[Lldb-commits] [lldb] [NFC][LLDB][BoundsSatety] Add `InstrumentationRuntime::MatchAllModules` (PR #166001)

[Dan Liew via lldb-commits]

https://github.com/delcypher created https://github.com/llvm/llvm-project/pull/166001

This adds a virtual method that allows `InstrumentationRuntime` sub classes to match against all modules rather than just a library that matches a particular regex. When the implementation returns true `GetPatternForRuntimeLibrary()` is ignored and all modules are iterated over. The default implementation returns false which was the previous behavior which uses `GetPatternForRuntimeLibrary()` to only match a particular runtime library.

The intended use case here is for implementing an
`InstrumentationRuntime` where the runtime library of interest can have multiple implementations and whose name is not known ahead of time.

The concrete use case here is for a `InstrumentationRuntime` plugin for implementations of the `-fbounds-safety` soft-trap runtime which can have multiple different implementations and so the module containing the runtime functions isn't known ahead of time. This plug-in will be upstreamed as part of the process of upstreaming `-fbounds-safety`.

An alternative to this would be for the `GetPatternForRuntimeLibrary()` function to return a regex that matches everything. While that technically works this new API more clearly indicates in the intent. We probably also save a little perf by not executing the regex match for every loaded module but I have not measured this.

rdar://163230807

>From 21ceb6e19e0830fff43666bb936ccb06ab2fac1e Mon Sep 17 00:00:00 2001
From: Dan Liew <dan at su-root.co.uk>
Date: Tue, 28 Oct 2025 08:54:22 -0700
Subject: [PATCH] [NFC][LLDB][BoundsSatety] Add
 `InstrumentationRuntime::MatchAllModules`

This adds a virtual method that allows `InstrumentationRuntime`
sub classes to match against all modules rather than just a library
that matches a particular regex. When the implementation returns
true `GetPatternForRuntimeLibrary()` is ignored and all modules
are iterated over. The default implementation returns false which
was the previous behavior which uses `GetPatternForRuntimeLibrary()`
to only match a particular runtime library.

The intended use case here is for implementing an
`InstrumentationRuntime` where the runtime library of interest can have
multiple implementations and whose name is not known ahead of time.

The concrete use case here is for a `InstrumentationRuntime` plugin for
implementations of the `-fbounds-safety` soft-trap runtime which can
have multiple different implementations and so the module containing the
runtime functions isn't known ahead of time. This plug-in will be
upstreamed as part of the process of upstreaming `-fbounds-safety`.

An alternative to this would be for the `GetPatternForRuntimeLibrary()`
function to return a regex that matches everything. While that
technically works this new API more clearly indicates in the intent.
We probably also save a little perf by not executing the regex match for
every loaded module but I have not measured this.

rdar://163230807
---
 lldb/include/lldb/Target/InstrumentationRuntime.h | 7 +++++++
 lldb/source/Target/InstrumentationRuntime.cpp     | 3 ++-
 2 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/lldb/include/lldb/Target/InstrumentationRuntime.h b/lldb/include/lldb/Target/InstrumentationRuntime.h
index a6121c24b9560..d2499528e97ab 100644
--- a/lldb/include/lldb/Target/InstrumentationRuntime.h
+++ b/lldb/include/lldb/Target/InstrumentationRuntime.h
@@ -73,6 +73,13 @@ class InstrumentationRuntime
   /// is guaranteed to be loaded.
   virtual void Activate() = 0;
 
+  /// \return true if `CheckIfRuntimeIsValid` should be called on all modules.
+  /// In this case the return value of `GetPatternForRuntimeLibrary` will be
+  /// ignored. Return false if `CheckIfRuntimeIsValid` should only be called
+  /// for modules whose name matches `GetPatternForRuntimeLibrary`.
+  ///
+  virtual bool MatchAllModules() { return false; }
+
 public:
   static void ModulesDidLoad(lldb_private::ModuleList &module_list,
                              Process *process,
diff --git a/lldb/source/Target/InstrumentationRuntime.cpp b/lldb/source/Target/InstrumentationRuntime.cpp
index 7e58e8bf26cb1..d9800a8541f4e 100644
--- a/lldb/source/Target/InstrumentationRuntime.cpp
+++ b/lldb/source/Target/InstrumentationRuntime.cpp
@@ -55,7 +55,8 @@ void InstrumentationRuntime::ModulesDidLoad(
       return IterationAction::Continue;
 
     const RegularExpression &runtime_regex = GetPatternForRuntimeLibrary();
-    if (runtime_regex.Execute(file_spec.GetFilename().GetCString()) ||
+    if (MatchAllModules() ||
+        runtime_regex.Execute(file_spec.GetFilename().GetCString()) ||
         module_sp->IsExecutable()) {
       if (CheckIfRuntimeIsValid(module_sp)) {
         SetRuntimeModuleSP(module_sp);