[Crosstoolchain-logs] [device-tree-compiler] 285/357: dtc: Clean up lexing of include files

[Hector Oron]

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zumbi pushed a commit to branch upstream/1.3.x
in repository device-tree-compiler.

commit 76e0622b687d795bb1379cf183c6ce8613e14658
Author: David Gibson <david at gibson.dropbear.id.au>
Date:   Thu Jun 26 17:08:57 2008 +1000

    dtc: Clean up lexing of include files
    
    Currently we scan the /include/ directive as two tokens, the
    "/include/" keyword itself, then the string giving the file name to
    include.  We use a special scanner state to keep the two linked
    together, and use the scanner state stack to keep track of the
    original state while we're parsing the two /include/ tokens.
    
    This does mean that we need to enable the 'stack' option in flex,
    which results in a not-easily-suppressed warning from the flex
    boilerplate code.  This is mildly irritating.
    
    However, this two-token scanning of the /include/ directive also has
    some extremely strange edge cases, because there are a variety of
    tokens recognized in all scanner states, including INCLUDE.  For
    example the following strange dts file:
    
    	/include/ /dts-v1/;
    	/ {
    		 /* ... */
    	};
    
    Will be processed successfully with the /include/ being effectively
    ignored: the '/dts-v1/' and ';' are recognized even in INCLUDE state,
    then the ';' transitions us to PROPNODENAME state, throwing away
    INCLUDE, and the previous state is never popped off the stack.  Or
    for another example this construct:
    	foo /include/ = "somefile.dts"
    will be parsed as though it were:
    	foo = /include/ "somefile.dts"
    Again, the '=' is scanned without leaving INCLUDE state, then the next
    string triggers the include logic.
    
    And finally, we use a different regexp for the string with the
    included filename than the normal string regexpt, which is also
    potentially weird.
    
    This patch, therefore, cleans up the lexical handling of the /include/
    directive.  Instead of the INCLUDE state, we instead scan the whole
    include directive, both keyword and filename as a single token.  This
    does mean a bit more complexity in extracting the filename out of
    yytext, but I think it's worth it to avoid the strageness described
    above.  It also means it's no longer possible to put a comment between
    the /include/ and the filename, but I'm really not very worried about
    breaking files using such a strange construct.
---
 convert-dtsv0-lexer.l | 24 ++++++++----------------
 dtc-lexer.l           | 32 +++++++++++++-------------------
 2 files changed, 21 insertions(+), 35 deletions(-)

diff --git a/convert-dtsv0-lexer.l b/convert-dtsv0-lexer.l
index 64e2916..12b45ea 100644
--- a/convert-dtsv0-lexer.l
+++ b/convert-dtsv0-lexer.l
@@ -17,7 +17,7 @@
  *                                                                   USA
  */
 
-%option noyywrap nounput stack
+%option noyywrap nounput
 
 %x INCLUDE
 %x BYTESTRING
@@ -26,6 +26,11 @@
 PROPNODECHAR	[a-zA-Z0-9,._+*#?@-]
 PATHCHAR	({PROPNODECHAR}|[/])
 LABEL		[a-zA-Z_][a-zA-Z0-9_]*
+STRING		\"([^\\"]|\\.)*\"
+WS		[[:space:]]
+COMMENT		"/*"([^*]|\*+[^*/])*\*+"/"
+LINECOMMENT	"//".*\n
+GAP		({WS}|{COMMENT}|{LINECOMMENT})*
 
 %{
 #include <string.h>
@@ -91,16 +96,7 @@ const struct {
 %}
 
 %%
-<*>"/include/"	{
-			ECHO;
-			yy_push_state(INCLUDE);
-		}
-
-<INCLUDE>\"[^"\n]*\"	{
-			ECHO;
-			yy_pop_state();
-		}
-
+<*>"/include/"{GAP}{STRING}	ECHO;
 
 <*>\"([^\\"]|\\.)*\"	ECHO;
 
@@ -193,11 +189,7 @@ const struct {
 			BEGIN(INITIAL);
 		}
 
-<*>[[:space:]]+		ECHO;
-
-<*>"/*"([^*]|\*+[^*/])*\*+"/" ECHO;
-
-<*>"//".*\n		ECHO;
+<*>{GAP}	ECHO;
 
 <*>-		{	/* Hack to convert old style memreserves */
 			saw_hyphen = 1;
diff --git a/dtc-lexer.l b/dtc-lexer.l
index 8f15c4d..44dbfd3 100644
--- a/dtc-lexer.l
+++ b/dtc-lexer.l
@@ -18,7 +18,7 @@
  *                                                                   USA
  */
 
-%option noyywrap nounput yylineno stack
+%option noyywrap nounput yylineno
 
 %x INCLUDE
 %x BYTESTRING
@@ -28,6 +28,10 @@
 PROPNODECHAR	[a-zA-Z0-9,._+*#?@-]
 PATHCHAR	({PROPNODECHAR}|[/])
 LABEL		[a-zA-Z_][a-zA-Z0-9_]*
+STRING		\"([^\\"]|\\.)*\"
+WS		[[:space:]]
+COMMENT		"/*"([^*]|\*+[^*/])*\*+"/"
+LINECOMMENT	"//".*\n
 
 %{
 #include "dtc.h"
@@ -58,22 +62,19 @@ static int pop_input_file(void);
 %}
 
 %%
-<*>"/include/"		yy_push_state(INCLUDE);
-
-<INCLUDE>\"[^"\n]*\"	{
-			yytext[strlen(yytext) - 1] = 0;
-			push_input_file(yytext + 1);
-			yy_pop_state();
+<*>"/include/"{WS}*{STRING} {
+			char *name = strchr(yytext, '\"') + 1;
+			yytext[yyleng-1] = '\0';
+			push_input_file(name);
 		}
 
-
 <*><<EOF>>		{
 			if (!pop_input_file()) {
 				yyterminate();
 			}
 		}
 
-<*>\"([^\\"]|\\.)*\"	{
+<*>{STRING}	{
 			yylloc.file = srcpos_file;
 			yylloc.first_line = yylineno;
 			DPRINT("String: %s\n", yytext);
@@ -197,16 +198,9 @@ static int pop_input_file(void);
 			return DT_INCBIN;
 		}
 
-<*>[[:space:]]+	/* eat whitespace */
-
-<*>"/*"([^*]|\*+[^*/])*\*+"/"	{
-			yylloc.file = srcpos_file;
-			yylloc.first_line = yylineno;
-			DPRINT("Comment: %s\n", yytext);
-			/* eat comments */
-		}
-
-<*>"//".*\n	/* eat line comments */
+<*>{WS}+	/* eat whitespace */
+<*>{COMMENT}+	/* eat C-style comments */
+<*>{LINECOMMENT}+ /* eat C++-style comments */
 
 <*>.		{
 			yylloc.file = srcpos_file;

-- 
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