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
This patch avoid minimizing input files that contributed to a PCH or its modules. This prevents the implicit modular build to fail on unexpected file size. Depends on D106146.
Reviewed By: dexonsmith
Differential Revision: https://reviews.llvm.org/D104536
This patch separates the local and global caches of `DependencyScanningFilesystem` into two buckets: minimized files and original files. This is necessary to deal with precompiled modules/headers.
Consider a single worker with its instance of filesystem:
1. Build system uses the worker to scan dependencies of module A => filesystem cache gets populated with minimized input files.
2. Build system uses the results to explicitly build module A => explicitly built module captures the state of the real filesystem (containing non-minimized input files).
3. Build system uses the prebuilt module A as an explicit precompiled dependency for another compile job B.
4. Build system uses the same worker to scan dependencies for job B => worker uses implicit modular build to discover dependencies, which validates the filesystem state embedded in the prebuilt module (non-minimized files) to the current view of the filesystem (minimized files), resulting in validation failures.
This problem can be avoided in step 4 by collecting input files from the precompiled module and marking them as "ignored" in the minimizing filesystem. This way, the validation should succeed, since we should be always dealing with the original (non-minized) input files. However, the filesystem already minimized the input files in step 1 and put it in the cache, which gets used in step 4 as well even though it's marked ignored (do not minimize). This patch essentially fixes this oversight by making the `"file is minimized"` part of the cache key (from high level).
Depends on D106064.
Reviewed By: dexonsmith
Differential Revision: https://reviews.llvm.org/D106146
This patch normalizes filenames in `DependencyScanningWorkerFilesystem` so that lookup of ignored files works correctly on Windows (where `/` and `\` are equivalent).
Reviewed By: dexonsmith
Differential Revision: https://reviews.llvm.org/D106064
The dependency scanning worker uses `std::move` to "reset" `DependencyOutputOptions` in the `CompilerInstance` that performs the implicit build. It's probably preferable to replace the object with value-initialized instance, rather than depending on the behavior of a moved-from object.
Reviewed By: dexonsmith
Differential Revision: https://reviews.llvm.org/D104106
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
This patch moves enabling system header deps from `clang-scan-deps` into the `DependencyScanning` library. This will make it easier to preserve semantics of the original TU command-line for modular dependencies (see D104036).
Reviewed By: arphaman
Differential Revision: https://reviews.llvm.org/D104033
This moves another piece of logic specific to `clang-scan-deps` into the `DependencyScanning` library. This makes it easier to check how the original command-line looked like in the library and will enable the library to stop inventing `-Wno-error` for modular dependencies (see D104036).
Reviewed By: arphaman
Differential Revision: https://reviews.llvm.org/D104031
The `clang-scan-deps` tool has some logic that parses and modifies the original Clang command-line. The goal is to setup `DependencyOutputOptions` by injecting `-M -MT <target>` and prevent the creation of output files.
This patch moves the logic into the `DependencyScanning` library, and uses the parsed `CompilerInvocation` instead of the raw command-line. The code simpler and can be used from the C++ API as well.
The `-o /dev/null` arguments are not necessary, since the `DependencyScanning` library only runs a preprocessing action, so there's no way it'll produce an actual object file.
Related: The `-M` argument implies `-w`, which would appear on the command-line of modular dependencies even though it was not on the original TU command line (see D104036).
Some related tests were updated.
Reviewed By: arphaman
Differential Revision: https://reviews.llvm.org/D104030
To prevent the creation of diagnostics file, `clang-scan-deps` strips the corresponding command-line argument. This behavior is useful even when using the C++ `DependencyScanner` library.
This patch transforms stripping of command-line in `clang-scan-deps` into stripping of `CompilerInvocation` in `DependencyScanning`.
AFAIK, the `clang-cl` driver doesn't even accept `--serialize-diagnostics`, so I've removed the test. (It would fail with an unknown command-line argument otherwise.)
Note: Since we're generating command-lines for modular dependencies from `CompilerInvocation`, the `--serialize-diagnostics` will be dropped. This was already happening in `clang-scan-deps` before this patch, but it will now happen also when using `DependencyScanning` library directly. This is resolved in D104036.
Reviewed By: dexonsmith, arphaman
Differential Revision: https://reviews.llvm.org/D104012
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
When a project uses PCH with explicit modules, the build will look like this:
1. scan PCH dependencies
2. explicitly build PCH
3. scan TU dependencies
4. explicitly build TU
Step 2 produces an object file for the PCH, which the dependency scanner needs to read in step 3. This patch adds support for this.
The `clang-scan-deps` invocation in the attached test would fail without this change.
Depends on D103516.
Reviewed By: Bigcheese
Differential Revision: https://reviews.llvm.org/D103519
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
The context hash of modular dependencies can be different from the context hash of the original translation unit if we modify their `CompilerInvocation`s.
Stop assuming the TU's context hash everywhere.
No functionality change here, since we're still currently using the unmodified TU CompilerInvocation to compute the context hash.
Reviewed By: dexonsmith
Differential Revision: https://reviews.llvm.org/D102473
Add option to `clang-scan-deps` to enable/disable generation of command-line arguments with absolute paths. This is essentially a revert of D100533, but with improved naming and added test.
Reviewed By: dexonsmith
Differential Revision: https://reviews.llvm.org/D101051
This patch removes the `FullDependencies::AdditionalNonPathCommandLine` member, as it's value-initialized and never mutated.
Reviewed By: dexonsmith
Differential Revision: https://reviews.llvm.org/D100536
This patch uses the new `CompilerInvocation::generateCC1CommandLine` to generate the full canonical command line for modular dependencies, instead of only appending additional arguments.
Reviewed By: dexonsmith
Differential Revision: https://reviews.llvm.org/D100534
This patch removes the `-full-command-line` option from `clang-scan-deps`. It's only used with `-format=experimental-full`, where omitting the command lines doesn't make much sense. There are no tests without `-full-command-line`.
Depends on D100531.
Reviewed By: Bigcheese
Differential Revision: https://reviews.llvm.org/D100533
This patch simplifies (and renames) the `appendCommonModuleArguments` function.
It no longer tries to construct the command line for explicitly building modules. Instead, it only performs the DFS traversal of modular dependencies and queries the callbacks to collect paths to `.pcm` and `.modulemap` files.
This makes it more flexible and usable in two contexts:
* Generating additional command line arguments for the main TU in modular build. The `std::vector<std::string>` output parameters can be used to manually generate appropriate command line flags.
* Generate full command line for a module. The output parameters can be the corresponding parts of `CompilerInvocation`. (In a follow-up patch.)
Reviewed By: dexonsmith
Differential Revision: https://reviews.llvm.org/D100531
This patch documents how `ModuleDepCollector{,PP}` work and what their members store. Also renames somewhat vague `MainDeps` to `FileDeps` and `Deps` to `ModularDeps`.
Depends on D98943.
Reviewed By: Bigcheese
Differential Revision: https://reviews.llvm.org/D98950
This patch extracts the `ModuleName` and `ContextHash` members of `ClangModuleDep`, `FullDependencies` and `ModuleDeps` into a single struct `ModuleID`. This makes it easier to understand how the full dependency graph works.
Reviewed By: Bigcheese, dexonsmith
Differential Revision: https://reviews.llvm.org/D98943
Allow a `std::unique_ptr` to be moved into the an `IntrusiveRefCntPtr`,
and remove a couple of now-unnecessary `release()` calls.
Differential Revision: https://reviews.llvm.org/D92888
`SourceManager::getFileEntryRefForID`'s remaining callers just want the
filename component, which is coming from the `FileInfo`. Replace the API
with `getNonBuiltinFilenameForID`, which also removes another use of
`FileEntryRef::FileEntryRef` outside of `FileManager`.
Both callers are collecting file dependencies, and one of them relied on
this API to filter out built-ins (as exposed by
clang/test/ClangScanDeps/modules-full.cpp). It seems nice to continue
providing that service.
Differential Revision: https://reviews.llvm.org/D89508
This is a prep patch for changing SourceManager to return
`Optional<MemoryBufferRef>` instead of `MemoryBuffer`. With that change the
address of the MemoryBuffer will be gone, so instead use the start of the
buffer as the key for this map.
No functionality change intended, as it's expected that the pointer identity
matches between the buffers and the buffer data.
Radar-Id: rdar://70139990
Differential Revision: https://reviews.llvm.org/D89136
The goal of this patch is to maximize CPU utilization on multi-socket or high core count systems, so that parallel computations such as LLD/ThinLTO can use all hardware threads in the system. Before this patch, on Windows, a maximum of 64 hardware threads could be used at most, in some cases dispatched only on one CPU socket.
== Background ==
Windows doesn't have a flat cpu_set_t like Linux. Instead, it projects hardware CPUs (or NUMA nodes) to applications through a concept of "processor groups". A "processor" is the smallest unit of execution on a CPU, that is, an hyper-thread if SMT is active; a core otherwise. There's a limit of 32-bit processors on older 32-bit versions of Windows, which later was raised to 64-processors with 64-bit versions of Windows. This limit comes from the affinity mask, which historically is represented by the sizeof(void*). Consequently, the concept of "processor groups" was introduced for dealing with systems with more than 64 hyper-threads.
By default, the Windows OS assigns only one "processor group" to each starting application, in a round-robin manner. If the application wants to use more processors, it needs to programmatically enable it, by assigning threads to other "processor groups". This also means that affinity cannot cross "processor group" boundaries; one can only specify a "preferred" group on start-up, but the application is free to allocate more groups if it wants to.
This creates a peculiar situation, where newer CPUs like the AMD EPYC 7702P (64-cores, 128-hyperthreads) are projected by the OS as two (2) "processor groups". This means that by default, an application can only use half of the cores. This situation could only get worse in the years to come, as dies with more cores will appear on the market.
== The problem ==
The heavyweight_hardware_concurrency() API was introduced so that only *one hardware thread per core* was used. Once that API returns, that original intention is lost, only the number of threads is retained. Consider a situation, on Windows, where the system has 2 CPU sockets, 18 cores each, each core having 2 hyper-threads, for a total of 72 hyper-threads. Both heavyweight_hardware_concurrency() and hardware_concurrency() currently return 36, because on Windows they are simply wrappers over std:🧵:hardware_concurrency() -- which can only return processors from the current "processor group".
== The changes in this patch ==
To solve this situation, we capture (and retain) the initial intention until the point of usage, through a new ThreadPoolStrategy class. The number of threads to use is deferred as late as possible, until the moment where the std::threads are created (ThreadPool in the case of ThinLTO).
When using hardware_concurrency(), setting ThreadCount to 0 now means to use all the possible hardware CPU (SMT) threads. Providing a ThreadCount above to the maximum number of threads will have no effect, the maximum will be used instead.
The heavyweight_hardware_concurrency() is similar to hardware_concurrency(), except that only one thread per hardware *core* will be used.
When LLVM_ENABLE_THREADS is OFF, the threading APIs will always return 1, to ensure any caller loops will be exercised at least once.
Differential Revision: https://reviews.llvm.org/D71775
This is how it should've been and brings it more in line with
std::string_view. There should be no functional change here.
This is mostly mechanical from a custom clang-tidy check, with a lot of
manual fixups. It uncovers a lot of minor inefficiencies.
This doesn't actually modify StringRef yet, I'll do that in a follow-up.
Differential Revision: https://reviews.llvm.org/D70268
This is a recommit of f978ea4983 with a fix for the PowerPC failure.
The issue was that:
* `CompilerInstance::ExecuteAction` calls
`getTarget().adjust(getLangOpts());`.
* `PPCTargetInfo::adjust` changes `LangOptions::HasAltivec`.
* This happens after the first few calls to `getModuleHash`.
There’s even a FIXME saying:
```
// FIXME: We shouldn't need to do this, the target should be immutable once
// created. This complexity should be lifted elsewhere.
```
This only showed up on PowerPC because it's one of the few targets that
almost always changes a hashed langopt.
I looked into addressing the fixme, but that would be a much larger
change, and it's not the only thing that happens in `ExecuteAction` that
can change the module context hash. Instead I changed the code to not
call `getModuleHash` until after it has been modified in `ExecuteAction`.
Fix the confusing naming of `CompilerInstance::ModuleManager`. This is
actually an instance of `ASTReader`, which contains an instance of
`ModuleManager`. I have to assume there was a point in the past where
they were just one class, but it's been pretty confusing for a while. I
think it's time to fix it.
The new name is `TheASTReader`; the annoying `The` prefix is so that we
don't shadow the `ASTReader` class. I tried out `ASTRdr` but that
seemed less clear, and this choice matches `ThePCHContainerOperations`
just a couple of declarations below.
Also rename `CompilerInstance::getModuleManager` and
`CompilerInstance::createModuleManager` to `*ASTReader`, making some
cases of `getModuleManager().getModuleManager()` a little more clear.
https://reviews.llvm.org/D70583
Previously, given a CompilationDatabase with two commands for the same
source file we would report that file twice with the union of the
dependencies for each command both times.
This was due to the way `ClangTool` runs actions given an input source
file (see the comment in `DependencyScanningTool.cpp`). This commit adds
a `SingleCommandCompilationDatabase` that is created with each
`CompileCommand` in the original CDB, which is then used for each
`ClangTool` invocation. This gives us a single run of
`DependencyScanningAction` per `CompileCommand`.
I looked at using `AllTUsToolExecutor` which is a parallel tool
executor, but I'm not sure it's suitable for `clang-scan-deps` as it
does a lot more sharing of state than `AllTUsToolExecutor` expects.
Differential Revision: https://reviews.llvm.org/D69643
This is a recommit of d8a4ef0e68 with the nondeterminism fixed.
This adds experimental support for extracting a Clang module dependency graph
from a compilation database. The output format is experimental and will change.
It is currently a concatenation of JSON outputs for each compilation. Future
patches will change this to deduplicate modules between compilations.
Differential Revision: https://reviews.llvm.org/D69420
This adds experimental support for extracting a Clang module dependency graph
from a compilation database. The output format is experimental and will change.
It is currently a concatenation of JSON outputs for each compilation. Future
patches will change this to deduplicate modules between compilations.
Differential Revision: https://reviews.llvm.org/D69420
This fixes two issues that prevent simple uses of modules from working.
* We would previously minimize _every_ file opened by clang, even module maps
and module pcm files. Now we only minimize files with known extensions. It
would be better if we knew which files clang intended to open as a source
file, but this works for now.
* We previously cached every lookup, even failed lookups. This is a problem
because clang stats the module cache directory before building a module and
creating that directory. If we cache that failure then the subsequent pcm
load doesn't see the module cache and fails.
Overall this still leaves us building minmized modules on disk during scanning.
This will need to be improved eventually for performance, but this is correct,
and works for now.
Differential Revision: https://reviews.llvm.org/D68835
Christopher Di Bella