Fix non-deterministic compilation for const-string...

... in inlined methods that are not in the boot profile.
If such string is not in the boot image for other reasons,
do not resolve the string and use the kBssEntry load kind.

Boot image sizes for aosp_taimen-userdebug:
 - before:
   arm/boot*.art: 12349440
   arm/boot*.oat: 19862024
   arm64/boot*.art: 16609280
   arm64/boot*.oat: 23568592
 - after:
   arm/boot*.art: 12324864 (-24KiB)
   arm/boot*.oat: 19936612 (+73KiB)
   arm64/boot*.art: 16580608 (-28KiB)
   arm64/boot*.oat: 23642120 (+72KiB)

Test: aosp_taimen-userdebug boots.
Test: m test-art-host-gtest
Bug: 26687569
Change-Id: I3e0b72cd5e8c67904517856208f25a6c379ab601

8 files changed, 18 insertions, 12 deletions

diff --git a/compiler/optimizing/code_generator_arm64.cc b/compiler/optimizing/code_generator_arm64.cc
index ff99a3eff2..3086882678 100644
--- a/compiler/optimizing/code_generator_arm64.cc
+++ b/compiler/optimizing/code_generator_arm64.cc
@@ -4840,7 +4840,6 @@ void InstructionCodeGeneratorARM64::VisitLoadString(HLoadString* load) NO_THREAD
       // Add ADRP with its PC-relative String .bss entry patch.
       const DexFile& dex_file = load->GetDexFile();
       const dex::StringIndex string_index = load->GetStringIndex();
-      DCHECK(!codegen_->GetCompilerOptions().IsBootImage());
       Register temp = XRegisterFrom(out_loc);
       vixl::aarch64::Label* adrp_label = codegen_->NewStringBssEntryPatch(dex_file, string_index);
       codegen_->EmitAdrpPlaceholder(adrp_label, temp);
diff --git a/compiler/optimizing/code_generator_arm_vixl.cc b/compiler/optimizing/code_generator_arm_vixl.cc
index 9c155f86d8..c8db3d6229 100644
--- a/compiler/optimizing/code_generator_arm_vixl.cc
+++ b/compiler/optimizing/code_generator_arm_vixl.cc
@@ -7246,7 +7246,6 @@ void InstructionCodeGeneratorARMVIXL::VisitLoadString(HLoadString* load) NO_THRE
       return;
     }
     case HLoadString::LoadKind::kBssEntry: {
-      DCHECK(!codegen_->GetCompilerOptions().IsBootImage());
       CodeGeneratorARMVIXL::PcRelativePatchInfo* labels =
           codegen_->NewStringBssEntryPatch(load->GetDexFile(), load->GetStringIndex());
       codegen_->EmitMovwMovtPlaceholder(labels, out);
diff --git a/compiler/optimizing/code_generator_mips.cc b/compiler/optimizing/code_generator_mips.cc
index f7f37db26a..72334afa40 100644
--- a/compiler/optimizing/code_generator_mips.cc
+++ b/compiler/optimizing/code_generator_mips.cc
@@ -8449,7 +8449,6 @@ void InstructionCodeGeneratorMIPS::VisitLoadString(HLoadString* load) NO_THREAD_
       return;
     }
     case HLoadString::LoadKind::kBssEntry: {
-      DCHECK(!codegen_->GetCompilerOptions().IsBootImage());
       CodeGeneratorMIPS::PcRelativePatchInfo* info_high =
           codegen_->NewStringBssEntryPatch(load->GetDexFile(), load->GetStringIndex());
       CodeGeneratorMIPS::PcRelativePatchInfo* info_low =
diff --git a/compiler/optimizing/code_generator_mips64.cc b/compiler/optimizing/code_generator_mips64.cc
index 8b6328f097..0d3cb3b8ca 100644
--- a/compiler/optimizing/code_generator_mips64.cc
+++ b/compiler/optimizing/code_generator_mips64.cc
@@ -6442,7 +6442,6 @@ void InstructionCodeGeneratorMIPS64::VisitLoadString(HLoadString* load) NO_THREA
       return;
     }
     case HLoadString::LoadKind::kBssEntry: {
-      DCHECK(!codegen_->GetCompilerOptions().IsBootImage());
       CodeGeneratorMIPS64::PcRelativePatchInfo* info_high =
           codegen_->NewStringBssEntryPatch(load->GetDexFile(), load->GetStringIndex());
       CodeGeneratorMIPS64::PcRelativePatchInfo* info_low =
diff --git a/compiler/optimizing/code_generator_x86.cc b/compiler/optimizing/code_generator_x86.cc
index 766ff78fa4..95118b0b6d 100644
--- a/compiler/optimizing/code_generator_x86.cc
+++ b/compiler/optimizing/code_generator_x86.cc
@@ -4991,7 +4991,6 @@ void CodeGeneratorX86::RecordBootImageStringPatch(HLoadString* load_string) {
 }
 
 Label* CodeGeneratorX86::NewStringBssEntryPatch(HLoadString* load_string) {
-  DCHECK(!GetCompilerOptions().IsBootImage());
   HX86ComputeBaseMethodAddress* method_address =
       load_string->InputAt(0)->AsX86ComputeBaseMethodAddress();
   string_bss_entry_patches_.emplace_back(
diff --git a/compiler/optimizing/code_generator_x86_64.cc b/compiler/optimizing/code_generator_x86_64.cc
index 67a2aa561b..7c293b8605 100644
--- a/compiler/optimizing/code_generator_x86_64.cc
+++ b/compiler/optimizing/code_generator_x86_64.cc
@@ -1115,7 +1115,6 @@ void CodeGeneratorX86_64::RecordBootImageStringPatch(HLoadString* load_string) {
 }
 
 Label* CodeGeneratorX86_64::NewStringBssEntryPatch(HLoadString* load_string) {
-  DCHECK(!GetCompilerOptions().IsBootImage());
   string_bss_entry_patches_.emplace_back(
       &load_string->GetDexFile(), load_string->GetStringIndex().index_);
   return &string_bss_entry_patches_.back().label;
diff --git a/compiler/optimizing/sharpening.cc b/compiler/optimizing/sharpening.cc
index 885a08d459..8637db13ad 100644
--- a/compiler/optimizing/sharpening.cc
+++ b/compiler/optimizing/sharpening.cc
@@ -303,11 +303,26 @@ void HSharpening::ProcessLoadString(
       // Compiling boot image. Resolve the string and allocate it if needed, to ensure
       // the string will be added to the boot image.
       DCHECK(!runtime->UseJitCompilation());
-      string = class_linker->ResolveString(string_index, dex_cache);
-      CHECK(string != nullptr);
       if (compiler_options.GetCompilePic()) {
         DCHECK(ContainsElement(compiler_options.GetDexFilesForOatFile(), &dex_file));
-        desired_load_kind = HLoadString::LoadKind::kBootImageLinkTimePcRelative;
+        if (compiler_options.IsForceDeterminism()) {
+          // Strings for methods we're compiling should be pre-resolved but Strings in inlined
+          // methods may not be if these inlined methods are not in the boot image profile.
+          // Multiple threads allocating new Strings can cause non-deterministic boot image
+          // because of the image relying on the order of GC roots we walk. (We could fix that
+          // by ordering the roots we walk in ImageWriter.) Therefore we avoid allocating these
+          // strings even if that results in omitting them from the boot image and using the
+          // sub-optimal load kind kBssEntry.
+          string = class_linker->LookupString(string_index, dex_cache.Get());
+        } else {
+          string = class_linker->ResolveString(string_index, dex_cache);
+          CHECK(string != nullptr);
+        }
+        if (string != nullptr) {
+          desired_load_kind = HLoadString::LoadKind::kBootImageLinkTimePcRelative;
+        } else {
+          desired_load_kind = HLoadString::LoadKind::kBssEntry;
+        }
       } else {
         // Test configuration, do not sharpen.
         desired_load_kind = HLoadString::LoadKind::kRuntimeCall;
diff --git a/dex2oat/linker/oat_writer.cc b/dex2oat/linker/oat_writer.cc
index be9a0cb0a2..f7de593a25 100644
--- a/dex2oat/linker/oat_writer.cc
+++ b/dex2oat/linker/oat_writer.cc
@@ -2309,9 +2309,6 @@ void OatWriter::InitBssLayout(InstructionSet instruction_set) {
   }
 
   DCHECK_EQ(bss_size_, 0u);
-  if (GetCompilerOptions().IsBootImage()) {
-    DCHECK(bss_string_entries_.empty());
-  }
   if (bss_method_entries_.empty() &&
       bss_type_entries_.empty() &&
       bss_string_entries_.empty()) {