[clang-format] Do not treat asm clobber [ as ObjCExpr, refined
Summary:
r346756 refined clang-format to not treat the `[` in `asm (...: [] ..)` as an
ObjCExpr. However that's not enough, as we might have a comma-separated list of
such clobbers as in the newly added test.
This updates the detection to instead look at the Line's first token being `asm`
and not mark `[`-s as ObjCExprs in this case.
Alexey Bataev [Wed, 21 Nov 2018 21:04:34 +0000 (21:04 +0000)]
[OPENMP][NVPTX]Emit default locations as constant with undefined mode.
For the NVPTX target default locations should be emitted as constants +
additional info must be emitted in the reserved_2 field of the ident_t
structure. The 1st bit controls the execution mode and the 2nd bit
controls use of the lightweight runtime. The combination of the bits for
Non-SPMD mode + lightweight runtime represents special undefined mode,
used outside of the target regions for orphaned directives or functions.
Should allow and additional optimization inside of the target regions.
Petr Hosek [Wed, 21 Nov 2018 20:33:12 +0000 (20:33 +0000)]
[Driver] Use --push/pop-state with Sanitizer link deps
Sanitizer runtime link deps handling passes --no-as-needed because of
PR15823, but it never undoes it and this flag may affect other libraries
that come later on the link line. To avoid this, wrap Sanitizer link
deps in --push/pop-state.
Alexey Bataev [Wed, 21 Nov 2018 19:41:10 +0000 (19:41 +0000)]
[OPENMP]Fix handling of the LCVs in loop-based directives.
Loop-control variables with the default data-sharing attributes should
not be captured in the OpenMP region as they are private by default.
Also, default attributes should be emitted for such variables in the
inner OpenMP regions for the correct data sharing during codegen.
Kelvin Li [Wed, 21 Nov 2018 19:10:48 +0000 (19:10 +0000)]
[OPENMP] Support relational-op != (not-equal) as one of the canonical
forms of random access iterator
In OpenMP 4.5, only 4 relational operators are supported: <, <=, >,
and >=. This work is to enable support for relational operator
!= (not-equal) as one of the canonical forms.
Petr Hosek [Wed, 21 Nov 2018 04:33:44 +0000 (04:33 +0000)]
[Driver] Link sanitizer runtime deps on Fuchsia when needed
Even though these deps weren't needed, this makes Fuchsia driver
better match other drivers, and it may be necessary when trying to
use different C libraries on Fuchsia.
clang::tooling::Diagnostic: Don't store offset in the scratch space.
These offsets are useless (and even harmful in certain cases) in exported
diagnostics. The test will be added to clang-tidy, since it's the main user of
the clang::tooling::Diagnostic class.
Sam McCall [Tue, 20 Nov 2018 22:06:54 +0000 (22:06 +0000)]
[CodeComplete] Penalize inherited ObjC properties for auto-completion
Summary:
Similar to auto-completion for ObjC methods, inherited properties
should be penalized / direct class and category properties should
be prioritized.
Note that currently, the penalty for using a result from a base class
(CCD_InBaseClass) is equal to the penalty for using a method as a
property (CCD_MethodAsProperty).
Joel E. Denny [Tue, 20 Nov 2018 22:05:23 +0000 (22:05 +0000)]
[OpenMP] Update CHECK-DAG usage in target_parallel_codegen.cpp
This patch adjusts a test not to depend on deprecated FileCheck
behavior that permits overlapping matches within a block of CHECK-DAG
directives. Thus, this patch also removes uses of FileCheck's
-allow-deprecated-dag-overlap command-line option.
There were two issues in this test:
1. There were sets of patterns for store instructions in which a
pattern X could match a superset of a pattern Y. While X appeared
before Y, Y's intended match appeared before X's intended match. The
result was that X matched Y's intended match. Under the old
overlapping behavior, Y also matched Y's intended match. Under the
new non-overlapping behavior, Y had nothing left to match. This patch
fixes this by gathering these sets in one place and putting the most
specific patterns (Y) before the more general patterns (X).
2. The CHECK-DAG patterns involving the variables CBPADDR3 and
CBPADDR4 were the same, but there was only one match in the text, so
CBPADDR4 patterns had nothing to match under the new non-overlapping
behavior. Moreover, a preceding related series of directives had
variables (SADDR0, BPADDR0, etc.) numbered only 0 through 4, but this
series had variables numbered 0 through 5. Assuming CBPADDR4's
directives were not intended, this patch removes them.
Joel E. Denny [Tue, 20 Nov 2018 22:04:45 +0000 (22:04 +0000)]
[OpenMP] Update CHECK-DAG usage in for_codegen.cpp
This patch adjusts a test not to depend on deprecated FileCheck
behavior that permits overlapping matches within a block of CHECK-DAG
directives. Thus, this patch also removes uses of FileCheck's
-allow-deprecated-dag-overlap command-line option.
Specifically, the FileCheck variables DBG_LOC_START, DBG_LOC_END, and
DBG_LOC_CANCEL were all set to the same value. As a result, three
TERM_DEBUG-DAG patterns, one for each variable, all matched the same
text under the old overlapping behavior. Under the new
non-overlapping behavior, that's not permitted. This patch's solution
is to replace these variables with one variable and replace these
patterns with one pattern.
Summary:
clang has `-Wextra-semi` (D43162), which is not dictated by the currently selected standard.
While that is great, there is at least one more source of need-less semis - 'null statements'.
Sometimes, they are needed:
```
for(int x = 0; continueToDoWork(x); x++)
; // Ugly code, but the semi is needed here.
```
But sometimes they are just there for no reason:
```
switch(X) {
case 0:
return -2345;
case 5:
return 0;
default:
return 42;
}; // <- oops
;;;;;;;;;;; <- OOOOPS, still not diagnosed. Clearly this is junk.
```
for (; // <- empty init-statement
int y : S())
;
}
As usual, things may or may not go sideways in the presence of macros.
While evaluating this diag on my codebase of interest, it was unsurprisingly
discovered that Google Test macros are *very* prone to this.
And it seems many issues are deep within the GTest itself, not
in the snippets passed from the codebase that uses GTest.
So after some thought, i decided not do issue a diagnostic if the semi
is within *any* macro, be it either from the normal header, or system header.
Aaron Ballman [Tue, 20 Nov 2018 15:23:07 +0000 (15:23 +0000)]
Update the documentation for attribute feature tests.
This clarifies that __has_cpp_attribute is no longer always an extension since it's now available in C++2a. Also, Both __has_cpp_attribute and __has_c_attribute can accept attribute scope tokens with alternative spelling (clang vs _Clang and gnu vs __gnu__).
Gabor Marton [Tue, 20 Nov 2018 14:19:39 +0000 (14:19 +0000)]
[ASTImporter] Set redecl chain of functions before any other import
Summary:
FunctionDecl import starts with a lookup and then we create a new Decl.
Then in case of CXXConstructorDecl we further import other Decls
(base classes, members through CXXConstructorDecl::inits()) before connecting
the redecl chain. During those in-between imports structural eq fails
because the canonical decl is different. This commit fixes this.
Synthesizing a test seemed extremely hard, however, Xerces analysis
reproduces the problem.
Vassil Vassilev [Tue, 20 Nov 2018 13:53:20 +0000 (13:53 +0000)]
Allow force updating the NumCreatedFIDsForFileID.
Our internal clients implement parsing cache based on FileID. In order for the
Preprocessor to reenter the cached FileID it needs to reset its
NumCreatedFIDsForFileID.
Bill Wendling [Tue, 20 Nov 2018 08:53:30 +0000 (08:53 +0000)]
Use is.constant intrinsic for __builtin_constant_p
Summary:
A __builtin_constant_p may end up with a constant after inlining. Use
the is.constant intrinsic if it's a variable that's in a context where
it may resolve to a constant, e.g., an argument to a function after
inlining.
Driver: SCS is compatible with every other sanitizer.
Because SCS relies on system-provided runtime support, we can use it
together with any other sanitizer simply by linking the runtime for
the other sanitizer.
Vedant Kumar [Mon, 19 Nov 2018 20:10:21 +0000 (20:10 +0000)]
[Sema] Fix PR38987: keep end location of a direct initializer list
If PerformConstructorInitialization of a direct initializer list constructor is
called while instantiating a template, it has brace locations in its BraceLoc
arguments but not in the Kind argument.
This reverts the hunk https://reviews.llvm.org/D41921#inline-468844.
Roman Lebedev [Mon, 19 Nov 2018 19:56:43 +0000 (19:56 +0000)]
[clang][CodeGen] Implicit Conversion Sanitizer: discover the world of CompoundAssign operators
Summary:
As reported by @regehr (thanks!) on twitter (https://twitter.com/johnregehr/status/1057681496255815686),
we (me) has completely forgot about the binary assignment operator.
In AST, it isn't represented as separate `ImplicitCastExpr`'s,
but as a single `CompoundAssignOperator`, that does all the casts internally.
Which means, out of these two, only the first one is diagnosed:
```
auto foo() {
unsigned char c = 255;
c = c + 1;
return c;
}
auto bar() {
unsigned char c = 255;
c += 1;
return c;
}
```
https://godbolt.org/z/JNyVc4
This patch does handle the `CompoundAssignOperator`:
```
int main() {
unsigned char c = 255;
c += 1;
return c;
}
```
```
$ ./bin/clang -g -fsanitize=integer /tmp/test.c && ./a.out
/tmp/test.c:3:5: runtime error: implicit conversion from type 'int' of value 256 (32-bit, signed) to type 'unsigned char' changed the value to 0 (8-bit, unsigned)
#0 0x2392b8 in main /tmp/test.c:3:5
#1 0x7fec4a612b16 in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x22b16)
#2 0x214029 in _start (/build/llvm-build-GCC-release/a.out+0x214029)
```
However, the pre/post increment/decrement is still not handled.
Paul Robinson [Mon, 19 Nov 2018 18:29:28 +0000 (18:29 +0000)]
[DebugInfo] DISubprogram flags get their own flags word. NFC.
This will hold flags specific to subprograms. In the future
we could potentially free up scarce bits in DIFlags by moving
subprogram-specific flags from there to the new flags word.
This patch does not change IR/bitcode formats, that will be
done in a follow-up.
Zachary Turner [Mon, 19 Nov 2018 15:12:34 +0000 (15:12 +0000)]
Fix some issues with LLDB's lit configuration files.
Recently I tried to port LLDB's lit configuration files over to use a
on the surface, but broke some cases that weren't broken before and also
exposed some additional problems with the old approach that we were just
getting lucky with.
When we set up a lit environment, the goal is to make it as hermetic as
possible. We should not be relying on PATH and enabling the use of
arbitrary shell commands. Instead, only whitelisted commands should be
allowed. These are, generally speaking, the lit builtins such as echo,
cd, etc, as well as anything for which substitutions have been
explicitly set up for. These substitutions should map to the build
output directory, but in some cases it's useful to be able to override
this (for example to point to an installed tools directory).
This is, of course, how it's supposed to work. What was actually
happening is that we were bringing in PATH and LD_LIBRARY_PATH and then
just running the given run line as a shell command. This led to problems
such as finding the wrong version of clang-cl on PATH since it wasn't
even a substitution, and flakiness / non-determinism since the
environment the tests were running in would change per-machine. On the
other hand, it also made other things possible. For example, we had some
tests that were explicitly running cl.exe and link.exe instead of
clang-cl and lld-link and the only reason it worked at all is because it
was finding them on PATH. Unfortunately we can't entirely get rid of
these tests, because they support a few things in debug info that
clang-cl and lld-link don't (notably, the LF_UDT_MOD_SRC_LINE record
which makes some of the tests fail.
The high level changes introduced in this patch are:
1. Removal of functionality - The lit test suite no longer respects
LLDB_TEST_C_COMPILER and LLDB_TEST_CXX_COMPILER. This means there is no
more support for gcc, but nobody was using this anyway (note: The
functionality is still there for the dotest suite, just not the lit test
suite). There is no longer a single substitution %cxx and %cc which maps
to <arbitrary-compiler>, you now explicitly specify the compiler with a
substitution like %clang or %clangxx or %clang_cl. We can revisit this
in the future when someone needs gcc.
2. Introduction of the LLDB_LIT_TOOLS_DIR directory. This does in spirit
what LLDB_TEST_C_COMPILER and LLDB_TEST_CXX_COMPILER used to do, but now
more friendly. If this is not specified, all tools are expected to be
the just-built tools. If it is specified, the tools which are not
themselves being tested but are being used to construct and run checks
(e.g. clang, FileCheck, llvm-mc, etc) will be searched for in this
directory first, then the build output directory.
3. Changes to core llvm lit files. The use_lld() and use_clang()
functions were introduced long ago in anticipation of using them in
lldb, but since they were never actually used anywhere but their
respective problems, there were some issues to be resolved regarding
generality and ability to use them outside their project.
4. Changes to .test files - These are all just replacing things like
clang-cl with %clang_cl and %cxx with %clangxx, etc.
5. Changes to lit.cfg.py - Previously we would load up some system
environment variables and then add some new things to them. Then do a
bunch of work building out our own substitutions. First, we delete the
system environment variable code, making the environment hermetic. Then,
we refactor the substitution logic into two separate helper functions,
one which sets up substitutions for the tools we want to test (which
must come from the build output directory), and another which sets up
substitutions for support tools (like compilers, etc).
6. New substitutions for MSVC -- Previously we relied on location of
MSVC by bringing in the entire parent's PATH and letting
subprocess.Popen just run the command line. Now we set up real
substitutions that should have the same effect. We use PATH to find
them, and then look for INCLUDE and LIB to construct a substitution
command line with appropriate /I and /LIBPATH: arguments. The nice thing
about this is that it opens the door to having separate %msvc-cl32 and
%msvc-cl64 substitutions, rather than only requiring the user to run
vcvars first. Because we can deduce the path to 32-bit libraries from
64-bit library directories, and vice versa. Without these substitutions
this would have been impossible.
Sam McCall [Mon, 19 Nov 2018 13:37:46 +0000 (13:37 +0000)]
[FileManager] getFile(open=true) after getFile(open=false) should open the file.
Summary:
Old behavior is to just return the cached entry regardless of opened-ness.
That feels buggy (though I guess nobody ever actually needed this).
This came up in the context of clangd+clang-tidy integration: we're
going to getFile(open=false) to replay preprocessor actions obscured by
the preamble, but the compilation may subsequently getFile(open=true)
for non-preamble includes.
Kristof Umann [Sun, 18 Nov 2018 11:34:10 +0000 (11:34 +0000)]
[analyzer][UninitializedObjectChecker] Uninit regions are only reported once
Especially with pointees, a lot of meaningless reports came from uninitialized
regions that were already reported. This is fixed by storing all reported fields
to the GDM.
Jan Kratochvil [Sun, 18 Nov 2018 09:36:36 +0000 (09:36 +0000)]
cmake: z3: Remove EXACT from 4.7.1 after being compatible with 4.8.1
After check-in of D54391 a comment there by @mikhail.ramalho says:
Since we're supporting version 4.8.1 now, the cmake file should be changed to
"minimum" instead of "exact".
Calixte Denizet [Sat, 17 Nov 2018 19:41:39 +0000 (19:41 +0000)]
[Clang] Add options -fprofile-filter-files and -fprofile-exclude-files to filter the files to instrument with gcov (after revert https://reviews.llvm.org/rL346659)
Summary:
the previous patch (https://reviews.llvm.org/rC346642) has been reverted because of test failure under windows.
So this patch fix the test cfe/trunk/test/CodeGen/code-coverage-filter.c.
Petr Hosek [Fri, 16 Nov 2018 23:07:03 +0000 (23:07 +0000)]
[CMake] Use lld and llvm-objcopy for first stage compiler in Fuchsia
When cross-compiling the second stage to a different target, we need to
make sure that the first-stage compiler can produce binaries for that
target. Using lld and llvm-objcopy as the default linker and objcopy
tool eliminates some of the dependencies on the host toolchain.
Alexey Bataev [Fri, 16 Nov 2018 21:13:33 +0000 (21:13 +0000)]
[OPENMP]Fix PR39694: do not capture `this` in non-`this` region.
If lambda is used inside of the OpenMP region and captures `this`, we
should recapture it in the OpenMP region also. But we should do this
only if the OpenMP region is used in the context of the same class, just
like the lambda.
Alexey Bataev [Fri, 16 Nov 2018 19:38:21 +0000 (19:38 +0000)]
[OPENMP][NVPTX]Emit correct reduction code for teams/parallel
reductions.
Fixed previously committed code for the reduction support in
teams/parallel constructs taking into account new design of the NVPTX
support in the compiler. Teams reduction are not fully functional yet,
it is going to be fixed in the following patches.
Reid Kleckner [Fri, 16 Nov 2018 18:47:41 +0000 (18:47 +0000)]
[codeview] Expose -gcodeview-ghash for global type hashing
Summary:
Experience has shown that the functionality is useful. It makes linking
optimized clang with debug info for me a lot faster, 20s to 13s. The
type merging phase of PDB writing goes from 10s to 3s.
This removes the LLVM cl::opt and replaces it with a metadata flag.
After this change, users can do the following to use ghash:
- add -gcodeview-ghash to compiler flags
- replace /DEBUG with /DEBUG:GHASH in linker flags
[OpenCL] Enable address spaces for references in C++
Added references to the addr spaces deduction and enabled
CL2.0 features (program scope variables and storage class
qualifiers) to work in C++ mode too.
Fixed several address space conversion issues in CodeGen
for references.
George Rimar [Fri, 16 Nov 2018 07:59:24 +0000 (07:59 +0000)]
[clang] - Simplify tools::SplitDebugName.
This should be NFC change.
SplitDebugName recently started to accept the `Output` that
can be used to simplify the logic a bit, also it
seems that code in SplitDebugName that uses
OPT_fdebug_compilation_dir is simply dead.
Petr Hosek [Fri, 16 Nov 2018 04:46:48 +0000 (04:46 +0000)]
[CMake] Support cross-compiling with multi-stage builds
When using multi-stage builds, we would like support cross-compilation.
Example is 2-stage build when the first stage is compiled for host while
the second stage is compiled for the target.
Normally, the second stage would be also used for compiling runtimes,
but that's not possible when cross-compiling, so we use the first stage
compiler instead. However, we still want to use the second stage paths.
To do so, we set the -resource-dir of the first stage compiler to point
to the resource directory of the second stage.
We also need compiler tools that support the target architecture. These
tools are not guaranteed to be present on the host, but in case of
multi-stage build, we can build these tools in the first stage.
Zi Xuan Wu [Fri, 16 Nov 2018 03:00:00 +0000 (03:00 +0000)]
[Clang][Sema]Choose a better candidate in overload function call if there is a compatible vector conversion instead of ambiguous call error
There are 2 function variations with vector type parameter. When we call them with argument of different vector type we would prefer to
choose the variation with implicit argument conversion of compatible vector type instead of incompatible vector type. For example,
It fixes the case when Objective-C framework is added as a subframework
through a symlink. When parent framework infers a module map and fails
to detect a symlink, it would add a subframework as a submodule. And
when we parse module map for the subframework, we would encounter an
error like
> error: umbrella for module 'WithSubframework.Foo' already covers this directory
By implementing `getRealPath` "an egregious but useful hack" in
`ModuleMap::inferFrameworkModule` works as expected.
Kristof Umann [Fri, 16 Nov 2018 01:00:55 +0000 (01:00 +0000)]
[analyzer] ConversionChecker: handle floating point
Extend the alpha.core.Conversion checker to handle implicit converions
where a too large integer value is converted to a floating point type. Each
floating point type has a range where it can exactly represent all integers; we
emit a warning when the integer value is above this range. Although it is
possible to exactly represent some integers which are outside of this range
(those that are divisible by a large enough power of 2); we still report cast
involving those, because their usage may lead to bugs. (For example, if 1<<24
is stored in a float variable x, then x==x+1 holds.)
Heejin Ahn [Fri, 16 Nov 2018 00:48:58 +0000 (00:48 +0000)]
[WebAssembly] Change type of wake count to unsigned int
Summary:
We discussed this at the Nov 12th CG meeting, and decided to use the
unsigned semantics for the wake count.
Corresponding spec change:
https://github.com/WebAssembly/threads/pull/110
Bruno Ricci [Thu, 15 Nov 2018 17:31:16 +0000 (17:31 +0000)]
[AST] Store the string data in StringLiteral in a trailing array of chars
Use the newly available space in the bit-fields of Stmt and store the
string data in a trailing array of chars after the trailing array
of SourceLocation. This cuts the size of StringLiteral by 2 pointers.
Also refactor slightly StringLiteral::Create and StringLiteral::CreateEmpty
so that StringLiteral::Create is just responsible for the allocation, and the
constructor is responsible for doing all the initialization. This match what
is done for the other classes in general.
This patch should have no other functional changes apart from this.
A concern was raised during review about the interaction between
this patch and serialization abbreviations. I believe however that
there is currently no abbreviation defined for StringLiteral.
The only statements/expressions which have abbreviations are currently
DeclRefExpr, IntegerLiteral, CharacterLiteral and ImplicitCastExpr.
Bruno Ricci [Thu, 15 Nov 2018 16:42:14 +0000 (16:42 +0000)]
[AST][NFC] Various NFCs in StringLiteral
Factored out of D54166
([AST] Store the string data in StringLiteral in a trailing array of chars):
* For-range loops in containsNonAscii and containsNonAsciiOrNull.
* Comments and style fixes.
* int -> unsigned in mapCharByteWidth since TargetInfo::getCharWidth
and friends return an unsigned, and StringLiteral manipulates and
stores CharByteWidth as an unsigned.
David Blaikie [Thu, 15 Nov 2018 03:04:21 +0000 (03:04 +0000)]
Fix combining pragma __debug dump & parser_crash with -E
Previously these would be transformed into annotation tokens and the
preprocessor would then assume they were real tokens with source
locations and assert/UB.
Other pragmas that produce annotation tokens aren't a problem because
they aren't handled if the parser isn't hooked up - ParsePragma.cpp
registers those handlers & isn't run for pure preprocessing. So they're
treated as unknown pragmas & printed verbatim by the preprocessor.
Perhaps these pragmas should be treated the same way? But they got mixed
in with other __debug pragmas that do need to be handled during
preprocessing.
The third __debug pragma that produces an annotation token is 'captured'
- which had its own fix for this issue - by not inserting the annotation
token in the first place if it detected that it was in preprocessing
mode. I've removed that fix (from Lex/Pragma.cpp) in favor of the more
general one in Frontend/PrintPreprocessedOutput.cpp.
David Blaikie [Thu, 15 Nov 2018 03:04:19 +0000 (03:04 +0000)]
Rewrite-imports on crash: Simplify handling
-frewrite-imports already implies -frewrite-includes (it piggy-backs
on/extends the implementation) so there's no need to conditionally pass
-frewrite-includes when already using -frewrite-imports (& especially I
don't think these would want to be different between crash reporting and
not crash reporting)
JF Bastien [Thu, 15 Nov 2018 00:19:18 +0000 (00:19 +0000)]
CGDecl::emitStoresForConstant fix synthesized constant's name
Summary: The name of the synthesized constants for constant initialization was using mangling for statics, which isn't generally correct and (in a yet-uncommitted patch) causes the mangler to assert out because the static ends up trying to mangle function parameters and this makes no sense. Instead, mangle to `"__const." + FunctionName + "." + DeclName`.
Reid Kleckner [Wed, 14 Nov 2018 22:59:27 +0000 (22:59 +0000)]
[codeview] Make "clang -g" emit codeview by default when targetting MSVC
Summary:
If you're using the Microsoft ABI, chances are that you want PDBs and
codeview debug info. Currently, everyone has to remember to specific
-gcodeview by default, when it would be nice if the standard -g option
did the right thing by default.
Also, do some related cleanup of -cc1 options. When targetting the MS
C++ ABI, we probably shouldn't pass -debugger-tuning=gdb. We were also
passing -gcodeview twice, which is silly.
Richard Smith [Wed, 14 Nov 2018 21:04:34 +0000 (21:04 +0000)]
[c++20] Implement P0482R6: enable -fchar8_t by default in C++20 mode.
This unfortunately results in a substantial breaking change when
switching to C++20, but it's not yet clear what / how much we should
do about that. We may want to add a compatibility conversion from
u8 string literals to const char*, similar to how C++98 provided a
compatibility conversion from string literals to non-const char*,
but that's not handled by this patch.
The feature can be disabled in C++20 mode with -fno-char8_t.
Scott Linder [Wed, 14 Nov 2018 19:39:59 +0000 (19:39 +0000)]
[Support] Teach YAMLIO about polymorphic types
Add support for "polymorphic" types to YAMLIO.
PolymorphicTraits can dynamically switch between other traits (Scalar, Map, or
Sequence). When inputting, the PolymorphicTraits type is told which type to
become, and when outputting the PolymorphicTraits type is asked which type it
currently is.
Also add support for TaggedScalarTraits to allow dynamically differentiating
between multiple scalar types using YAML tags.
Serialize empty maps as "{}" and empty sequences as "[]", so that types
are preserved when round-tripping PolymorphicTraits. This change has
equivalent semantics, but may break e.g. tests which compare output
verbatim.
Sam McCall [Wed, 14 Nov 2018 10:33:30 +0000 (10:33 +0000)]
[AST] Allow limiting the scope of common AST traversals (getParents, RAV).
Summary:
The goal is to allow analyses such as clang-tidy checks to run on a
subset of the AST, e.g. "only on main-file decls" for interactive tools.
Today, these become "problematically global" by running RecursiveASTVisitors
rooted at the TUDecl, or by navigating up via ASTContext::getParent().
The scope is restricted using a set of top-level-decls that RecursiveASTVisitors
should be rooted at. This also applies to the visitor that populates the
parent map, and so the top-level-decls are considered to have no parents.
This patch makes the traversal scope a mutable property of ASTContext.
The more obvious way to do this is to pass the top-level decls to
relevant functions directly, but this has some problems:
- it's error-prone: accidentally mixing restricted and unrestricted
scopes is a performance trap. Interleaving multiple analyses is
common (many clang-tidy checks run matchers or RAVs from matcher callbacks)
- it doesn't map well to the actual use cases, where we really do want
*all* traversals to be restricted.
- it involves a lot of plumbing in parts of the code that don't care
about traversals.
This approach was tried out in D54259 and D54261, I wanted to like it
but it feels pretty awful in practice.
Caveats: to get scope-limiting behavior of RecursiveASTVisitors, callers
have to call the new TraverseAST(Ctx) function instead of TraverseDecl(TU).
I think this is an improvement to the API regardless.
projects / clang / log