Print correctly dependency paths on Windows

[xbolva00]

Summary

Before:
main.o: main.c ../include/lib\test.h

After:
main.o: main.c ../include/lib/test.h

Fixes PR38877

[xbolva00]

Remove some dead code

[zturner]

What prints this? How do you exercise this codepath?

[xbolva00]

In D51847#1228927, @zturner wrote:

What prints this? How do you exercise this codepath?

DFGImpl::OutputDependencyFile() -> for (StringRef File : Files)

[zturner]

I mean in practice. What command do i run to hit this and what will the
output look like? Can you paste some terminal output showing the command
and output?

[xbolva00]

Please see PR38877.

[zturner]

Alright I see it. The reason I'm asking is because after your change you're now printing main.o: main.c ../include/lib/test.h. But I wonder if you should instead be printing main.o: main.c ..\include\lib\test.h. It seems like paths that we show to the user should be in the native path style.

lib/Frontend/DependencyFile.cpp

389

This looks like a dangling reference -- undefined behavior.

[xbolva00]

In D51847#1230766, @zturner wrote:

Alright I see it. The reason I'm asking is because after your change you're now printing main.o: main.c ../include/lib/test.h. But I wonder if you should instead be printing main.o: main.c ..\include\lib\test.h. It seems like paths that we show to the user should be in the native path style.

Possibly, or should we follow GGC behavior here? GCC prints main.o: main.c ../include/lib/test.h. But conversion to native paths sounds fine for me as well.

[zturner]

clang-cl in general tries to do the thing that makes native Windows developers the most comfortable, while gcc in general tries to do the thing that makes Unix developers most comfortable. So I think we should probably use \ here. If anyone complains we can revisit.

[xbolva00]

Convert paths to platform native paths

[xbolva00]

• Fixed failing test

[cfe-commits]

Lgtm

• msg-6991-166.txt159 BDownload

[xbolva00]

Adjusted regexes in two more tests

lib/Frontend/DependencyFile.cpp

 ///
 /// NMake/Jom has a different set of scary characters, but wraps filespecs in
 /// double-quotes to avoid misinterpreting them; see
 /// https://msdn.microsoft.com/en-us/library/dd9y37ha.aspx for NMake info,
 /// https://msdn.microsoft.com/en-us/library/windows/desktop/aa365247(v=vs.85).aspx
 /// for Windows file-naming info.
 static void PrintFilename(raw_ostream &OS, StringRef Filename,
                           DependencyOutputFormat OutputFormat) {
+  // Convert filename to platform native path
+  llvm::SmallString<256> NativePath;
+  llvm::sys::path::native(Filename.str(), NativePath);
+
   if (OutputFormat == DependencyOutputFormat::NMake) {
     // Add quotes if needed. These are the characters listed as "special" to
     // NMake, that are legal in a Windows filespec, and that could cause
     // misinterpretation of the dependency string.
-    if (Filename.find_first_of(" #${}^!") != StringRef::npos)
-      OS << '\"' << Filename << '\"';
+    if (NativePath.find_first_of(" #${}^!") != StringRef::npos)
+      OS << '\"' << NativePath << '\"';
     else
-      OS << Filename;
+      OS << NativePath;
     return;
   }
   assert(OutputFormat == DependencyOutputFormat::Make);
-  for (unsigned i = 0, e = Filename.size(); i != e; ++i) {
-    if (Filename[i] == '#') // Handle '#' the broken gcc way.
+  for (unsigned i = 0, e = NativePath.size(); i != e; ++i) {
+    if (NativePath[i] == '#') // Handle '#' the broken gcc way.
       OS << '\\';
-    else if (Filename[i] == ' ') { // Handle space correctly.
+    else if (NativePath[i] == ' ') { // Handle space correctly.
       OS << '\\';
       unsigned j = i;
-      while (j > 0 && Filename[--j] == '\\')
+      while (j > 0 && NativePath[--j] == '\\')
         OS << '\\';
-    } else if (Filename[i] == '$') // $ is escaped by $$.
+    } else if (NativePath[i] == '$') // $ is escaped by $$.
       OS << '$';
-    OS << Filename[i];
+    OS << NativePath[i];
   }
 }
 
 void DFGImpl::OutputDependencyFile() {
   if (SeenMissingHeader) {
     llvm::sys::fs::remove(OutputFile);
     return;
   }

test/Frontend/dependency-gen-escaping.c

 #include "    .h"
 #include "$$.h"
 #include "##.h"
 #include "normal.h"
 
 // Backslash followed by # or space should escape both characters, because
 // that's what GNU Make wants.  GCC does the right thing with space, but not
 // #, so Clang does too. (There should be 3 backslashes before the #.)
-// SEP2F: a\b\\#c\\\ d.h
+// SEP2F: a{{[/\\]}}b{{[/\\]}}\#c{{/|\\\\}}\ d.h
 // With -fms-compatibility, Backslashes in #include are treated as path separators.
 // Backslashes are given in the emission for special characters, like 0x20 or 0x23.
 // SEP5C: a{{[/\\]}}b{{[/\\]}}\#c{{/|\\\\}}\ d.h
 // These combinations are just another case for NMAKE.
 // NMAKE: "a{{[/\\]}}b{{[/\\]}}#c{{[/\\]}} d.h"
 
 #include "a\b\#c\ d.h"

test/Frontend/dependency-gen.c

 // Basic test
 // RUN: rm -rf %t.dir
 // RUN: mkdir -p %t.dir/a/b
 // RUN: echo > %t.dir/a/b/x.h
 // RUN: cd %t.dir
 // RUN: %clang -MD -MF - %s -fsyntax-only -I a/b | FileCheck -check-prefix=CHECK-ONE %s
-// CHECK-ONE: {{ }}a/b{{[/\\]}}x.h
+// CHECK-ONE: {{ }}a{{[/\\]}}b{{[/\\]}}x.h
 
 // PR8974 (-include flag)
 // RUN: %clang -MD -MF - %s -fsyntax-only -include a/b/x.h -DINCLUDE_FLAG_TEST | FileCheck -check-prefix=CHECK-TWO %s
-// CHECK-TWO: {{ }}a/b/x.h
+// CHECK-TWO: {{ }}a{{[/\\]}}b{{[/\\]}}x.h
 
 // rdar://problem/9734352 (paths involving ".")
 // RUN: %clang -MD -MF - %s -fsyntax-only -I ./a/b | FileCheck -check-prefix=CHECK-THREE %s
-// CHECK-THREE: {{ }}a/b{{[/\\]}}x.h
+// CHECK-THREE: {{ }}a{{[/\\]}}b{{[/\\]}}x.h
 // RUN: %clang -MD -MF - %s -fsyntax-only -I .//./a/b/ | FileCheck -check-prefix=CHECK-FOUR %s
-// CHECK-FOUR: {{ }}a/b{{[/\\]}}x.h
+// CHECK-FOUR: {{ }}a{{[/\\]}}b{{[/\\]}}x.h
 // RUN: %clang -MD -MF - %s -fsyntax-only -I a/b/. | FileCheck -check-prefix=CHECK-FIVE %s
-// CHECK-FIVE: {{ }}a/b/.{{[/\\]}}x.h
+// CHECK-FIVE: {{ }}a{{[/\\]}}b{{[/\\]}}.{{[/\\]}}x.h
 // RUN: cd a/b
 // RUN: %clang -MD -MF - %s -fsyntax-only -I ./ | FileCheck -check-prefix=CHECK-SIX %s
 // CHECK-SIX: {{ }}x.h
 // RUN: echo "fun:foo" > %t.blacklist
 // RUN: %clang -MD -MF - %s -fsyntax-only -resource-dir=%S/Inputs/resource_dir_with_cfi_blacklist -fsanitize=cfi-vcall -flto -fvisibility=hidden -fsanitize-blacklist=%t.blacklist -I ./ | FileCheck -check-prefix=CHECK-SEVEN %s
 // CHECK-SEVEN: .blacklist
 // CHECK-SEVEN: {{ }}x.h
 #ifndef INCLUDE_FLAG_TEST
 #include <x.h>
 #endif

test/Modules/relative-dep-gen.cpp

 // RUN: cd %t
 // RUN: %clang_cc1 -fmodules -fno-implicit-modules -fmodule-file=%t/mod-cwd.pcm -dependency-file %t/use-explicit-no-map-cwd.d -MT use.o relative-dep-gen.cpp -fsyntax-only -fmodule-map-file-home-is-cwd
 // RUN: cat %t/use-explicit-no-map-cwd.d
 // RUN: FileCheck --check-prefix=CHECK-USE %s < %t/use-explicit-no-map-cwd.d
 
 #include "Inputs/relative-dep-gen-1.h"
 
 // CHECK-BUILD: mod.pcm:
-// CHECK-BUILD:   {{[ \t]}}Inputs/relative-dep-gen{{(-cwd)?}}.modulemap
-// CHECK-BUILD:   {{[ \t]}}Inputs/relative-dep-gen-1.h
-// CHECK-BUILD:   {{[ \t]}}Inputs/relative-dep-gen-2.h
+// CHECK-BUILD:   {{[ \t]}}Inputs{{[/\\]}}relative-dep-gen{{(-cwd)?}}.modulemap
+// CHECK-BUILD:   {{[ \t]}}Inputs{{[/\\]}}relative-dep-gen-1.h
+// CHECK-BUILD:   {{[ \t]}}Inputs{{[/\\]}}relative-dep-gen-2.h
 // CHECK-USE: use.o:
 // CHECK-USE-DAG:   {{[ \t]}}relative-dep-gen.cpp
 // CHECK-EXPLICIT-DAG:   mod.pcm
 // CHECK-IMPLICIT-DAG:   {{[ \t]}}Inputs{{[/\\]}}relative-dep-gen-1.h