---

yaml
---
r: 344063
b: refs/heads/master-rebranch
c: 4fcef2b
h: refs/heads/master
i:
  344061: 75aefee
  344059: 86b162b
  344055: 1a7f4a3
  344047: 50e2673
  344031: 047cc43
  343999: 5584e73
  343935: c9ce9bd
  343807: aefcb24
  343551: 29c818f
  343039: ac9f22a
  342015: 9ff9009
  339967: 9abfd9b
  335871: f3948ef
  327679: a75c9d3

Author: slavapestov

[refs]

@@ -1455,7 +1455,7 @@ refs/tags/swift-DEVELOPMENT-SNAPSHOT-2019-08-02-a: ddd2b2976aa9bfde5f20fe37f6bd2
 refs/tags/swift-DEVELOPMENT-SNAPSHOT-2019-08-03-a: 171cc166f2abeb5ca2a4003700a8a78a108bd300
 refs/heads/benlangmuir-patch-1: baaebaf39d52f3bf36710d4fe40cf212e996b212
 refs/heads/i-do-redeclare: 8c4e6d5de5c1e3f0a2cedccf319df713ea22c48e
-refs/heads/master-rebranch: 78ae7ac9dbf3beb10933a18026c194906233f3f1
+refs/heads/master-rebranch: 4fcef2b9f458d24f4aabe425900a86e51832fbdd
 refs/heads/rdar-53901732: 9bd06af3284e18a109cdbf9aa59d833b24eeca7b
 refs/heads/revert-26776-subst-always-returns-a-type: 1b8e18fdd391903a348970a4c848995d4cdd789c
 refs/heads/tensorflow-merge: 8b854f62f80d4476cb383d43c4aac2001dde3cec

branches/master-rebranch/docs/SIL.rst

@@ -17,8 +17,10 @@ the Swift programming language. SIL accommodates the following use cases:
   such as definitive initialization of variables and constructors, code
   reachability, switch coverage.
 - High-level optimization passes, including retain/release optimization,
-  dynamic method devirtualization, closure inlining, memory allocation promotion,
-  and generic function instantiation.
+  dynamic method devirtualization, closure inlining, promoting heap allocations
+  to stack allocations, promoting stack allocations to SSA registers, scalar
+  replacement of aggregates (splitting aggregate allocations into multiple
+  smaller allocations), and generic function instantiation.
 - A stable distribution format that can be used to distribute "fragile"
   inlineable or generic code with Swift library modules, to be optimized into
   client binaries.

branches/master-rebranch/include/swift/Reflection/ReflectionContext.h

@@ -123,7 +123,6 @@ class ReflectionContext
     return sizeof(StoredPointer) * 2;
   }
 
-#if defined(__APPLE__) && defined(__MACH__)
   template <typename T> bool readMachOSections(RemoteAddress ImageStart) {
     auto Buf =
         this->getReader().readBytes(ImageStart, sizeof(typename T::Header));
@@ -277,22 +276,6 @@ class ReflectionContext
     return true;
   }
 
-  bool addImage(RemoteAddress ImageStart) {
-    // We start reading 4 bytes. The first 4 bytes are supposed to be
-    // the magic, so we understand whether this is a 32-bit executable or
-    // a 64-bit one.
-    auto Buf = this->getReader().readBytes(ImageStart, sizeof(uint32_t));
-    if (!Buf)
-      return false;
-    auto HeaderMagic = reinterpret_cast<const uint32_t *>(Buf.get());
-    if (*HeaderMagic == llvm::MachO::MH_MAGIC)
-      return readMachOSections<MachOTraits<4>>(ImageStart);
-    if (*HeaderMagic == llvm::MachO::MH_MAGIC_64)
-      return readMachOSections<MachOTraits<8>>(ImageStart);
-    return false;
-  }
-
-#elif defined(_WIN32)
   bool readPECOFFSections(RemoteAddress ImageStart) {
     auto DOSHdrBuf = this->getReader().readBytes(
         ImageStart, sizeof(llvm::object::dos_header));
@@ -384,15 +367,13 @@ class ReflectionContext
     return true;
   }
 
-  bool addImage(RemoteAddress ImageStart) {
+  bool readPECOFF(RemoteAddress ImageStart) {
     auto Buf = this->getReader().readBytes(ImageStart,
                                            sizeof(llvm::object::dos_header));
     if (!Buf)
       return false;
 
     auto DOSHdr = reinterpret_cast<const llvm::object::dos_header *>(Buf.get());
-    if (!(DOSHdr->Magic[0] == 'M' && DOSHdr->Magic[1] == 'Z'))
-      return false;
 
     auto PEHeaderAddress =
         ImageStart.getAddressData() + DOSHdr->AddressOfNewExeHeader;
@@ -407,7 +388,7 @@ class ReflectionContext
 
     return readPECOFFSections(ImageStart);
   }
-#else // ELF platforms.
+
   template <typename T> bool readELFSections(RemoteAddress ImageStart) {
     auto Buf =
         this->getReader().readBytes(ImageStart, sizeof(typename T::Header));
@@ -506,8 +487,8 @@ class ReflectionContext
     savedBuffers.push_back(std::move(Buf));
     return true;
   }
-
-  bool addImage(RemoteAddress ImageStart) {
+         
+  bool readELF(RemoteAddress ImageStart) {
     auto Buf =
         this->getReader().readBytes(ImageStart, sizeof(llvm::ELF::Elf64_Ehdr));
 
@@ -527,12 +508,48 @@ class ReflectionContext
       return false;
     }
   }
-#endif
+
+  bool addImage(RemoteAddress ImageStart) {
+    // Read the first few bytes to look for a magic header.
+    auto Magic = this->getReader().readBytes(ImageStart, sizeof(uint32_t));
+    if (!Magic)
+      return false;
+    
+    uint32_t MagicWord;
+    memcpy(&MagicWord, Magic.get(), sizeof(MagicWord));
+    
+    // 32- and 64-bit Mach-O.
+    if (MagicWord == llvm::MachO::MH_MAGIC) {
+      return readMachOSections<MachOTraits<4>>(ImageStart);
+    }
+    
+    if (MagicWord == llvm::MachO::MH_MAGIC_64) {
+      return readMachOSections<MachOTraits<8>>(ImageStart);
+    }
+    
+    // PE. (This just checks for the DOS header; `readPECOFF` will further
+    // validate the existence of the PE header.)
+    auto MagicBytes = (const char*)Magic.get();
+    if (MagicBytes[0] == 'M' && MagicBytes[1] == 'Z') {
+      return readPECOFF(ImageStart);
+    }
+    
+    // ELF.
+    if (MagicBytes[0] == llvm::ELF::ElfMagic[0]
+        && MagicBytes[1] == llvm::ELF::ElfMagic[1]
+        && MagicBytes[2] == llvm::ELF::ElfMagic[2]
+        && MagicBytes[3] == llvm::ELF::ElfMagic[3]) {
+      return readELF(ImageStart);
+    }
+    
+    // We don't recognize the format.
+    return false;
+  }
 
   void addReflectionInfo(ReflectionInfo I) {
     getBuilder().addReflectionInfo(I);
   }
-  
+
   bool ownsObject(RemoteAddress ObjectAddress) {
     auto MetadataAddress = readMetadataFromInstance(ObjectAddress.getAddressData());
     if (!MetadataAddress)