Merge pull request #28576 from adrian-prantl/57110020-5.1

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

Author: fredriss

lib/ASTSectionImporter/ASTSectionImporter.cpp

@@ -63,7 +63,7 @@ bool swift::parseASTSection(MemoryBufferSerializedModuleLoader &Loader,
       return false;
     }
 
-    buf = buf.substr(info.bytes);
+    buf = buf.substr(llvm::alignTo(info.bytes, 4));
   }
 
   return true;

lib/IRGen/IRGen.cpp

@@ -1238,7 +1238,7 @@ swift::createSwiftModuleObjectFile(SILModule &SILMod, StringRef Buffer,
     break;
   }
   ASTSym->setSection(Section);
-  ASTSym->setAlignment(8);
+  ASTSym->setAlignment(4);
   ::performLLVM(Opts, &Ctx.Diags, nullptr, nullptr, IGM.getModule(),
                 IGM.TargetMachine.get(),
                 Ctx.LangOpts.EffectiveLanguageVersion,

test/DebugInfo/ASTSection-multi.swift

@@ -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
+// 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!
+