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.
Currently cmMakefile calls MakeRelative on a copy of the backtrace,
emits the copy to the stream once, then discards the copy. There
is no need to have API for the path conversion.
The backtrace will soon not be implemented in terms of a stack of
cmListFileContext objects. Keep the cmListFileContext in the API
for convenience for now.
Use the clang RemoveCStrCalls tool to automatically migrate the
code. This was only run on linux, so does not have any positive or
negative effect on other platforms.
Teach the CMake language parser to recognize Lua-style "long bracket"
arguments. These start with two '[' separated by zero or more '='
characters e.g. "[[" or "[=[" or "[==[". They end with two ']'
separated by the same number of '=' as the opening bracket. There is no
nesting of brackets of the same level (number of '='). No escapes,
variable expansion, or other processing is performed on the content
between such brackets so they always represent exactly one argument.
Also teach CMake to parse and ignore "long comment" syntax. A long
comment starts with "#" immediately followed by an opening long bracket.
It ends at the matching close long bracket.
Teach the RunCMake.Syntax test to cover long bracket and long comment
cases.
Teach the lexer to read a UTF-8, UTF-16 BE/LE, or UTF-32 BE/LE
Byte-Order-Mark from the start of a file if any is present. Report an
error on files using UTF-16 or UTF-32 and accept a UTF-8 or missing BOM.
Since commit 58e52416 (Warn about arguments not separated by whitespace,
2013-02-16) we warn about arguments not separated by spaces. Loosen the
warning to not complain about left parens not separated by spaces from
the preceding token. This is common in code like "if(NOT(X))".
Teach the RunCMake.Syntax test to cover cases of left parens not
separated by spaces and check that no warning appears.
In the future CMake will introduce Lua-style long bracket syntax.
Warn about unquoted arguments that in the future will be treated
as opening long brackets.
Teach the RunCMake.Syntax test to cover such cases and ensure that the
warning appears.
Teach the lexer to return tokens for whitespace. Teach the parser to
tolerate the space tokens where whitespace is allowed. Also teach the
parser to diagnose and warn about cases of quoted arguments followed
immediately by another argument. This was accidentally allowed
previously, so we only warn.
Update the RunCMake.Syntax test case StringNoSpace expected stderr to
include the warnings.
Replace the boolean value that indicates whether an argument is unquoted
or quoted with a generalized enumeration of possible argument types.
For now "Quoted" and "Unquoted" remain the only types.
This converts the CMake license to a pure 3-clause OSI-approved BSD
License. We drop the previous license clause requiring modified
versions to be plainly marked. We also update the CMake copyright to
cover the full development time range.
to help with debugging later on. The same should be done in the import
target files (but I didn't have time to do it yet).
STYLE: fix line length in cmListFileCache.cxx
Alex
- Message for missing cmake_minimum_required is not issued
until the end of processing the top CMakeLists.txt file
- During processing a cmake_policy command may set behavior
- OLD behavior is to silently ignore the problem
- NEW behavior is to issue an error instead of a warning
- Update policy CMP0000 to require use of the command
cmake_minimum_required and not cmake_policy
so there is only one way to avoid it.
- Explicitly specify the line users should add.
- Reference policy CMP0000 only at the end.
- Fix policy CMP0000 documentation to not suggest
use of the cmake_policy command.
- Add cmListFileBacktrace to record stack traces
- Move main IssueMessage method to the cmake class instance
(make the backtrace an explicit argument)
- Change cmMakefile::IssueMessage to construct a backtrace
and call the cmake instance version
- Record a backtrace at the point a target is created
(useful later for messages issued by generators)
- Remove CMP_0001 (no slash in target name) and restore
old CMAKE_BACKWARDS_COMPATIBILITY check for it
- Replace all checks of CMAKE_BACKWARDS_COMPATIBILITY
with cmLocalGenerator::NeedBackwardsCompatibility calls
- Create new CMP_0001 to determine whether or not
CMAKE_BACKWARDS_COMPATIBILITY is used.
(old = use, new = ignore)
- Show CMAKE_BACKWARDS_COMPATIBILITY in cache only when
CMP_0001 is set to OLD or WARN
- Update documentation of cmake_policy and cmake_minimum_required
to indicate their relationship and the 2.4 version boundary
- When no cmake policy version is set in top level makefile
implicitly call cmake_policy(VERSION 2.4) which restores
CMAKE_BACKWARDS_COMPATIBILITY and other 2.4 compatibility
- Fix tests MakeClean and Preprocess to call
cmake_policy(VERSION 2.6) because they depend on new policies
- Add cmMakefile methods IssueError and IssueWarning
- Maintain an explicit call stack in cmMakefile
- Include context/call-stack info in messages
- Nested errors now unwind the call stack
- Use new mechanism for policy warnings and errors
- Improve policy error message
- Include cmExecutionStatus pointer in call stack
so that errors deeper in the C++ stack under
a command invocation will become errors for the
command
Brad King
Felix Geyer
Stephen Kelly
Ben Boeckel
Kitware Robot
Ken Martin
Alexander Neundorf
Bill Hoffman