[Lldb-commits] [lldb] [lldb][CPlusPlus] Make C++ frame-format work without debug-info (PR #137408)
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Fri Apr 25 15:29:11 PDT 2025
llvmbot wrote:
<!--LLVM PR SUMMARY COMMENT-->
@llvm/pr-subscribers-lldb
Author: Michael Buch (Michael137)
<details>
<summary>Changes</summary>
This patch makes the frame-format variables introduced in https://github.com/llvm/llvm-project/pull/131836 also work when no debug-info is available. Previously, we assumed `sc.function` was available, but without debug-info we might only have `sc.symbol`. We don't really need the `sc.function` apart from when formatting arguments.
For the function arguments case I added a fallback that will just print the arguments we get from the demangler (which is what LLDB does for stacktraces with no debug-info anyway). Ideally we'd have a separate `FormatEntity::Entry::Type::FunctionArguments` that will just print the arguments from the demangler and have something like the following in the `plugin.cplusplus.display.function-name-format`:
```
{ ${function.formatted-arguments} || ${function.arguments} }
```
I.e., when we can't format the arguments, print the ones from the demangler. But we currently don't have the `||` operator in the frame-format language yet.
---
Full diff: https://github.com/llvm/llvm-project/pull/137408.diff
8 Files Affected:
- (modified) lldb/source/Core/FormatEntity.cpp (+5-4)
- (modified) lldb/source/Plugins/Language/CPlusPlus/CPlusPlusLanguage.cpp (+36-2)
- (modified) lldb/test/Shell/Settings/TestFrameFormatFunctionBasename.test (+5-1)
- (modified) lldb/test/Shell/Settings/TestFrameFormatFunctionFormattedArguments.test (+10-1)
- (modified) lldb/test/Shell/Settings/TestFrameFormatFunctionQualifiers.test (+5-1)
- (modified) lldb/test/Shell/Settings/TestFrameFormatFunctionReturn.test (+5-1)
- (modified) lldb/test/Shell/Settings/TestFrameFormatFunctionScope.test (+6-3)
- (modified) lldb/test/Shell/Settings/TestFrameFormatFunctionTemplateArguments.test (+6-2)
``````````diff
diff --git a/lldb/source/Core/FormatEntity.cpp b/lldb/source/Core/FormatEntity.cpp
index e352d07fe487d..4ac50e2d30f3c 100644
--- a/lldb/source/Core/FormatEntity.cpp
+++ b/lldb/source/Core/FormatEntity.cpp
@@ -1809,11 +1809,12 @@ bool FormatEntity::Format(const Entry &entry, Stream &s,
case Entry::Type::FunctionReturnRight:
case Entry::Type::FunctionReturnLeft:
case Entry::Type::FunctionQualifiers: {
- if (!sc->function)
- return false;
+ Language *language_plugin = nullptr;
+ if (sc->function)
+ language_plugin = Language::FindPlugin(sc->function->GetLanguage());
+ else if (sc->symbol)
+ language_plugin = Language::FindPlugin(sc->symbol->GetLanguage());
- Language *language_plugin =
- Language::FindPlugin(sc->function->GetLanguage());
if (!language_plugin)
return false;
diff --git a/lldb/source/Plugins/Language/CPlusPlus/CPlusPlusLanguage.cpp b/lldb/source/Plugins/Language/CPlusPlus/CPlusPlusLanguage.cpp
index 283e867d53bb7..ab8e9883868ce 100644
--- a/lldb/source/Plugins/Language/CPlusPlus/CPlusPlusLanguage.cpp
+++ b/lldb/source/Plugins/Language/CPlusPlus/CPlusPlusLanguage.cpp
@@ -381,6 +381,34 @@ GetDemangledScope(const SymbolContext &sc) {
return demangled_name.slice(info->ScopeRange.first, info->ScopeRange.second);
}
+static bool PrintDemangledArgumentList(Stream &s, const SymbolContext &sc) {
+ assert(sc.symbol);
+
+ Mangled mangled = sc.GetPossiblyInlinedFunctionName();
+ if (!mangled)
+ return false;
+
+ auto demangled_name = mangled.GetDemangledName().GetStringRef();
+ if (demangled_name.empty())
+ return false;
+
+ const std::optional<DemangledNameInfo> &info = mangled.GetDemangledInfo();
+ if (!info)
+ return false;
+
+ // Function without a basename is nonsense.
+ if (!info->hasBasename())
+ return false;
+
+ if (info->ArgumentsRange.second < info->ArgumentsRange.first)
+ return false;
+
+ s << demangled_name.slice(info->ArgumentsRange.first,
+ info->ArgumentsRange.second);
+
+ return true;
+}
+
bool CPlusPlusLanguage::CxxMethodName::TrySimplifiedParse() {
// This method tries to parse simple method definitions which are presumably
// most comman in user programs. Definitions that can be parsed by this
@@ -1890,8 +1918,6 @@ bool CPlusPlusLanguage::GetFunctionDisplayName(
bool CPlusPlusLanguage::HandleFrameFormatVariable(
const SymbolContext &sc, const ExecutionContext *exe_ctx,
FormatEntity::Entry::Type type, Stream &s) {
- assert(sc.function);
-
switch (type) {
case FormatEntity::Entry::Type::FunctionScope: {
std::optional<llvm::StringRef> scope = GetDemangledScope(sc);
@@ -1925,6 +1951,14 @@ bool CPlusPlusLanguage::HandleFrameFormatVariable(
}
case FormatEntity::Entry::Type::FunctionFormattedArguments: {
+ // This ensures we print the arguments even when no debug-info is available.
+ //
+ // FIXME: we should have a Entry::Type::FunctionArguments and
+ // use it in the plugin.cplusplus.display.function-name-format
+ // once we have a "fallback operator" in the frame-format language.
+ if (!sc.function && sc.symbol)
+ return PrintDemangledArgumentList(s, sc);
+
VariableList args;
if (auto variable_list_sp = GetFunctionVariableList(sc))
variable_list_sp->AppendVariablesWithScope(eValueTypeVariableArgument,
diff --git a/lldb/test/Shell/Settings/TestFrameFormatFunctionBasename.test b/lldb/test/Shell/Settings/TestFrameFormatFunctionBasename.test
index 249a5fac5b55e..35d443d872c7d 100644
--- a/lldb/test/Shell/Settings/TestFrameFormatFunctionBasename.test
+++ b/lldb/test/Shell/Settings/TestFrameFormatFunctionBasename.test
@@ -1,10 +1,14 @@
# Test the ${function.basename} frame-format variable.
# RUN: split-file %s %t
-# RUN: %build %t/main.cpp -o %t.out
+# RUN: %clang_host -g %t/main.cpp -o %t.out
# RUN: %lldb -x -b -s %t/commands.input %t.out -o exit 2>&1 \
# RUN: | FileCheck %s
#
+# RUN: %clang_host -O0 %t/main.cpp -o %t-nodebug.out
+# RUN: %lldb -x -b -s %t/commands.input %t-nodebug.out -o exit 2>&1 \
+# RUN: | FileCheck %s
+
#--- main.cpp
namespace ns {
template<typename T>
diff --git a/lldb/test/Shell/Settings/TestFrameFormatFunctionFormattedArguments.test b/lldb/test/Shell/Settings/TestFrameFormatFunctionFormattedArguments.test
index 5554830d3a247..46fb518158ce2 100644
--- a/lldb/test/Shell/Settings/TestFrameFormatFunctionFormattedArguments.test
+++ b/lldb/test/Shell/Settings/TestFrameFormatFunctionFormattedArguments.test
@@ -1,9 +1,13 @@
# Test the ${function.formatted-arguments} frame-format variable.
# RUN: split-file %s %t
-# RUN: %build %t/main.cpp -o %t.out
+# RUN: %clang_host -g %t/main.cpp -o %t.out
# RUN: %lldb -x -b -s %t/commands.input %t.out -o exit 2>&1 \
# RUN: | FileCheck %s
+#
+# RUN: %clang_host -O0 %t/main.cpp -o %t-nodebug.out
+# RUN: %lldb -x -b -s %t/commands.input %t-nodebug.out -o exit 2>&1 \
+# RUN: | FileCheck %s --check-prefix=CHECK-NODEBUG
#--- main.cpp
struct Foo {
@@ -40,3 +44,8 @@ bt
# CHECK: custom-frame '((null)=5, x=10)'
# CHECK: custom-frame '(str="hello", fptr=({{.*}}.out`foo(int, int) at main.cpp:{{[0-9]+}}))'
# CHECK: custom-frame '(argc=1, argv={{.*}})'
+
+# CHECK-NODEBUG: custom-frame '()'
+# CHECK-NODEBUG: custom-frame '()'
+# CHECK-NODEBUG: custom-frame '(int, int)'
+# CHECK-NODEBUG: custom-frame '(char const*, void (*)(int, int))'
diff --git a/lldb/test/Shell/Settings/TestFrameFormatFunctionQualifiers.test b/lldb/test/Shell/Settings/TestFrameFormatFunctionQualifiers.test
index 95a3be3811d85..ad7ea65d0a261 100644
--- a/lldb/test/Shell/Settings/TestFrameFormatFunctionQualifiers.test
+++ b/lldb/test/Shell/Settings/TestFrameFormatFunctionQualifiers.test
@@ -1,9 +1,13 @@
# Test the ${function.qualifiers} frame-format variable.
# RUN: split-file %s %t
-# RUN: %build %t/main.cpp -o %t.out
+# RUN: %clang_host -g %t/main.cpp -o %t.out
# RUN: %lldb -x -b -s %t/commands.input %t.out -o exit 2>&1 \
# RUN: | FileCheck %s
+#
+# RUN: %clang_host -O0 %t/main.cpp -o %t-nodebug.out
+# RUN: %lldb -x -b -s %t/commands.input %t-nodebug.out -o exit 2>&1 \
+# RUN: | FileCheck %s
#--- main.cpp
struct Foo {
diff --git a/lldb/test/Shell/Settings/TestFrameFormatFunctionReturn.test b/lldb/test/Shell/Settings/TestFrameFormatFunctionReturn.test
index a5e49a1054c86..dd4cc68817712 100644
--- a/lldb/test/Shell/Settings/TestFrameFormatFunctionReturn.test
+++ b/lldb/test/Shell/Settings/TestFrameFormatFunctionReturn.test
@@ -2,9 +2,13 @@
# frame-format variables.
# RUN: split-file %s %t
-# RUN: %build %t/main.cpp -o %t.out
+# RUN: %clang_host -g %t/main.cpp -o %t.out
# RUN: %lldb -x -b -s %t/commands.input %t.out -o exit 2>&1 \
# RUN: | FileCheck %s
+#
+# RUN: %clang_host -O0 %t/main.cpp -o %t-nodebug.out
+# RUN: %lldb -x -b -s %t/commands.input %t-nodebug.out -o exit 2>&1 \
+# RUN: | FileCheck %s
#--- main.cpp
namespace ns::ns2 {
diff --git a/lldb/test/Shell/Settings/TestFrameFormatFunctionScope.test b/lldb/test/Shell/Settings/TestFrameFormatFunctionScope.test
index 28f0ab7ca39e3..a1d4cc01054db 100644
--- a/lldb/test/Shell/Settings/TestFrameFormatFunctionScope.test
+++ b/lldb/test/Shell/Settings/TestFrameFormatFunctionScope.test
@@ -1,9 +1,12 @@
# Test the ${function.scope} frame-format variable.
# RUN: split-file %s %t
-# RUN: %build %t/main.cpp -o %t.out
-# RUN: %lldb -o "settings set interpreter.stop-command-source-on-error false" \
-# RUN: -x -b -s %t/commands.input %t.out -o exit 2>&1 \
+# RUN: %clang_host -g %t/main.cpp -o %t.out
+# RUN: %lldb -x -b -s %t/commands.input %t.out -o exit 2>&1 \
+# RUN: | FileCheck %s
+#
+# RUN: %clang_host -O0 %t/main.cpp -o %t-nodebug.out
+# RUN: %lldb -x -b -s %t/commands.input %t-nodebug.out -o exit 2>&1 \
# RUN: | FileCheck %s
#--- main.cpp
diff --git a/lldb/test/Shell/Settings/TestFrameFormatFunctionTemplateArguments.test b/lldb/test/Shell/Settings/TestFrameFormatFunctionTemplateArguments.test
index 396dd29dfd02c..384ba0adc4ce9 100644
--- a/lldb/test/Shell/Settings/TestFrameFormatFunctionTemplateArguments.test
+++ b/lldb/test/Shell/Settings/TestFrameFormatFunctionTemplateArguments.test
@@ -1,8 +1,12 @@
# Test the ${function.template-arguments} frame-format variable.
# RUN: split-file %s %t
-# RUN: %build %t/main.cpp -o %t.cxx.out
-# RUN: %lldb -x -b -s %t/commands.input %t.cxx.out -o exit 2>&1 \
+# RUN: %clang_host -g %t/main.cpp -o %t.out
+# RUN: %lldb -x -b -s %t/commands.input %t.out -o exit 2>&1 \
+# RUN: | FileCheck %s
+#
+# RUN: %clang_host -O0 %t/main.cpp -o %t-nodebug.out
+# RUN: %lldb -x -b -s %t/commands.input %t-nodebug.out -o exit 2>&1 \
# RUN: | FileCheck %s
#--- main.cpp
``````````
</details>
https://github.com/llvm/llvm-project/pull/137408
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