[llvm-commits] [llvm] r169438 - /llvm/trunk/tools/llvm-objdump/COFFDump.cpp

[Kai]

Hi Michael!

The attached patch removes the warning. I now use the memory address of 
the member and the base address of the section to calculate the 
distances. Please have a look at it. Thanks.

Regards
Kai

On 05.12.2012 23:55, Michael Spencer wrote:
>
> Kai,
>
> Please fix this in a less hacky way.
>
> The problem is that RuntimeFunction is not a POD type in c++03, and
> offsetof is only well defined for POD types. clang warns on this in
> c++03 mode.
>
> - Michael Spencer
>

-------------- next part --------------
diff --git a/tools/llvm-objdump/COFFDump.cpp b/tools/llvm-objdump/COFFDump.cpp
index 30faecb..b44ac6e 100644
--- a/tools/llvm-objdump/COFFDump.cpp
+++ b/tools/llvm-objdump/COFFDump.cpp
@@ -30,6 +30,13 @@ using namespace llvm;
 using namespace object;
 using namespace llvm::Win64EH;
 
+// Calculates the offset of member using base as base address.
+// The implementation of Endian.h guaranties that the offsets are right.
+static uint64_t offsetOf(const RuntimeFunction *base,
+                         const support::ulittle32_t *member) {
+    return reinterpret_cast<size_t>(member) - reinterpret_cast<size_t>(base);
+}
+
 // Returns the name of the unwind code.
 static StringRef getUnwindCodeTypeName(uint8_t Code) {
   switch(Code) {
@@ -270,33 +277,30 @@ void llvm::printCOFFUnwindInfo(const COFFObjectFile *Obj) {
                   reinterpret_cast<const RuntimeFunction *>(Contents.data()),
                                   Contents.size() / sizeof(RuntimeFunction));
     for (const RuntimeFunction *I = RFs.begin(), *E = RFs.end(); I < E; ++I) {
-      const uint64_t SectionOffset = std::distance(RFs.begin(), I)
-                                     * sizeof(RuntimeFunction);
-
       outs() << "Function Table:\n";
 
       outs() << "  Start Address: ";
-      printCOFFSymbolAddress(outs(), Rels, SectionOffset +
-                             /*offsetof(RuntimeFunction, StartAddress)*/ 0,
+      printCOFFSymbolAddress(outs(), Rels,
+                             offsetOf(RFs.begin(), &I->StartAddress),
                              I->StartAddress);
       outs() << "\n";
 
       outs() << "  End Address: ";
-      printCOFFSymbolAddress(outs(), Rels, SectionOffset +
-                             /*offsetof(RuntimeFunction, EndAddress)*/ 4,
+      printCOFFSymbolAddress(outs(), Rels,
+                             offsetOf(RFs.begin(), &I->EndAddress),
                              I->EndAddress);
       outs() << "\n";
 
       outs() << "  Unwind Info Address: ";
-      printCOFFSymbolAddress(outs(), Rels, SectionOffset +
-                             /*offsetof(RuntimeFunction, UnwindInfoOffset)*/ 8,
+      printCOFFSymbolAddress(outs(), Rels,
+                             offsetOf(RFs.begin(), &I->UnwindInfoOffset),
                              I->UnwindInfoOffset);
       outs() << "\n";
 
       ArrayRef<uint8_t> XContents;
       uint64_t UnwindInfoOffset = 0;
-      if (error(getSectionContents(Obj, Rels, SectionOffset +
-                              /*offsetof(RuntimeFunction, UnwindInfoOffset)*/ 8,
+      if (error(getSectionContents(Obj, Rels,
+                                   offsetOf(RFs.begin(), &I->UnwindInfoOffset),
                                    XContents, UnwindInfoOffset))) continue;
       if (XContents.empty()) continue;