Open chongchai opened 3 years ago
I thinkextern "C" will cause this error. Can you support this situation?
It seems that your guessing is correct. Following change is for ignoring the code between "#ifdef __cplusplus ~ #endif. @pragmaware, how do you think about my approach?
$ git diff | cat
diff --git a/parsers/cpreprocessor.c b/parsers/cpreprocessor.c
index 668171f0..4ad6087d 100644
--- a/parsers/cpreprocessor.c
+++ b/parsers/cpreprocessor.c
@@ -953,10 +953,31 @@ static void directivePragma (int c)
Cpp.directive.state = DRCTV_NONE;
}
+static bool isDefCondition (const int c, const char *condition)
+{
+ if (*condition == '\0')
+ return true;
+ else if (c == EOF)
+ return false;
+
+ if (*condition != '\0' && c == condition[0])
+ {
+ const int next = cppGetcFromUngetBufferOrFile ();
+ return isDefCondition (next, condition + 1);
+ }
+
+ return false;
+}
+
static bool directiveIf (const int c)
{
DebugStatement ( const bool ignore0 = isIgnore (); )
- const bool ignore = pushConditional ((bool) (c != '0'));
+ bool firstBranchChosen = true;
+
+ if (c == '0' || isDefCondition (c, "__cplusplus"))
+ firstBranchChosen = false;
+
+ const bool ignore = pushConditional (firstBranchChosen);
Cpp.directive.state = DRCTV_NONE;
DebugStatement ( debugCppNest (true, Cpp.directive.nestLevel);
$ u-ctags --output-format=json --langmap=c:+.inc --kinds-c=+plz --fields=+nie -o - /tmp/foo.c
u-ctags --output-format=json --langmap=c:+.inc --kinds-c=+plz --fields=+nie -o - /tmp/foo.c
{"_type": "tag", "name": "NB1", "path": "/tmp/foo.c", "pattern": "/^ #define NB1 /", "file": true, "line": 7, "kind": "macro", "end": 7}
{"_type": "tag", "name": "NB2", "path": "/tmp/foo.c", "pattern": "/^ #define NB2 /", "file": true, "line": 10, "kind": "macro", "end": 10}
{"_type": "tag", "name": "NB3", "path": "/tmp/foo.c", "pattern": "/^ #define NB3 /", "file": true, "line": 19, "kind": "macro", "end": 19}
{"_type": "tag", "name": "NB4", "path": "/tmp/foo.c", "pattern": "/^ #define NB4 /", "file": true, "line": 22, "kind": "macro", "end": 22}
{"_type": "tag", "name": "testMax1", "path": "/tmp/foo.c", "pattern": "/^ void testMax1() {}$/", "line": 6, "typeref": "typename:void", "kind": "function", "end": 6}
{"_type": "tag", "name": "testMax2", "path": "/tmp/foo.c", "pattern": "/^ void testMax2() {}$/", "line": 9, "typeref": "typename:void", "kind": "function", "end": 9}
{"_type": "tag", "name": "testMax3", "path": "/tmp/foo.c", "pattern": "/^ void testMax3() {}$/", "line": 18, "typeref": "typename:void", "kind": "function", "end": 18}
{"_type": "tag", "name": "testMax4", "path": "/tmp/foo.c", "pattern": "/^ void testMax4() {}$/", "line": 21, "typeref": "typename:void", "kind": "function", "end": 21}
Well, if it fixes the problem and doesn't break tests then it looks good.
However, I don't understand the relation between the #ifdef __cplusplus define and the #ifdef MAX one. They shouldn't influence each other in terms of choosing one or multiple branches... or I'm missing something?
My analysis is that it is related to how c parser handles extern "C" { }.
$ cat /tmp/foo.c
cat /tmp/foo.c
extern "C" {
#ifdef MAX
void testMax1() {}
#define NB1 11
#else
void testMax2() {}
#define NB2 22
#endif
}
$ u-ctags --output-format=xref --kinds-c=+plz --fields=+nie -o - /tmp/foo.c
u-ctags --output-format=xref --kinds-c=+plz --fields=+nie -o - /tmp/foo.c
NB1 macro 5 /tmp/foo.c #define NB1 11
testMax1 function 4 /tmp/foo.c void testMax1() {}
$ cat /tmp/bar.c
cat /tmp/bar.c
// extern "C" {
#ifdef MAX
void testMax1() {}
#define NB1 11
#else
void testMax2() {}
#define NB2 22
#endif
// }
$ u-ctags --output-format=xref --kinds-c=+plz --fields=+nie -o - /tmp/bar.c
u-ctags --output-format=xref --kinds-c=+plz --fields=+nie -o - /tmp/bar.c
NB1 macro 5 /tmp/bar.c #define NB1 11
NB2 macro 8 /tmp/bar.c #define NB2 22
testMax1 function 4 /tmp/bar.c void testMax1() {}
testMax2 function 7 /tmp/bar.c void testMax2() {}
If cpreprocessor parser suppresses the area #ifdef __cplusplus ~ #end, c parser doesn't read the line extern "C" { and }.
I have to add one more condition to the patch (https://github.com/universal-ctags/ctags/issues/2647#issuecomment-693859110). The condition is "if the client parser of cpreprocessor parser is c parser" or "if the client parser of cpreprocessor parser is not c++ parser".
Though I still don't understand why. In theory the behaviour of an #ifdef should not be influenced by any previous #ifdef... ... it seems to be more of a bug in the handling of the second #ifdef, not the first one...
I found this is nothing to do with extern "C" { ... }. I can reproduce the behavior with struct s { ... }:
[yamato@control]~/var/ctags-github% cat /tmp/f.c
cat /tmp/f.c
struct s {
#ifdef X
int i;
#else
int j;
#endif
};
[yamato@control]~/var/ctags-github% ./ctags -o - /tmp/f.c
./ctags -o - /tmp/f.c
i /tmp/f.c /^ int i;$/;" m language:C struct:s typeref:typename:int file:
s /tmp/f.c /^struct s {$/;" s language:C file:
[yamato@control]~/var/ctags-github% cat /tmp/g.c
cat /tmp/g.c
#ifdef X
int i;
#else
int j;
#endif
[yamato@control]~/var/ctags-github% ./ctags -o - /tmp/g.c
./ctags -o - /tmp/g.c
i /tmp/g.c /^ int i;$/;" v language:C typeref:typename:int
j /tmp/g.c /^ int j;$/;" v language:C typeref:typename:int
[yamato@control]~/var/ctags-github%
I can add another testcase for thier behavior. Local variable In function body like follows
[yklhard@gotpc12]$ cat a.c
void test() {
#ifdef X
int i = 1;
#else
int j = 2;
#endif
}
[yklhard@gotpc12]$ ./ctags-src/ctags --kinds-c=+l -o - a.c
i a.c /^ int i = 1;$/;" l function:test typeref:typename:int file:
test a.c /^void test() {$/;" f typeref:typename:void
[yklhard@gotpc12]$ cat b.c
#ifdef X
int i = 1;
#else
int j = 2;
#endif
[yklhard@gotpc12]$ ./ctags-src/ctags --kinds-c=+l -o - b.c
i b.c /^ int i = 1;$/;" v typeref:typename:int
j b.c /^ int j = 2;$/;" v typeref:typename:int
Seems that we should not call cppBeginStatement()
here https://github.com/universal-ctags/ctags/blob/master/parsers/cxx/cxx_parser_block.c#L262 :
I find the definition will not be parsed in the
#else
andextern "C"
.The sample code:
I use following command to parse:
Result is:
The
testMax2
andNB2
are not parsed, whiletestMax4
andNB4
are parsed. I thinkextern "C"
will cause this error. Can you support this situation?