[clang] [SystemZ][z/OS] Implement #pragma export (PR #141671)

[Erich Keane via cfe-commits]

================
@@ -1386,6 +1402,74 @@ bool Parser::HandlePragmaMSAllocText(StringRef PragmaName,
   return true;
 }
 
+bool Parser::zOSHandlePragmaHelper(tok::TokenKind PragmaKind) {
+  assert(Tok.is(PragmaKind));
+
+  StringRef PragmaName = "export";
+
+  using namespace clang::charinfo;
+  auto *TheTokens =
+      (std::pair<std::unique_ptr<Token[]>, size_t> *)Tok.getAnnotationValue();
+  PP.EnterTokenStream(std::move(TheTokens->first), TheTokens->second, true,
+                      false);
+  ConsumeAnnotationToken();
+
+  do {
+    PP.Lex(Tok);
+    if (Tok.isNot(tok::l_paren)) {
+      PP.Diag(Tok.getLocation(), diag::warn_pragma_expected_lparen)
+          << PragmaName;
+      return false;
+    }
+
+    PP.Lex(Tok);
+    if (Tok.isNot(tok::identifier)) {
+      PP.Diag(Tok.getLocation(), diag::warn_pragma_expected_identifier)
+          << PragmaName;
+      return false;
+    }
+
+    IdentifierInfo *IdentName = Tok.getIdentifierInfo();
+    SourceLocation IdentNameLoc = Tok.getLocation();
+    PP.Lex(Tok);
+
+    if (Tok.isNot(tok::r_paren)) {
+      PP.Diag(Tok.getLocation(), diag::warn_pragma_expected_rparen)
+          << PragmaName;
+      return false;
+    }
+
+    PP.Lex(Tok);
+    Actions.ActOnPragmaExport(IdentName, IdentNameLoc, getCurScope());
+
+    // Because export is also a C++ keyword, we also check for that.
+    if (Tok.is(tok::identifier) || Tok.is(tok::kw_export)) {
+      PragmaName = Tok.getIdentifierInfo()->getName();
+      if (PragmaName != "export")
+        PP.Diag(Tok.getLocation(), diag::warn_pragma_extra_tokens_at_eol)
+            << PragmaName;
+    } else if (Tok.isNot(tok::eof)) {
+      PP.Diag(Tok.getLocation(), diag::warn_pragma_extra_tokens_at_eol)
+          << PragmaName;
+      return false;
+    }
+  } while (Tok.isNot(tok::eof));
+  PP.Lex(Tok);
+  return true;
+}
+
+void Parser::HandlePragmaExport() {
+  assert(Tok.is(tok::annot_pragma_export));
+
+  if (!zOSHandlePragmaHelper(tok::annot_pragma_export)) {
+    // Parsing pragma failed, and has been diagnosed.  Slurp up the
+    // tokens until eof (really end of line) to prevent follow-on errors.
+    while (Tok.isNot(tok::eof))
----------------
erichkeane wrote:

Ah!  Just saw this. , Above comment which I've lost asked for something like this, but this is fine.  This plus the next line is just:

`SkipUntil(tok::eof)`.

https://github.com/llvm/llvm-project/pull/141671