3 files changed, 8 insertions, 2 deletions
diff --git a/flang/lib/Parser/Fortran-parsers.cpp b/flang/lib/Parser/Fortran-parsers.cpp
index fbe629a..d33a18f 100644
--- a/flang/lib/Parser/Fortran-parsers.cpp
+++ b/flang/lib/Parser/Fortran-parsers.cpp
@@ -1100,14 +1100,14 @@ TYPE_PARSER(construct<EquivalenceObject>(indirect(designator)))
 // R873 common-stmt ->
 //        COMMON [/ [common-block-name] /] common-block-object-list
 //        [[,] / [common-block-name] / common-block-object-list]...
-TYPE_PARSER(
+TYPE_PARSER(sourced(
     construct<CommonStmt>("COMMON" >> defaulted("/" >> maybe(name) / "/"),
         nonemptyList("expected COMMON block objects"_err_en_US,
             Parser<CommonBlockObject>{}),
         many(maybe(","_tok) >>
             construct<CommonStmt::Block>("/" >> maybe(name) / "/",
                 nonemptyList("expected COMMON block objects"_err_en_US,
-                    Parser<CommonBlockObject>{})))))
+                    Parser<CommonBlockObject>{}))))))
 
 // R874 common-block-object -> variable-name [( array-spec )]
 TYPE_PARSER(construct<CommonBlockObject>(name, maybe(arraySpec)))
diff --git a/flang/lib/Parser/parsing.cpp b/flang/lib/Parser/parsing.cpp
index 8a8c6ef..2df6881 100644
--- a/flang/lib/Parser/parsing.cpp
+++ b/flang/lib/Parser/parsing.cpp
@@ -85,6 +85,7 @@ const SourceFile *Parsing::Prescan(const std::string &path, Options options) {
   if (options.features.IsEnabled(LanguageFeature::OpenACC) ||
       (options.prescanAndReformat && noneOfTheAbove)) {
     prescanner.AddCompilerDirectiveSentinel("$acc");
+    prescanner.AddCompilerDirectiveSentinel("@acc");
   }
   if (options.features.IsEnabled(LanguageFeature::OpenMP) ||
       (options.prescanAndReformat && noneOfTheAbove)) {
diff --git a/flang/lib/Parser/prescan.cpp b/flang/lib/Parser/prescan.cpp
index 865c149..66e5b2c 100644
--- a/flang/lib/Parser/prescan.cpp
+++ b/flang/lib/Parser/prescan.cpp
@@ -147,6 +147,11 @@ void Prescanner::Statement() {
         directiveSentinel_[4] == '\0') {
       // CUDA conditional compilation line.
       condOffset = 5;
+    } else if (directiveSentinel_[0] == '@' && directiveSentinel_[1] == 'a' &&
+        directiveSentinel_[2] == 'c' && directiveSentinel_[3] == 'c' &&
+        directiveSentinel_[4] == '\0') {
+      // OpenACC conditional compilation line.
+      condOffset = 5;
     }
     if (condOffset && !preprocessingOnly_) {
       at_ += *condOffset, column_ += *condOffset;