Teach LTOModule to emit linker flags for dllexported symbols, plus interface cleanup.
This change unifies how LTOModule and the backend obtain linker flags
for globals: via a new TargetLoweringObjectFile member function named
emitLinkerFlagsForGlobal. A new function LTOModule::getLinkerOpts() returns
the list of linker flags as a single concatenated string.
This change affects the C libLTO API: the function lto_module_get_*deplibs now
exposes an empty list, and lto_module_get_*linkeropts exposes a single element
which combines the contents of all observed flags. libLTO should never have
tried to parse the linker flags; it is the linker's job to do so. Because
linkers will need to be able to parse flags in regular object files, it
makes little sense for libLTO to have a redundant mechanism for doing so.
The new API is compatible with the old one. It is valid for a user to specify
multiple linker flags in a single pragma directive like this:
#pragma comment(linker, "/defaultlib:foo /defaultlib:bar")
The previous implementation would not have exposed
either flag via lto_module_get_*deplibs (as the test in
TargetLoweringObjectFileCOFF::getDepLibFromLinkerOpt was case sensitive)
and would have exposed "/defaultlib:foo /defaultlib:bar" as a single flag via
lto_module_get_*linkeropts. This may have been a bug in the implementation,
but it does give us a chance to fix the interface.
Differential Revision: http://reviews.llvm.org/D10548
llvm-svn: 241010
diff --git a/llvm/lib/LTO/LTOModule.cpp b/llvm/lib/LTO/LTOModule.cpp
index bbb3b6d..6131c31 100644
--- a/llvm/lib/LTO/LTOModule.cpp
+++ b/llvm/lib/LTO/LTOModule.cpp
@@ -19,6 +19,7 @@
#include "llvm/IR/Constants.h"
#include "llvm/IR/DiagnosticPrinter.h"
#include "llvm/IR/LLVMContext.h"
+#include "llvm/IR/Mangler.h"
#include "llvm/IR/Metadata.h"
#include "llvm/IR/Module.h"
#include "llvm/MC/MCExpr.h"
@@ -642,6 +643,8 @@
/// parseMetadata - Parse metadata from the module
void LTOModule::parseMetadata() {
+ raw_string_ostream OS(LinkerOpts);
+
// Linker Options
if (Metadata *Val = getModule().getModuleFlag("Linker Options")) {
MDNode *LinkerOptions = cast<MDNode>(Val);
@@ -649,20 +652,19 @@
MDNode *MDOptions = cast<MDNode>(LinkerOptions->getOperand(i));
for (unsigned ii = 0, ie = MDOptions->getNumOperands(); ii != ie; ++ii) {
MDString *MDOption = cast<MDString>(MDOptions->getOperand(ii));
- // FIXME: Make StringSet::insert match Self-Associative Container
- // requirements, returning <iter,bool> rather than bool, and use that
- // here.
- StringRef Op =
- _linkeropt_strings.insert(MDOption->getString()).first->first();
- StringRef DepLibName =
- _target->getObjFileLowering()->getDepLibFromLinkerOpt(Op);
- if (!DepLibName.empty())
- _deplibs.push_back(DepLibName.data());
- else if (!Op.empty())
- _linkeropts.push_back(Op.data());
+ OS << " " << MDOption->getString();
}
}
}
+ // Globals
+ Mangler Mang;
+ for (const NameAndAttributes &Sym : _symbols) {
+ if (!Sym.symbol)
+ continue;
+ _target->getObjFileLowering()->emitLinkerFlagsForGlobal(OS, Sym.symbol,
+ Mang);
+ }
+
// Add other interesting metadata here.
}