added parsing for COMMON statement

5 files changed, 93 insertions, 13 deletions

diff --git a/include/flang/Sema/Sema.h b/include/flang/Sema/Sema.h
index 1e9da62e70..a7eb4813a2 100644
--- a/include/flang/Sema/Sema.h
+++ b/include/flang/Sema/Sema.h
@@ -377,6 +377,10 @@ public:
 
   bool CheckEquivalenceType(QualType ExpectedType, const Expr *E);
 
+  void ActOnCOMMON(ASTContext &C, SourceLocation Loc, SourceLocation BlockLoc,
+                   SourceLocation IDLoc, const IdentifierInfo *BlockID,
+                   const IdentifierInfo *IDInfo, ArrayRef<ArraySpec *> Dimensions);
+
   // DATA statement:
   StmtResult ActOnDATA(ASTContext &C, SourceLocation Loc,
                        ArrayRef<Expr*> LHS, ArrayRef<Expr*> Values,
diff --git a/lib/Parse/ParseSpecStmt.cpp b/lib/Parse/ParseSpecStmt.cpp
index c9bd985f73..9e39d0e5ac 100644
--- a/lib/Parse/ParseSpecStmt.cpp
+++ b/lib/Parse/ParseSpecStmt.cpp
@@ -130,6 +130,73 @@ Parser::StmtResult Parser::ParseEQUIVALENCEStmt() {
   return Actions.ActOnCompoundStmt(Context, Loc, StmtList, StmtLabel);
 }
 
+/// ParseCOMMONStmt - Parse the COMMON statement.
+///
+///   [5.5.2] R557:
+///     common-stmt :=
+///         COMMON #
+///         # [ / [common-block-name] / ] common-block-object-list #
+///         # [ [,] / [common-block-name / #
+///         #   common-block-object-list ] ...
+Parser::StmtResult Parser::ParseCOMMONStmt() {
+  // Check if this is an assignment.
+  if (IsNextToken(tok::equal))
+    return StmtResult();
+
+  auto Loc = ConsumeToken();
+  SmallVector<Stmt*, 8> StmtList;
+  SmallVector<Expr*, 8> ObjectList;
+
+  SourceLocation BlockIDLoc;
+  const IdentifierInfo *BlockID = nullptr;
+
+  bool Error = false;
+  do {
+    if(ConsumeIfPresent(tok::slash)) {
+      if(ConsumeIfPresent(tok::slash))
+        BlockID = nullptr;
+      else {
+        BlockIDLoc = Tok.getLocation();
+        BlockID = Tok.getIdentifierInfo();
+        if(!ExpectAndConsume(tok::identifier)) {
+          Error = true;
+          break;
+        }
+        if(!ExpectAndConsume(tok::slash)) {
+          Error = true;
+          break;
+        }
+      }
+    } else if(ConsumeIfPresent(tok::slashslash))
+      BlockID = nullptr;
+
+    auto IDLoc = Tok.getLocation();
+    auto IDInfo = Tok.getIdentifierInfo();
+    SmallVector<ArraySpec*, 8> Dimensions;
+
+    if(!ExpectAndConsume(tok::identifier)) {
+      Error = true;
+      break;
+    }
+    if(IsPresent(tok::l_paren)) {
+      if(ParseArraySpec(Dimensions)) {
+        Error = true;
+        break;
+      }
+    }
+
+    Actions.ActOnCOMMON(Context, Loc, BlockIDLoc,
+                        IDLoc, BlockID, IDInfo,
+                        Dimensions);
+  } while(ConsumeIfPresent(tok::comma));
+
+
+  if(Error) SkipUntilNextStatement();
+  else ExpectStatementEnd();
+
+  return Actions.ActOnCompoundStmt(Context, Loc, StmtList, StmtLabel);
+}
+
 /// ParsePARAMETERStmt - Parse the PARAMETER statement.
 ///
 ///   [R548]:
diff --git a/lib/Parse/Parser.cpp b/lib/Parse/Parser.cpp
index f78af6a444..4202ead4c1 100644
--- a/lib/Parse/Parser.cpp
+++ b/lib/Parse/Parser.cpp
@@ -1462,7 +1462,7 @@ bool Parser::ParseSpecificationStmt() {
     goto notImplemented;
   case tok::kw_COMMON:
     Result = ParseCOMMONStmt();
-    goto notImplemented;
+    break;
   case tok::kw_PARAMETER:
     Result = ParsePARAMETERStmt();
     break;
@@ -1594,18 +1594,6 @@ Parser::StmtResult Parser::ParseBINDStmt() {
   return StmtResult();
 }
 
-/// ParseCOMMONStmt - Parse the COMMON statement.
-///
-///   [5.5.2] R557:
-///     common-stmt :=
-///         COMMON #
-///         # [ / [common-block-name] / ] common-block-object-list #
-///         # [ [,] / [common-block-name / #
-///         #   common-block-object-list ] ...
-Parser::StmtResult Parser::ParseCOMMONStmt() {
-  return StmtResult();
-}
-
 /// ParseDATAStmt - Parse the DATA statement.
 ///
 ///   [R524]:
diff --git a/lib/Sema/SemaDecl.cpp b/lib/Sema/SemaDecl.cpp
index 6c39ce2166..ddb059a159 100644
--- a/lib/Sema/SemaDecl.cpp
+++ b/lib/Sema/SemaDecl.cpp
@@ -395,6 +395,12 @@ Decl *Sema::ActOnEntityDecl(ASTContext &C, DeclSpec &DS, SourceLocation IDLoc,
   return ActOnEntityDecl(C, T, IDLoc, IDInfo);
 }
 
+void Sema::ActOnCOMMON(ASTContext &C, SourceLocation Loc, SourceLocation BlockLoc,
+                       SourceLocation IDLoc, const IdentifierInfo *BlockID,
+                       const IdentifierInfo *IDInfo, ArrayRef<ArraySpec*> Dimensions) {
+
+}
+
 //
 // derived types
 //
diff --git a/test/Parser/common.f95 b/test/Parser/common.f95
new file mode 100644
index 0000000000..003d4ec6e8
--- /dev/null
+++ b/test/Parser/common.f95
@@ -0,0 +1,15 @@
+! RUN: %flang -fsyntax-only -verify < %s
+
+program test
+  integer x,y,z,w,i,j,k
+  real r
+
+  common x,y, /a/ z, /w/ w
+  common /a/ i(10,-5:8)
+  common // j,k
+  common / / r
+
+  common /a/ ! expected-error {{expected identifier}}
+  common     ! expected-error {{expected identifier}}
+
+end program