[PATCH 10/10] userdiff: have 'cpp' hunk header pattern catch more C++ anchor points
- From
Johannes Sixt <j6t@kdbg.org>
- Date
- Mar 21, 2014, 21:07 UTC
- Message-ID
- <49db8b0f66c725ef6ff0b8a4d536c43e6397879a.1395433874.git.j6t@kdbg.org>
- In-Reply-To
- <cover.1395433874.git.j6t@kdbg.org>
The hunk header pattern 'cpp' is intended for C and C++ source code, but it is actually not particularly useful for the latter, and even misses some use-cases for the former.
The parts of the pattern have the following flaws:
- The first part matches an identifier followed immediately by a colon and arbitrary text and is intended to reject goto labels and C++ access specifiers (public, private, protected). But this pattern also rejects C++ constructs, which look like this:
MyClass::MyClass()
MyClass::~MyClass()
MyClass::Item MyClass::Find(...- The second part matches an identifier followed by a list of qualified names (i.e. identifiers separated by the C++ scope operator '::') separated by space or '*' followed by an opening parenthesis (with space between the tokens). It matches function declarations like
struct item* get_head(...
int Outer::Inner::Func(...Since the pattern requires at least two identifiers, GNU-style function definitions are ignored:
void
func(...Moreover, since the pattern does not allow punctuation other than '*', the following C++ constructs are not recognized:
. template definitions:
template<class T> int func(T arg) . functions returning references:
const string& get_message() . functions returning templated types:
vector<int> foo() . operator definitions:
Value operator+(Value l, Value r)- The third part of the pattern finally matches compound definitions. But it forgets about unions and namespaces, and also skips single-line definitions
struct random_iterator_tag {};because no semicolon can occur on the line.
Change the first pattern to require a colon at the end of the line (except for trailing space and comments), so that it does not reject constructor or destructor definitions.
Notice that all interesting anchor points begin with an identifier or keyword. But since there is a large variety of syntactical constructs after the first "word", the simplest is to require only this word and accept everything else. Therefore, this boils down to a line that begins with a letter or underscore (optionally preceded by the C++ scope operator '::' to accept functions returning a type anchored at the global namespace). Replace the second and third part by a single pattern that picks such a line.
This has the following desirable consequence:
- All constructs mentioned above are recognized.
and the following likely desirable consequences:
- Definitions of global variables and typedefs are recognized:
int num_entries = 0;
extern const char* help_text;
typedef basic_string<wchar_t> wstring;- Commonly used marco-ized boilerplate code is recognized:
BEGIN_MESSAGE_MAP(CCanvas,CWnd)
Q_DECLARE_METATYPE(MyStruct)
PATTERNS("tex",...)(The last one is from this very patch.)
but also the following possibly undesirable consequence:
- When a label is not on a line by itself (except for a comment) it is no longer rejected, but can appear as a hunk header if it occurs at the beginning of a line:
next:;
IMO, the benefits of the change outweigh the (possible) regressions by a large margin.
Signed-off-by: Johannes Sixt <j6t@kdbg.org> --- t/t4018/cpp-class-constructor | 1 - t/t4018/cpp-class-constructor-mem-init | 1 - t/t4018/cpp-class-destructor | 1 - t/t4018/cpp-function-returning-global-type | 1 - t/t4018/cpp-function-returning-nested | 1 - t/t4018/cpp-function-returning-reference | 1 - t/t4018/cpp-gnu-style-function | 1 - t/t4018/cpp-namespace-definition | 1 - t/t4018/cpp-operator-definition | 1 - t/t4018/cpp-struct-single-line | 1 - t/t4018/cpp-template-function-definition | 1 - t/t4018/cpp-union-definition | 1 - userdiff.c | 8 +++----- 13 files changed, 3 insertions(+), 17 deletions(-)
diff --git a/t/t4018/cpp-class-constructor b/t/t4018/cpp-class-constructor index 4c4925c..ec4f115 100644 --- a/t/t4018/cpp-class-constructor +++ b/t/t4018/cpp-class-constructor @@ -1,5 +1,4 @@ Item::Item(int RIGHT) { ChangeMe; - broken; } diff --git a/t/t4018/cpp-class-constructor-mem-init b/t/t4018/cpp-class-constructor-mem-init index eec1d7c..49a69f3 100644 --- a/t/t4018/cpp-class-constructor-mem-init +++ b/t/t4018/cpp-class-constructor-mem-init @@ -2,5 +2,4 @@ Item::Item(int RIGHT) : member(0) { ChangeMe; - broken; } diff --git a/t/t4018/cpp-class-destructor b/t/t4018/cpp-class-destructor index 03aa51c..5487665 100644 --- a/t/t4018/cpp-class-destructor +++ b/t/t4018/cpp-class-destructor @@ -1,5 +1,4 @@ RIGHT::~RIGHT() { ChangeMe; - broken; } diff --git a/t/t4018/cpp-function-returning-global-type b/t/t4018/cpp-function-returning-global-type index bff3e5f..1084d59 100644 --- a/t/t4018/cpp-function-returning-global-type +++ b/t/t4018/cpp-function-returning-global-type @@ -1,5 +1,4 @@ ::Item get::it::RIGHT() { ChangeMe; - broken; } diff --git a/t/t4018/cpp-function-returning-nested b/t/t4018/cpp-function-returning-nested index 41700f2..d9750aa 100644 --- a/t/t4018/cpp-function-returning-nested +++ b/t/t4018/cpp-function-returning-nested @@ -1,6 +1,5 @@ get::Item get::it::RIGHT() { ChangeMe; - broken; } diff --git a/t/t4018/cpp-function-returning-reference b/t/t4018/cpp-function-returning-reference index 29e2bd4..01b051d 100644 --- a/t/t4018/cpp-function-returning-reference +++ b/t/t4018/cpp-function-returning-reference @@ -1,5 +1,4 @@ string& get::it::RIGHT(char *ptr) { ChangeMe; - broken; } diff --git a/t/t4018/cpp-gnu-style-function b/t/t4018/cpp-gnu-style-function index d65fc74..08c7c75 100644 --- a/t/t4018/cpp-gnu-style-function +++ b/t/t4018/cpp-gnu-style-function @@ -2,5 +2,4 @@ const char * RIGHT(int arg) { ChangeMe; - broken; } diff --git a/t/t4018/cpp-namespace-definition b/t/t4018/cpp-namespace-definition index 6b88dd9..6749980 100644 --- a/t/t4018/cpp-namespace-definition +++ b/t/t4018/cpp-namespace-definition @@ -1,5 +1,4 @@ namespace RIGHT { ChangeMe; - broken; } diff --git a/t/t4018/cpp-operator-definition b/t/t4018/cpp-operator-definition index f2bd167..1acd827 100644 --- a/t/t4018/cpp-operator-definition +++ b/t/t4018/cpp-operator-definition @@ -1,5 +1,4 @@ Value operator+(Value LEFT, Value RIGHT) { ChangeMe; - broken; } diff --git a/t/t4018/cpp-struct-single-line b/t/t4018/cpp-struct-single-line index ad6fa8b..a0de5fb 100644 --- a/t/t4018/cpp-struct-single-line +++ b/t/t4018/cpp-struct-single-line @@ -5,4 +5,3 @@ void wrong() struct RIGHT_iterator_tag {}; int ChangeMe; -// broken diff --git a/t/t4018/cpp-template-function-definition b/t/t4018/cpp-template-function-definition index a410298..0cdf5ba 100644 --- a/t/t4018/cpp-template-function-definition +++ b/t/t4018/cpp-template-function-definition @@ -1,5 +1,4 @@ template<class T> int RIGHT(T arg) { ChangeMe; - broken; } diff --git a/t/t4018/cpp-union-definition b/t/t4018/cpp-union-definition index 133b662..7ec94df 100644 --- a/t/t4018/cpp-union-definition +++ b/t/t4018/cpp-union-definition @@ -1,5 +1,4 @@ union RIGHT { double v; int ChangeMe; - broken; }; diff --git a/userdiff.c b/userdiff.c index 8830417..fad52d6 100644 --- a/userdiff.c +++ b/userdiff.c @@ -125,11 +125,9 @@ "\\\\[a-zA-Z@]+|\\\\.|[a-zA-Z0-9\x80-\xff]+"), PATTERNS("cpp", /* Jump targets or access declarations */ - "!^[ \t]*[A-Za-z_][A-Za-z_0-9]*:.*$\n" - /* C/++ functions/methods at top level */ - "^([A-Za-z_][A-Za-z_0-9]*([ \t*]+[A-Za-z_][A-Za-z_0-9]*([ \t]*::[ \t]*[^[:space:]]+)?){1,}[ \t]*\\([^;]*)$\n" - /* compound type at top level */ - "^((struct|class|enum)[^;]*)$", + "!^[ \t]*[A-Za-z_][A-Za-z_0-9]*:[[:space:]]*($|/[/*])\n" + /* functions/methods, variables, and compounds at top level */ + "^((::[[:space:]]*)?[A-Za-z_].*)$", /* -- */ "[a-zA-Z_][a-zA-Z0-9_]*" "|[-+0-9.e]+[fFlL]?|0[xXbB]?[0-9a-fA-F]+[lLuU]*"
-- 1.8.5.2.244.g9fb3fb1