$ clang t.c
- t.c:5:28: warning: use of GNU old-style field designator extension
+ t.c:5:28: warning: use of GNU old-style field designator extension
struct point origin = { x: 0.0, y: 0.0 };
~~ ^
.x =
- t.c:5:36: warning: use of GNU old-style field designator extension
+ t.c:5:36: warning: use of GNU old-style field designator extension
struct point origin = { x: 0.0, y: 0.0 };
~~ ^
.y =
-The underlined code should be removed, then replaced with the code below the caret line (".x =" or ".y =", respectively). "Fix-it" hints are most useful for working around common user errors and misconceptions. For example, C++ users commonly forget the syntax for explicit specialization of class templates, as in the following error:
+The underlined code should be removed, then replaced with the code below the +caret line (".x =" or ".y =", respectively). "Fix-it" hints are most useful for +working around common user errors and misconceptions. For example, C++ users +commonly forget the syntax for explicit specialization of class templates, +as in the following error:
$ clang t.cpp
- t.cpp:9:3: error: template specialization requires 'template<>'
+ t.cpp:9:3: error: template specialization requires 'template<>'
struct iterator_traits<file_iterator> {
^
template<>
@@ -244,7 +248,7 @@ Clang helps you out:
t.c: In function 'test':
t.c:80: error: invalid operands to binary < (have 'struct mystruct' and 'float')
$ clang -fsyntax-only t.c
- t.c:80:3: error: invalid operands to binary expression ('typeof(P)' (aka 'struct mystruct') and 'typeof(F)' (aka 'float'))
+ t.c:80:3: error: invalid operands to binary expression ('typeof(P)' (aka 'struct mystruct') and 'typeof(F)' (aka 'float'))
X = MYMAX(P, F);
^~~~~~~~~~~
t.c:76:94: note: instantiated from:
@@ -260,7 +264,7 @@ implements the "wwopen" class of APIs):
$ clang -fsyntax-only t.c
- t.c:22:2: warning: type specifier missing, defaults to 'int'
+ t.c:22:2: warning: type specifier missing, defaults to 'int'
ILPAD();
^
t.c:17:17: note: instantiated from:
@@ -274,6 +278,45 @@ implements the "wwopen" class of APIs):
In practice, we've found that this is actually more useful in multiply nested
macros that in simple ones.
+Quality of Implementation and Attention to Detail
+
+Finally, we have put a lot of work polishing the little things, because
+little things add up over time and contribute to a great user experience. Two
+examples are:
+
+
+ $ gcc-4.2 t.c
+ t.c: In function 'foo':
+ t.c:5: error: expected ';' before '}' token
+ $ clang t.c
+ t.c:4:8: error: expected ';' after expression
+ bar()
+ ^
+ ;
+
+
+This shows a trivial little tweak, where we tell you to put the semicolon at
+the end of the line that is missing it (line 8) instead of at the beginning of
+the following line (line 9). This is particularly important with fixit hints
+and caret diagnostics, because otherwise you don't get the important context.
+
+
+
+ $ gcc-4.2 t.c
+ t.c:3: error: expected '=', ',', ';', 'asm' or '__attribute__' before '*' token
+ $ clang t.c
+ t.c:3:1: error: unknown type name 'foo_t'
+ foo_t *P = 0;
+ ^
+
+
+This shows an example of much better error recovery. The message coming out
+of GCC is completely useless for diagnosing the problem, Clang tries much harder
+and produces a much more useful diagnosis of the problem.
+
+While each of these details is minor, we feel that they all add up to provide
+a much more polished experience.
+