[VFS] Remove 'ignore-non-existent-contents' attribute for YAML-based VFS.

[vsapsai]

Summary

'ignore-non-existent-contents' stopped working after r342232 in a way
that the actual attribute value isn't used and it works as if it is
always true.

Common use case for VFS iteration is iterating through files in umbrella
directories for modules. Ability to detect if some VFS entries point to
non-existing files is nice but non-critical. Instead of adding back
support for 'ignore-non-existent-contents': false I am removing the
attribute, because such scenario isn't used widely enough and stricter
checks don't provide enough value to justify the maintenance.

rdar://problem/45176119

[bruno]

LGTM.

[vsapsai]

Thanks for the review.

lib/Frontend/ModuleDependencyCollector.cpp

if (Seen.empty())
     return;
 
   StringRef VFSDir = getDest();
 
   // Default to use relative overlay directories in the VFS yaml file. This
   // allows crash reproducer scripts to work across machines.
   VFSWriter.setOverlayDir(VFSDir);
 
-  // Do not ignore non existent contents otherwise we might skip something
-  // that should have been collected here.
-  VFSWriter.setIgnoreNonExistentContents(false);
-
   // Explicitly set case sensitivity for the YAML writer. For that, find out
   // the sensitivity at the path where the headers all collected to.
   VFSWriter.setCaseSensitivity(isCaseSensitivePath(VFSDir));
 
   // Do not rely on real path names when executing the crash reproducer scripts
   // since we only want to actually use the files we have on the VFS cache.
   VFSWriter.setUseExternalNames(false);
 

test/Modules/crash-vfs-headermaps.m

 // CHECKSH: "-I" "/[[INCPATH:.*]]/foo.hmap"
 // CHECKSH: "crash-vfs-{{[^ ]*}}.m"
 // CHECKSH: "-ivfsoverlay" "crash-vfs-{{[^ ]*}}.cache/vfs/vfs.yaml"
 // CHECKSH: "-fmodules-cache-path=crash-vfs-{{[^ ]*}}.cache/repro-modules"
 
 // CHECKYAML: 'case-sensitive':
 // CHECKYAML-NEXT: 'use-external-names': 'false',
 // CHECKYAML-NEXT: 'overlay-relative': 'true',
-// CHECKYAML-NEXT: 'ignore-non-existent-contents': 'false'
 // CHECKYAML: 'type': 'directory'
 // CHECKYAML: 'name': "/[[PATH:.*]]/Foo.framework/Headers",
 // CHECKYAML-NEXT: 'contents': [
 // CHECKYAML-NEXT:   {
 // CHECKYAML-NEXT:     'type': 'file',
 // CHECKYAML-NEXT:     'name': "Foo.h",
 // CHECKYAML-NEXT:     'external-contents': "/[[PATH]]/Foo.framework/Headers/Foo.h"
 // CHECKYAML: 'type': 'directory'
 // CHECKYAML: 'name': "/[[PATH:.*]]/i",
 // CHECKYAML-NEXT: 'contents': [
 // CHECKYAML-NEXT:   {
 // CHECKYAML-NEXT:     'type': 'file',
 // CHECKYAML-NEXT:     'name': "foo.hmap",
 // CHECKYAML-NEXT:     'external-contents': "/[[PATH]]/i/foo.hmap"

test/Modules/crash-vfs-include-pch.m

 // CHECKSH: "-include-pch" "/[[INCPATH:.*]]/out/pch-used.h.pch"
 // CHECKSH: "crash-vfs-{{[^ ]*}}.m"
 // CHECKSH: "-ivfsoverlay" "crash-vfs-{{[^ ]*}}.cache/vfs/vfs.yaml"
 // CHECKSH: "-fmodules-cache-path=crash-vfs-{{[^ ]*}}.cache/repro-modules"
 
 // CHECKYAML: 'case-sensitive':
 // CHECKYAML-NEXT: 'use-external-names': 'false',
 // CHECKYAML-NEXT: 'overlay-relative': 'true',
-// CHECKYAML-NEXT: 'ignore-non-existent-contents': 'false'
 // CHECKYAML: 'type': 'directory'
 // CHECKYAML: 'name': "/[[PATH:.*]]/out",
 // CHECKYAML-NEXT: 'contents': [
 // CHECKYAML-NEXT:   {
 // CHECKYAML-NEXT:     'type': 'file',
 // CHECKYAML-NEXT:     'name': "pch-used.h.pch",
 // CHECKYAML-NEXT:     'external-contents': "/[[PATH]]/out/pch-used.h.pch"

test/Modules/crash-vfs-ivfsoverlay.m

 // CHECKSH-NEXT: "-cc1"
 // CHECKSH: "crash-vfs-{{[^ ]*}}.m"
 // CHECKSH: "-ivfsoverlay" "crash-vfs-{{[^ ]*}}.cache/vfs/vfs.yaml"
 // CHECKSH: "-fmodules-cache-path=crash-vfs-{{[^ ]*}}.cache/repro-modules"
 
 // CHECKYAML: 'case-sensitive':
 // CHECKYAML-NEXT: 'use-external-names': 'false',
 // CHECKYAML-NEXT: 'overlay-relative': 'true',
-// CHECKYAML-NEXT: 'ignore-non-existent-contents': 'false'
 // CHECKYAML: 'type': 'directory'
 // CHECKYAML: 'name': "/[[PATH:.*]]/example"
 // CHECKYAML: 'contents': [
 // CHECKYAML-NEXT:   {
 // CHECKYAML-NEXT:     'type': 'file',
 // CHECKYAML-NEXT:     'name': "module.map",
 // CHECKYAML-NEXT:     'external-contents': "/[[OTHERPATH:.*]]/actual_module2.map"

test/Modules/crash-vfs-relative-incdir.m

 // CHECKSH: "-I" "/[[INCPATH:.*]]/include"
 // CHECKSH: "crash-vfs-{{[^ ]*}}.m"
 // CHECKSH: "-ivfsoverlay" "crash-vfs-{{[^ ]*}}.cache/vfs/vfs.yaml"
 // CHECKSH: "-fmodules-cache-path=crash-vfs-{{[^ ]*}}.cache/repro-modules"
 
 // CHECKYAML: 'case-sensitive':
 // CHECKYAML-NEXT: 'use-external-names': 'false',
 // CHECKYAML-NEXT: 'overlay-relative': 'true',
-// CHECKYAML-NEXT: 'ignore-non-existent-contents': 'false'
 // CHECKYAML: 'type': 'directory'
 // CHECKYAML: 'name': "/[[PATH:.*]]/Inputs/crash-recovery/usr/include",
 // CHECKYAML-NEXT: 'contents': [
 // CHECKYAML-NEXT:   {
 // CHECKYAML-NEXT:     'type': 'file',
 // CHECKYAML-NEXT:     'name': "module.map",
 // CHECKYAML-NOT:      'external-contents': "{{[^ ]*}}.cache
 // CHECKYAML-NEXT:     'external-contents': "/[[PATH]]/Inputs/crash-recovery/usr/include/module.map"

test/Modules/crash-vfs-run-reproducer.m

 // CHECKSH: "-isysroot" "{{[^"]*}}/i/"
 // CHECKSH: "crash-vfs-{{[^ ]*}}.m"
 // CHECKSH: "-ivfsoverlay" "crash-vfs-{{[^ ]*}}.cache/vfs/vfs.yaml"
 // CHECKSH: "-fmodules-cache-path=crash-vfs-{{[^ ]*}}.cache/repro-modules"
 
 // CHECKYAML: 'case-sensitive':
 // CHECKYAML-NEXT: 'use-external-names': 'false',
 // CHECKYAML-NEXT: 'overlay-relative': 'true',
-// CHECKYAML-NEXT: 'ignore-non-existent-contents': 'false'
 // CHECKYAML: 'type': 'directory'
 // CHECKYAML: 'name': "/[[PATH:.*]]/Inputs/crash-recovery/usr/include",
 // CHECKYAML-NEXT: 'contents': [
 // CHECKYAML-NEXT:   {
 // CHECKYAML-NEXT:     'type': 'file',
 // CHECKYAML-NEXT:     'name': "module.map",
 // CHECKYAML-NOT:      'external-contents': "{{[^ ]*}}.cache
 // CHECKYAML-NEXT:     'external-contents': "/[[PATH]]/Inputs/crash-recovery/usr/include/module.map"

test/VFS/Inputs/MissingVFS/vfsoverlay.yaml

 {
   'version': 0,
-  'ignore-non-existent-contents': false,
   'roots': [
     { 'name': 'INPUT_DIR', 'type': 'directory',
       'contents': [
         { 'name': 'a.h', 'type': 'file',
           'external-contents': 'OUT_DIR/a.h'
         }
       ]
     }
   ]
 }

test/VFS/Inputs/Nonmodular/nonmodular-headers.yaml

 {
   'version': 0,
   'case-sensitive': 'false',
-  'ignore-non-existent-contents': 'true',
   'roots': [
     {
       'type': 'directory',
       'name': "VDIR/Nonmodular.framework/Headers",
       'contents': [
         {
           'type': 'file',
           'name': "umbrella.h",

test/VFS/Inputs/bar-headers.yaml

 {
   'version': 0,
   'case-sensitive': 'false',
-  'ignore-non-existent-contents': 'true',
   'roots': [
     {
       'type': 'directory',
       'name': "VDIR/Bar.framework/Headers",
       'contents': [
         {
           'type': 'file',
           'name': "A.h",

test/VFS/Inputs/vfsoverlay2.yaml

 {
   'version': 0,
-  'ignore-non-existent-contents': false,
   'roots': [
     { 'name': 'OUT_DIR', 'type': 'directory',
       'contents': [
         { 'name': 'module.map', 'type': 'file',
           'external-contents': 'INPUT_DIR/actual_module2.map'
         }
       ]
     }
   ]
 }