X87: Refactor BreakLocationIterator

src/x87/assembler-x87.cc

Index: src/x87/assembler-x87.cc
diff --git a/src/x87/assembler-x87.cc b/src/x87/assembler-x87.cc
index 0d0a49435840d99422bf5d1aacd3b4d753a66500..95b65879256890e4399177a1522cba1d10014df8 100644
--- a/src/x87/assembler-x87.cc
+++ b/src/x87/assembler-x87.cc
@@ -102,6 +102,37 @@ bool RelocInfo::IsInConstantPool() {
 }
 
 
+// Patch the code at the current PC with a call to the target address.
+// Additional guard int3 instructions can be added if required.
+void RelocInfo::PatchCodeWithCall(Address target, int guard_bytes) {
+  // Call instruction takes up 5 bytes and int3 takes up one byte.
+  static const int kCallCodeSize = 5;
+  int code_size = kCallCodeSize + guard_bytes;
+
+  // Create a code patcher.
+  CodePatcher patcher(pc_, code_size);
+
+// Add a label for checking the size of the code used for returning.
+#ifdef DEBUG
+  Label check_codesize;
+  patcher.masm()->bind(&check_codesize);
+#endif
+
+  // Patch the code.
+  patcher.masm()->call(target, RelocInfo::NONE32);
+
+  // Check that the size of the code generated is as expected.
+  DCHECK_EQ(kCallCodeSize,
+            patcher.masm()->SizeOfCodeGeneratedSince(&check_codesize));
+
+  // Add the requested number of int3 instructions after the call.
+  DCHECK_GE(guard_bytes, 0);
+  for (int i = 0; i < guard_bytes; i++) {
+    patcher.masm()->int3();
+  }
+}
+
+
 // -----------------------------------------------------------------------------
 // Implementation of Operand