[Mesa-dev] [PATCH 2/5] glsl/glcpp: Treat CR+LF pair as a single newline

[Carl Worth]

The GLSL specification says that either carriage-return, line-feed, or both
together can be used to terminate lines. Further, it says that when used
together, the pair of terminators shall be interpreted as a single line.

This final requirement has not been respected by glcpp up until now, (it has
been emitting two newlines for every CR+LF pair).

Here, we fix the lexer by using a regular expression for NEWLINE that eats
up both "\r\n" (or even "\n\r") if possible before also considering a single
'\n' or a single '\r' as a line terminator.

Before this commit, the test results are as follows:

	\r:	135/143 tests pass
	\r\n:	  4/143 tests pass
	\n\r:	  4/143 tests pass

After this commit, the test results are as follows:

	\r:	135/143 tests pass
	\r\n:	140/143 tests pass
	\n\r:	139/143 tests pass

So, obviously, a dramatic improvement.
---
 src/glsl/glcpp/glcpp-lex.l      | 9 +++++----
 src/glsl/glcpp/tests/.gitignore | 3 +++
 2 files changed, 8 insertions(+), 4 deletions(-)
 create mode 100644 src/glsl/glcpp/tests/.gitignore

diff --git a/src/glsl/glcpp/glcpp-lex.l b/src/glsl/glcpp/glcpp-lex.l
index 1b7bb85..bcc1337 100644
--- a/src/glsl/glcpp/glcpp-lex.l
+++ b/src/glsl/glcpp/glcpp-lex.l
@@ -172,6 +172,7 @@ SPACE		[[:space:]]
 NONSPACE	[^[:space:]]
 HSPACE		[ \t]
 HASH		#
+NEWLINE		(\r\n|\n\r|\r|\n)
 IDENTIFIER	[_a-zA-Z][_a-zA-Z0-9]*
 PP_NUMBER	[.]?[0-9]([._a-zA-Z0-9]|[eEpP][-+])*
 PUNCTUATION	[][(){}.&*~!/%<>^|;,=+-]
@@ -256,9 +257,9 @@ HEXADECIMAL_INTEGER	0[xX][0-9a-fA-F]+[uU]?
 	/* Multi-line comments */
 <INITIAL,DEFINE,HASH>"/*"   { yy_push_state(COMMENT, yyscanner); }
 <COMMENT>[^*\r\n]*
-<COMMENT>[^*\r\n]*[\r\n]    { yylineno++; yycolumn = 0; parser->commented_newlines++; }
+<COMMENT>[^*\r\n]*{NEWLINE} { yylineno++; yycolumn = 0; parser->commented_newlines++; }
 <COMMENT>"*"+[^*/\r\n]*
-<COMMENT>"*"+[^*/\r\n]*[\r\n] { yylineno++; yycolumn = 0; parser->commented_newlines++; }
+<COMMENT>"*"+[^*/\r\n]*{NEWLINE} { yylineno++; yycolumn = 0; parser->commented_newlines++; }
 <COMMENT>"*"+"/"        {
 	yy_pop_state(yyscanner);
 	/* In the <HASH> start condition, we don't want any SPACE token. */
@@ -289,7 +290,7 @@ HEXADECIMAL_INTEGER	0[xX][0-9a-fA-F]+[uU]?
 
 	/* Swallow empty #pragma directives, (to avoid confusing the
 	 * downstream compiler). */
-<HASH>pragma{HSPACE}*/[\r\n] {
+<HASH>pragma{HSPACE}*/{NEWLINE} {
 	BEGIN INITIAL;
 }
 
@@ -516,7 +517,7 @@ HEXADECIMAL_INTEGER	0[xX][0-9a-fA-F]+[uU]?
 
 	/* We preserve all newlines, even between #if 0..#endif, so no
 	skipping.. */
-<*>[\r\n] {
+<*>{NEWLINE} {
 	if (parser->commented_newlines) {
 		BEGIN NEWLINE_CATCHUP;
 	} else {
diff --git a/src/glsl/glcpp/tests/.gitignore b/src/glsl/glcpp/tests/.gitignore
new file mode 100644
index 0000000..f18a9bb
--- /dev/null
+++ b/src/glsl/glcpp/tests/.gitignore
@@ -0,0 +1,3 @@
+subtest-cr/
+subtest-cr-lf/
+subtest-lf-cr/
-- 
2.0.0