Implement C99 scoping rules for Solidity >= 0.5.0

crates/solidity/inputs/language/bindings/rules.msgb

@@ -186,31 +186,53 @@ attribute symbol_reference = symbol  => type = "push_symbol", symbol = symbol, i
 @stmt [Statement] {
   node @stmt.lexical_scope
   node @stmt.defs
-}
 
-;; FIXME: For C99 scoping, we should link each statement's lexical_scope to the
-;; previous lexical_scope, and to the statement's defs (to make the def
-;; available to the statement itself).
-;; Only the first statement in the block connects to the block's lexical_scope.
+  if (version-matches VERSION ">= 0.5.0") {
+    ;; For Solidity >= 0.5.0, definitions are immediately available in the
+    ;; statement scope. For < 0.5.0 this is also true, but resolved through the
+    ;; enclosing block's lexical scope.
+    edge @stmt.lexical_scope -> @stmt.defs
+    attr (@stmt.lexical_scope -> @stmt.defs) precedence = 1
+  }
+}
 
-@block [Block ... [Statements ... @stmt [Statement]...] ...] {
-  edge @stmt.lexical_scope -> @block.lexical_scope
+;; The first statement in a block
+@block [Block ... [Statements @stmt [Statement] ...] ...] {
+  if (version-matches VERSION ">= 0.5.0") {
+    edge @stmt.lexical_scope -> @block.lexical_scope
+  }
+}
 
-  ;; FIXME: doesn't work for C99 scoping
-  edge @block.lexical_scope -> @stmt.defs
-  attr (@block.lexical_scope -> @stmt.defs) precedence = 1
+;; Two consecutive statements
+[Statements ... @left_stmt [Statement] @right_stmt [Statement] ...] {
+  if (version-matches VERSION ">= 0.5.0") {
+    edge @right_stmt.lexical_scope -> @left_stmt.lexical_scope
+  }
+}
 
-  ;; Hoist statement definitions (< 0.5.0)
+@block [Block ... [Statements ... @stmt [Statement]...] ...] {
+  ;; Hoist statement definitions for Solidity < 0.5.0
   if (version-matches VERSION "< 0.5.0") {
+    ;; definitions are carried over to the block
     edge @block.defs -> @stmt.defs
+
+    ;; resolution happens in the context of the block
+    edge @stmt.lexical_scope -> @block.lexical_scope
+
+    ;; and the statement definitions are available block's scope
+    edge @block.lexical_scope -> @stmt.defs
+    attr (@block.lexical_scope -> @stmt.defs) precedence = 1
   }
 }
 
+;; Statements of type block
 @stmt [Statement @block variant: [Block]] {
   edge @block.lexical_scope -> @stmt.lexical_scope
 
   ;; Hoist block definitions (< 0.5.0)
-  edge @stmt.defs -> @block.defs
+  if (version-matches VERSION "< 0.5.0") {
+    edge @stmt.defs -> @block.defs
+  }
 }
 
 ;; Connect the function body's block lexical scope to the function

crates/solidity/testing/snapshots/bindings_assertions/lexical/shadowing.sol → crates/solidity/testing/snapshots/bindings_assertions/lexical/c99_scopes.sol

@@ -19,8 +19,13 @@ contract Foo {
         }
     }
 
-    function another_func() returns (uint) {
-        return x;
-        //     ^ref:1
+    function another_func() returns (uint y) {
+        //                                ^def:5
+        y = x + w;
+        //      ^ref:!
+        //  ^ref:1
+     // ^ref:5
+        uint w = 5;
+        //   ^def:6
     }
 }

crates/solidity/testing/snapshots/bindings_assertions/lexical/params.sol

@@ -10,4 +10,12 @@ contract Foo {
         return z + 2;
         //     ^ref:!
     }
+
+    function quux(int x) returns (int y) {
+        //                            ^def:2
+        //            ^def:3
+        y = x + 5;
+    //      ^ref:3
+    //  ^ref:2
+    }
 }

crates/solidity/testing/snapshots/bindings_output/lexical/generated/local_vars.sol.mmd

@@ -65,81 +65,81 @@ line 109 column 15`"]
 @block.lexical_scope
 line 183 column 15`"]
 	N16 --> N5
-	N16 --> N21
-	N16 --> N23
 	N17["`**17** @(2, 34)
 @block.defs
 line 184 column 15`"]
 	N18["`**18** @(10, 33)
 @block.lexical_scope
 line 183 column 15`"]
 	N18 --> N7
-	N18 --> N25
 	N19["`**19** @(10, 33)
 @block.defs
 line 184 column 15`"]
 	N20["`**20** @(3, 1)
 @stmt.lexical_scope
 line 188 column 14`"]
 	N20 --> N16
+	N20 --> N21
 	N21["`**21** @(3, 1)
 @stmt.defs
 line 189 column 14`"]
 	N21 --> N26
 	N22["`**22** @(4, 1)
 @stmt.lexical_scope
 line 188 column 14`"]
-	N22 --> N16
+	N22 --> N20
+	N22 --> N23
 	N23["`**23** @(4, 1)
 @stmt.defs
 line 189 column 14`"]
 	N24["`**24** @(11, 1)
 @stmt.lexical_scope
 line 188 column 14`"]
 	N24 --> N18
+	N24 --> N25
 	N25["`**25** @(11, 1)
 @stmt.defs
 line 189 column 14`"]
 	N26[\"`**x** @(3, 1)
 def
-line 228 column 8`"/]
+line 250 column 8`"/]
 	N27["`**27** @(3, 17)
 @expr.lexical_scope
-line 316 column 14`"]
+line 338 column 14`"]
 	N27 --> N20
 	N28["`**28** @(6, 15)
 @expr.lexical_scope
-line 316 column 14`"]
+line 338 column 14`"]
 	N28 --> N22
 	N29["`**29** @(6, 15)
 @expr.lexical_scope
-line 316 column 14`"]
+line 338 column 14`"]
 	N29 --> N28
 	N30["`**30** @(6, 19)
 @expr.lexical_scope
-line 316 column 14`"]
+line 338 column 14`"]
 	N30 --> N28
 	N31["`**31** @(11, 15)
 @expr.lexical_scope
-line 316 column 14`"]
+line 338 column 14`"]
 	N31 --> N24
 	N32["`**32** @(11, 15)
 @expr.lexical_scope
-line 316 column 14`"]
+line 338 column 14`"]
 	N32 --> N31
 	N33["`**33** @(11, 19)
 @expr.lexical_scope
-line 316 column 14`"]
+line 338 column 14`"]
 	N33 --> N31
 	N34[/"`**x** @(6, 15)
 ref
-line 320 column 8`"\]
+line 342 column 8`"\]
 	N34 --> N29
 	N35[/"`**w** @(11, 15)
 ref
-line 320 column 8`"\]
+line 342 column 8`"\]
 	N35 --> N32
 	N36[/"`**x** @(11, 19)
 ref
-line 320 column 8`"\]
+line 342 column 8`"\]
 	N36 --> N33

crates/solidity/testing/snapshots/bindings_output/lexical/generated/params.sol.mmd

@@ -77,61 +77,61 @@ line 113 column 8`"/]
 @block.lexical_scope
 line 183 column 15`"]
 	N19 --> N5
-	N19 --> N24
 	N20["`**20** @(2, 40)
 @block.defs
 line 184 column 15`"]
 	N21["`**21** @(9, 33)
 @block.lexical_scope
 line 183 column 15`"]
 	N21 --> N7
-	N21 --> N26
 	N22["`**22** @(9, 33)
 @block.defs
 line 184 column 15`"]
 	N23["`**23** @(3, 1)
 @stmt.lexical_scope
 line 188 column 14`"]
 	N23 --> N19
+	N23 --> N24
 	N24["`**24** @(3, 1)
 @stmt.defs
 line 189 column 14`"]
 	N25["`**25** @(10, 1)
 @stmt.lexical_scope
 line 188 column 14`"]
 	N25 --> N21
+	N25 --> N26
 	N26["`**26** @(10, 1)
 @stmt.defs
 line 189 column 14`"]
 	N27["`**27** @(5, 15)
 @expr.lexical_scope
-line 316 column 14`"]
+line 338 column 14`"]
 	N27 --> N23
 	N28["`**28** @(5, 15)
 @expr.lexical_scope
-line 316 column 14`"]
+line 338 column 14`"]
 	N28 --> N27
 	N29["`**29** @(5, 19)
 @expr.lexical_scope
-line 316 column 14`"]
+line 338 column 14`"]
 	N29 --> N27
 	N30["`**30** @(10, 15)
 @expr.lexical_scope
-line 316 column 14`"]
+line 338 column 14`"]
 	N30 --> N25
 	N31["`**31** @(10, 15)
 @expr.lexical_scope
-line 316 column 14`"]
+line 338 column 14`"]
 	N31 --> N30
 	N32["`**32** @(10, 19)
 @expr.lexical_scope
-line 316 column 14`"]
+line 338 column 14`"]
 	N32 --> N30
 	N33[/"`**z** @(5, 15)
 ref
-line 320 column 8`"\]
+line 342 column 8`"\]
 	N33 --> N28
 	N34[/"`**z** @(10, 15)
 ref
-line 320 column 8`"\]
+line 342 column 8`"\]
 	N34 --> N31