L ## 'a' is valid; so's L ## "a"HEADmaster

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

2 files changed, 41 insertions, 1 deletions

diff --git a/pre-process.c b/pre-process.c
index 9e5df5c3..e5f56b40 100644
--- a/pre-process.c
+++ b/pre-process.c
@@ -407,6 +407,8 @@ static void expand_arguments(int count, struct arg *args)
  * Possibly valid combinations:
  *  - ident + ident -> ident
  *  - ident + number -> ident unless number contains '.', '+' or '-'.
+ *  - 'L' + char constant -> wide char constant
+ *  - 'L' + string literal -> wide string literal
  *  - number + number -> number
  *  - number + ident -> number
  *  - number + '.' -> number
@@ -422,6 +424,13 @@ static enum token_type combine(struct token *left, struct token *right, char *p)
 	if (t1 != TOKEN_IDENT && t1 != TOKEN_NUMBER && t1 != TOKEN_SPECIAL)
 		return TOKEN_ERROR;
 
+	if (t1 == TOKEN_IDENT && left->ident == &L_ident) {
+		if (t2 >= TOKEN_CHAR && t2 < TOKEN_WIDE_CHAR)
+			return t2 + TOKEN_WIDE_CHAR - TOKEN_CHAR;
+		if (t2 == TOKEN_STRING)
+			return TOKEN_WIDE_STRING;
+	}
+
 	if (t2 != TOKEN_IDENT && t2 != TOKEN_NUMBER && t2 != TOKEN_SPECIAL)
 		return TOKEN_ERROR;
 
@@ -464,9 +473,10 @@ static enum token_type combine(struct token *left, struct token *right, char *p)
 static int merge(struct token *left, struct token *right)
 {
 	static char buffer[512];
+	enum token_type res = combine(left, right, buffer);
 	int n;
 
-	switch (combine(left, right, buffer)) {
+	switch (res) {
 	case TOKEN_IDENT:
 		left->ident = built_in_ident(buffer);
 		left->pos.noexpand = 0;
@@ -489,6 +499,21 @@ static int merge(struct token *left, struct token *right)
 				return 1;
 			}
 		}
+		break;
+
+	case TOKEN_WIDE_CHAR:
+	case TOKEN_WIDE_STRING:
+		token_type(left) = res;
+		left->pos.noexpand = 0;
+		left->string = right->string;
+		return 1;
+
+	case TOKEN_WIDE_CHAR + 1 ... TOKEN_WIDE_CHAR + 4:
+		token_type(left) = res;
+		left->pos.noexpand = 0;
+		memcpy(left->embedded, right->embedded, 4);
+		return 1;
+
 	default:
 		;
 	}
diff --git a/validation/preprocessor/wide.c b/validation/preprocessor/wide.c
new file mode 100644
index 00000000..21b643ce
--- /dev/null
+++ b/validation/preprocessor/wide.c
@@ -0,0 +1,15 @@
+#define A(x) L##x
+A('a')
+A("bc")
+/*
+ * check-name: wide char token-pasting
+ * check-description: Used to cause infinite recursion.
+ * check-command: sparse -E $file
+ *
+ * check-output-start
+
+L'a'
+L"bc"
+ * check-output-end
+ */
+