imagehlp: add ImageRvaToSection() and ImageRvaToVa()

[Marcus R. Brown]

My first Wine patch.  Cheers.

	* dlls/imagehlp/access.c:
	Marcus R. Brown <mrbrown at 0xd6.org>
	Implement ImageRvaToSection() and ImageRvaToVa().

Index: dlls/imagehlp/access.c
===================================================================
RCS file: /home/wine/wine/dlls/imagehlp/access.c,v
retrieving revision 1.18
diff -u -b -B -w -p -r1.18 access.c
--- dlls/imagehlp/access.c	5 Sep 2003 23:08:37 -0000	1.18
+++ dlls/imagehlp/access.c	21 Nov 2003 11:58:37 -0000
@@ -151,8 +151,22 @@ PIMAGE_NT_HEADERS WINAPI ImageNtHeader(P
 PIMAGE_SECTION_HEADER WINAPI ImageRvaToSection(
   PIMAGE_NT_HEADERS NtHeaders, PVOID Base, ULONG Rva)
 {
-  FIXME("(%p, %p, %ld): stub\n", NtHeaders, Base, Rva);
-  SetLastError(ERROR_CALL_NOT_IMPLEMENTED);
+  PIMAGE_SECTION_HEADER pCurSection;
+  INT i;
+  WORD numSections;
+
+  TRACE("(%p, %p, %lx)\n", NtHeaders, Base, Rva);
+
+  pCurSection = IMAGE_FIRST_SECTION(NtHeaders);
+  numSections = NtHeaders->FileHeader.NumberOfSections;
+
+  for (i = 0; i < numSections; i++, pCurSection++) {
+    /* Is the RVA within this section?  */
+    if (Rva >= pCurSection->VirtualAddress &&
+        Rva < (pCurSection->VirtualAddress + pCurSection->SizeOfRawData))
+      return pCurSection;
+  }
+
   return NULL;
 }
 
@@ -163,11 +177,23 @@ PVOID WINAPI ImageRvaToVa(
   PIMAGE_NT_HEADERS NtHeaders, PVOID Base, ULONG Rva,
   PIMAGE_SECTION_HEADER *LastRvaSection)
 {
-  FIXME("(%p, %p, %ld, %p): stub\n",
-    NtHeaders, Base, Rva, LastRvaSection
-  );
-  SetLastError(ERROR_CALL_NOT_IMPLEMENTED);
+  PIMAGE_SECTION_HEADER pSection = NULL;
+
+  TRACE("(%p, %p, %lx, %p)\n", NtHeaders, Base, Rva, LastRvaSection);
+
+  if (!LastRvaSection || !(pSection = *LastRvaSection) ||
+      (Rva < pSection->VirtualAddress ||
+       Rva >= (pSection->VirtualAddress + pSection->SizeOfRawData)))
+    pSection = ImageRvaToSection(NtHeaders, Base, Rva);
+
+  if (!pSection)
   return NULL;
+
+  if (LastRvaSection)
+    *LastRvaSection = pSection;
+
+  return (PVOID)((LPBYTE)Base +
+          (pSection->PointerToRawData - pSection->VirtualAddress + Rva));
 }
 
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