commit 4dc0b1ac60f947c23bbb0e20a7efb636c214b0a8
author Reid Kleckner <rnk@google.com> Thu Nov 01 19:54:45 2018 +0000
committer Reid Kleckner <rnk@google.com> Thu Nov 01 19:54:45 2018 +0000
tree be694515ce144c8d6ab1d1031b1f44817faac9ae
parent de4f7747837cbd9db9cb393c05283964fbc4a985

Fix clang -Wimplicit-fallthrough warnings across llvm, NFC

This patch should not introduce any behavior changes. It consists of
mostly one of two changes:
1. Replacing fall through comments with the LLVM_FALLTHROUGH macro
2. Inserting 'break' before falling through into a case block consisting
   of only 'break'.

We were already using this warning with GCC, but its warning behaves
slightly differently. In this patch, the following differences are
relevant:
1. GCC recognizes comments that say "fall through" as annotations, clang
   doesn't
2. GCC doesn't warn on "case N: foo(); default: break;", clang does
3. GCC doesn't warn when the case contains a switch, but falls through
   the outer case.

I will enable the warning separately in a follow-up patch so that it can
be cleanly reverted if necessary.

Reviewers: alexfh, rsmith, lattner, rtrieu, EricWF, bollu

Differential Revision: https://reviews.llvm.org/D53950

llvm-svn: 345882

clang/lib/Frontend/CompilerInstance.cpp

diff --git a/clang/lib/Frontend/CompilerInstance.cpp b/clang/lib/Frontend/CompilerInstance.cpp
index ea424bb..719474d 100644
--- a/clang/lib/Frontend/CompilerInstance.cpp
+++ b/clang/lib/Frontend/CompilerInstance.cpp
@@ -1272,7 +1272,7 @@
           << Module->Name << Locked.getErrorMessage();
       // Clear out any potential leftover.
       Locked.unsafeRemoveLockFile();
-      // FALLTHROUGH
+      LLVM_FALLTHROUGH;
     case llvm::LockFileManager::LFS_Owned:
       // We're responsible for building the module ourselves.
       if (!compileModuleImpl(ImportingInstance, ModuleNameLoc, Module,

clang/lib/Frontend/CompilerInvocation.cpp

diff --git a/clang/lib/Frontend/CompilerInvocation.cpp b/clang/lib/Frontend/CompilerInvocation.cpp
index 92a421d..912afba 100644
--- a/clang/lib/Frontend/CompilerInvocation.cpp
+++ b/clang/lib/Frontend/CompilerInvocation.cpp
@@ -1474,7 +1474,7 @@
       Opts.ProgramAction = frontend::EmitObj; break;
     case OPT_fixit_EQ:
       Opts.FixItSuffix = A->getValue();
-      // fall-through!
+      LLVM_FALLTHROUGH;
     case OPT_fixit:
       Opts.ProgramAction = frontend::FixIt; break;
     case OPT_emit_module:

clang/lib/Frontend/Rewrite/InclusionRewriter.cpp

diff --git a/clang/lib/Frontend/Rewrite/InclusionRewriter.cpp b/clang/lib/Frontend/Rewrite/InclusionRewriter.cpp
index 1631ecc..2e7baa3 100644
--- a/clang/lib/Frontend/Rewrite/InclusionRewriter.cpp
+++ b/clang/lib/Frontend/Rewrite/InclusionRewriter.cpp
@@ -586,6 +586,7 @@
                               LocalEOL, Line, /*EnsureNewline=*/ true);
             WriteLineInfo(FileName, Line, FileType);
             RawLex.SetKeepWhitespaceMode(false);
+            break;
           }
           default:
             break;