])) { |
| prescanner->Error( |
| "#define: missing or invalid argument name"_en_US, |
| dir.GetTokenProvenance(j)); |
| return; |
| } |
| argName.push_back(an); |
| } |
| j = SkipBlanks(dir, j + 1, tokens); |
| if (j == tokens) { |
| prescanner->Error("#define: malformed argument list"_en_US, |
| dir.GetTokenProvenance(tokens - 1)); |
| return; |
| } |
| std::string punc{dir.TokenAt(j).ToString()}; |
| if (punc == ")") { |
| break; |
| } |
| if (isVariadic || punc != ",") { |
| prescanner->Error("#define: malformed argument list"_en_US, |
| dir.GetTokenProvenance(j)); |
| return; |
| } |
| j = SkipBlanks(dir, j + 1, tokens); |
| if (j == tokens) { |
| prescanner->Error("#define: malformed argument list"_en_US, |
| dir.GetTokenProvenance(tokens - 1)); |
| return; |
| } |
| } |
| if (std::set<std::string>(argName.begin(), argName.end()).size() != |
| argName.size()) { |
| prescanner->Error("#define: argument names are not distinct"_en_US, |
| dir.GetTokenProvenance(dirOffset)); |
| return; |
| } |
| } |
| j = SkipBlanks(dir, j + 1, tokens); |
| definitions_.emplace(std::make_pair( |
| nameToken, Definition{argName, dir, j, tokens - j, isVariadic})); |
| } else { |
| j = SkipBlanks(dir, j, tokens); |
| definitions_.emplace( |
| std::make_pair(nameToken, Definition{dir, j, tokens - j})); |
| } |
| } else if (dirName == "undef") { |
| if (nameToken.empty()) { |
| prescanner->Error("# missing or invalid name"_en_US, |
| dir.GetTokenProvenance(tokens - 1)); |
| } else { |
| j = SkipBlanks(dir, j + 1, tokens); |
| if (j != tokens) { |
| prescanner->Error("#undef: excess tokens at end of directive"_en_US, |
| dir.GetTokenProvenance(j)); |
| } else { |
| definitions_.erase(nameToken); |
| } |
| } |
| } else if (dirName == "ifdef" || dirName == "ifndef") { |
| if (nameToken.empty()) { |
| prescanner->Error( |
| MessageFormattedText("#%s: missing name"_en_US, dirName.data()), |
| dir.GetTokenProvenance(tokens - 1)); |
| return; |
| } |
| j = SkipBlanks(dir, j + 1, tokens); |
| if (j != tokens) { |
| prescanner->Error( |
| MessageFormattedText( |
| "#%s: excess tokens at end of directive"_en_US, dirName.data()), |
| dir.GetTokenProvenance(j)); |
| } else if (IsNameDefined(nameToken) == (dirName == "ifdef")) { |
| ifStack_.push(CanDeadElseAppear::Yes); |
| } else { |
| SkipDisabledConditionalCode(dirName, IsElseActive::Yes, prescanner, |
| dir.GetTokenProvenance(dirOffset)); |
| } |
| } else if (dirName == "if") { |
| if (IsIfPredicateTrue(dir, j, tokens - j, prescanner)) { |
| ifStack_.push(CanDeadElseAppear::Yes); |
| } else { |
| SkipDisabledConditionalCode(dirName, IsElseActive::Yes, prescanner, |
| dir.GetTokenProvenance(dirOffset)); |
| } |
| } else if (dirName == "else") { |
| if (j != tokens) { |
| prescanner->Error("#else: excess tokens at end of directive"_en_US, |
| dir.GetTokenProvenance(j)); |
| } else if (ifStack_.empty()) { |
| prescanner->Error( |
| "#else: not nested within #if, #ifdef, or #ifndef"_en_US, |
| dir.GetTokenProvenance(tokens - 1)); |
| } else if (ifStack_.top() != CanDeadElseAppear::Yes) { |
| prescanner->Error( |
| "#else: already appeared within this #if, #ifdef, or #ifndef"_en_US, |
| dir.GetTokenProvenance(tokens - 1)); |
| } else { |
| ifStack_.pop(); |
| SkipDisabledConditionalCode("else", IsElseActive::No, prescanner, |
| dir.GetTokenProvenance(dirOffset)); |
| } |
| } else if (dirName == "elif") { |
| if (ifStack_.empty()) { |
| prescanner->Error( |
| "#elif: not nested within #if, #ifdef, or #ifndef"_en_US, |
| dir.GetTokenProvenance(tokens - 1)); |
| } else if (ifStack_.top() != CanDeadElseAppear::Yes) { |
| prescanner->Error("#elif: #else previously appeared within this " |
| "#if, #ifdef, or #ifndef"_en_US, |
| dir.GetTokenProvenance(tokens - 1)); |
| } else { |
| ifStack_.pop(); |
| SkipDisabledConditionalCode("elif", IsElseActive::No, prescanner, |
| dir.GetTokenProvenance(dirOffset)); |
| } |
| } else if (dirName == "endif") { |
| if (j != tokens) { |
| prescanner->Error("#endif: excess tokens at end of directive"_en_US, |
| dir.GetTokenProvenance(j)); |
| } else if (ifStack_.empty()) { |
| prescanner->Error("#endif: no #if, #ifdef, or #ifndef"_en_US, |
| dir.GetTokenProvenance(tokens - 1)); |
| } else { |
| ifStack_.pop(); |
| } |
| } else if (dirName == "error") { |
| prescanner->Error( |
| MessageFormattedText("#error: %s"_en_US, dir.ToString().data()), |
| dir.GetTokenProvenance(dirOffset)); |
| } else if (dirName == "warning") { |
| prescanner->Complain( |
| MessageFormattedText("#warning: %s"_en_US, dir.ToString().data()), |
| dir.GetTokenProvenance(dirOffset)); |
| } else if (dirName == "include") { |
| if (j == tokens) { |
| prescanner->Error("#include: missing name of file to include"_en_US, |
| dir.GetTokenProvenance(tokens - 1)); |
| return; |
| } |
| std::string include; |
| if (dir.TokenAt(j).ToString() == "<") { |
| if (dir.TokenAt(tokens - 1).ToString() != ">") { |
| prescanner->Error("#include: expected '>' at end of directive"_en_US, |
| dir.GetTokenProvenance(tokens - 1)); |
| return; |
| } |
| TokenSequence braced{dir, j + 1, tokens - j - 2}; |
| include = ReplaceMacros(braced, *prescanner).ToString(); |
| } else if (j + 1 == tokens && |
| (include = dir.TokenAt(j).ToString()).substr(0, 1) == "\"" && |
| include.substr(include.size() - 1, 1) == "\"") { |
| include = include.substr(1, include.size() - 2); |
| } else { |
| prescanner->Error("#include: expected name of file to include"_en_US, |
| dir.GetTokenProvenance(j < tokens ? j : tokens - 1)); |
| return; |
| } |
| if (include.empty()) { |
| prescanner->Error("#include: empty include file name"_en_US, |
| dir.GetTokenProvenance(dirOffset)); |
| return; |
| } |
| std::stringstream error; |
| const SourceFile *included{allSources_.Open(include, &error)}; |
| if (included == nullptr) { |
| prescanner->Error( |
| MessageFormattedText("#include: %s"_en_US, error.str().data()), |
| dir.GetTokenProvenance(dirOffset)); |
| return; |
| } |
| if (included->bytes() == 0) { |
| return; |
| } |
| ProvenanceRange fileRange{ |
| allSources_.AddIncludedFile(*included, dir.GetProvenanceRange())}; |
| if (!Prescanner{*prescanner}.Prescan(fileRange)) { |
| prescanner->set_anyFatalErrors(); |
| } |
| } else { |
| prescanner->Error( |
| MessageFormattedText( |
| "#%s: unknown or unimplemented directive"_en_US, dirName.data()), |
| dir.GetTokenProvenance(dirOffset)); |
| } |
| } |
| |
| CharBlock Preprocessor::SaveTokenAsName(const CharBlock &t) { |
| names_.push_back(t.ToString()); |
| return {names_.back().data(), names_.back().size()}; |
| } |
| |
| bool Preprocessor::IsNameDefined(const CharBlock &token) { |
| return definitions_.find(token) != definitions_.end(); |
| } |
| |
| static std::string GetDirectiveName( |
| const TokenSequence &line, std::size_t *rest) { |
| std::size_t tokens{line.SizeInTokens()}; |
| std::size_t j{SkipBlanks(line, 0, tokens)}; |
| if (j == tokens || line.TokenAt(j).ToString() != "#") { |
| *rest = tokens; |
| return ""; |
| } |
| j = SkipBlanks(line, j + 1, tokens); |
| if (j == tokens) { |
| *rest = tokens; |
| return ""; |
| } |
| *rest = SkipBlanks(line, j + 1, tokens); |
| return ToLowerCaseLetters(line.TokenAt(j).ToString()); |
| } |
| |
| void Preprocessor::SkipDisabledConditionalCode(const std::string &dirName, |
| IsElseActive isElseActive, Prescanner *prescanner, Provenance provenance) { |
| int nesting{0}; |
| while (!prescanner->IsAtEnd()) { |
| if (!prescanner->IsNextLinePreprocessorDirective()) { |
| prescanner->NextLine(); |
| continue; |
| } |
| TokenSequence line{prescanner->TokenizePreprocessorDirective()}; |
| std::size_t rest{0}; |
| std::string dn{GetDirectiveName(line, &rest)}; |
| if (dn == "ifdef" || dn == "ifndef" || dn == "if") { |
| ++nesting; |
| } else if (dn == "endif") { |
| if (nesting-- == 0) { |
| return; |
| } |
| } else if (isElseActive == IsElseActive::Yes && nesting == 0) { |
| if (dn == "else") { |
| ifStack_.push(CanDeadElseAppear::No); |
| return; |
| } |
| if (dn == "elif" && |
| IsIfPredicateTrue( |
| line, rest, line.SizeInTokens() - rest, prescanner)) { |
| ifStack_.push(CanDeadElseAppear::Yes); |
| return; |
| } |
| } |
| } |
| prescanner->Error( |
| MessageFormattedText("#%s: missing #endif"_en_US, dirName.data()), |
| provenance); |
| } |
| |
| // Precedence level codes used here to accommodate mixed Fortran and C: |
| // 15: parentheses and constants, logical !, bitwise ~ |
| // 14: unary + and - |
| // 13: ** |
| // 12: *, /, % (modulus) |
| // 11: + and - |
| // 10: << and >> |
| // 9: bitwise & |
| // 8: bitwise ^ |
| // 7: bitwise | |
| // 6: relations (.EQ., ==, &c.) |
| // 5: .NOT. |
| // 4: .AND., && |
| // 3: .OR., || |
| // 2: .EQV. and .NEQV. / .XOR. |
| // 1: ? : |
| // 0: , |
| static std::int64_t ExpressionValue(const TokenSequence &token, |
| int minimumPrecedence, std::size_t *atToken, |
| std::optional<Message> *error) { |
| enum Operator { |
| PARENS, |
| CONST, |
| NOTZERO, // ! |
| COMPLEMENT, // ~ |
| UPLUS, |
| UMINUS, |
| POWER, |
| TIMES, |
| DIVIDE, |
| MODULUS, |
| ADD, |
| SUBTRACT, |
| LEFTSHIFT, |
| RIGHTSHIFT, |
| BITAND, |
| BITXOR, |
| BITOR, |
| LT, |
| LE, |
| EQ, |
| NE, |
| GE, |
| GT, |
| NOT, |
| AND, |
| OR, |
| EQV, |
| NEQV, |
| SELECT, |
| COMMA |
| }; |
| static const int precedence[]{ |
| 15, 15, 15, 15, // (), 6, !, ~ |
| 14, 14, // unary +, - |
| 13, 12, 12, 12, 11, 11, 10, 10, // **, *, /, %, +, -, <<, >> |
| 9, 8, 7, // &, ^, | |
| 6, 6, 6, 6, 6, 6, // relations |
| 5, 4, 3, 2, 2, // .NOT., .AND., .OR., .EQV., .NEQV. |
| 1, 0 // ?: and , |
| }; |
| static const int operandPrecedence[]{0, -1, 15, 15, 15, 15, 13, 12, 12, 12, |
| 11, 11, 11, 11, 9, 8, 7, 7, 7, 7, 7, 7, 7, 6, 4, 3, 3, 3, 1, 0}; |
| |
| static std::map<std::string, enum Operator> opNameMap; |
| if (opNameMap.empty()) { |
| opNameMap["("] = PARENS; |
| opNameMap["!"] = NOTZERO; |
| opNameMap["~"] = COMPLEMENT; |
| opNameMap["**"] = POWER; |
| opNameMap["*"] = TIMES; |
| opNameMap["/"] = DIVIDE; |
| opNameMap["%"] = MODULUS; |
| opNameMap["+"] = ADD; |
| opNameMap["-"] = SUBTRACT; |
| opNameMap["<<"] = LEFTSHIFT; |
| opNameMap[">>"] = RIGHTSHIFT; |
| opNameMap["&"] = BITAND; |
| opNameMap["^"] = BITXOR; |
| opNameMap["|"] = BITOR; |
| opNameMap[".lt."] = opNameMap["<"] = LT; |
| opNameMap[".le."] = opNameMap["<="] = LE; |
| opNameMap[".eq."] = opNameMap["=="] = EQ; |
| opNameMap[".ne."] = opNameMap["/="] = opNameMap["!="] = NE; |
| opNameMap[".ge."] = opNameMap[">="] = GE; |
| opNameMap[".gt."] = opNameMap[">"] = GT; |
| opNameMap[".not."] = NOT; |
| opNameMap[".and."] = opNameMap[".a."] = opNameMap["&&"] = AND; |
| opNameMap[".or."] = opNameMap[".o."] = opNameMap["||"] = OR; |
| opNameMap[".eqv."] = EQV; |
| opNameMap[".neqv."] = opNameMap[".xor."] = opNameMap[".x."] = NEQV; |
| opNameMap["?"] = SELECT; |
| opNameMap[","] = COMMA; |
| } |
| |
| std::size_t tokens{token.SizeInTokens()}; |
| if (*atToken >= tokens) { |
| *error = Message{ |
| token.GetTokenProvenance(tokens - 1), "incomplete expression"_en_US}; |
| return 0; |
| } |
| |
| // Parse and evaluate a primary or a unary operator and its operand. |
| std::size_t opAt{*atToken}; |
| std::string t{token.TokenAt(opAt).ToString()}; |
| enum Operator op; |
| std::int64_t left{0}; |
| if (t == "(") { |
| op = PARENS; |
| } else if (IsDecimalDigit(t[0])) { |
| op = CONST; |
| std::size_t consumed{0}; |
| left = std::stoll(t, &consumed, 0 /*base to be detected*/); |
| if (consumed < t.size()) { |
| *error = Message{token.GetTokenProvenance(opAt), |
| MessageFormattedText( |
| "uninterpretable numeric constant '%s'"_en_US, t.data())}; |
| return 0; |
| } |
| } else if (IsLegalIdentifierStart(t[0])) { |
| // undefined macro name -> zero |
| // TODO: BOZ constants? |
| op = CONST; |
| } else if (t == "+") { |
| op = UPLUS; |
| } else if (t == "-") { |
| op = UMINUS; |
| } else if (t == "." && *atToken + 2 < tokens && |
| ToLowerCaseLetters(token.TokenAt(*atToken + 1).ToString()) == "not" && |
| token.TokenAt(*atToken + 2).ToString() == ".") { |
| op = NOT; |
| *atToken += 2; |
| } else { |
| auto it = opNameMap.find(t); |
| if (it != opNameMap.end()) { |
| op = it->second; |
| } else { |
| *error = Message{token.GetTokenProvenance(tokens - 1), |
| "operand expected in expression"_en_US}; |
| return 0; |
| } |
| } |
| if (precedence[op] < minimumPrecedence) { |
| *error = Message{ |
| token.GetTokenProvenance(opAt), "operator precedence error"_en_US}; |
| return 0; |
| } |
| ++*atToken; |
| if (op != CONST) { |
| left = ExpressionValue(token, operandPrecedence[op], atToken, error); |
| if (error->has_value()) { |
| return 0; |
| } |
| switch (op) { |
| case PARENS: |
| if (*atToken < tokens && token.TokenAt(*atToken).ToString() == ")") { |
| ++*atToken; |
| } else { |
| *error = Message{token.GetTokenProvenance(tokens - 1), |
| "')' missing from expression"_en_US}; |
| return 0; |
| } |
| break; |
| case NOTZERO: left = !left; break; |
| case COMPLEMENT: left = ~left; break; |
| case UPLUS: break; |
| case UMINUS: left = -left; break; |
| case NOT: left = -!left; break; |
| default: CRASH_NO_CASE; |
| } |
| } |
| if (*atToken >= tokens) { |
| return left; |
| } |
| |
| // Parse and evaluate a binary operator and its second operand, if present. |
| int advance{1}; |
| t = token.TokenAt(*atToken).ToString(); |
| if (t == "." && *atToken + 2 < tokens && |
| token.TokenAt(*atToken + 2).ToString() == ".") { |
| t += ToLowerCaseLetters(token.TokenAt(*atToken + 1).ToString()) + '.'; |
| advance = 3; |
| } |
| auto it = opNameMap.find(t); |
| if (it == opNameMap.end()) { |
| return left; |
| } |
| op = it->second; |
| if (precedence[op] < minimumPrecedence) { |
| return left; |
| } |
| opAt = *atToken; |
| *atToken += advance; |
| std::int64_t right{ |
| ExpressionValue(token, operandPrecedence[op], atToken, error)}; |
| if (error->has_value()) { |
| return 0; |
| } |
| switch (op) { |
| case POWER: |
| if (left == 0 && right < 0) { |
| *error = |
| Message{token.GetTokenProvenance(opAt), "0 ** negative power"_en_US}; |
| return 0; |
| } |
| if (left == 0 || left == 1 || right == 1) { |
| return left; |
| } |
| if (right <= 0) { |
| return !right; |
| } |
| { |
| std::int64_t power{1}; |
| for (; right > 0; --right) { |
| if ((power * left) / left != power) { |
| *error = Message{token.GetTokenProvenance(opAt), |
| "overflow in exponentation"_en_US}; |
| return 0; |
| } |
| power *= left; |
| } |
| return power; |
| } |
| case TIMES: |
| if (left == 0 || right == 0) { |
| return 0; |
| } |
| if ((left * right) / left != right) { |
| *error = Message{ |
| token.GetTokenProvenance(opAt), "overflow in multiplication"_en_US}; |
| } |
| return left * right; |
| case DIVIDE: |
| if (right == 0) { |
| *error = |
| Message{token.GetTokenProvenance(opAt), "division by zero"_en_US}; |
| return 0; |
| } |
| return left / right; |
| case MODULUS: |
| if (right == 0) { |
| *error = Message{token.GetTokenProvenance(opAt), "modulus by zero"_en_US}; |
| return 0; |
| } |
| return left % right; |
| case ADD: |
| if ((left < 0) == (right < 0) && (left < 0) != (left + right < 0)) { |
| *error = |
| Message{token.GetTokenProvenance(opAt), "overflow in addition"_en_US}; |
| } |
| return left + right; |
| case SUBTRACT: |
| if ((left < 0) != (right < 0) && (left < 0) == (left - right < 0)) { |
| *error = Message{ |
| token.GetTokenProvenance(opAt), "overflow in subtraction"_en_US}; |
| } |
| return left - right; |
| case LEFTSHIFT: |
| if (right < 0 || right > 64) { |
| *error = |
| Message{token.GetTokenProvenance(opAt), "bad left shift count"_en_US}; |
| } |
| return right >= 64 ? 0 : left << right; |
| case RIGHTSHIFT: |
| if (right < 0 || right > 64) { |
| *error = Message{ |
| token.GetTokenProvenance(opAt), "bad right shift count"_en_US}; |
| } |
| return right >= 64 ? 0 : left >> right; |
| case BITAND: |
| case AND: return left & right; |
| case BITXOR: return left ^ right; |
| case BITOR: |
| case OR: return left | right; |
| case LT: return -(left < right); |
| case LE: return -(left <= right); |
| case EQ: return -(left == right); |
| case NE: return -(left != right); |
| case GE: return -(left >= right); |
| case GT: return -(left > right); |
| case EQV: return -(!left == !right); |
| case NEQV: return -(!left != !right); |
| case SELECT: |
| if (*atToken >= tokens || token.TokenAt(*atToken).ToString() != ":") { |
| *error = Message{token.GetTokenProvenance(opAt), |
| "':' required in selection expression"_en_US}; |
| return left; |
| } else { |
| ++*atToken; |
| std::int64_t third{ |
| ExpressionValue(token, operandPrecedence[op], atToken, error)}; |
| return left != 0 ? right : third; |
| } |
| case COMMA: return right; |
| default: CRASH_NO_CASE; |
| } |
| return 0; // silence compiler warning |
| } |
| |
| bool Preprocessor::IsIfPredicateTrue(const TokenSequence &expr, |
| std::size_t first, std::size_t exprTokens, Prescanner *prescanner) { |
| TokenSequence expr1{StripBlanks(expr, first, first + exprTokens)}; |
| TokenSequence expr2; |
| for (std::size_t j{0}; j < expr1.SizeInTokens(); ++j) { |
| if (ToLowerCaseLetters(expr1.TokenAt(j).ToString()) == "defined") { |
| CharBlock name; |
| if (j + 3 < expr1.SizeInTokens() && |
| expr1.TokenAt(j + 1).ToString() == "(" && |
| expr1.TokenAt(j + 3).ToString() == ")") { |
| name = expr1.TokenAt(j + 2); |
| j += 3; |
| } else if (j + 1 < expr1.SizeInTokens() && |
| IsLegalIdentifierStart(expr1.TokenAt(j + 1))) { |
| name = expr1.TokenAt(j++); |
| } |
| if (!name.empty()) { |
| char truth{IsNameDefined(name) ? '1' : '0'}; |
| expr2.Put(&truth, 1, allSources_.CompilerInsertionProvenance(truth)); |
| continue; |
| } |
| } |
| expr2.Put(expr1, j); |
| } |
| TokenSequence expr3{ReplaceMacros(expr2, *prescanner)}; |
| TokenSequence expr4{StripBlanks(expr3, 0, expr3.SizeInTokens())}; |
| std::size_t atToken{0}; |
| std::optional<Message> error; |
| bool result{ExpressionValue(expr4, 0, &atToken, &error) != 0}; |
| if (error.has_value()) { |
| prescanner->Error(std::move(*error)); |
| } else if (atToken < expr4.SizeInTokens()) { |
| prescanner->Error(atToken == 0 ? "could not parse any expression"_en_US |
| : "excess characters after expression"_en_US, |
| expr4.GetTokenProvenance(atToken)); |
| } |
| return result; |
| } |
| } // namespace parser |
| } // namespace Fortran |
