Fix diagnostics that appear on macOS with clang-tidy-8. Suppress cases
where we intentionally take an argument by value to let the caller
choose whether to copy or move.
They are unused, but if someone used them they would lead to
problems since they would copy the internal raw pointers
and the destructor would cause double delete
We use a comma-in-paren expression to evaluate multiple statements
in a condition. Clang warns that this may be incorrect. Follow
its suggestion to cast all but the last expression to `void` to
silence the warning.
Replace use of raw pointers and explicit reference counting with
`std::shared_ptr<>`. Use a discriminated union to store either the
bottom level or a call/file context in each heap-allocated entry.
This avoids storing a copy of the bottom in every `cmListFileBacktrace`
instance and shrinks the structure to a single `shared_ptr`.
Store both the as-written and lower-case command names and use
the latter to avoid case-insensitive string comparisons.
With this I obtain 2-6% speed increase (on Windows) for the configure
step with no significant changes in memory usage. A case-insensitive
comparison is a lot slower than just calling `==` because the operator
will use things like memcmp, so prefer the latter.
The `cmSystemTools::LowerCase` function allocates a new string each time
it is called, so before this change we were allocating in:
* cmMakefile::Configure two times for each function
(to look for `cmake_minimum_required` and `project`)
* cmMakefile::ExecuteCommand twice by function by calling
cmState::GetCommand and copying the name
Now we are only allocating once by function instead of four.
Per-source copyright/license notice headers that spell out copyright holder
names and years are hard to maintain and often out-of-date or plain wrong.
Precise contributor information is already maintained automatically by the
version control tool. Ultimately it is the receiver of a file who is
responsible for determining its licensing status, and per-source notices are
merely a convenience. Therefore it is simpler and more accurate for
each source to have a generic notice of the license name and references to
more detailed information on copyright holders and full license terms.
Our `Copyright.txt` file now contains a list of Contributors whose names
appeared source-level copyright notices. It also references version control
history for more precise information. Therefore we no longer need to spell
out the list of Contributors in each source file notice.
Replace CMake per-source copyright/license notice headers with a short
description of the license and links to `Copyright.txt` and online information
available from "https://cmake.org/licensing". The online URL also handles
cases of modules being copied out of our source into other projects, so we
can drop our notices about replacing links with full license text.
Run the `Utilities/Scripts/filter-notices.bash` script to perform the majority
of the replacements mechanically. Manually fix up shebang lines and trailing
newlines in a few files. Manually update the notices in a few files that the
script does not handle.
Use clang-tidy's readability-simplify-boolean-expr checker.
After applying the fix-its, revise all changes *very* carefully.
Be aware of false positives and invalid changes.
Run the `Utilities/Scripts/clang-format.bash` script to update
all our C++ code to a new style defined by `.clang-format`.
Use `clang-format` version 3.8.
* If you reached this commit for a line in `git blame`, re-run the blame
operation starting at the parent of this commit to see older history
for the content.
* See the parent commit for instructions to rebase a change across this
style transition commit.
The clang-format tool can do a good job formatting most code, but
well-organized streaming blocks are best left manually formatted.
Find blocks of the form
os <<
"...\n"
"...\n"
;
using the command
$ git ls-files -z -- Source |
egrep -v -z '^Source/kwsys/' |
xargs -0 pcregrep -M --color=always -B 1 -A 1 -n \
'<<[^\n]*\n(^ *("[^\n]*("|<<|;)$|;)\n){2,}'
Find blocks of the form
os << "...\n"
<< "...\n"
<< "...\n";
using the command
$ git ls-files -z -- Source |
egrep -v -z '^Source/kwsys/' |
xargs -0 pcregrep -M --color=always -B 1 -A 1 -n \
'<<[^\n]*\n(^ *<<[^\n]*(\\n"|<<|;)$\n){2,}'
Surround such blocks with the pair
/* clang-format off */
...
/* clang-format on */
in order to protect them from update by clang-format. Use the C-style
`/*...*/` comments instead of C++-style `//...` comments in order to
prevent them from ever being swallowed by re-formatting of surrounding
comments.
Sort include directives within each block (separated by a blank line) in
lexicographic order (except to prioritize `sys/types.h` first). First
run `clang-format` with the config file:
---
SortIncludes: false
...
Commit the result temporarily. Then run `clang-format` again with:
---
SortIncludes: true
IncludeCategories:
- Regex: 'sys/types.h'
Priority: -1
...
Commit the result temporarily. Start a new branch and cherry-pick the
second commit. Manually resolve conflicts to preserve indentation of
re-ordered includes. This cleans up the include ordering without
changing any other style.
Use the following command to run `clang-format`:
$ git ls-files -z -- \
'*.c' '*.cc' '*.cpp' '*.cxx' '*.h' '*.hh' '*.hpp' '*.hxx' |
egrep -z -v '(Lexer|Parser|ParserHelper)\.' |
egrep -z -v '^Source/cm_sha2' |
egrep -z -v '^Source/(kwsys|CursesDialog/form)/' |
egrep -z -v '^Utilities/(KW|cm).*/' |
egrep -z -v '^Tests/Module/GenerateExportHeader' |
egrep -z -v '^Tests/RunCMake/CommandLine/cmake_depends/test_UTF-16LE.h' |
xargs -0 clang-format -i
This selects source files that do not come from a third-party.
Inspired-by: Daniel Pfeifer <daniel@pfeifer-mail.de>
Since commit v3.4.0-rc1~321^2~2 (Genex: Store a backtrace, not a pointer
to one, 2015-07-08) we treat cmListFileBacktrace instances as
lightweight values. This was true at the time only because the
backtrace information was kept in the cmState snapshot hierarchy.
However, that forced us to accumulate a lot of otherwise short-lived
snapshots just to have the backtrace fields available for reference by
cmListFileBacktrace instances. Recent refactoring made backtrace
instances independent of the snapshot hierarchy to avoid accumulating
short-lived snapshots. This came at the cost of making backtrace values
heavy again, leading to lots of string coying and slower execution.
Fix this by refactoring cmListFileBacktrace to provide value semantics
with efficient shared storage underneath. Teach cmMakefile to maintain
its call stack using an instance of cmListFileBacktrace. This approach
allows the current backtrace to be efficiently saved whenever it is
needed.
Also teach cmListFileBacktrace the notion of a file-level scope. This
is useful for messages about the whole file (e.g. during parsing) that
are not specific to any line within it. Push the CMakeLists.txt scope
for each directory and never pop it. This ensures that we always have
some context information and simplifies cmMakefile::IssueMessage.
Push/pop a file-level scope as each included file is processed. This
supersedes cmParseFileScope and improves diagnostic message context
information in a few places. Fix the corresponding test cases to expect
the improved output.
Changes during post-3.3/pre-3.4 development refactored storage of most
configure-time information, including variable bindings and function
scopes. All scopes (even short-lived) were kept persistently for
possible future debugging features, causing huge accumulated memory
usage. This was mostly addressed by commit v3.4.1~4^2 (cmState: Avoid
accumulating snapshot storage for short-lived scopes, 2015-11-24).
Since then we still keep short-lived scopes when they are needed for a
backtrace. This is because since commit v3.4.0-rc1~378^2
(cmListFileBacktrace: Implement in terms of cmState::Snapshot,
2015-05-29) backtraces have been lightweight objects that simply point
into the snapshot tree. While the intention of this approach was to
avoid duplicating the call stack file path strings, the cost turned out
to be holding on to the entire call stack worth of scope snapshots,
which is much worse.
Furthermore, since commit v3.4.0-rc2~1^2 (cmIfCommand: Issue CMP0054
warning with appropriate context, 2015-10-20) all conditions used in
`if()` commands hold a backtrace for use in diagnostic messages. Even
though the backtrace is short-lived it still causes the scope snapshot
to be kept. This means that code like
function(foo)
if(0)
endif()
endfunction()
foreach(i RANGE 1000000)
foo()
endforeach()
accumulates storage for the function call scope snapshots.
Fix this by partially reverting commit v3.4.0-rc1~378^2 and saving the
entire call stack during cmListFileBacktrace construction. This way
we can avoid keeping short-lived scope snapshot storage in all cases.
