Basic support for -mms-bitfields, from Carl Norum!
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@124661 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/AST/RecordLayoutBuilder.cpp b/lib/AST/RecordLayoutBuilder.cpp
index 7e15dcc..730ec21 100644
--- a/lib/AST/RecordLayoutBuilder.cpp
+++ b/lib/AST/RecordLayoutBuilder.cpp
@@ -1402,6 +1402,20 @@
std::pair<uint64_t, unsigned> FieldInfo = Context.getTypeInfo(D->getType());
FieldSize = FieldInfo.first;
FieldAlign = FieldInfo.second;
+
+ if (Context.getLangOptions().MSBitfields) {
+ // If MS bitfield layout is required, figure out what type is being
+ // laid out and align the field to the width of that type.
+
+ // Resolve all typedefs down to their base type and round up the field
+ // alignment if necessary.
+ QualType T = Context.getBaseElementType(D->getType());
+ if (const BuiltinType *BTy = T->getAs<BuiltinType>()) {
+ uint64_t TypeSize = Context.getTypeSize(BTy);
+ if (TypeSize > FieldAlign)
+ FieldAlign = TypeSize;
+ }
+ }
}
// The align if the field is not packed. This is to check if the attribute
diff --git a/lib/Driver/Tools.cpp b/lib/Driver/Tools.cpp
index d11db7e..8f8c64d 100644
--- a/lib/Driver/Tools.cpp
+++ b/lib/Driver/Tools.cpp
@@ -1028,6 +1028,10 @@
// work around a linker bug; see <rdar://problem/7651567>.
if (getToolChain().getTriple().getOS() != llvm::Triple::Darwin)
CmdArgs.push_back("-mconstructor-aliases");
+
+ if (Args.hasArg(options::OPT_mms_bitfields)) {
+ CmdArgs.push_back("-mms-bitfields");
+ }
// This is a coarse approximation of what llvm-gcc actually does, both
// -fasynchronous-unwind-tables and -fnon-call-exceptions interact in more
diff --git a/lib/Frontend/CompilerInvocation.cpp b/lib/Frontend/CompilerInvocation.cpp
index 3fdbc16..9ad4145 100644
--- a/lib/Frontend/CompilerInvocation.cpp
+++ b/lib/Frontend/CompilerInvocation.cpp
@@ -583,6 +583,8 @@
Res.push_back("-fsjlj-exceptions");
if (!Opts.RTTI)
Res.push_back("-fno-rtti");
+ if (Opts.MSBitfields)
+ Res.push_back("-mms-bitfields");
if (!Opts.NeXTRuntime)
Res.push_back("-fgnu-runtime");
if (Opts.Freestanding)
@@ -1445,6 +1447,7 @@
Diags);
Opts.NumLargeByValueCopy = Args.getLastArgIntValue(OPT_Wlarge_by_value_copy,
0, Diags);
+ Opts.MSBitfields = Args.hasArg(OPT_mms_bitfields);
Opts.NeXTRuntime = !Args.hasArg(OPT_fgnu_runtime);
Opts.ObjCConstantStringClass =
Args.getLastArgValue(OPT_fconstant_string_class);
diff --git a/lib/Serialization/ASTReader.cpp b/lib/Serialization/ASTReader.cpp
index 7e7bd25..1e07e76 100644
--- a/lib/Serialization/ASTReader.cpp
+++ b/lib/Serialization/ASTReader.cpp
@@ -96,6 +96,7 @@
PARSE_LANGOPT_IMPORTANT(AltiVec, diag::warn_pch_altivec);
PARSE_LANGOPT_IMPORTANT(Exceptions, diag::warn_pch_exceptions);
PARSE_LANGOPT_IMPORTANT(SjLjExceptions, diag::warn_pch_sjlj_exceptions);
+ PARSE_LANGOPT_IMPORTANT(MSBitfields, diag::warn_pch_ms_bitfields);
PARSE_LANGOPT_IMPORTANT(NeXTRuntime, diag::warn_pch_objc_runtime);
PARSE_LANGOPT_IMPORTANT(Freestanding, diag::warn_pch_freestanding);
PARSE_LANGOPT_IMPORTANT(NoBuiltin, diag::warn_pch_builtins);
@@ -2613,6 +2614,7 @@
PARSE_LANGOPT(AltiVec);
PARSE_LANGOPT(Exceptions);
PARSE_LANGOPT(SjLjExceptions);
+ PARSE_LANGOPT(MSBitfields);
PARSE_LANGOPT(NeXTRuntime);
PARSE_LANGOPT(Freestanding);
PARSE_LANGOPT(NoBuiltin);
diff --git a/lib/Serialization/ASTWriter.cpp b/lib/Serialization/ASTWriter.cpp
index e906407..b85aac1 100644
--- a/lib/Serialization/ASTWriter.cpp
+++ b/lib/Serialization/ASTWriter.cpp
@@ -911,6 +911,7 @@
Record.push_back(LangOpts.Exceptions); // Support exception handling.
Record.push_back(LangOpts.SjLjExceptions);
+ Record.push_back(LangOpts.MSBitfields); // MS-compatible structure layout
Record.push_back(LangOpts.NeXTRuntime); // Use NeXT runtime.
Record.push_back(LangOpts.Freestanding); // Freestanding implementation
Record.push_back(LangOpts.NoBuiltin); // Do not use builtin functions (-fno-builtin)