carbon-language/carbon-lang
1
0
Fork 0
mirror of https://github.com/carbon-language/carbon-lang.git synced 2026-09-24 19:20:13 +01:00
Code Issues Packages Projects Releases 10 Wiki Activity

Avoid creating a vector of bools to mark which C++ thunk parameter types were modified (#5941)

Browse Source 
Instead, check which types were modified.
This simplifies the logic and could make it easier to add return value
support.

Part of #5514.
This commit is contained in:
Boaz Brickner
2025-08-11 15:01:51 +00:00
committed by GitHub
parent fd3eb136af
commit 5b328da0aa
1 changed files with 11 additions and 18 deletions
Download Patch File Download Diff File Expand all files Collapse all files
toolchain/check/cpp_thunk.cpp
+11 -18
View File
@@ -119,20 +119,13 @@ static auto IsSimpleAbiType(clang::ASTContext& ast_context,
return false;
}
// Creates the thunk parameter types given the callee function. Also returns for
// each type whether it is different from the matching callee function parameter
// type.
// Creates the thunk parameter types given the callee function.
static auto BuildThunkParameterTypes(
clang::ASTContext& ast_context,
const clang::FunctionDecl& callee_function_decl)
-> std::tuple<llvm::SmallVector<clang::QualType>, llvm::SmallVector<bool>> {
std::tuple<llvm::SmallVector<clang::QualType>, llvm::SmallVector<bool>>
result;
auto& [thunk_param_types, param_type_changed] = result;
unsigned num_params = callee_function_decl.getNumParams();
thunk_param_types.reserve(num_params);
param_type_changed.reserve(num_params);
-> llvm::SmallVector<clang::QualType> {
llvm::SmallVector<clang::QualType> thunk_param_types;
thunk_param_types.reserve(callee_function_decl.getNumParams());
for (const clang::ParmVarDecl* callee_param :
callee_function_decl.parameters()) {
@@ -143,11 +136,10 @@ static auto BuildThunkParameterTypes(
param_type = ast_context.getAttributedType(
clang::NullabilityKind::NonNull, pointer_type, pointer_type);
}
param_type_changed.push_back(!is_simple_abi_type);
thunk_param_types.push_back(param_type);
}
return result;
return thunk_param_types;
}
// Returns the thunk parameters using the callee function parameter identifiers.
@@ -225,11 +217,11 @@ static auto CreateThunkFunctionDecl(
// callee function which is the thunk parameter or its address.
static auto BuildCalleeArgs(clang::Sema& sema,
clang::FunctionDecl* thunk_function_decl,
llvm::ArrayRef<bool> param_type_changed)
const clang::FunctionDecl& callee_function_decl)
-> llvm::SmallVector<clang::Expr*> {
llvm::SmallVector<clang::Expr*> call_args;
size_t num_params = thunk_function_decl->getNumParams();
CARBON_CHECK(param_type_changed.size() == num_params);
CARBON_CHECK(callee_function_decl.getNumParams() == num_params);
call_args.reserve(num_params);
for (unsigned i = 0; i < num_params; ++i) {
clang::ParmVarDecl* thunk_param = thunk_function_decl->getParamDecl(i);
@@ -237,7 +229,8 @@ static auto BuildCalleeArgs(clang::Sema& sema,
clang::Expr* call_arg = sema.BuildDeclRefExpr(
thunk_param, thunk_param->getType(), clang::VK_LValue, clang_loc);
if (param_type_changed[i]) {
if (thunk_param->getType() !=
callee_function_decl.getParamDecl(i)->getType()) {
// TODO: Consider inserting a cast to an rvalue. Note that we currently
// pass pointers to non-temporary objects as the argument when calling a
// thunk, so we'll need to either change that or generate different thunks
@@ -288,7 +281,7 @@ auto BuildCppThunk(Context& context, const SemIR::Function& callee_function)
CARBON_CHECK(callee_function_decl);
// Build the thunk function declaration.
auto [thunk_param_types, param_type_changed] =
auto thunk_param_types =
BuildThunkParameterTypes(context.ast_context(), *callee_function_decl);
clang::FunctionDecl* thunk_function_decl = CreateThunkFunctionDecl(
context, *callee_function_decl, thunk_param_types);
@@ -299,7 +292,7 @@ auto BuildCppThunk(Context& context, const SemIR::Function& callee_function)
sema.ActOnStartOfFunctionDef(nullptr, thunk_function_decl);
llvm::SmallVector<clang::Expr*> call_args =
BuildCalleeArgs(sema, thunk_function_decl, param_type_changed);
BuildCalleeArgs(sema, thunk_function_decl, *callee_function_decl);
clang::Stmt* body = BuildThunkBody(sema, callee_function_decl, call_args);
sema.ActOnFinishFunctionBody(thunk_function_decl, body);
if (!body) {