parsetools: Suppress Dialyzer-warnings

When using Yecc's operator precedence declarations (Right, Nonassoc, Left), it is possible that some clauses of the generated code are unreachable. Dialyzer complains, at least if SET_LIMIT in erl_types is set sufficiently high (to avoid sets of integers to collapse to the integer() type). Rather than trying to figure out exactly which clauses are unreachable, Yecc generates a Dialyzer suppression.
erlang · Sep 12, 2016 · edaa208 · edaa208
1 parent 86d1fb0
commit edaa208
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Showing 2 changed files with 6 additions and 5 deletions.
diff --git a/lib/parsetools/src/yecc.erl b/lib/parsetools/src/yecc.erl
@@ -1978,7 +1978,8 @@ output_goto(St, [{_Nonterminal, []} | Go], StateInfo) ->
     output_goto(St, Go, StateInfo);
 output_goto(St0, [{Nonterminal, List} | Go], StateInfo) ->
     F = function_name(yeccgoto, Nonterminal),
-    St10 = output_goto1(St0, List, F, StateInfo, true),
+    St05 = fwrite(St0, <<"-dialyzer({nowarn_function, ~w/7}).\n">>, [F]),
+    St10 = output_goto1(St05, List, F, StateInfo, true),
     St = output_goto_fini(F, Nonterminal, St10),
     output_goto(St, Go, StateInfo);
 output_goto(St, [], _StateInfo) ->

diff --git a/lib/parsetools/test/yecc_SUITE.erl b/lib/parsetools/test/yecc_SUITE.erl
@@ -342,7 +342,7 @@ syntax(Config) when is_list(Config) ->
                               {L2,_,{bad_inline,{yeccpars2_2_,1}}}]}],
                    []} = compile:file(Parserfile1, [basic_validation,return]),
             ?line L1 = 31 + SzYeccPre,
-            ?line L2 = 38 + SzYeccPre
+            ?line L2 = 39 + SzYeccPre
     end(),
 
     %% Bad macro in action. OTP-7224.
@@ -360,7 +360,7 @@ syntax(Config) when is_list(Config) ->
                               {L2,_,{bad_inline,{yeccpars2_2_,1}}}]}],
                    []} = compile:file(Parserfile1, [basic_validation,return]),
             ?line L1 = 31 + SzYeccPre,
-            ?line L2 = 38 + SzYeccPre
+            ?line L2 = 39 + SzYeccPre
     end(),
 
     %% Check line numbers. OTP-7224.
@@ -1623,7 +1623,7 @@ otp_7292(Config) when is_list(Config) ->
                    [{_,[{16,_,{unused_function,{foo,0}}}]}]} = 
                 compile:file(Parserfile1, [basic_validation, return]),
             L1 = 41 + SzYeccPre,
-            L2 = 48 + SzYeccPre
+            L2 = 49 + SzYeccPre
     end(),
 
     YeccPre = filename:join(Dir, "yeccpre.hrl"),
@@ -1641,7 +1641,7 @@ otp_7292(Config) when is_list(Config) ->
                    [{_,[{16,_,{unused_function,{foo,0}}}]}]} = 
                 compile:file(Parserfile1, [basic_validation, return]),
             ?line L1 = 40 + SzYeccPre,
-            ?line L2 = 47 + SzYeccPre
+            ?line L2 = 48 + SzYeccPre
     end(),
 
     file:delete(YeccPre),