Teach sparse about the __COUNTER__ predefined macro

__COUNTER__ macro is expanded to a sequential number starting from 0.
This is sometimes used to declare unique variable names.

Implement support for __COUNTER__ in sparse including a set of
small test programs for the test suite.

Signed-off-by: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Tested-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Christopher Li <sparse@chrisli.org>

6 files changed, 46 insertions, 0 deletions

diff --git a/ident-list.h b/ident-list.h
index d5a145f8..b65b667d 100644
--- a/ident-list.h
+++ b/ident-list.h
@@ -108,6 +108,7 @@ __IDENT(__TIME___ident, "__TIME__", 0);
 __IDENT(__func___ident, "__func__", 0);
 __IDENT(__FUNCTION___ident, "__FUNCTION__", 0);
 __IDENT(__PRETTY_FUNCTION___ident, "__PRETTY_FUNCTION__", 0);
+__IDENT(__COUNTER___ident, "__COUNTER__", 0);
 
 /* Sparse commands */
 IDENT_RESERVED(__context__);
diff --git a/pre-process.c b/pre-process.c
index 5c386a85..7c57ba1c 100644
--- a/pre-process.c
+++ b/pre-process.c
@@ -45,6 +45,7 @@
 #include "scope.h"
 
 static int false_nesting = 0;
+static int counter_macro = 0;		// __COUNTER__ expansion
 
 #define INCLUDEPATHS 300
 const char *includepath[INCLUDEPATHS+1] = {
@@ -181,6 +182,8 @@ static int expand_one_symbol(struct token **list)
 			time(&t);
 		strftime(buffer, 9, "%T", localtime(&t));
 		replace_with_string(token, buffer);
+	} else if (token->ident == &__COUNTER___ident) {
+		replace_with_integer(token, counter_macro++);
 	}
 	return 1;
 }
@@ -1894,6 +1897,7 @@ static void init_preprocessor(void)
 		sym->normal = 0;
 	}
 
+	counter_macro = 0;
 }
 
 static void handle_preprocessor_line(struct stream *stream, struct token **line, struct token *start)
diff --git a/validation/preprocessor/counter1.c b/validation/preprocessor/counter1.c
new file mode 100644
index 00000000..98187ee6
--- /dev/null
+++ b/validation/preprocessor/counter1.c
@@ -0,0 +1,12 @@
+__COUNTER__
+__COUNTER__
+/*
+ * check-name: __COUNTER__ #1
+ * check-command: sparse -E $file
+ *
+ * check-output-start
+
+0
+1
+ * check-output-end
+ */
diff --git a/validation/preprocessor/counter2.c b/validation/preprocessor/counter2.c
new file mode 100644
index 00000000..9883b682
--- /dev/null
+++ b/validation/preprocessor/counter2.c
@@ -0,0 +1,14 @@
+__FILE__ __COUNTER__
+#include <counter2.h>
+__FILE__ __COUNTER__
+/*
+ * check-name: __COUNTER__ #2
+ * check-command: sparse -Ipreprocessor -E $file
+ *
+ * check-output-start
+
+"preprocessor/counter2.c" 0
+"preprocessor/counter2.h" 1
+"preprocessor/counter2.c" 2
+ * check-output-end
+ */
diff --git a/validation/preprocessor/counter2.h b/validation/preprocessor/counter2.h
new file mode 100644
index 00000000..447b70ab
--- /dev/null
+++ b/validation/preprocessor/counter2.h
@@ -0,0 +1 @@
+__FILE__ __COUNTER__
diff --git a/validation/preprocessor/counter3.c b/validation/preprocessor/counter3.c
new file mode 100644
index 00000000..fa3f173b
--- /dev/null
+++ b/validation/preprocessor/counter3.c
@@ -0,0 +1,14 @@
+/*
+ * check-name: __COUNTER__ #3
+ * check-command: sparse -Ipreprocessor -E preprocessor/counter1.c $file
+ *
+ * check-output-start
+
+0
+1
+"preprocessor/counter2.c" 0
+"preprocessor/counter2.h" 1
+"preprocessor/counter2.c" 2
+ * check-output-end
+ */
+#include "counter2.c"