Merge #985

985: Parse macro!(); as MacroInvocation with semicolon r=CohenArthur a=CohenArthur

When parsing a macro invocation as a statement, the parser would parse
an expression and then try parsing a semicolon. Since no actual
lookahead was done (which is a good thing), we couldn't convert a
`MacroInvocation` to a `MacroInvocationSemi` after the fact.

Since, unlike function calls, macro invocations can act differently
based on whether or not they are followed by a semicolon, we actually
need to differentiate between the two up until expansion.

This commits adds a new virtual method for ExprWithoutBlock when
converting to ExprStmtWithoutBlock so that classes inheriting
ExprWithoutBlock can specify a new behavior. In the case of our
MacroInvocation class, it simply means toggling a boolean: If we're
converting a macro from an expression to a statement, it must mean that
it should contain a semicolon.

Closes #941 

Co-authored-by: Arthur Cohen <arthur.cohen@embecosm.com>

5 files changed, 25 insertions, 8 deletions

diff --git a/gcc/rust/resolve/rust-ast-resolve-base.h b/gcc/rust/resolve/rust-ast-resolve-base.h
index 6ee5f3d..eca9694 100644
--- a/gcc/rust/resolve/rust-ast-resolve-base.h
+++ b/gcc/rust/resolve/rust-ast-resolve-base.h
@@ -38,7 +38,6 @@ public:
   void visit (AST::IdentifierExpr &) {}
   void visit (AST::Lifetime &) {}
   void visit (AST::LifetimeParam &) {}
-  void visit (AST::MacroInvocationSemi &) {}
   void visit (AST::PathInExpression &) {}
   void visit (AST::TypePathSegment &) {}
   void visit (AST::TypePathSegmentGeneric &) {}
diff --git a/gcc/rust/resolve/rust-ast-resolve-implitem.h b/gcc/rust/resolve/rust-ast-resolve-implitem.h
index ce7234c..7393393 100644
--- a/gcc/rust/resolve/rust-ast-resolve-implitem.h
+++ b/gcc/rust/resolve/rust-ast-resolve-implitem.h
@@ -49,8 +49,11 @@ public:
     item->accept_vis (resolver);
   }
 
-  void visit (AST::MacroInvocationSemi &invoc) override
+  void visit (AST::MacroInvocation &invoc) override
   {
+    if (!invoc.has_semicolon ())
+      return;
+
     AST::ASTFragment &fragment = invoc.get_fragment ();
     for (auto &node : fragment.get_nodes ())
       node.accept_vis (*this);
@@ -144,8 +147,11 @@ public:
     item->accept_vis (resolver);
   };
 
-  void visit (AST::MacroInvocationSemi &invoc) override
+  void visit (AST::MacroInvocation &invoc) override
   {
+    if (!invoc.has_semicolon ())
+      return;
+
     AST::ASTFragment &fragment = invoc.get_fragment ();
     for (auto &node : fragment.get_nodes ())
       node.accept_vis (*this);
@@ -254,8 +260,11 @@ public:
     item->accept_vis (resolver);
   };
 
-  void visit (AST::MacroInvocationSemi &invoc) override
+  void visit (AST::MacroInvocation &invoc) override
   {
+    if (!invoc.has_semicolon ())
+      return;
+
     AST::ASTFragment &fragment = invoc.get_fragment ();
     for (auto &node : fragment.get_nodes ())
       node.accept_vis (*this);
diff --git a/gcc/rust/resolve/rust-ast-resolve-item.h b/gcc/rust/resolve/rust-ast-resolve-item.h
index 48f93e5..2cb0006 100644
--- a/gcc/rust/resolve/rust-ast-resolve-item.h
+++ b/gcc/rust/resolve/rust-ast-resolve-item.h
@@ -45,8 +45,11 @@ public:
     item->accept_vis (resolver);
   };
 
-  void visit (AST::MacroInvocationSemi &invoc) override
+  void visit (AST::MacroInvocation &invoc) override
   {
+    if (!invoc.has_semicolon ())
+      return;
+
     AST::ASTFragment &fragment = invoc.get_fragment ();
     for (auto &node : fragment.get_nodes ())
       node.accept_vis (*this);
@@ -234,8 +237,11 @@ public:
     item->accept_vis (resolver);
   };
 
-  void visit (AST::MacroInvocationSemi &invoc) override
+  void visit (AST::MacroInvocation &invoc) override
   {
+    if (!invoc.has_semicolon ())
+      return;
+
     AST::ASTFragment &fragment = invoc.get_fragment ();
     for (auto &node : fragment.get_nodes ())
       node.accept_vis (*this);
diff --git a/gcc/rust/resolve/rust-ast-resolve-stmt.h b/gcc/rust/resolve/rust-ast-resolve-stmt.h
index 7521739..785f3de 100644
--- a/gcc/rust/resolve/rust-ast-resolve-stmt.h
+++ b/gcc/rust/resolve/rust-ast-resolve-stmt.h
@@ -44,8 +44,11 @@ public:
     stmt->accept_vis (resolver);
   };
 
-  void visit (AST::MacroInvocationSemi &invoc) override
+  void visit (AST::MacroInvocation &invoc) override
   {
+    if (!invoc.has_semicolon ())
+      return;
+
     AST::ASTFragment &fragment = invoc.get_fragment ();
 
     for (auto &node : fragment.get_nodes ())
diff --git a/gcc/rust/resolve/rust-ast-resolve-toplevel.h b/gcc/rust/resolve/rust-ast-resolve-toplevel.h
index 39d6818..1f528fe 100644
--- a/gcc/rust/resolve/rust-ast-resolve-toplevel.h
+++ b/gcc/rust/resolve/rust-ast-resolve-toplevel.h
@@ -43,7 +43,7 @@ public:
     item->accept_vis (resolver);
   };
 
-  void visit (AST::MacroInvocationSemi &invoc) override
+  void visit (AST::MacroInvocation &invoc) override
   {
     AST::ASTFragment &fragment = invoc.get_fragment ();
     for (auto &node : fragment.get_nodes ())