Add EOFNEWLINE warning when missing a newline at EOF.

Changes

@@ -11,6 +11,7 @@ Verilator 4.201 devel
 
 **Minor:**
 
+* Add EOFNEWLINE warning when missing a newline at EOF.
 * Verilated signals now use VlWide and VlPacked in place of C arrays.
 * Fix class unpacked-array compile error (#2774). [Iru Cai]
 * Fix exceeding command-line ar limit (#2834). [Yinan Xu]

bin/verilator

@@ -1730,8 +1730,9 @@ received from third parties.
 
 Disable all code style related warning messages (note by default they are
 already disabled).  This is equivalent to "-Wno-DECLFILENAME -Wno-DEFPARAM
--Wno-IMPORTSTAR -Wno-INCABSPATH -Wno-PINCONNECTEMPTY -Wno-PINNOCONNECT
--Wno-SYNCASYNCNET -Wno-UNDRIVEN -Wno-UNUSED -Wno-VARHIDDEN".
+-Wno-EOFNEWLINE -Wno-IMPORTSTAR -Wno-INCABSPATH -Wno-PINCONNECTEMPTY
+-Wno-PINNOCONNECT -Wno-SYNCASYNCNET -Wno-UNDRIVEN -Wno-UNUSED
+-Wno-VARHIDDEN".
 
 =item -Wpedantic
 
@@ -1756,9 +1757,9 @@ enabled), but do not affect style messages.  This is equivalent to
 =item -Wwarn-style
 
 Enable all code style related warning messages.  This is equivalent to
-"-Wwarn ASSIGNDLY -Wwarn-DECLFILENAME -Wwarn-DEFPARAM -Wwarn-INCABSPATH
--Wwarn-PINNOCONNECT -Wwarn-SYNCASYNCNET -Wwarn-UNDRIVEN -Wwarn-UNUSED
--Wwarn-VARHIDDEN".
+"-Wwarn ASSIGNDLY -Wwarn-DECLFILENAME -Wwarn-DEFPARAM -Wwarn-EOFNEWLINE
+-Wwarn-INCABSPATH -Wwarn-PINNOCONNECT -Wwarn-SYNCASYNCNET -Wwarn-UNDRIVEN
+-Wwarn-UNUSED -Wwarn-VARHIDDEN".
 
 =item --x-assign 0
 
@@ -4501,6 +4502,15 @@ the label attached to the block start.
 Ignoring this warning will only suppress the lint check, it will simulate
 correctly.
 
+=item EOFNEWLINE
+
+Warns that a file does not end in a newline.  POSIX defines that a line
+must end in newline, as otherwise for example 'cat' of the file may produce
+undesirable results.
+
+Disabled by default as this is a code style warning; it will simulate
+correctly.
+
 =item GENCLK
 
 Deprecated and no longer used as a warning.  Used to indicate that the

src/V3Error.h

@@ -82,6 +82,7 @@ public:
         DECLFILENAME,   // Declaration doesn't match filename
         DEPRECATED,     // Feature will be deprecated
         ENDLABEL,       // End lable name mismatch
+        EOFNEWLINE,     // End-of-file missing newline
         GENCLK,         // Generated Clock
         HIERBLOCK,      // Ignored hierarchical block setting
         IFDEPTH,        // If statements too deep
@@ -160,7 +161,7 @@ public:
             "CASEINCOMPLETE", "CASEOVERLAP", "CASEWITHX", "CASEX", "CASTCONST", "CDCRSTLOGIC", "CLKDATA",
             "CMPCONST", "COLONPLUS", "COMBDLY", "CONTASSREG",
             "DEFPARAM", "DECLFILENAME", "DEPRECATED",
-            "ENDLABEL", "GENCLK", "HIERBLOCK",
+            "ENDLABEL", "EOFNEWLINE", "GENCLK", "HIERBLOCK",
             "IFDEPTH", "IGNOREDRETURN",
             "IMPERFECTSCH", "IMPLICIT", "IMPORTSTAR", "IMPURE",
             "INCABSPATH", "INFINITELOOP", "INITIALDLY", "INSECURE",
@@ -207,9 +208,10 @@ public:
     // Warnings that are style only
     bool styleError() const {
         return (m_e == ASSIGNDLY  // More than style, but for backward compatibility
-                || m_e == BLKSEQ || m_e == DEFPARAM || m_e == DECLFILENAME || m_e == IMPORTSTAR
-                || m_e == INCABSPATH || m_e == PINCONNECTEMPTY || m_e == PINNOCONNECT
-                || m_e == SYNCASYNCNET || m_e == UNDRIVEN || m_e == UNUSED || m_e == VARHIDDEN);
+                || m_e == BLKSEQ || m_e == DEFPARAM || m_e == DECLFILENAME || m_e == EOFNEWLINE
+                || m_e == IMPORTSTAR || m_e == INCABSPATH || m_e == PINCONNECTEMPTY
+                || m_e == PINNOCONNECT || m_e == SYNCASYNCNET || m_e == UNDRIVEN || m_e == UNUSED
+                || m_e == VARHIDDEN);
     }
 };
 inline bool operator==(const V3ErrorCode& lhs, const V3ErrorCode& rhs) {

src/V3FileLine.h

@@ -148,11 +148,19 @@ public:
 #endif
     // METHODS
     void newContent();
+    void contentLineno(int num) {
+        lineno(num);
+        m_contentLineno = num;
+    }
     void lineno(int num) {
         m_firstLineno = num;
         m_lastLineno = num;
         m_firstColumn = m_lastColumn = 1;
     }
+    void column(int firstColumn, int lastColumn) {
+        m_firstColumn = firstColumn;
+        m_lastColumn = lastColumn;
+    }
     void language(V3LangCode lang) { singleton().numberToLang(filenameno(), lang); }
     void filename(const string& name) { m_filenameno = singleton().nameToNumber(name); }
     void parent(FileLine* fileline) { m_parent = fileline; }

src/V3PreProc.cpp

@@ -810,6 +810,8 @@ void V3PreProcImp::openFile(FileLine*, VInFilter* filterp, const string& filenam
     // Filter all DOS CR's en-mass.  This avoids bugs with lexing CRs in the wrong places.
     // This will also strip them from strings, but strings aren't supposed
     // to be multi-line without a "\"
+    int eof_newline = 0;  // Number of characters following last newline
+    int eof_lineno = 1;
     for (StrList::iterator it = wholefile.begin(); it != wholefile.end(); ++it) {
         // We don't end-loop at \0 as we allow and strip mid-string '\0's (for now).
         bool strip = false;
@@ -821,6 +823,12 @@ void V3PreProcImp::openFile(FileLine*, VInFilter* filterp, const string& filenam
                 strip = true;
                 break;
             }
+            if (VL_UNLIKELY(*cp == '\n')) {
+                eof_newline = 0;
+                ++eof_lineno;
+            } else {
+                ++eof_newline;
+            }
         }
         if (strip) {
             string out;
@@ -836,6 +844,15 @@ void V3PreProcImp::openFile(FileLine*, VInFilter* filterp, const string& filenam
         // Reclaim memory; the push saved the string contents for us
         *it = "";
     }
+
+    // Warning check
+    if (eof_newline) {
+        FileLine* fl = new FileLine{flsp};
+        fl->contentLineno(eof_lineno);
+        fl->column(eof_newline + 1, eof_newline + 1);
+        fl->v3warn(EOFNEWLINE, "Missing newline at end of file (POSIX 3.206)."
+                                   << fl->warnMore() << "... Suggest add newline.");
+    }
 }
 
 void V3PreProcImp::insertUnreadbackAtBol(const string& text) {

test_regress/t/t_lint_eofline.out

@@ -0,0 +1,3 @@
+`line 1 "obj_vlt/t_lint_eofline/t_lint_eofline_bad.v" 1
+
+`line 2 "obj_vlt/t_lint_eofline/t_lint_eofline_bad.v" 2

test_regress/t/t_lint_eofline.pl

@@ -0,0 +1,34 @@
+#!/usr/bin/env perl
+if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); die; }
+# DESCRIPTION: Verilator: Verilog Test driver/expect definition
+#
+# Copyright 2003 by Wilson Snyder. This program is free software; you
+# can redistribute it and/or modify it under the terms of either the GNU
+# Lesser General Public License Version 3 or the Perl Artistic License
+# Version 2.0.
+# SPDX-License-Identifier: LGPL-3.0-only OR Artistic-2.0
+
+use IO::File;
+use strict;
+use vars qw($Self);
+
+scenarios(vlt => 1);
+
+sub gen {
+    my $filename = shift;
+
+    my $fh = IO::File->new(">$filename");
+    # Empty file should not EOFLINE warn
+}
+
+top_filename("$Self->{obj_dir}/t_lint_eofline_bad.v");
+
+gen($Self->{top_filename});
+
+lint(
+    verilator_flags2 => ["--lint-only -Wall -Wno-DECLFILENAME -E"],
+    expect_filename => $Self->{golden_filename},
+    );
+
+ok(1);
+1;

test_regress/t/t_lint_eofline_bad.out

@@ -0,0 +1,5 @@
+%Warning-EOFNEWLINE: obj_vlt/t_lint_eofline_bad/t_lint_eofline_bad.v:4:10: Missing newline at end of file (POSIX 3.206).                                                                         : ... Suggest add newline.
+    4 | endmodule
+      |          ^
+                     ... Use "/* verilator lint_off EOFNEWLINE */" and lint_on around source to disable this message.
+%Error: Exiting due to

test_regress/t/t_lint_eofline_bad.pl

@@ -0,0 +1,38 @@
+#!/usr/bin/env perl
+if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); die; }
+# DESCRIPTION: Verilator: Verilog Test driver/expect definition
+#
+# Copyright 2003 by Wilson Snyder. This program is free software; you
+# can redistribute it and/or modify it under the terms of either the GNU
+# Lesser General Public License Version 3 or the Perl Artistic License
+# Version 2.0.
+# SPDX-License-Identifier: LGPL-3.0-only OR Artistic-2.0
+
+use IO::File;
+use strict;
+use vars qw($Self);
+
+scenarios(vlt => 1);
+
+sub gen {
+    my $filename = shift;
+
+    my $fh = IO::File->new(">$filename");
+    $fh->print("// Generated by t_lint_eofline_bad.pl\n");
+    $fh->print("module t;\n");
+    $fh->print("// No newline below:\n");
+    $fh->print("endmodule");  # Intentionally no newline
+}
+
+top_filename("$Self->{obj_dir}/t_lint_eofline_bad.v");
+
+gen($Self->{top_filename});
+
+lint(
+    verilator_flags2 => ["--lint-only -Wall -Wno-DECLFILENAME"],
+    fails => 1,
+    expect_filename => $Self->{golden_filename},
+    );
+
+ok(1);
+1;