bindexplib: Revert support for constants symbols

Revert the main logic change of commit v3.9.0-rc1~192^2 (bindexplib: fix
constants symbols export, 2017-04-26) and its test case.  Unfortunately
some constants may be provided by multiple object files with different
`@...` suffixes, leading to ambiguous references.  Revert support
pending further investigation.

Fixes: #17045

3 files changed, 12 insertions, 22 deletions

diff --git a/Source/bindexplib.cxx b/Source/bindexplib.cxx
index cd1fb8a..e96226a 100644
--- a/Source/bindexplib.cxx
+++ b/Source/bindexplib.cxx
@@ -242,24 +242,26 @@ public:
 
           // Check whether it is "Scalar deleting destructor" and "Vector
           // deleting destructor"
-          // if scalarPrefix and vectorPrefix are not found then print the
-          // symbol
+          // if scalarPrefix and vectorPrefix are not found then print
+          // the symbol
           const char* scalarPrefix = "??_G";
           const char* vectorPrefix = "??_E";
+          // The original code had a check for
+          //     symbol.find("real@") == std::string::npos)
+          // but this disallows member functions with the name "real".
           if (symbol.compare(0, 4, scalarPrefix) &&
               symbol.compare(0, 4, vectorPrefix)) {
             SectChar = this->SectionHeaders[pSymbolTable->SectionNumber - 1]
                          .Characteristics;
-
             // skip symbols containing a dot
             if (symbol.find('.') == std::string::npos) {
-              if (SectChar & IMAGE_SCN_MEM_EXECUTE) {
-                this->Symbols.insert(symbol);
-              } else if (SectChar & IMAGE_SCN_MEM_READ) {
-                // skip __real@ and __xmm@
-                if (symbol.find("_real") == std::string::npos &&
-                    symbol.find("_xmm") == std::string::npos) {
-                  this->DataSymbols.insert(symbol);
+              if (!pSymbolTable->Type && (SectChar & IMAGE_SCN_MEM_WRITE)) {
+                // Read only (i.e. constants) must be excluded
+                this->DataSymbols.insert(symbol);
+              } else {
+                if (pSymbolTable->Type || !(SectChar & IMAGE_SCN_MEM_READ) ||
+                    (SectChar & IMAGE_SCN_MEM_EXECUTE)) {
+                  this->Symbols.insert(symbol);
                 }
               }
             }
diff --git a/Tests/RunCMake/AutoExportDll/foo.c b/Tests/RunCMake/AutoExportDll/foo.c
index e70fbb5..4b1318b 100644
--- a/Tests/RunCMake/AutoExportDll/foo.c
+++ b/Tests/RunCMake/AutoExportDll/foo.c
@@ -13,5 +13,3 @@ int bar()
 {
   return 5;
 }
-
-const char testconst[] = "testconst";
diff --git a/Tests/RunCMake/AutoExportDll/say.cxx b/Tests/RunCMake/AutoExportDll/say.cxx
index eb9c0ff..51060e8 100644
--- a/Tests/RunCMake/AutoExportDll/say.cxx
+++ b/Tests/RunCMake/AutoExportDll/say.cxx
@@ -13,14 +13,6 @@ int WINAPI foo();
 int bar();
 int objlib();
 void justnop();
-
-// test const export
-#ifdef _WIN32
-// data symbols must be explicitly imported
-__declspec(dllimport) extern const char testconst[];
-#else
-extern const char testconst[];
-#endif
 }
 
 // test c++ functions
@@ -51,8 +43,6 @@ int main()
   bar();
   objlib();
   printf("\n");
-  printf("%s", testconst);
-  printf("\n");
 #ifdef HAS_JUSTNOP
   justnop();
 #endif