[Lldb-commits] [lldb] r368688 - [lldb] Reland "Refactor guard variable checks in IRForTarget"
Raphael Isemann via lldb-commits
lldb-commits at lists.llvm.org
Tue Aug 13 06:09:18 PDT 2019
Author: teemperor
Date: Tue Aug 13 06:09:18 2019
New Revision: 368688
URL: http://llvm.org/viewvc/llvm-project?rev=368688&view=rev
Log:
[lldb] Reland "Refactor guard variable checks in IRForTarget"
It seems the broken guard variable check for Windows was a feature(TM)
and not a bug, so let's keep add a flag to the guard check that keeps
the old behavior in the places where we ignored guard variables before.
Modified:
lldb/trunk/source/Plugins/ExpressionParser/Clang/IRForTarget.cpp
Modified: lldb/trunk/source/Plugins/ExpressionParser/Clang/IRForTarget.cpp
URL: http://llvm.org/viewvc/llvm-project/lldb/trunk/source/Plugins/ExpressionParser/Clang/IRForTarget.cpp?rev=368688&r1=368687&r2=368688&view=diff
==============================================================================
--- lldb/trunk/source/Plugins/ExpressionParser/Clang/IRForTarget.cpp (original)
+++ lldb/trunk/source/Plugins/ExpressionParser/Clang/IRForTarget.cpp Tue Aug 13 06:09:18 2019
@@ -155,6 +155,15 @@ clang::NamedDecl *IRForTarget::DeclForGl
return DeclForGlobal(global_val, m_module);
}
+/// Returns true iff the mangled symbol is for a static guard variable.
+static bool isGuardVariableSymbol(llvm::StringRef mangled_symbol,
+ bool check_ms_abi = true) {
+ bool result = mangled_symbol.startswith("_ZGV"); // Itanium ABI guard variable
+ if (check_ms_abi)
+ result |= mangled_symbol.startswith("@4IA"); // Microsoft ABI
+ return result;
+}
+
bool IRForTarget::CreateResultVariable(llvm::Function &llvm_function) {
lldb_private::Log *log(
lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_EXPRESSIONS));
@@ -172,15 +181,17 @@ bool IRForTarget::CreateResultVariable(l
for (StringMapEntry<llvm::Value *> &value_symbol : value_symbol_table) {
result_name = value_symbol.first();
- if (result_name.contains("$__lldb_expr_result_ptr") &&
- !result_name.startswith("_ZGV")) {
+ // Check if this is a guard variable. It seems this causes some hiccups
+ // on Windows, so let's only check for Itanium guard variables.
+ bool is_guard_var = isGuardVariableSymbol(result_name, /*MS ABI*/ false);
+
+ if (result_name.contains("$__lldb_expr_result_ptr") && !is_guard_var) {
found_result = true;
m_result_is_pointer = true;
break;
}
- if (result_name.contains("$__lldb_expr_result") &&
- !result_name.startswith("_ZGV")) {
+ if (result_name.contains("$__lldb_expr_result") && !is_guard_var) {
found_result = true;
m_result_is_pointer = false;
break;
@@ -1528,14 +1539,12 @@ bool IRForTarget::ResolveExternals(Funct
}
static bool isGuardVariableRef(Value *V) {
- Constant *Old = nullptr;
+ Constant *Old = dyn_cast<Constant>(V);
- if (!(Old = dyn_cast<Constant>(V)))
+ if (!Old)
return false;
- ConstantExpr *CE = nullptr;
-
- if ((CE = dyn_cast<ConstantExpr>(V))) {
+ if (auto CE = dyn_cast<ConstantExpr>(V)) {
if (CE->getOpcode() != Instruction::BitCast)
return false;
@@ -1544,12 +1553,8 @@ static bool isGuardVariableRef(Value *V)
GlobalVariable *GV = dyn_cast<GlobalVariable>(Old);
- if (!GV || !GV->hasName() ||
- (!GV->getName().startswith("_ZGV") && // Itanium ABI guard variable
- !GV->getName().endswith("@4IA"))) // Microsoft ABI guard variable
- {
+ if (!GV || !GV->hasName() || !isGuardVariableSymbol(GV->getName()))
return false;
- }
return true;
}
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