[lld] r308953 - [COFF] Correctly set the thumb bit in DLL export addresses

[Martin Storsjo via llvm-commits]

Author: mstorsjo
Date: Mon Jul 24 23:10:44 2017
New Revision: 308953

URL: http://llvm.org/viewvc/llvm-project?rev=308953&view=rev
Log:
[COFF] Correctly set the thumb bit in DLL export addresses

The same adjustment is already done for the entry point in
Writer.cpp and for relocations that point to executable code
in Chunks.cpp.

Differential Revision: https://reviews.llvm.org/D35767

Added:
    lld/trunk/test/COFF/export-armnt.yaml
Modified:
    lld/trunk/COFF/DLL.cpp

Modified: lld/trunk/COFF/DLL.cpp
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/COFF/DLL.cpp?rev=308953&r1=308952&r2=308953&view=diff
==============================================================================
--- lld/trunk/COFF/DLL.cpp (original)
+++ lld/trunk/COFF/DLL.cpp Mon Jul 24 23:10:44 2017
@@ -319,12 +319,16 @@ public:
   size_t getSize() const override { return Size * 4; }
 
   void writeTo(uint8_t *Buf) const override {
+    uint32_t Bit = 0;
+    // Pointer to thumb code must have the LSB set, so adjust it.
+    if (Config->Machine == ARMNT)
+      Bit = 1;
     for (Export &E : Config->Exports) {
       uint8_t *P = Buf + OutputSectionOff + E.Ordinal * 4;
       if (E.ForwardChunk) {
-        write32le(P, E.ForwardChunk->getRVA());
+        write32le(P, E.ForwardChunk->getRVA() | Bit);
       } else {
-        write32le(P, cast<Defined>(E.Sym)->getRVA());
+        write32le(P, cast<Defined>(E.Sym)->getRVA() | Bit);
       }
     }
   }

Added: lld/trunk/test/COFF/export-armnt.yaml
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/test/COFF/export-armnt.yaml?rev=308953&view=auto
==============================================================================
--- lld/trunk/test/COFF/export-armnt.yaml (added)
+++ lld/trunk/test/COFF/export-armnt.yaml Mon Jul 24 23:10:44 2017
@@ -0,0 +1,72 @@
+# REQUIRES: arm
+
+# RUN: yaml2obj < %s > %t.obj
+#
+# RUN: lld-link /out:%t.dll /dll %t.obj /export:exportfn1 /export:exportfn2
+# RUN: llvm-objdump -p %t.dll | FileCheck %s
+
+# CHECK:      Export Table:
+# CHECK:      DLL name: export-armnt.yaml.tmp.dll
+# CHECK:      Ordinal      RVA  Name
+# CHECK-NEXT:       0        0
+# CHECK-NEXT:       1   0x1005  exportfn1
+# CHECK-NEXT:       2   0x1009  exportfn2
+# CHECK-NEXT:       3   0x1009  exportfn3
+
+--- !COFF
+header:
+  Machine:         IMAGE_FILE_MACHINE_ARMNT
+  Characteristics: []
+sections:
+  - Name:            .text
+    Characteristics: [ IMAGE_SCN_CNT_CODE, IMAGE_SCN_MEM_EXECUTE, IMAGE_SCN_MEM_READ ]
+    Alignment:       4
+    SectionData:     704700bf704700bf704700bf
+  - Name:            .drectve
+    Characteristics: [ IMAGE_SCN_LNK_INFO, IMAGE_SCN_LNK_REMOVE ]
+    Alignment:       1
+    SectionData:     2f6578706f72743a6578706f7274666e3300  # /export:exportfn3
+symbols:
+  - Name:            .text
+    Value:           0
+    SectionNumber:   1
+    SimpleType:      IMAGE_SYM_TYPE_NULL
+    ComplexType:     IMAGE_SYM_DTYPE_NULL
+    StorageClass:    IMAGE_SYM_CLASS_STATIC
+    SectionDefinition:
+      Length:          12
+      NumberOfRelocations: 0
+      NumberOfLinenumbers: 0
+      CheckSum:        0
+      Number:          0
+  - Name:            _DllMainCRTStartup
+    Value:           0
+    SectionNumber:   1
+    SimpleType:      IMAGE_SYM_TYPE_NULL
+    ComplexType:     IMAGE_SYM_DTYPE_NULL
+    StorageClass:    IMAGE_SYM_CLASS_EXTERNAL
+  - Name:            exportfn1
+    Value:           4
+    SectionNumber:   1
+    SimpleType:      IMAGE_SYM_TYPE_NULL
+    ComplexType:     IMAGE_SYM_DTYPE_NULL
+    StorageClass:    IMAGE_SYM_CLASS_EXTERNAL
+  - Name:            exportfn2
+    Value:           8
+    SectionNumber:   1
+    SimpleType:      IMAGE_SYM_TYPE_NULL
+    ComplexType:     IMAGE_SYM_DTYPE_NULL
+    StorageClass:    IMAGE_SYM_CLASS_EXTERNAL
+  - Name:            exportfn3
+    Value:           8
+    SectionNumber:   1
+    SimpleType:      IMAGE_SYM_TYPE_NULL
+    ComplexType:     IMAGE_SYM_DTYPE_NULL
+    StorageClass:    IMAGE_SYM_CLASS_EXTERNAL
+  - Name:            '?mangled@@YAHXZ'
+    Value:           8
+    SectionNumber:   1
+    SimpleType:      IMAGE_SYM_TYPE_NULL
+    ComplexType:     IMAGE_SYM_DTYPE_NULL
+    StorageClass:    IMAGE_SYM_CLASS_EXTERNAL
+...