Parse nonblocking event trigger operator '->>'. LRM 15.5.1

Also factored out a kRepeatControl grammar rule for reuse. 'delay_or_event_control' now matches LRM description. Renamed event trigger constructs to distinguish between blocking/nonblocking. Also handle new operator in formatter token_annotator. Adds new and missing tests for '->' and '->>'. fixes #227 PiperOrigin-RevId: 299368975
chipsalliance · Mar 11, 2020 · 4ecb59b · 4ecb59b
1 parent 48ced6e
commit 4ecb59b
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Showing 7 changed files with 77 additions and 4 deletions.
diff --git a/verilog/CST/verilog_nonterminals.h b/verilog/CST/verilog_nonterminals.h
@@ -175,7 +175,8 @@ enum class NodeEnum {
   kIfBody,
   kElseBody,
   kDisableStatement,
-  kEventTriggerStatement,
+  kBlockingEventTriggerStatement,
+  kNonblockingEventTriggerStatement,
   kForLoopStatement,
   kLoopHeader,
   kJumpStatement,

diff --git a/verilog/formatting/token_annotator_test.cc b/verilog/formatting/token_annotator_test.cc
@@ -2375,6 +2375,52 @@ TEST(TokenAnnotatorTest, AnnotateFormattingWithContextTest) {
           {0, SpacingOptions::MustAppend},
       },
 
+      // Handle '->' as a unary prefix expression.
+      {
+          DefaultStyle,
+          {TK_TRIGGER, "->"},
+          {verilog_tokentype::SymbolIdentifier, "a"},
+          {/* any context */},             // context
+          {0, SpacingOptions::Undecided},  // could be MustAppend though
+      },
+      {
+          DefaultStyle,
+          {TK_NONBLOCKING_TRIGGER, "->>"},
+          {verilog_tokentype::SymbolIdentifier, "a"},
+          {/* any context */},             // context
+          {0, SpacingOptions::Undecided},  // could be MustAppend though
+      },
+
+      // Handle '->' as a binary operator
+      {
+          DefaultStyle,
+          {TK_LOGICAL_IMPLIES, "->"},
+          {verilog_tokentype::SymbolIdentifier, "right"},
+          {/* any context */},  // context
+          {1, SpacingOptions::Undecided},
+      },
+      {
+          DefaultStyle,
+          {verilog_tokentype::SymbolIdentifier, "left"},
+          {TK_LOGICAL_IMPLIES, "->"},
+          {/* any context */},  // context
+          {1, SpacingOptions::Undecided},
+      },
+      {
+          DefaultStyle,
+          {TK_CONSTRAINT_IMPLIES, "->"},
+          {verilog_tokentype::SymbolIdentifier, "right"},
+          {/* any context */},  // context
+          {1, SpacingOptions::Undecided},
+      },
+      {
+          DefaultStyle,
+          {verilog_tokentype::SymbolIdentifier, "left"},
+          {TK_CONSTRAINT_IMPLIES, "->"},
+          {/* any context */},  // context
+          {1, SpacingOptions::Undecided},
+      },
+
       // Inside dimension ranges, force space preservation if not around ':'
       {
           DefaultStyle,

diff --git a/verilog/formatting/verilog_token.cc b/verilog/formatting/verilog_token.cc
@@ -491,7 +491,6 @@ static const auto* FormatTokenTypeMap =
         {verilog_tokentype::TK_TAND, FTT::binary_operator},
         {verilog_tokentype::TK_NXOR, FTT::binary_operator},
         {verilog_tokentype::TK_LOGEQUIV, FTT::binary_operator},
-        {verilog_tokentype::TK_TRIGGER, FTT::binary_operator},
         {verilog_tokentype::TK_LOGICAL_IMPLIES, FTT::binary_operator},
         {verilog_tokentype::TK_CONSTRAINT_IMPLIES, FTT::binary_operator},
         {verilog_tokentype::TK_COLON_EQ, FTT::binary_operator},
@@ -536,6 +535,8 @@ static const auto* FormatTokenTypeMap =
         {verilog_tokentype::TK_DECR, FTT::unary_operator},
         {verilog_tokentype::TK_NAND, FTT::unary_operator},
         {verilog_tokentype::TK_NOR, FTT::unary_operator},
+        {verilog_tokentype::TK_TRIGGER, FTT::unary_operator},
+        {verilog_tokentype::TK_NONBLOCKING_TRIGGER, FTT::unary_operator},
 
         // hierarchy
         {verilog_tokentype::TK_SCOPE_RES, FTT::hierarchy},

diff --git a/verilog/parser/verilog.lex b/verilog/parser/verilog.lex
@@ -795,6 +795,7 @@ zi_zp { UpdateLocation(); return TK_zi_zp; }
 "~^" { UpdateLocation(); return TK_NXOR; }
 "^~" { UpdateLocation(); return TK_NXOR; }
 "~&" { UpdateLocation(); return TK_NAND; }
+"->>" { UpdateLocation(); return TK_NONBLOCKING_TRIGGER; }
 "->" { UpdateLocation(); return _TK_RARROW; }
 "<->" { UpdateLocation(); return TK_LOGEQUIV; }
 "+:" { UpdateLocation(); return TK_PO_POS; }

diff --git a/verilog/parser/verilog.y b/verilog/parser/verilog.y
@@ -659,6 +659,7 @@ is not locally defined, so the grammar here uses only generic identifiers.
 // or "^~"
 %token TK_LOGEQUIV "<->"
 
+%token TK_NONBLOCKING_TRIGGER "->>"
 %token _TK_RARROW "->"
 // _TK_RARROW is disambiguated into one of the following symbols
 // (see verilog_lexical_context.cc):
@@ -6614,8 +6615,10 @@ conditional_statement
 
 event_trigger
   : TK_TRIGGER reference ';'
-    { $$ = MakeTaggedNode(N::kEventTriggerStatement, $1, $2, $3); }
-  /* TODO(fangism): ->> operator */
+    { $$ = MakeTaggedNode(N::kBlockingEventTriggerStatement, $1, $2, $3); }
+  | TK_NONBLOCKING_TRIGGER delay_or_event_control_opt reference ';'
+    { $$ = MakeTaggedNode(N::kNonblockingEventTriggerStatement,
+                          $1, $2, $3, $4); }
   ;
 
 repeat_control

diff --git a/verilog/parser/verilog_lexer_unittest.cc b/verilog/parser/verilog_lexer_unittest.cc
@@ -1223,6 +1223,7 @@ static std::initializer_list<LexerTestData> kKeywordTests = {
     {{TK_NAND, "~&"}},
     {{TK_NOR, "~|"}},
     {{TK_NXOR, "~^"}},
+    {{TK_NONBLOCKING_TRIGGER, "->>"}},
     {{_TK_RARROW, "->"}},  // This can disambiguate to different enums,
                            // depending on context.
     {{TK_LOGEQUIV, "<->"}},

diff --git a/verilog/parser/verilog_parser_unittest.cc b/verilog/parser/verilog_parser_unittest.cc
@@ -1931,6 +1931,26 @@ static const char* kModuleTests[] = {
     "    x = 0;\n"
     "  end\n"
     "endmodule\n",
+    "module triggerer;\n"
+    "  always @* begin\n"
+    "    ->>c;\n"  // nonblocking event trigger
+    "  end\n"
+    "endmodule\n",
+    "module triggerer;\n"
+    "  always @* begin\n"
+    "    ->> #5 c;\n"  // nonblocking event trigger, delayed
+    "  end\n"
+    "endmodule\n",
+    "module triggerer;\n"
+    "  always @* begin\n"
+    "    ->> @(posedge y) c;\n"  // nonblocking event trigger, edge
+    "  end\n"
+    "endmodule\n",
+    "module triggerer;\n"
+    "  always @* begin\n"
+    "    ->> repeat(2) @foo c;\n"  // nonblocking event trigger, repeat
+    "  end\n"
+    "endmodule\n",
     // streaming concatenations with macros
     "module streaming_cats;\n"
     "assign s1 = {>>`BAR};\n"