diff options
| -rw-r--r-- | AGENTS/ARCH.md | 4 | ||||
| -rw-r--r-- | tools/driver/EmbeddedRunner.cc | 74 |
2 files changed, 52 insertions, 26 deletions
diff --git a/AGENTS/ARCH.md b/AGENTS/ARCH.md index 0479641..2e122a5 100644 --- a/AGENTS/ARCH.md +++ b/AGENTS/ARCH.md @@ -141,7 +141,9 @@ Driver behavior (`tools/driver/main.cc`): Windows x86_64 keeps the GNU C++ runtime and `__gxx_personality_seh0` with a small in-process COFF adapter: per-graph `__ImageBase` shared by relocations and SEH registration, default backend liveness for `.pdata`, JITLink - pointer-jump stubs for the `.xdata` personality references, and + pointer-jump stubs for external direct CALL/JMP PCRel32 references in user + objects and `.xdata` personality references (shared per target; data references + are preserved), and `RtlAddFunctionTable`/`RtlDeleteFunctionTable` via JITLink allocation actions covering teardown and link-failure cleanup, with table validation in the registration callback; registration failure blocks entry. diff --git a/tools/driver/EmbeddedRunner.cc b/tools/driver/EmbeddedRunner.cc index 742a6e4..f7077f2 100644 --- a/tools/driver/EmbeddedRunner.cc +++ b/tools/driver/EmbeddedRunner.cc @@ -36,11 +36,55 @@ namespace { // which does not apply to the current MinGW build. This plugin provides only // the linking and registration pieces needed for in-process execution: // a per-graph __ImageBase shared by relocations and SEH registration, -// JITLink stubs for the GNU personality symbols referenced from .xdata, +// JITLink stubs for external direct branches and GNU personalities in .xdata, // and RtlAddFunctionTable/RtlDeleteFunctionTable via JITLink allocation // actions. Exception propagation still uses the existing C++ ABI, LLVM // exception instructions and platform unwinder. +static llvm::Error addCOFFJumpStubs(llvm::jitlink::LinkGraph &G) { + using namespace llvm; + using namespace llvm::jitlink; + using namespace llvm::jitlink::x86_64; + GOTTableManager GOT(G); + PLTTableManager PLT(G, GOT); + // Creating a stub may add sections/blocks. Visit only the original blocks. + std::vector<Block *> Blocks(G.blocks().begin(), G.blocks().end()); + for (auto *B : Blocks) { + bool Executable = (B->getSection().getMemProt() & orc::MemProt::Exec) != + orc::MemProt::None; + for (auto &E : B->edges()) { + Symbol &Target = E.getTarget(); + if (!Target.isExternal()) + continue; + bool Personality = false; + if (B->getSection().getName() == ".xdata" && Target.hasName()) { + StringRef Name = *Target.getName(); + Personality = Name == "__gxx_personality_seh0" || + Name == "__gxx_personality_sj0" || + Name == "__gxx_personality_v0"; + } + // COFF's private PCRel32 kind is lowered only in PreFixup. + // Use its name rather than confusing it with x86_64::PCRel32. + // Only E8/E9 direct branches with a plain symbol target need a + // jump stub; RIP-relative data and indirect calls must stay intact. + bool DirectBranch = false; + if (Executable && !B->isZeroFill() && E.getAddend() == 0 && + StringRef(G.getEdgeKindName(E.getKind())) == "PCRel32") { + auto Content = B->getContent(); + size_t Offset = E.getOffset(); + if (Offset > 0 && Offset <= Content.size() && + Content.size() - Offset >= 4) { + unsigned char Opcode = Content[Offset - 1]; + DirectBranch = Opcode == 0xe8 || Opcode == 0xe9; + } + } + if (Personality || DirectBranch) + E.setTarget(PLT.getEntryForTarget(G, Target)); + } + } + return Error::success(); +} + static llvm::Error registerSEHTable(llvm::orc::ExecutorAddrRange TableRange, llvm::orc::ExecutorAddr ImageBase) { using llvm::make_error; @@ -127,30 +171,10 @@ public: // must live near JIT code. Retarget .xdata personality references // to this graph's anonymous pointer jump stubs; the stub pointer // itself uses a 64-bit relocation to reach the far host runtime. - // The same target reuses the same stub. Only personality symbols - // are rewritten here. - Config.PostPrunePasses.push_back([](LinkGraph &G) -> Error { - auto *XDataSec = G.findSectionByName(".xdata"); - if (!XDataSec) - return Error::success(); - using namespace llvm::jitlink::x86_64; - GOTTableManager GOT(G); - PLTTableManager PLT(G, GOT); - for (auto *B : XDataSec->blocks()) { - for (auto &E : B->edges()) { - Symbol &Target = E.getTarget(); - if (!Target.isExternal() || !Target.hasName()) - continue; - StringRef Name = *Target.getName(); - if (Name != "__gxx_personality_seh0" && - Name != "__gxx_personality_sj0" && - Name != "__gxx_personality_v0") - continue; - E.setTarget(PLT.getEntryForTarget(G, Target)); - } - } - return Error::success(); - }); + // External direct calls/jumps from user objects also need nearby + // stubs: their PCRel32 displacement cannot reach a distant CRT DLL. + // The same target reuses the same stub, including personality uses. + Config.PostPrunePasses.push_back(addCOFFJumpStubs); // COFF unwind tables use 32-bit image-relative addresses, so the // image base must sit at or below the lowest JIT address. Alias the |