In `ASTWriter`, input files are sorted based on whether they are system or user. The current implementation used single `std::queue` with `push_back` and `push_front`. This resulted in the user files being reversed.
This patch fixes that by keeping the system/user distinction, but otherwise serializing files in the order they were loaded by the `SourceManager`. This is then used in the dependency scanner to report module map dependencies in the correct order.
Depends on D134224.
Reviewed By: Bigcheese
Differential Revision: https://reviews.llvm.org/D134248
Module map files describing excluded headers do affect compilation. Track them in the compiler, serialize them into the PCM file and report them in the scanner.
Depends on D134222.
Reviewed By: Bigcheese
Differential Revision: https://reviews.llvm.org/D134224
This patch fixes compilation failure with explicit modules caused by scanner not reporting the module map describing the module whose implementation is being compiled.
Below is a breakdown of the attached test case. Note the VFS that makes frameworks "A" and "B" share the same header "shared/H.h".
In non-modular build, Clang skips the last import, since the "shared/H.h" header has already been included.
During scan (or implicit build), the compiler handles "tu.m" as follows:
* `@import B` imports module "B", as expected,
* `#import <A/H.h>` is resolved textually (due to `-fmodule-name=A`) to "shared/H.h" (due to the VFS remapping),
* `#import <B/H.h>` is resolved to import module "A_Private", since the header "shared/H.h" is already known to be part of that module, and the import is skipped.
In the end, the only modular dependency of the TU is "B".
In explicit modular build without `-fmodule-name=A`, TU does depend on module "A_Private" properly, not just textually. Clang therefore builds & loads its PCM, and knows to ignore the last import, since "shared/H.h" is known to be part of "A_Private".
But with current scanner behavior and `-fmodule-name=A` present, the last import fails during explicit build. Clang doesn't know about "A_Private" (it's included textually) and tries to import "B_Private" instead, which it doesn't know about either (the scanner correctly didn't report it as dependency). This is fixed by reporting the module map describing "A" and matching the semantics of implicit build.
Reviewed By: Bigcheese
Differential Revision: https://reviews.llvm.org/D134222
Attempt to fix the test failures observed in CI:
* Add Option dependency, which caused BUILD_SHARED_LIBS builds to fail
* Adapt tests that accidentally depended on the host platform: platforms
that don't use an integrated assembler (e.g. AIX) get a different set
of commands from the driver. Most dependency scanner tests can use
-fsyntax-only or -E instead of -c to avoid this, and in the rare case
we want to check -c specifically, set an explicit target so the
behaviour is independent of the host.
Original commit message follows.
---
Instead of trying to "fix" the original driver invocation by appending
arguments to it, split it into multiple commands, and for each -cc1
command use a CompilerInvocation to give precise control over the
invocation.
This change should make it easier to (in the future) canonicalize the
command-line (e.g. to improve hits in something like ccache), apply
optimizations, or start supporting multi-arch builds, which would
require different modules for each arch.
In the long run it may make sense to treat the TU commands as a
dependency graph, each with their own dependencies on modules or earlier
TU commands, but for now they are simply a list that is executed in
order, and the dependencies are simply duplicated. Since we currently
only support single-arch builds, there is no parallelism available in
the execution.
Differential Revision: https://reviews.llvm.org/D132405
Instead of trying to "fix" the original driver invocation by appending
arguments to it, split it into multiple commands, and for each -cc1
command use a CompilerInvocation to give precise control over the
invocation.
This change should make it easier to (in the future) canonicalize the
command-line (e.g. to improve hits in something like ccache), apply
optimizations, or start supporting multi-arch builds, which would
require different modules for each arch.
In the long run it may make sense to treat the TU commands as a
dependency graph, each with their own dependencies on modules or earlier
TU commands, but for now they are simply a list that is executed in
order, and the dependencies are simply duplicated. Since we currently
only support single-arch builds, there is no parallelism available in
the execution.
Differential Revision: https://reviews.llvm.org/D132405
* Factor module map and module file path functions out
* Use a secondary mapping to lookup module deps by ID instead of the
preprocessor module map.
* Sink DirectPrebuiltModularDeps into MDC.
Differential Revision: https://reviews.llvm.org/D132617
The invocation is only ever used to serialize cc1 arguments from, so
instead serialize the arguments inside the dep scanner to simplify the
interface.
Differential Revision: https://reviews.llvm.org/D132616
When compiling a module, its semantics and Clang's behavior are affected by other modules. These modules are typically the **imported** ones. However, during implicit build, some modules end up being compiled and read without being actually imported. This patch starts tracking such modules and serializing them into `.pcm` files. This enables the dependency scanner to construct explicit compilations that mimic implicit build.
Reviewed By: benlangmuir
Differential Revision: https://reviews.llvm.org/D132430
Move copying compiler arguments to a vector<string> and modifying
common module-related options into CompilerInvocation in preparation for
using some of them in more places and to avoid duplicating this code
accidentally in the future.
Differential Revision: https://reviews.llvm.org/D132419
This patch introduces new option `-eager-load-pcm` to `clang-scan-deps`, which controls whether the resulting command-lines will load PCM files eagerly (at the start of compilation) or lazily (when handling import directive). This patch also switches the default from eager to lazy.
To reduce the potential for churn in LIT tests in the future, this patch also removes redundant checks of command-line arguments and introduces new test `modules-dep-args.c` as a substitute.
Reviewed By: benlangmuir
Differential Revision: https://reviews.llvm.org/D132066
Instead of delaying the generation of command-lines to after all
dependencies are reported, compute them immediately. This is partly in
preparation for splitting the TU driver command into its constituent cc1
and other jobs, but it also just simplifies working with the compiler
invocation for modules if they are not "without paths".
Also change the computation of the default output path in
clang-scan-deps to scrape the implicit module cache from the
command-line rather than get it from the dependency, since that is now
unavailable at the time we make the callback.
Differential Revision: https://reviews.llvm.org/D131934
Since D129389 (and downstream PR https://github.com/apple/llvm-project/pull/4965), the dependency scanner is responsible for generating full command-lines, including the modules paths. This patch removes the flag that was making this an opt-in behavior in clang-scan-deps.
Reviewed By: benlangmuir
Differential Revision: https://reviews.llvm.org/D131420
It's an accident that we started return asbolute paths from
FileEntry::getName for all relative paths. Prepare for getName to get
(closer to) return the requested path. Note: conceptually it might make
sense for the dependency scanner to allow relative paths and have the
DependencyConsumer decide if it wants to make them absolute, but we
currently document that it's absolute and I didn't want to change
behaviour here.
Differential Revision: https://reviews.llvm.org/D130934
The "strict context hash" is insufficient to identify module
dependencies during scanning, leading to different module build commands
being produced for a single module, and non-deterministically choosing
between them. This commit switches to hashing the canonicalized
`CompilerInvocation` of the module. By hashing the invocation we are
converting these from correctness issues to performance issues, and we
can then incrementally improve our ability to canonicalize
command-lines.
This change can cause a regression in the number of modules needed. Of
the 4 projects I tested, 3 had no regression, but 1, which was
clang+llvm itself, had a 66% regression in number of modules (4%
regression in total invocations). This is almost entirely due to
differences between -W options across targets. Of this, 25% of the
additional modules are system modules, which we could avoid if we
canonicalized -W options when -Wsystem-headers is not present --
unfortunately this is non-trivial due to some warnings being enabled in
system headers by default. The rest of the additional modules are mostly
real differences in potential warnings, reflecting incorrect behaviour
in the current scanner.
There were also a couple of differences due to `-DFOO`
`-fmodule-ignore-macro=FOO`, which I fixed here.
Since the output paths for the module depend on its context hash, we
hash the invocation before filling in outputs, and rely on the build
system to always return the same output paths for a given module.
Note: since the scanner itself uses an implicit modules build, there can
still be non-determinism, but it will now present as different
module+hashes rather than different command-lines for the same
module+hash.
Differential Revision: https://reviews.llvm.org/D129884
Follow-up to 6626f6fec3d3, this fixes the handling of -MT
* If no targets are provided, we need to invent one since cc1 expects
the driver to have handled it. The default is to use -o, quoting as
necessary for a make target.
* Fix the splitting for empty string, which was incorrectly treated as
{""} instead of {}.
* Add a way to test this behaviour in clang-scan-deps.
Differential Revision: https://reviews.llvm.org/D129607
When building modules, override secondary outputs (dependency file,
dependency targets, serialized diagnostic file) in addition to the pcm
file path. This avoids inheriting per-TU command-line options that
cause non-determinism in the results (non-deterministic command-line for
the module build, non-determinism in which TU's .diag and .d files will
contain the module outputs). In clang-scan-deps we infer whether to
generate dependency or serialized diagnostic files based on an original
command-line. In a real build system this should be modeled explicitly.
Differential Revision: https://reviews.llvm.org/D129389
Dependency scanning does not care about the order of submodules for
correctness, so sort the submodules so that we get the same
command-lines to build the module across different TUs. The order of
inferred submodules can vary depending on the order of #includes in the
including TU.
Differential Revision: https://reviews.llvm.org/D128008
Disable or canonicalize compiler options that are not relevant in
explicit module builds, similar to what we already did for the modules
cache path. This reduces uninteresting differences between
command-lines, which is particularly useful if there is a tool that can
cache the compilations.
Differential Revision: https://reviews.llvm.org/D127883
This fixes the underlying module dependencies, which had a
non-deterministic order, which was also visible in the order of calls to
DependencyConsumer methods. This was not directly observable in
the clang-scan-deps utility, because it was previously seeing a sorted
order from std::map in DependencyScanningTool. However, the underlying
API previously created a likely issue for any other clients. Note: if
you only apply the change from DependencyScanningTool, you can see the
issue in clang-scan-deps, and existing tests will fail
non-deterministicaly.
Differential Revision: https://reviews.llvm.org/D127243
This patch changes type of the `File` parameter in `PPCallbacks::InclusionDirective()` from `const FileEntry *` to `Optional<FileEntryRef>`.
With the API change in place, this patch then removes some uses of the deprecated `FileEntry::getName()` (e.g. in `DependencyGraph.cpp` and `ModuleDependencyCollector.cpp`).
Reviewed By: dexonsmith, bnbarham
Differential Revision: https://reviews.llvm.org/D123574
When pruning header search paths (to reduce the number of modules we need to build explicitly), we can't prune the search paths used in (transitive) dependencies of a module. Otherwise, we could end up with either of the following dependency graphs:
```
X:<hash1> -> Y:<hash2>
X:<hash1> -> Y:<hash3>
```
depending on the search paths of the translation unit we discovered `X` and `Y` from.
This patch fixes that.
Depends on D121295.
Reviewed By: dexonsmith
Differential Revision: https://reviews.llvm.org/D121303
With explicit modules build, the '-fmodules-cache-path=' argument is unused.
This patch removes the argument to avoid warnings or errors (with '-Werror') stemming from that.
Depends on D118915.
Reviewed By: dexonsmith
Differential Revision: https://reviews.llvm.org/D120474
The `clang-scan-deps` tool currently generates `-fmodule-file=` command-line arguments for the whole transitive closure of modular dependencies. This is not necessary, we only need to provide the direct dependencies on the command line. Information about transitive dependencies is stored within the `.pcm` files of direct dependencies. This makes the command lines shorter, but should be a NFC otherwise (unless there are bugs in the loading mechanism for explicit modules).
Depends on D120465.
Reviewed By: Bigcheese
Differential Revision: https://reviews.llvm.org/D118915
Since D113473, we don't report any module map files via `-fmodule-map-file=` in explicit builds. The ultimate goal here is to make sure Clang doesn't open/read/parse/evaluate unnecessary module maps.
However, implicit module maps still end up reading all reachable module maps. This patch disables implicit module maps in explicit builds.
Unfortunately, we still need to report some module map files that aren't encoded in PCM files of dependencies: module maps that are necessary to correctly evaluate includes in modules marked as `[no_undeclared_includes]`.
Depends on D120464.
Reviewed By: dexonsmith
Differential Revision: https://reviews.llvm.org/D120465
This re-lands:
- 04192422c4e3b730c580498b8e948088cb15580b
- 015e08c6badad6b27404d6f94569e25c18d79049
Which I reverted in ea835171389aa356b865bf9cb72ca8f4f84b64fd in error.
Differential Revision: https://reviews.llvm.org/D114206
This reverts commits:
- 04192422c4e3b730c580498b8e948088cb15580b.
- 015e08c6badad6b27404d6f94569e25c18d79049
D114206 was landed before it was approved - and was landed knowing that
the test crashed on windows, without an xfail. The promised follow-up
commit with fixes has not appeared since it was promised on December 14th.
Make clang-scan-deps use the virtual path for module maps instead of the on disk
path. This is needed so that modulemap relative lookups are done correctly in
the actual module builds. The file dependencies still use the on disk path as
that's what matters for build invalidation.
Differential Revision: https://reviews.llvm.org/D114206
Some command-line codegen arguments are likely to differ between identical modules discovered from different translation units. This patch removes them to make builds deterministic and/or reduce the number of built modules.
Reviewed By: Bigcheese
Differential Revision: https://reviews.llvm.org/D112923
During explicit modules build, when all modules are provided via `-fmodule-file=<path>` and implicit modules and implicit module maps are disabled (`-fno-implicit-modules`, `-fno-implicit-module-maps`), we don't need to load the original module map files at all. This patch stops emitting the `-fmodule-map-file=` arguments we don't need, saving some compilation time due to avoiding parsing such module maps and making the command line shorter.
Reviewed By: bnbarham
Differential Revision: https://reviews.llvm.org/D113473
The dependency scanner works with multiple instances of `Compiler{Instance,Invocation}`. From names of the variables/members, their purpose is not obvious.
This patch gives descriptive name to the generated `CompilerInvocation` that can be used to derive the command-line to build a modular dependency.
Depends on D111725.
Reviewed By: dexonsmith
Differential Revision: https://reviews.llvm.org/D111728
The dependency scanner works with multiple instances of `Compiler{Instance,Invocation}`. From names of the variables/members, their purpose is not obvious.
This patch gives a distinct name to the `CompilerInstance` that's used to run the implicit build during dependency scan.
Depends on D111724.
Reviewed By: dexonsmith
Differential Revision: https://reviews.llvm.org/D111725
The `ModuleDepCollectorPP` class holds a reference to `ModuleDepCollector` as well as `ModuleDepCollector`'s `CompilerInstance`. The fact that these refer to the same object is non-obvious.
This patch removes the `CompilerInvocation` reference from `ModuleDepCollectorPP` and accesses it through `ModuleDepCollector` instead.
Reviewed By: dexonsmith
Differential Revision: https://reviews.llvm.org/D111724
One of main goals of the dependency scanner is to be strict about module compatibility. This is achieved through strict context hash. This patch ensures that strict context hash is enabled not only during the scan itself (and its minimized implicit build), but also when actually reporting the dependency.
Reviewed By: dexonsmith
Differential Revision: https://reviews.llvm.org/D111720
To reduce the number of explicit builds of a single module, we can try to squash multiple occurrences of the module with different command-lines (and context hashes) by removing benign command-line options. The greatest contributors to benign differences between command-lines are the header search paths.
In this patch, the lookup cache in `HeaderSearch` is used to identify paths that were actually used when implicitly building the module during scanning. This information is serialized into the unhashed control block of the implicitly-built PCM. The dependency scanner then loads this and may use it to prune the header search paths before computing the context hash of the module and generating the command-line.
We could also prune the header search paths when serializing `HeaderSearchOptions` into the PCM. That way, we could do it only once instead of every load of the PCM file by dependency scanner. However, that would result in a PCM file whose contents don't produce the same context hash as the original build, which is probably highly surprising.
There is an alternative approach to storing extra information into the PCM: wire up preprocessor callbacks to capture the used header search paths on-the-fly during preprocessing of modularized headers (similar to what we currently do for the main source file and textual headers). Right now, that's not compatible with the fact that we do an actual implicit build producing PCM files during dependency scanning. The second run of dependency scanner loads the PCM from the first run, skipping the preprocessing altogether, which would result in different results between runs. We can revisit this approach when we stop building implicitly during dependency scanning.
Depends on D102923.
Reviewed By: dexonsmith
Differential Revision: https://reviews.llvm.org/D102488
There are a number of language and preprocessor options that are reset in the `CompilerInvocation` that describes the build of an implicit module. This patch uses the logic for explicit modules as well.
Reviewed By: dexonsmith
Differential Revision: https://reviews.llvm.org/D108710
The `ASTReader` populates `Module::PresumedModuleMapFile` only for top-level modules, not submodules. To avoid generating empty `-fmodule-map-file=` arguments, make discovered modules depend on top-level precompiled modules. The granularity of submodules is not important here.
The documentation of `Module::PresumedModuleMapFile` says this field is non-empty only when building from preprocessed source. This means there can still be cases where the dependency scanner generates empty `-fmodule-map-file=` arguments. That's being addressed in separate patch: D108544.
Reviewed By: dexonsmith
Differential Revision: https://reviews.llvm.org/D108647
In this patch, the dependency scanner starts collecting precompiled dependencies from all encountered submodules, not only from top-level modules.
Reviewed By: dexonsmith
Differential Revision: https://reviews.llvm.org/D108540
Some files still contained the old University of Illinois Open Source
Licence header. This patch replaces that with the Apache 2 with LLVM
Exception licence.
Differential Revision: https://reviews.llvm.org/D107528
Whenever -fmodule-name=top_level_module name is parsed, and clang actually tries to
import top_level_module, the headers are imported textually and the module isn't actually
built. However, the dependency scanner could still record it as a potential dependency
if the module was reimported and thus recorded by the preprocessor callbacks.
This change avoids collecting this kind of module as a dependency by verifying that we don't
collect top level modules without actual PCM files.
Differential Revision: https://reviews.llvm.org/D106100
There's no need to pass `DependencyOutputOptions` to each call of `handleFileDependency`, since the options don't ever change.
This patch adds new `handleDependencyOutputOpts` method to the `DependencyConsumer` interface and the dependency scanner uses it to report the options only once.
Reviewed By: dexonsmith
Differential Revision: https://reviews.llvm.org/D104104
One of the goals of the dependency scanner is to generate command-lines that can be used to explicitly build modular dependencies of a translation unit. The only modifications to these command-lines should be for the purposes of explicit modular build.
However, the current version of dependency scanner leaks its implementation details into the command-lines.
The first problem is that the `clang-scan-deps` tool adjusts the original textual command-line (adding `-Eonly -M -MT <target> -sys-header-deps -Wno-error -o /dev/null `, removing `--serialize-diagnostics`) in order to set up the `DependencyScanning` library. This has been addressed in D103461, D104012, D104030, D104031, D104033. With these patches, the `DependencyScanning` library receives the unmodified `CompilerInvocation`, sets it up and uses it for the implicit modular build.
Finally, to prevent leaking the implementation details to the resulting command-lines, this patch generates them from the **original** unmodified `CompilerInvocation` rather than from the one that drives the implicit build.
Reviewed By: dexonsmith
Differential Revision: https://reviews.llvm.org/D104036
When a translation unit uses a PCH and imports the same modules as the PCH, we'd prefer to resolve to those modules instead of inventing new modules and reporting them as modular dependencies. Since the PCH modules have already been built nudge the compiler to reuse them when deciding whether to build a new module and don't report them as regular modular dependencies.
Depends on D103524 & D103802.
Reviewed By: dexonsmith
Differential Revision: https://reviews.llvm.org/D103526
The `PreprocessOnlyAction` doesn't support loading the AST file of a precompiled header. This is problematic for dependency scanning, since the `#include` manufactured for the PCH is treated as textual. This means the PCH contents get scanned with each TU, which is redundant. Moreover, dependencies of the PCH end up being considered dependency of the TU.
To handle AST file of PCH properly, this patch creates new `FrontendAction` that behaves the same way `PreprocessorOnlyAction` does, but treats the manufactured PCH `#include` as a normal compilation would (by not claiming it only uses a preprocessor and creating the default AST consumer).
The AST file is now reported as a file dependency of the TU.
Depends on D103519.
Reviewed By: Bigcheese
Differential Revision: https://reviews.llvm.org/D103524
This reverts commit c98833cdaad01787ea70ecdfabb05a7e142a6671.
The test `ClangScanDeps/modules-inferred-explicit-build.m` creates files
in the current directory.
This reapplies commit 95033eb3 that reverted commit 1d9e8e13.
The tests were failing on Windows due to spaces and backslashes in paths not being handled carefully.
This patch adds support for inferred modules to the dependency scanner.
Effectively a cherry-pick of https://github.com/apple/llvm-project/pull/699 authored by @Bigcheese with libclang and other changes omitted.
Contains following changes:
1. [Clang][ScanDeps] Ignore __inferred_module.map dependency.
* This shows up with inferred modules, but it doesn't exist on disk, so don't report it as a dependency.
2. [Clang][ScanDeps] Use the module map a module was inferred from for inferred modules.
Also includes a smoke test that uses clang-scan-deps output to perform an explicit build. There's no intention to duplicate whatever `test/Modules` contains, just to verify the produced command-line does "work" (with very loose definition of work).
Split from D100934.
Reviewed By: dexonsmith
Differential Revision: https://reviews.llvm.org/D102495
This patch eagerly constructs and modifies CompilerInvocation of modular dependencies in order to report the correct context hash instead of the hash of the original translation unit.
No functionality change here, since we currently don't modify CompilerInvocation in a way that affects the context hash.
Depends on D102473.
Reviewed By: dexonsmith
Differential Revision: https://reviews.llvm.org/D102482
