[flang] Do not allow "-" to denote standard input on INCLUDE/#include.

Original-commit: flang-compiler/f18@f645036a16
Reviewed-on: https://github.com/flang-compiler/f18/pull/42
Tree-same-pre-rewrite: false

flang/lib/parser/preprocessor.cc

@@ -569,20 +569,22 @@ void Preprocessor::Directive(const TokenSequence &dir, Prescanner *prescanner) {
           dir.GetTokenProvenance(dirOffset));
       return;
     }
+    if (include == "-") {
+      prescanner->Say("#include: can't include standard input"_err_en_US,
+          dir.GetTokenProvenance(dirOffset));
+      return;
+    }
     std::stringstream error;
     const SourceFile *included{allSources_.Open(include, &error)};
     if (included == nullptr) {
       prescanner->Say(
           MessageFormattedText("#include: %s"_err_en_US, error.str().data()),
           dir.GetTokenProvenance(dirOffset));
-      return;
+    } else if (included->bytes() > 0) {
+      ProvenanceRange fileRange{
+          allSources_.AddIncludedFile(*included, dir.GetProvenanceRange())};
+      Prescanner{*prescanner}.Prescan(fileRange);
     }
-    if (included->bytes() == 0) {
-      return;
-    }
-    ProvenanceRange fileRange{
-        allSources_.AddIncludedFile(*included, dir.GetProvenanceRange())};
-    Prescanner{*prescanner}.Prescan(fileRange);
   } else {
     prescanner->Say(MessageFormattedText(
                         "#%s: unknown or unimplemented directive"_err_en_US,

flang/lib/parser/prescan.cc

@@ -540,7 +540,7 @@ std::optional<std::size_t> Prescanner::IsIncludeLine(const char *start) const {
   return {};
 }
 
-bool Prescanner::FortranInclude(const char *firstQuote) {
+void Prescanner::FortranInclude(const char *firstQuote) {
   const char *p{firstQuote};
   while (*p != '"' && *p != '\'') {
     ++p;
@@ -558,13 +558,17 @@ bool Prescanner::FortranInclude(const char *firstQuote) {
   }
   if (*p != quote) {
     Say("malformed path name string"_err_en_US, GetProvenance(p));
-    return true;
+    return;
   }
   for (++p; *p == ' ' || *p == '\t'; ++p) {
   }
   if (*p != '\n' && *p != '!') {
     Say("excess characters after path name"_en_US, GetProvenance(p));
   }
+  if (path == "-") {
+    Say("cannot INCLUDE standard input"_err_en_US, GetProvenance(p));
+    return;
+  }
   std::stringstream error;
   Provenance provenance{GetProvenance(lineStart_)};
   AllSources &allSources{cooked_.allSources()};
@@ -579,17 +583,13 @@ bool Prescanner::FortranInclude(const char *firstQuote) {
   if (included == nullptr) {
     Say(MessageFormattedText("INCLUDE: %s"_err_en_US, error.str().data()),
         provenance);
-    return true;
+  } else if (included->bytes() > 0) {
+    ProvenanceRange includeLineRange{
+        provenance, static_cast<std::size_t>(p - lineStart_)};
+    ProvenanceRange fileRange{
+        allSources.AddIncludedFile(*included, includeLineRange)};
+    Prescanner{*this}.Prescan(fileRange);
   }
-  if (included->bytes() == 0) {
-    return true;
-  }
-  ProvenanceRange includeLineRange{
-      provenance, static_cast<std::size_t>(p - lineStart_)};
-  ProvenanceRange fileRange{
-      allSources.AddIncludedFile(*included, includeLineRange)};
-  Prescanner{*this}.Prescan(fileRange);
-  return true;
 }
 
 bool Prescanner::IsPreprocessorDirectiveLine(const char *start) const {

flang/lib/parser/prescan.h

@@ -132,7 +132,7 @@ private:
   bool IsFixedFormCommentLine(const char *) const;
   bool IsFreeFormComment(const char *) const;
   std::optional<std::size_t> IsIncludeLine(const char *) const;
-  bool FortranInclude(const char *quote);
+  void FortranInclude(const char *quote);
   bool IsPreprocessorDirectiveLine(const char *) const;
   const char *FixedFormContinuationLine();
   bool FixedFormContinuation();