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Use the same alignment for writing and reading .swift_ast section contents #28574

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Merged
merged 1 commit into from
Dec 5, 2019
Merged

Use the same alignment for writing and reading .swift_ast section contents #28574

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4 changes: 3 additions & 1 deletion lib/ASTSectionImporter/ASTSectionImporter.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -16,6 +16,7 @@
//===----------------------------------------------------------------------===//

#include "swift/ASTSectionImporter/ASTSectionImporter.h"
#include "../Serialization/ModuleFormat.h"
#include "swift/Basic/Dwarf.h"
#include "swift/Serialization/SerializedModuleLoader.h"
#include "swift/Serialization/Validation.h"
Expand Down Expand Up @@ -63,7 +64,8 @@ bool swift::parseASTSection(MemoryBufferSerializedModuleLoader &Loader,
return false;
}

buf = buf.substr(info.bytes);
buf = buf.substr(
llvm::alignTo(info.bytes, swift::serialization::SWIFTMODULE_ALIGNMENT));
}

return true;
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3 changes: 2 additions & 1 deletion lib/IRGen/IRGen.cpp
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Expand Up @@ -37,6 +37,7 @@
#include "swift/SILOptimizer/PassManager/PassPipeline.h"
#include "swift/SILOptimizer/PassManager/Passes.h"
#include "swift/Subsystems.h"
#include "../Serialization/ModuleFormat.h"
#include "clang/Basic/TargetInfo.h"
#include "llvm/ADT/StringSet.h"
#include "llvm/Analysis/AliasAnalysis.h"
Expand Down Expand Up @@ -1330,7 +1331,7 @@ swift::createSwiftModuleObjectFile(SILModule &SILMod, StringRef Buffer,
break;
}
ASTSym->setSection(Section);
ASTSym->setAlignment(8);
ASTSym->setAlignment(serialization::SWIFTMODULE_ALIGNMENT);
::performLLVM(Opts, &Ctx.Diags, nullptr, nullptr, IGM.getModule(),
IGM.TargetMachine.get(),
Ctx.LangOpts.EffectiveLanguageVersion,
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4 changes: 2 additions & 2 deletions lib/Serialization/ModuleFile.cpp
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Expand Up @@ -375,8 +375,8 @@ ValidationInfo serialization::validateSerializedAST(
ValidationInfo result;

// Check 32-bit alignment.
if (data.size() % 4 != 0 ||
reinterpret_cast<uintptr_t>(data.data()) % 4 != 0)
if (data.size() % SWIFTMODULE_ALIGNMENT != 0 ||
reinterpret_cast<uintptr_t>(data.data()) % SWIFTMODULE_ALIGNMENT != 0)
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It's probably not worth changing right now, but in the future, perhaps we could use the new Alignment.h helpers, like:

Align moduleAlignment = SWIFTMODULE_ALIGNMENT;
if (!isAligned(moduleAlignment, data.size()) || !isAddrAligned(moduleAlignment, data.data())) ...

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Oh, the // Check 32-bit alignment comment may need an update.

return result;

llvm::BitstreamCursor cursor(data);
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3 changes: 3 additions & 0 deletions lib/Serialization/ModuleFormat.h
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Expand Up @@ -39,6 +39,9 @@ using llvm::BCVBR;
/// Magic number for serialized module files.
const unsigned char SWIFTMODULE_SIGNATURE[] = { 0xE2, 0x9C, 0xA8, 0x0E };

/// Alignment of each serialized modules inside a .swift_ast section.
const unsigned char SWIFTMODULE_ALIGNMENT = 4;

/// Serialized module format major version number.
///
/// Always 0 for Swift 1.x - 4.x.
Expand Down
49 changes: 49 additions & 0 deletions test/DebugInfo/ASTSection-multi.swift
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@@ -0,0 +1,49 @@
// REQUIRES: OS=linux-gnu
// REQUIRES: executable_test
// REQUIRES: swift_tools_extra

// Test that concatenated .swift_ast sections of various sizes can be parsed.

// RUN: %empty-directory(%t)

// RUN: echo "public let a0 = 0" >%t/a0.swift

// RUN: echo "public let a1 = 0" >%t/a1.swift
// RUN: echo "public let b1 = 0" >>%t/a1.swift

// RUN: echo "public let a2 = 0" >%t/a2.swift
// RUN: echo "public let b2 = 0" >>%t/a2.swift
// RUN: echo "public let c2 = 0" >>%t/a2.swift

// RUN: echo "public let a3 = 0" >%t/a3.swift
// RUN: echo "public let b3 = 0" >>%t/a3.swift
// RUN: echo "public let c3 = 0" >>%t/a3.swift
// RUN: echo "public let d3 = 0" >>%t/a3.swift

// RUN: %target-build-swift %t/a0.swift -c -g -o %t/a0.o -parse-as-library
// RUN: %target-build-swift %t/a1.swift -c -g -o %t/a1.o -parse-as-library
// RUN: %target-build-swift %t/a2.swift -c -g -o %t/a2.o -parse-as-library
// RUN: %target-build-swift %t/a3.swift -c -g -o %t/a3.o -parse-as-library

// RUN: %target-build-swift %t/a0.swift -emit-module -emit-module-path %t/a0.swiftmodule
// RUN: %target-build-swift %t/a1.swift -emit-module -emit-module-path %t/a1.swiftmodule
// RUN: %target-build-swift %t/a2.swift -emit-module -emit-module-path %t/a2.swiftmodule
// RUN: %target-build-swift %t/a3.swift -emit-module -emit-module-path %t/a3.swiftmodule

// RUN: %target-swift-modulewrap %t/a0.swiftmodule -o %t/a0-mod.o
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Does swift-modulewrap build a MachO container for a swiftmodule?

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Technically that would work, but it's not wired up correctly at the moment and returns an IRGen error "Unable to find a runtime library path".

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Ah, sorry, my unfamiliarity with this code is showing. What does swift-modulewrap do?

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it invokes swift -modulewrap which is used on Linux (where we don't control the linker) to wrap a .swfitmodule inside a .swift_ast section in an object file, so it can be linked together with the program. The linker concatenates all the .swift_ast sections for LLDB to be found.

// RUN: %target-swift-modulewrap %t/a1.swiftmodule -o %t/a1-mod.o
// RUN: %target-swift-modulewrap %t/a2.swiftmodule -o %t/a2-mod.o
// RUN: %target-swift-modulewrap %t/a3.swiftmodule -o %t/a3-mod.o

// RUN: %target-build-swift -o %t/a.out %s \
// RUN: %t/a0.o %t/a0-mod.o \
// RUN: %t/a1.o %t/a1-mod.o \
// RUN: %t/a2.o %t/a2-mod.o \
// RUN: %t/a3.o %t/a3-mod.o

// RUN: %lldb-moduleimport-test -verbose %t/a.out | %FileCheck %s
// CHECK: Importing a0... ok!
// CHECK: Importing a1... ok!
// CHECK: Importing a2... ok!
// CHECK: Importing a3... ok!