Merge remote-tracking branch 'origin/apple/stable/20190619' into stable

Author: swift-ci

lib/CodeGen/CGCall.cpp

@@ -3868,6 +3868,11 @@ RValue CodeGenFunction::EmitCall(const CGFunctionInfo &CallInfo,
   Address swiftErrorTemp = Address::invalid();
   Address swiftErrorArg = Address::invalid();
 
+  // When passing arguments using temporary allocas, we need to add the
+  // appropriate lifetime markers. This vector keeps track of all the lifetime
+  // markers that need to be ended right after the call.
+  SmallVector<CallLifetimeEnd, 2> CallLifetimeEndAfterCall;
+
   // Translate all of the arguments as necessary to match the IR lowering.
   assert(CallInfo.arg_size() == CallArgs.size() &&
          "Mismatch between function signature & arguments.");
@@ -3984,6 +3989,18 @@ RValue CodeGenFunction::EmitCall(const CGFunctionInfo &CallInfo,
           Address AI = CreateMemTempWithoutCast(
               I->Ty, ArgInfo.getIndirectAlign(), "byval-temp");
           IRCallArgs[FirstIRArg] = AI.getPointer();
+
+          // Emit lifetime markers for the temporary alloca.
+          uint64_t ByvalTempElementSize =
+              CGM.getDataLayout().getTypeAllocSize(AI.getElementType());
+          llvm::Value *LifetimeSize =
+              EmitLifetimeStart(ByvalTempElementSize, AI.getPointer());
+
+          // Add cleanup code to emit the end lifetime marker after the call.
+          if (LifetimeSize) // In case we disabled lifetime markers.
+            CallLifetimeEndAfterCall.emplace_back(AI, LifetimeSize);
+
+          // Generate the copy.
           I->copyInto(*this, AI);
         } else {
           // Skip the extra memcpy call.
@@ -4551,6 +4568,11 @@ RValue CodeGenFunction::EmitCall(const CGFunctionInfo &CallInfo,
     }
   }
 
+  // Explicitly call CallLifetimeEnd::Emit just to re-use the code even though
+  // we can't use the full cleanup mechanism.
+  for (CallLifetimeEnd &LifetimeEnd : CallLifetimeEndAfterCall)
+    LifetimeEnd.Emit(*this, /*Flags=*/{});
+
   return Ret;
 }
 

lib/Lex/DependencyDirectivesSourceMinimizer.cpp

@@ -185,17 +185,6 @@ static void skipRawString(const char *&First, const char *const End) {
   }
 }
 
-static void skipString(const char *&First, const char *const End) {
-  assert(*First == '\'' || *First == '"' || *First == '<');
-  const char Terminator = *First == '<' ? '>' : *First;
-  for (++First; First != End && *First != Terminator; ++First)
-    if (*First == '\\')
-      if (++First == End)
-        return;
-  if (First != End)
-    ++First; // Finish off the string.
-}
-
 // Returns the length of EOL, either 0 (no end-of-line), 1 (\n) or 2 (\r\n)
 static unsigned isEOL(const char *First, const char *const End) {
   if (First == End)
@@ -206,6 +195,35 @@ static unsigned isEOL(const char *First, const char *const End) {
   return !!isVerticalWhitespace(First[0]);
 }
 
+static void skipString(const char *&First, const char *const End) {
+  assert(*First == '\'' || *First == '"' || *First == '<');
+  const char Terminator = *First == '<' ? '>' : *First;
+  for (++First; First != End && *First != Terminator; ++First) {
+    // String and character literals don't extend past the end of the line.
+    if (isVerticalWhitespace(*First))
+      return;
+    if (*First != '\\')
+      continue;
+    // Skip past backslash to the next character. This ensures that the
+    // character right after it is skipped as well, which matters if it's
+    // the terminator.
+    if (++First == End)
+      return;
+    if (!isWhitespace(*First))
+      continue;
+    // Whitespace after the backslash might indicate a line continuation.
+    const char *FirstAfterBackslashPastSpace = First;
+    skipOverSpaces(FirstAfterBackslashPastSpace, End);
+    if (unsigned NLSize = isEOL(FirstAfterBackslashPastSpace, End)) {
+      // Advance the character pointer to the next line for the next
+      // iteration.
+      First = FirstAfterBackslashPastSpace + NLSize - 1;
+    }
+  }
+  if (First != End)
+    ++First; // Finish off the string.
+}
+
 // Returns the length of the skipped newline
 static unsigned skipNewline(const char *&First, const char *End) {
   if (First == End)

test/CodeGen/aarch64-byval-temp.c

@@ -0,0 +1,89 @@
+// RUN: %clang_cc1 -emit-llvm -triple arm64-- -o - %s -O0 | FileCheck %s --check-prefix=CHECK-O0
+// RUN: %clang_cc1 -emit-llvm -disable-llvm-optzns -triple arm64-- -o - %s -O3 | FileCheck %s --check-prefix=CHECK-O3
+
+struct large {
+    void* pointers[8];
+};
+
+void pass_large(struct large);
+
+// For arm64, we don't use byval to pass structs but instead we create
+// temporary allocas.
+//
+// Make sure we generate the appropriate lifetime markers for the temporary
+// allocas so that the optimizer can re-use stack slots if possible.
+void example() {
+    struct large l = {0};
+    pass_large(l);
+    pass_large(l);
+}
+// CHECK-O0-LABEL: define void @example(
+// The alloca for the struct on the stack.
+// CHECK-O0: %[[l:[0-9A-Za-z-]+]] = alloca %struct.large, align 8
+// The alloca for the temporary stack space that we use to pass the argument.
+// CHECK-O0-NEXT: %[[byvaltemp:[0-9A-Za-z-]+]] = alloca %struct.large, align 8
+// Another one to pass the argument to the second function call.
+// CHECK-O0-NEXT: %[[byvaltemp1:[0-9A-Za-z-]+]] = alloca %struct.large, align 8
+// First, memset `l` to 0.
+// CHECK-O0-NEXT: %[[bitcastl:[0-9A-Za-z-]+]] = bitcast %struct.large* %[[l]] to i8*
+// CHECK-O0-NEXT: call void @llvm.memset.p0i8.i64(i8* align 8 %[[bitcastl]], i8 0, i64 64, i1 false)
+// Then, memcpy `l` to the temporary stack space.
+// CHECK-O0-NEXT: %[[src:[0-9A-Za-z-]+]] = bitcast %struct.large* %[[byvaltemp]] to i8*
+// CHECK-O0-NEXT: %[[dst:[0-9A-Za-z-]+]] = bitcast %struct.large* %[[l]] to i8*
+// CHECK-O0-NEXT: call void @llvm.memcpy.p0i8.p0i8.i64(i8* align 8 %[[src]], i8* align 8 %[[dst]], i64 64, i1 false)
+// Finally, call using a pointer to the temporary stack space.
+// CHECK-O0-NEXT: call void @pass_large(%struct.large* %[[byvaltemp]])
+// Now, do the same for the second call, using the second temporary alloca.
+// CHECK-O0-NEXT: %[[src:[0-9A-Za-z-]+]] = bitcast %struct.large* %[[byvaltemp1]] to i8*
+// CHECK-O0-NEXT: %[[dst:[0-9A-Za-z-]+]] = bitcast %struct.large* %[[l]] to i8*
+// CHECK-O0-NEXT: call void @llvm.memcpy.p0i8.p0i8.i64(i8* align 8 %[[src]], i8* align 8 %[[dst]], i64 64, i1 false)
+// CHECK-O0-NEXT: call void @pass_large(%struct.large* %[[byvaltemp1]])
+// CHECK-O0-NEXT: ret void
+//
+// At O3, we should have lifetime markers to help the optimizer re-use the temporary allocas.
+//
+// CHECK-O3-LABEL: define void @example(
+// The alloca for the struct on the stack.
+// CHECK-O3: %[[l:[0-9A-Za-z-]+]] = alloca %struct.large, align 8
+// The alloca for the temporary stack space that we use to pass the argument.
+// CHECK-O3-NEXT: %[[byvaltemp:[0-9A-Za-z-]+]] = alloca %struct.large, align 8
+// Another one to pass the argument to the second function call.
+// CHECK-O3-NEXT: %[[byvaltemp1:[0-9A-Za-z-]+]] = alloca %struct.large, align 8
+//
+// Mark the start of the lifetime for `l`
+// CHECK-O3-NEXT: %[[bitcastl:[0-9A-Za-z-]+]] = bitcast %struct.large* %[[l]] to i8*
+// CHECK-O3-NEXT: call void @llvm.lifetime.start.p0i8(i64 64, i8* %[[bitcastl]])
+//
+// First, memset `l` to 0.
+// CHECK-O3-NEXT: %[[bitcastl:[0-9A-Za-z-]+]] = bitcast %struct.large* %[[l]] to i8*
+// CHECK-O3-NEXT: call void @llvm.memset.p0i8.i64(i8* align 8 %[[bitcastl]], i8 0, i64 64, i1 false)
+//
+// Lifetime of the first temporary starts here and ends right after the call.
+// CHECK-O3-NEXT: %[[bitcastbyvaltemp:[0-9A-Za-z-]+]] = bitcast %struct.large* %[[byvaltemp]] to i8*
+// CHECK-O3-NEXT: call void @llvm.lifetime.start.p0i8(i64 64, i8* %[[bitcastbyvaltemp]])
+//
+// Then, memcpy `l` to the temporary stack space.
+// CHECK-O3-NEXT: %[[src:[0-9A-Za-z-]+]] = bitcast %struct.large* %[[byvaltemp]] to i8*
+// CHECK-O3-NEXT: %[[dst:[0-9A-Za-z-]+]] = bitcast %struct.large* %[[l]] to i8*
+// CHECK-O3-NEXT: call void @llvm.memcpy.p0i8.p0i8.i64(i8* align 8 %[[src]], i8* align 8 %[[dst]], i64 64, i1 false)
+// Finally, call using a pointer to the temporary stack space.
+// CHECK-O3-NEXT: call void @pass_large(%struct.large* %[[byvaltemp]])
+//
+// The lifetime of the temporary used to pass a pointer to the struct ends here.
+// CHECK-O3-NEXT: %[[bitcastbyvaltemp:[0-9A-Za-z-]+]] = bitcast %struct.large* %[[byvaltemp]] to i8*
+// CHECK-O3-NEXT: call void @llvm.lifetime.end.p0i8(i64 64, i8* %[[bitcastbyvaltemp]])
+//
+// Now, do the same for the second call, using the second temporary alloca.
+// CHECK-O3-NEXT: %[[bitcastbyvaltemp:[0-9A-Za-z-]+]] = bitcast %struct.large* %[[byvaltemp1]] to i8*
+// CHECK-O3-NEXT: call void @llvm.lifetime.start.p0i8(i64 64, i8* %[[bitcastbyvaltemp]])
+// CHECK-O3-NEXT: %[[src:[0-9A-Za-z-]+]] = bitcast %struct.large* %[[byvaltemp1]] to i8*
+// CHECK-O3-NEXT: %[[dst:[0-9A-Za-z-]+]] = bitcast %struct.large* %[[l]] to i8*
+// CHECK-O3-NEXT: call void @llvm.memcpy.p0i8.p0i8.i64(i8* align 8 %[[src]], i8* align 8 %[[dst]], i64 64, i1 false)
+// CHECK-O3-NEXT: call void @pass_large(%struct.large* %[[byvaltemp1]])
+// CHECK-O3-NEXT: %[[bitcastbyvaltemp:[0-9A-Za-z-]+]] = bitcast %struct.large* %[[byvaltemp1]] to i8*
+// CHECK-O3-NEXT: call void @llvm.lifetime.end.p0i8(i64 64, i8* %[[bitcastbyvaltemp]])
+//
+// Mark the end of the lifetime of `l`.
+// CHECK-O3-NEXT: %[[bitcastl:[0-9A-Za-z-]+]] = bitcast %struct.large* %l to i8*
+// CHECK-O3-NEXT: call void @llvm.lifetime.end.p0i8(i64 64, i8* %[[bitcastl]])
+// CHECK-O3-NEXT: ret void

unittests/Lex/DependencyDirectivesSourceMinimizerTest.cpp

@@ -594,6 +594,50 @@ TEST(MinimizeSourceToDependencyDirectivesTest, PragmaOnce) {
   EXPECT_STREQ("#pragma once\n#include <test.h>\n", Out.data());
 }
 
+TEST(MinimizeSourceToDependencyDirectivesTest,
+     SkipLineStringCharLiteralsUntilNewline) {
+  SmallVector<char, 128> Out;
+
+  StringRef Source = R"(#if NEVER_ENABLED
+    #define why(fmt, ...) #error don't try me
+    #endif
+
+    void foo();
+)";
+  ASSERT_FALSE(minimizeSourceToDependencyDirectives(Source, Out));
+  EXPECT_STREQ(
+      "#if NEVER_ENABLED\n#define why(fmt,...) #error don't try me\n#endif\n",
+      Out.data());
+
+  Source = R"(#if NEVER_ENABLED
+      #define why(fmt, ...) "quote dropped
+      #endif
+
+      void foo();
+  )";
+  ASSERT_FALSE(minimizeSourceToDependencyDirectives(Source, Out));
+  EXPECT_STREQ(
+      "#if NEVER_ENABLED\n#define why(fmt,...) \"quote dropped\n#endif\n",
+      Out.data());
+}
+
+TEST(MinimizeSourceToDependencyDirectivesTest,
+     SupportWhitespaceBeforeLineContinuationInStringSkipping) {
+  SmallVector<char, 128> Out;
+
+  StringRef Source = "#define X '\\ \t\nx'\nvoid foo() {}";
+  ASSERT_FALSE(minimizeSourceToDependencyDirectives(Source, Out));
+  EXPECT_STREQ("#define X '\\ \t\nx'\n", Out.data());
+
+  Source = "#define X \"\\ \r\nx\"\nvoid foo() {}";
+  ASSERT_FALSE(minimizeSourceToDependencyDirectives(Source, Out));
+  EXPECT_STREQ("#define X \"\\ \r\nx\"\n", Out.data());
+
+  Source = "#define X \"\\ \r\nx\n#include <x>\n";
+  ASSERT_FALSE(minimizeSourceToDependencyDirectives(Source, Out));
+  EXPECT_STREQ("#define X \"\\ \r\nx\n#include <x>\n", Out.data());
+}
+
 TEST(MinimizeSourceToDependencyDirectivesTest, CxxModules) {
   SmallVector<char, 128> Out;
   SmallVector<Token, 4> Tokens;