[Clang][CodeGen] Add __builtin_bcopy

[cseo]

Summary

Add __builtin_bcopy to the list of GNU builtins. This was causing a series of
test failures in glibc.

Adjust the tests to reflect the changes in codegen.

Fixes #51409.
Fixes #63065.

[cseo]

Fix ppc bcopy test

[cseo]

Fix builtin definition and tests

[shafik]

clang/lib/CodeGen/CGBuiltin.cpp

3567

Maybe it is better to do these in order to be consistent with the rest of the code to avoid easy confusion.

3573

[cseo]

Address issues from the last revision.

[cseo]

FWIW, the pre-merge checks failed due to a problem with git-clang-format, not the tests themselves (they are all green).

[cseo]

Ping. Any other comments/concerns?

clang/include/clang/Basic/Builtins.def

 BUILTIN(__builtin___CFStringMakeConstantString, "FC*cC*", "ncE")
 BUILTIN(__builtin___NSStringMakeConstantString, "FC*cC*", "ncE")
 BUILTIN(__builtin_va_start, "vA.", "nt")
 BUILTIN(__builtin_va_end, "vA", "n")
 BUILTIN(__builtin_va_copy, "vAA", "n")
 BUILTIN(__builtin_stdarg_start, "vA.", "nt")
 BUILTIN(__builtin_assume_aligned, "v*vC*z.", "nctE")
 BUILTIN(__builtin_bcmp, "ivC*vC*z", "FnE")
-BUILTIN(__builtin_bcopy, "vv*v*z", "n")
+BUILTIN(__builtin_bcopy, "vvC*v*z", "n")
 BUILTIN(__builtin_bzero, "vv*z", "nF")
 BUILTIN(__builtin_free, "vv*", "nF")
 BUILTIN(__builtin_malloc, "v*z", "nF")
 BUILTIN(__builtin_memchr, "v*vC*iz", "nFE")
 BUILTIN(__builtin_memcmp, "ivC*vC*z", "nFE")
 BUILTIN(__builtin_memcpy, "v*v*vC*z", "nFE")
 BUILTIN(__builtin_memcpy_inline, "vv*vC*Iz", "n")
 BUILTIN(__builtin_memmove, "v*v*vC*z", "nFE")

 LIBBUILTIN(stpcpy, "c*c*cC*",     "f",     STRING_H, ALL_GNU_LANGUAGES)
 LIBBUILTIN(stpncpy, "c*c*cC*z",   "f",     STRING_H, ALL_GNU_LANGUAGES)
 LIBBUILTIN(strdup, "c*cC*",       "f",     STRING_H, ALL_GNU_LANGUAGES)
 LIBBUILTIN(strndup, "c*cC*z",     "f",     STRING_H, ALL_GNU_LANGUAGES)
 // POSIX strings.h
 LIBBUILTIN(index, "c*cC*i",       "f",     STRINGS_H, ALL_GNU_LANGUAGES)
 LIBBUILTIN(rindex, "c*cC*i",      "f",     STRINGS_H, ALL_GNU_LANGUAGES)
 LIBBUILTIN(bzero, "vv*z",         "f",     STRINGS_H, ALL_GNU_LANGUAGES)
+LIBBUILTIN(bcopy, "vvC*v*z",      "f",     STRINGS_H, ALL_GNU_LANGUAGES)
 LIBBUILTIN(bcmp, "ivC*vC*z",      "fE",    STRINGS_H, ALL_GNU_LANGUAGES)
 // In some systems str[n]casejmp is a macro that expands to _str[n]icmp.
 // We undefine then here to avoid wrong name.
 #undef strcasecmp
 #undef strncasecmp
 LIBBUILTIN(strcasecmp, "icC*cC*", "f",     STRINGS_H, ALL_GNU_LANGUAGES)
 LIBBUILTIN(strncasecmp, "icC*cC*z", "f",   STRINGS_H, ALL_GNU_LANGUAGES)
 // POSIX unistd.h

clang/lib/AST/Decl.cpp

unsigned FunctionDecl::getMemoryFunctionKind() const {
   case Builtin::BI__builtin_strlen:
   case Builtin::BIstrlen:
     return Builtin::BIstrlen;
 
   case Builtin::BI__builtin_bzero:
   case Builtin::BIbzero:
     return Builtin::BIbzero;
 
+  case Builtin::BI__builtin_bcopy:
+  case Builtin::BIbcopy:
+    return Builtin::BIbcopy;
+
   case Builtin::BIfree:
     return Builtin::BIfree;
 
   default:
     if (isExternC()) {
       if (FnInfo->isStr("memset"))
         return Builtin::BImemset;
       if (FnInfo->isStr("memcpy"))
if (isExternC()) {
       if (FnInfo->isStr("strncat"))
         return Builtin::BIstrncat;
       if (FnInfo->isStr("strndup"))
         return Builtin::BIstrndup;
       if (FnInfo->isStr("strlen"))
         return Builtin::BIstrlen;
       if (FnInfo->isStr("bzero"))
         return Builtin::BIbzero;
+      if (FnInfo->isStr("bcopy"))
+        return Builtin::BIbcopy;
     } else if (isInStdNamespace()) {
       if (FnInfo->isStr("free"))
         return Builtin::BIfree;
     }
     break;
   }
   return 0;
 }

clang/lib/CodeGen/CGBuiltin.cpp

   case Builtin::BI__builtin_bzero: {
     Address Dest = EmitPointerWithAlignment(E->getArg(0));
     Value *SizeVal = EmitScalarExpr(E->getArg(1));
     EmitNonNullArgCheck(RValue::get(Dest.getPointer()), E->getArg(0)->getType(),
                         E->getArg(0)->getExprLoc(), FD, 0);
     Builder.CreateMemSet(Dest, Builder.getInt8(0), SizeVal, false);
     return RValue::get(nullptr);
   }
+
+  case Builtin::BIbcopy:
+  case Builtin::BI__builtin_bcopy: {
+    Address Dest = EmitPointerWithAlignment(E->getArg(1));
+    Address Src = EmitPointerWithAlignment(E->getArg(0));
+    Value *SizeVal = EmitScalarExpr(E->getArg(2));
+    EmitNonNullArgCheck(RValue::get(Dest.getPointer()), E->getArg(1)->getType(),
+                        E->getArg(1)->getExprLoc(), FD, 0);
+    EmitNonNullArgCheck(RValue::get(Src.getPointer()), E->getArg(0)->getType(),
+                        E->getArg(0)->getExprLoc(), FD, 1);
+    Builder.CreateMemMove(Dest, Src, SizeVal, false);
+    return RValue::get(Dest.getPointer());
+  }
+
   case Builtin::BImemcpy:
   case Builtin::BI__builtin_memcpy:
   case Builtin::BImempcpy:
   case Builtin::BI__builtin_mempcpy: {
     Address Dest = EmitPointerWithAlignment(E->getArg(0));
     Address Src = EmitPointerWithAlignment(E->getArg(1));
     Value *SizeVal = EmitScalarExpr(E->getArg(2));
     EmitNonNullArgCheck(RValue::get(Dest.getPointer()), E->getArg(0)->getType(),

clang/test/Analysis/bstring.c

int memcmp8(char *a, size_t n) {
   return memcmp(a, b, n); // expected-warning{{Null pointer passed as 2nd argument to memory comparison function}}
 }
 
 //===----------------------------------------------------------------------===
 // bcopy()
 //===----------------------------------------------------------------------===
 
 #define bcopy BUILTIN(bcopy)
-// __builtin_bcopy is not defined with const in Builtins.def.
-void bcopy(/*const*/ void *s1, void *s2, size_t n);
+void bcopy(const void *s1, void *s2, size_t n);
 
 
 void bcopy0 (void) {
   char src[] = {1, 2, 3, 4};
   char dst[4] = {0};
 
   bcopy(src, dst, 4); // no-warning
 

clang/test/Analysis/security-syntax-checks.m

 // Obsolete function bcmp
 int bcmp(const void *, const void *, size_t);
 
 int test_bcmp(void *a, void *b, size_t n) {
   return bcmp(a, b, n); // expected-warning{{The bcmp() function is obsoleted by memcmp()}}
 }
 
 // Obsolete function bcopy
-void bcopy(void *, void *, size_t);
+void bcopy(const void *, void *, size_t);
 
-void test_bcopy(void *a, void *b, size_t n) {
+void test_bcopy(const void *a, void *b, size_t n) {
   bcopy(a, b, n); // expected-warning{{The bcopy() function is obsoleted by memcpy() or memmove(}}
 }
 
 // Obsolete function bzero
 void bzero(void *, size_t);
 
 void test_bzero(void *a, size_t n) {
   bzero(a, n); // expected-warning{{The bzero() function is obsoleted by memset()}}