Merge pull request #8811 from MarkoMin/erl_syntax_lib/annotate_maybe_…

…match_correctly erl_syntax_lib: annotate `maybe_match_expr` and `else_expr` correctly OTP-19405
erlang · Dec 18, 2024 · 0129381 · 0129381
2 parents 56ff90d + 95b849d
commit 0129381
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Showing 2 changed files with 100 additions and 2 deletions.
diff --git a/lib/syntax_tools/src/erl_syntax_lib.erl b/lib/syntax_tools/src/erl_syntax_lib.erl
@@ -470,8 +470,14 @@ vann(Tree, Env) ->
             {ann_bindings(Tree, Env, Bound, Free), Bound, Free};
         match_expr ->
             vann_match_expr(Tree, Env);
+        maybe_expr ->
+            vann_maybe_expr(Tree, Env);
+        maybe_match_expr ->
+            vann_maybe_match_expr(Tree, Env);
         case_expr ->
             vann_case_expr(Tree, Env);
+        else_expr ->
+            vann_else_expr(Tree, Env);
         if_expr ->
             vann_if_expr(Tree, Env);
         receive_expr ->
@@ -554,6 +560,27 @@ vann_match_expr(Tree, Env) ->
     Tree1 = rewrite(Tree, erl_syntax:match_expr(P1, E1)),
     {ann_bindings(Tree1, Env, Bound, Free), Bound, Free}.
 
+vann_maybe_expr(Tree, Env) ->
+    Body = erl_syntax:maybe_expr_body(Tree),
+    {B1, {_, Free1}} = vann_body(Body, Env),
+    Else = erl_syntax:maybe_expr_else(Tree),
+    {Else1, _, Free2} = vann_else_expr(Else, Env),
+    Free = ordsets:union(Free1, Free2),
+    Tree1 = rewrite(Tree, erl_syntax:maybe_expr(B1, Else1)),
+    Bound = [],
+    {ann_bindings(Tree1, Env, Bound, Free), Bound, Free}.
+
+vann_maybe_match_expr(Tree, Env) ->
+    E = erl_syntax:maybe_match_expr_body(Tree),
+    {E1, Bound1, Free1} = vann(E, Env),
+    Env1 = ordsets:union(Env, Bound1),
+    P = erl_syntax:maybe_match_expr_pattern(Tree),
+    {P1, Bound2, Free2} = vann_pattern(P, Env1),
+    Bound = ordsets:union(Bound1, Bound2),
+    Free = ordsets:union(Free1, Free2),
+    Tree1 = rewrite(Tree, erl_syntax:maybe_match_expr(P1, E1)),
+    {ann_bindings(Tree1, Env, Bound, Free), Bound, Free}.
+
 vann_case_expr(Tree, Env) ->
     E = erl_syntax:case_expr_argument(Tree),
     {E1, Bound1, Free1} = vann(E, Env),
@@ -565,6 +592,13 @@ vann_case_expr(Tree, Env) ->
     Tree1 = rewrite(Tree, erl_syntax:case_expr(E1, Cs1)),
     {ann_bindings(Tree1, Env, Bound, Free), Bound, Free}.
 
+vann_else_expr(Tree, Env) ->
+    Cs = erl_syntax:else_expr_clauses(Tree),
+    {Cs1, {_, Free}} = vann_clauses(Cs, Env),
+    Bound = [],
+    Tree1 = rewrite(Tree, erl_syntax:else_expr(Cs1)),
+    {ann_bindings(Tree1, Env, Bound, Free), Bound, Free}.
+
 vann_if_expr(Tree, Env) ->
     Cs = erl_syntax:if_expr_clauses(Tree),
     {Cs1, {Bound, Free}} = vann_clauses(Cs, Env),
@@ -765,6 +799,16 @@ vann_pattern(Tree, Env) ->
             Free = ordsets:union(Free1, Free2),
             Tree1 = rewrite(Tree, erl_syntax:match_expr(P1, E1)),
             {ann_bindings(Tree1, Env, Bound, Free), Bound, Free};
+        maybe_match_expr ->
+            %% Alias pattern
+            P = erl_syntax:maybe_match_expr_pattern(Tree),
+            {P1, Bound1, Free1} = vann_pattern(P, Env),
+            E = erl_syntax:maybe_match_expr_body(Tree),
+            {E1, Bound2, Free2} = vann_pattern(E, Env),
+            Bound = ordsets:union(Bound1, Bound2),
+            Free = ordsets:union(Free1, Free2),
+            Tree1 = rewrite(Tree, erl_syntax:maybe_match_expr(P1, E1)),
+            {ann_bindings(Tree1, Env, Bound, Free), Bound, Free};
         macro ->
             %% The macro name must be ignored. The arguments are treated
             %% as patterns.

diff --git a/lib/syntax_tools/test/syntax_tools_SUITE.erl b/lib/syntax_tools/test/syntax_tools_SUITE.erl
@@ -28,7 +28,8 @@
          wrapped_subtrees/1,
          t_abstract_type/1,t_erl_parse_type/1,t_type/1,
          t_epp_dodger/1,t_epp_dodger_clever/1,
-         t_comment_scan/1,t_prettypr/1,test_named_fun_bind_ann/1]).
+         t_comment_scan/1,t_prettypr/1,test_named_fun_bind_ann/1,
+         test_maybe_expr_ann/1]).
 
 suite() -> [{ct_hooks,[ts_install_cth]}].
 
@@ -38,7 +39,8 @@ all() ->
      wrapped_subtrees,
      t_abstract_type,t_erl_parse_type,t_type,
      t_epp_dodger,t_epp_dodger_clever,
-     t_comment_scan,t_prettypr,test_named_fun_bind_ann].
+     t_comment_scan,t_prettypr,test_named_fun_bind_ann,
+     test_maybe_expr_ann].
 
 groups() -> 
     [].
@@ -403,6 +405,58 @@ test_named_fun_bind_ann(Config) when is_list(Config) ->
     {'bound',['Test']} = CBound,
     {'free', []} = CFree.
 
+%% Test annotation of maybe_expr, maybe_match_expr and else_expr (PR #8811)
+test_maybe_expr_ann(Config) when is_list(Config) ->
+    %% maybe
+    %%  ok ?= Test,
+    %%  What ?= ok,
+    %%  Var = What,
+    %% else
+    %%  Error -> Error
+    %% end.
+    MaybeMatch1 = erl_syntax:maybe_match_expr(
+                    erl_syntax:atom(ok),
+                    erl_syntax:variable('Test')),
+    MaybeMatch2 = erl_syntax:maybe_match_expr(
+                    erl_syntax:variable('What'),
+                    erl_syntax:atom(ok)),
+    Match1 = erl_syntax:maybe_match_expr(
+                    erl_syntax:variable('Var'),
+                    erl_syntax:variable('What')),
+    Else = erl_syntax:else_expr(
+             [erl_syntax:clause(
+                [erl_syntax:variable('Err')],
+                'none',
+               [erl_syntax:variable('Err')])
+             ]),
+    Maybe = erl_syntax:maybe_expr([MaybeMatch1, MaybeMatch2, Match1], Else),
+
+    MaybeAnn = erl_syntax_lib:annotate_bindings(Maybe, []),
+    [Env, Bound, Free] = erl_syntax:get_ann(MaybeAnn),
+    {'env',[]} = Env,
+    {'bound',[]} = Bound,
+    {'free',['Test']} = Free,
+
+    [MaybeMatchAnn1, MaybeMatchAnn2, MatchAnn1] = erl_syntax:maybe_expr_body(MaybeAnn),
+    [Env1, Bound1, Free1] = erl_syntax:get_ann(MaybeMatchAnn1),
+    {'env',[]} = Env1,
+    {'bound',[]} = Bound1,
+    {'free',['Test']} = Free1,
+    [Env2, Bound2, Free2] = erl_syntax:get_ann(MaybeMatchAnn2),
+    {'env',[]} = Env2,
+    {'bound',['What']} = Bound2,
+    {'free',[]} = Free2,
+    [Env3, Bound3, Free3] = erl_syntax:get_ann(MatchAnn1),
+    {'env',['What']} = Env3,
+    {'bound',['Var']} = Bound3,
+    {'free',['What']} = Free3,
+
+    ElseAnn = erl_syntax:maybe_expr_else(MaybeAnn),
+    [Env4, Bound4, Free4] = erl_syntax:get_ann(ElseAnn),
+    {'env',[]} = Env4,
+    {'bound',[]} = Bound4,
+    {'free',[]} = Free4.
+
 test_files(Config) ->
     DataDir = ?config(data_dir, Config),
     [ filename:join(DataDir,Filename) || Filename <- test_files() ].