Consider the following scenario:
if(condition)
FOO();
else
bar();
Suppose FOO is defined as follows:
#define FOO() { bar(); baz(); }
Then it expands to the following:
if(condition)
// Syntax error, we are not allowed to put a semicolon at the end.
{ bar(); baz(); };
else
bar();
If we define FOO as follows:
#define FOO() do { bar(); baz(); } while(false)
Then it expands to the following:
if(condition)
do { bar(); baz(); } while(false);
else
bar();
Which is correct.
This makes error messages more useful during debugging.
Old:
START Running test compare_views
FAIL: ../AK/Tests/TestStringView.cpp:59: EXPECT_EQ(view1, "foobar") failed
New:
START Running test compare_views
FAIL: ../AK/Tests/TestStringView.cpp:59: EXPECT_EQ(view1, "foobar") failed: LHS="foo", RHS="foobar"
Previously, it would just print something with 'FAIL' to stderr which
would be picked up by CTest. However, some code assumes that
ASSERT_NOT_REACHED() doesn't return, for example:
bool foo(int value) {
switch(value) {
case 0:
return true;
case 1:
return false;
default:
ASSERT_NOT_REACHED();
}
// warning: control reaches end of non-void function
}
I've been using this in the new HTML parser and it makes it much easier
to understand the state of unfinished code branches.
TODO() is for places where it's okay to end up but we need to implement
something there.
ASSERT_NOT_REACHED() is for places where it's not okay to end up, and
something has gone wrong.
As suggested by Joshua, this commit adds the 2-clause BSD license as a
comment block to the top of every source file.
For the first pass, I've just added myself for simplicity. I encourage
everyone to add themselves as copyright holders of any file they've
added or modified in some significant way. If I've added myself in
error somewhere, feel free to replace it with the appropriate copyright
holder instead.
Going forward, all new source files should include a license header.
This was a workaround to be able to build on case-insensitive file
systems where it might get confused about <string.h> vs <String.h>.
Let's just not support building that way, so String.h can have an
objectively nicer name. :^)
Instead of aborting the program when we hit an assertion, just print a
message and keep going.
This allows us to write tests that provoke assertions on purpose.
