[llvm-branch-commits] [lldb] [lldb] Consult the platform before the symbol locator plugins (NFC) (PR #215392)
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Mon Aug 10 15:08:05 PDT 2026
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<!--LLVM PR SUMMARY COMMENT-->
@llvm/pr-subscribers-lldb
Author: Jonas Devlieghere (JDevlieghere)
<details>
<summary>Changes</summary>
A symbol locator plugin has no Platform to consult, so a platform that knows
where its binaries live cannot take part in a search. The only way to reach
one is Platform::GetSharedModule, which also creates the module and registers
it, so the lookup cannot be reused by a caller that wants to search for many
binaries before creating any.
Add a hook that only answers where the files are. An answer ends the search,
so an override owns what the plugins would otherwise have been asked for.
No platform overrides it yet. A follow-up moves PlatformDarwinKernel's kext
and kernel index lookups behind it.
Assisted-by: Claude
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Full diff: https://github.com/llvm/llvm-project/pull/215392.diff
5 Files Affected:
- (modified) lldb/include/lldb/Symbol/SymbolLocator.h (+4)
- (modified) lldb/include/lldb/Target/Platform.h (+18)
- (modified) lldb/source/Core/DynamicLoader.cpp (+1)
- (modified) lldb/source/Symbol/SymbolLocator.cpp (+10)
- (modified) lldb/unittests/Symbol/SymbolLocatorTest.cpp (+70)
``````````diff
diff --git a/lldb/include/lldb/Symbol/SymbolLocator.h b/lldb/include/lldb/Symbol/SymbolLocator.h
index 82e142ab18d9a..d86538fd9a2ce 100644
--- a/lldb/include/lldb/Symbol/SymbolLocator.h
+++ b/lldb/include/lldb/Symbol/SymbolLocator.h
@@ -41,6 +41,10 @@ class SymbolLocator : public PluginInterface {
/// What to look for.
ModuleSpec module_spec;
+ /// A platform that may know where the binary is. The locator plugins have
+ /// no Platform of their own to consult.
+ lldb::PlatformSP platform;
+
/// Allow contacting an external symbol server when the local searches come
/// up empty.
bool external_lookup = false;
diff --git a/lldb/include/lldb/Target/Platform.h b/lldb/include/lldb/Target/Platform.h
index b1a28d1b118a0..a8d9d0d6cbdf2 100644
--- a/lldb/include/lldb/Target/Platform.h
+++ b/lldb/include/lldb/Target/Platform.h
@@ -329,6 +329,24 @@ class Platform : public PluginInterface {
const ModuleSpec &module_spec, Target &target, lldb::ModuleSP &module_sp,
llvm::SmallVectorImpl<lldb::ModuleSP> *old_modules, bool *did_create_ptr);
+ /// Find a module's files on this host.
+ ///
+ /// The symbol locator plugins have no Platform to consult, so a platform
+ /// that knows where its binaries live answers here instead.
+ ///
+ /// An answer ends the search, so an override owns what the plugins would
+ /// otherwise have been asked for: the files it names have to exist, and have
+ /// to be the ones \a module_spec describes.
+ ///
+ /// \return
+ /// Where the files are, or std::nullopt if this platform has nothing to
+ /// say about this module.
+ virtual std::optional<ModuleSpec>
+ FindModuleFiles(const ModuleSpec &module_spec,
+ const FileSpecList &search_paths, StatisticsMap &statistics) {
+ return std::nullopt;
+ }
+
void CallLocateModuleCallbackIfSet(const ModuleSpec &module_spec,
lldb::ModuleSP &module_sp,
FileSpec &symbol_file_spec,
diff --git a/lldb/source/Core/DynamicLoader.cpp b/lldb/source/Core/DynamicLoader.cpp
index 5c12598ee4325..09f66e38f2097 100644
--- a/lldb/source/Core/DynamicLoader.cpp
+++ b/lldb/source/Core/DynamicLoader.cpp
@@ -271,6 +271,7 @@ static void SearchForBinary(Target &target, DynamicLoader::BinarySpec &bin_spec,
// Search for the binary and its symbols.
SymbolLocator::Request request;
request.module_spec = module_spec;
+ request.platform = target.GetPlatform();
request.external_lookup = bin_spec.force_symbol_search;
llvm::Expected<SymbolLocator::Result> located =
diff --git a/lldb/source/Symbol/SymbolLocator.cpp b/lldb/source/Symbol/SymbolLocator.cpp
index 8f22d32d72db9..1f32d69a0b618 100644
--- a/lldb/source/Symbol/SymbolLocator.cpp
+++ b/lldb/source/Symbol/SymbolLocator.cpp
@@ -12,6 +12,7 @@
#include "lldb/Core/PluginManager.h"
#include "lldb/Host/FileSystem.h"
#include "lldb/Host/Host.h"
+#include "lldb/Target/Platform.h"
#include "llvm/ADT/SmallSet.h"
#include "llvm/Support/ThreadPool.h"
@@ -37,6 +38,15 @@ SymbolLocator::Locate(const Request &request,
ModuleSpec &module_spec = result.module_spec;
module_spec = request.module_spec;
+ // The locator plugins have no Platform to consult, so ask it here.
+ if (request.platform) {
+ if (std::optional<ModuleSpec> found = request.platform->FindModuleFiles(
+ module_spec, search_paths, result.statistics)) {
+ result.module_spec = *found;
+ return result;
+ }
+ }
+
// Can lldb's symbol and executable location schemes find them locally?
module_spec.GetSymbolFileSpec() = PluginManager::LocateExecutableSymbolFile(
module_spec, search_paths, result.statistics);
diff --git a/lldb/unittests/Symbol/SymbolLocatorTest.cpp b/lldb/unittests/Symbol/SymbolLocatorTest.cpp
index 6456f4fc18ad0..bf0b9df308f9d 100644
--- a/lldb/unittests/Symbol/SymbolLocatorTest.cpp
+++ b/lldb/unittests/Symbol/SymbolLocatorTest.cpp
@@ -10,6 +10,7 @@
#include "lldb/Core/PluginManager.h"
#include "lldb/Host/FileSystem.h"
#include "lldb/Host/HostInfo.h"
+#include "lldb/Target/Platform.h"
#include "lldb/Utility/FileSpecList.h"
#include "llvm/Support/VirtualFileSystem.h"
@@ -70,6 +71,41 @@ bool DownloadObjectAndSymbolFile(ModuleSpec &, Status &error, bool force_lookup,
SymbolLocator *CreateSymbolLocator() { return nullptr; }
+/// A platform that answers out of an index of its own, the way
+/// PlatformDarwinKernel answers for kexts.
+class IndexedPlatform : public Platform {
+public:
+ IndexedPlatform() : Platform(/*is_host_platform=*/false) {}
+
+ llvm::StringRef GetPluginName() override { return "indexed"; }
+ llvm::StringRef GetDescription() override { return "test platform"; }
+ std::vector<ArchSpec> GetSupportedArchitectures(const ArchSpec &) override {
+ return {};
+ }
+ lldb::ProcessSP Attach(ProcessAttachInfo &, Debugger &, Target *,
+ Status &) override {
+ return nullptr;
+ }
+ void CalculateTrapHandlerSymbolNames() override {}
+ UserIDResolver &GetUserIDResolver() override {
+ return UserIDResolver::GetNoopResolver();
+ }
+
+ std::optional<ModuleSpec> FindModuleFiles(const ModuleSpec &spec,
+ const FileSpecList &,
+ StatisticsMap &) override {
+ ++find_module_files_calls;
+ if (!m_answer)
+ return {};
+ ModuleSpec found(spec);
+ found.GetFileSpec() = *m_answer;
+ return found;
+ }
+
+ std::optional<FileSpec> m_answer;
+ unsigned find_module_files_calls = 0;
+};
+
class SymbolLocatorTest : public testing::Test {
public:
SymbolLocatorTest()
@@ -197,3 +233,37 @@ TEST_F(SymbolLocatorTest, AnErrnoFromTheSymbolServerIsNotAPlainMiss) {
EXPECT_FALSE(error.isA<SymbolLocator::NotFound>());
llvm::consumeError(std::move(error));
}
+
+TEST_F(SymbolLocatorTest, ThePlatformAnswersBeforeThePlugins) {
+ auto platform = std::make_shared<IndexedPlatform>();
+ platform->m_answer = m_binary;
+
+ SymbolLocator::Request request;
+ request.platform = platform;
+
+ llvm::Expected<SymbolLocator::Result> result =
+ SymbolLocator::Locate(request, FileSpecList());
+
+ ASSERT_THAT_EXPECTED(result, llvm::Succeeded());
+ EXPECT_EQ(1u, platform->find_module_files_calls);
+ EXPECT_EQ(m_binary, result->module_spec.GetFileSpec());
+ EXPECT_FALSE(g_calls.located_symbol_file);
+ EXPECT_FALSE(g_calls.located_object_file);
+ EXPECT_FALSE(g_calls.downloaded);
+}
+
+TEST_F(SymbolLocatorTest, ThePluginsRunWhenThePlatformHasNothingToSay) {
+ auto platform = std::make_shared<IndexedPlatform>();
+ platform->m_answer = std::nullopt;
+ g_object_file = m_binary;
+
+ SymbolLocator::Request request;
+ request.platform = platform;
+
+ llvm::Expected<SymbolLocator::Result> result =
+ SymbolLocator::Locate(request, FileSpecList());
+
+ ASSERT_THAT_EXPECTED(result, llvm::Succeeded());
+ EXPECT_EQ(1u, platform->find_module_files_calls);
+ EXPECT_TRUE(g_calls.located_object_file);
+}
``````````
</details>
https://github.com/llvm/llvm-project/pull/215392
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