Improve documentation about StringFactory.newStringFromChars.
Make it clear that the native method requires its third
argument to be non-null, and therefore that the intrinsics
do not need a null check for it.
Bug: 27378573
Change-Id: Id2f78ceb0f7674f1066bc3f216b738358ca25542
diff --git a/compiler/dex/quick/gen_invoke.cc b/compiler/dex/quick/gen_invoke.cc
index 422d82f..fa7c961 100755
--- a/compiler/dex/quick/gen_invoke.cc
+++ b/compiler/dex/quick/gen_invoke.cc
@@ -1140,6 +1140,12 @@
RegLocation rl_offset = info->args[0];
RegLocation rl_count = info->args[1];
RegLocation rl_data = info->args[2];
+ // No need to emit code checking whether `rl_data` is a null
+ // pointer, as callers of the native method
+ //
+ // java.lang.StringFactory.newStringFromChars(int offset, int charCount, char[] data)
+ //
+ // all include a null check on `data` before calling that method.
CallRuntimeHelperRegLocationRegLocationRegLocation(
kQuickAllocStringFromChars, rl_offset, rl_count, rl_data, true);
RegLocation rl_return = GetReturn(kRefReg);
diff --git a/compiler/optimizing/intrinsics_arm.cc b/compiler/optimizing/intrinsics_arm.cc
index 4ce919e..448b425 100644
--- a/compiler/optimizing/intrinsics_arm.cc
+++ b/compiler/optimizing/intrinsics_arm.cc
@@ -1242,6 +1242,12 @@
void IntrinsicCodeGeneratorARM::VisitStringNewStringFromChars(HInvoke* invoke) {
ArmAssembler* assembler = GetAssembler();
+ // No need to emit code checking whether `locations->InAt(2)` is a null
+ // pointer, as callers of the native method
+ //
+ // java.lang.StringFactory.newStringFromChars(int offset, int charCount, char[] data)
+ //
+ // all include a null check on `data` before calling that method.
__ LoadFromOffset(
kLoadWord, LR, TR, QUICK_ENTRYPOINT_OFFSET(kArmWordSize, pAllocStringFromChars).Int32Value());
codegen_->RecordPcInfo(invoke, invoke->GetDexPc());
diff --git a/compiler/optimizing/intrinsics_arm64.cc b/compiler/optimizing/intrinsics_arm64.cc
index 4be1695..d05f5af 100644
--- a/compiler/optimizing/intrinsics_arm64.cc
+++ b/compiler/optimizing/intrinsics_arm64.cc
@@ -1392,6 +1392,12 @@
void IntrinsicCodeGeneratorARM64::VisitStringNewStringFromChars(HInvoke* invoke) {
vixl::MacroAssembler* masm = GetVIXLAssembler();
+ // No need to emit code checking whether `locations->InAt(2)` is a null
+ // pointer, as callers of the native method
+ //
+ // java.lang.StringFactory.newStringFromChars(int offset, int charCount, char[] data)
+ //
+ // all include a null check on `data` before calling that method.
__ Ldr(lr,
MemOperand(tr, QUICK_ENTRYPOINT_OFFSET(kArm64WordSize, pAllocStringFromChars).Int32Value()));
codegen_->RecordPcInfo(invoke, invoke->GetDexPc());
diff --git a/compiler/optimizing/intrinsics_mips64.cc b/compiler/optimizing/intrinsics_mips64.cc
index ca2652b..78b4360 100644
--- a/compiler/optimizing/intrinsics_mips64.cc
+++ b/compiler/optimizing/intrinsics_mips64.cc
@@ -1685,7 +1685,7 @@
invoke, GetAssembler(), codegen_, GetAllocator(), /* start_at_zero */ false);
}
-// java.lang.String.String(byte[] bytes)
+// java.lang.StringFactory.newStringFromBytes(byte[] data, int high, int offset, int byteCount)
void IntrinsicLocationsBuilderMIPS64::VisitStringNewStringFromBytes(HInvoke* invoke) {
LocationSummary* locations = new (arena_) LocationSummary(invoke,
LocationSummary::kCall,
@@ -1719,7 +1719,7 @@
__ Bind(slow_path->GetExitLabel());
}
-// java.lang.String.String(char[] value)
+// java.lang.StringFactory.newStringFromChars(int offset, int charCount, char[] data)
void IntrinsicLocationsBuilderMIPS64::VisitStringNewStringFromChars(HInvoke* invoke) {
LocationSummary* locations = new (arena_) LocationSummary(invoke,
LocationSummary::kCall,
@@ -1735,6 +1735,12 @@
void IntrinsicCodeGeneratorMIPS64::VisitStringNewStringFromChars(HInvoke* invoke) {
Mips64Assembler* assembler = GetAssembler();
+ // No need to emit code checking whether `locations->InAt(2)` is a null
+ // pointer, as callers of the native method
+ //
+ // java.lang.StringFactory.newStringFromChars(int offset, int charCount, char[] data)
+ //
+ // all include a null check on `data` before calling that method.
__ LoadFromOffset(kLoadDoubleword,
TMP,
TR,
diff --git a/compiler/optimizing/intrinsics_x86.cc b/compiler/optimizing/intrinsics_x86.cc
index 0df4553..bfa4e37 100644
--- a/compiler/optimizing/intrinsics_x86.cc
+++ b/compiler/optimizing/intrinsics_x86.cc
@@ -1564,6 +1564,12 @@
void IntrinsicCodeGeneratorX86::VisitStringNewStringFromChars(HInvoke* invoke) {
X86Assembler* assembler = GetAssembler();
+ // No need to emit code checking whether `locations->InAt(2)` is a null
+ // pointer, as callers of the native method
+ //
+ // java.lang.StringFactory.newStringFromChars(int offset, int charCount, char[] data)
+ //
+ // all include a null check on `data` before calling that method.
__ fs()->call(Address::Absolute(QUICK_ENTRYPOINT_OFFSET(kX86WordSize, pAllocStringFromChars)));
codegen_->RecordPcInfo(invoke, invoke->GetDexPc());
}
diff --git a/compiler/optimizing/intrinsics_x86_64.cc b/compiler/optimizing/intrinsics_x86_64.cc
index 2a9e684..15c3997 100644
--- a/compiler/optimizing/intrinsics_x86_64.cc
+++ b/compiler/optimizing/intrinsics_x86_64.cc
@@ -1659,6 +1659,12 @@
void IntrinsicCodeGeneratorX86_64::VisitStringNewStringFromChars(HInvoke* invoke) {
X86_64Assembler* assembler = GetAssembler();
+ // No need to emit code checking whether `locations->InAt(2)` is a null
+ // pointer, as callers of the native method
+ //
+ // java.lang.StringFactory.newStringFromChars(int offset, int charCount, char[] data)
+ //
+ // all include a null check on `data` before calling that method.
__ gs()->call(Address::Absolute(QUICK_ENTRYPOINT_OFFSET(kX86_64WordSize, pAllocStringFromChars),
/* no_rip */ true));
codegen_->RecordPcInfo(invoke, invoke->GetDexPc());
diff --git a/runtime/native/java_lang_StringFactory.cc b/runtime/native/java_lang_StringFactory.cc
index 34d6a37..5a219ef 100644
--- a/runtime/native/java_lang_StringFactory.cc
+++ b/runtime/native/java_lang_StringFactory.cc
@@ -50,8 +50,10 @@
return soa.AddLocalReference<jstring>(result);
}
+// The char array passed as `java_data` must not be a null reference.
static jstring StringFactory_newStringFromChars(JNIEnv* env, jclass, jint offset,
jint char_count, jcharArray java_data) {
+ DCHECK(java_data != nullptr);
ScopedFastNativeObjectAccess soa(env);
StackHandleScope<1> hs(soa.Self());
Handle<mirror::CharArray> char_array(hs.NewHandle(soa.Decode<mirror::CharArray*>(java_data)));
