[llvm] 8fc7a90 - Let normalize() for posix style convert backslash to slash unconditionally.

[Nico Weber via llvm-commits]

Author: Nico Weber
Date: 2020-05-05T13:54:55-04:00
New Revision: 8fc7a907b93a8e9eef96e872f8f926db3ebfe9b6

URL: https://github.com/llvm/llvm-project/commit/8fc7a907b93a8e9eef96e872f8f926db3ebfe9b6
DIFF: https://github.com/llvm/llvm-project/commit/8fc7a907b93a8e9eef96e872f8f926db3ebfe9b6.diff

LOG: Let normalize() for posix style convert backslash to slash unconditionally.

Currently, normalize() for posix replaces backslashes to slashes, except
that two backslashes in sequence are kept as-is.

clang calls normalize() to convert \ to / is microsoft compat mode. This
generally works well, but a path like "c:\\foo\\bar.h" with two
backslashes doesn't work due to the exception in normalize().

These paths happen naturally on Windows hosts with e.g.
`#include __FILE__`, and them not working on other hosts makes it
more difficult to write tests for this case.

The special case has been around without justification since this code
was added in r203611 (since then moved around in r215241 r215243).  No
integration tests fail if I remove it.

Try removing the special case.

Differential Revision: https://reviews.llvm.org/D79265

Added: 
    

Modified: 
    clang/test/Lexer/case-insensitive-include-ms.c
    llvm/lib/Support/Path.cpp
    llvm/unittests/Support/Path.cpp

Removed: 
    


################################################################################
diff  --git a/clang/test/Lexer/case-insensitive-include-ms.c b/clang/test/Lexer/case-insensitive-include-ms.c
index cf14d2530d01..f7af1fef8b4e 100644
--- a/clang/test/Lexer/case-insensitive-include-ms.c
+++ b/clang/test/Lexer/case-insensitive-include-ms.c
@@ -6,15 +6,17 @@
 // RUN: %clang_cc1 -fsyntax-only -fms-compatibility %s -include %s -I %t/Output -verify
 // RUN: %clang_cc1 -fsyntax-only -fms-compatibility -fdiagnostics-parseable-fixits %s -include %s -I %t/Output 2>&1 | FileCheck %s
 
-// FIXME: Add a test with repeated backslashes once clang can handle that
-// in ms-compat mode on non-Windows hosts.
 #include "..\Output\.\case-insensitive-include.h"
 #include "..\Output\.\Case-Insensitive-Include.h" // expected-warning {{non-portable path}}
 // CHECK: fix-it:"{{.*}}":{[[@LINE-1]]:10-[[@LINE-1]]:50}:"\"..\\Output\\.\\case-insensitive-include.h\""
+#include "..\\Output\.\\Case-Insensitive-Include.h" // expected-warning {{non-portable path}}
+// CHECK: fix-it:"{{.*}}":{[[@LINE-1]]:10-[[@LINE-1]]:52}:"\"..\\\\Output\\.\\\\case-insensitive-include.h\""
 #include "..\output\.\case-insensitive-include.h" // expected-warning {{non-portable path}}
 // CHECK: fix-it:"{{.*}}":{[[@LINE-1]]:10-[[@LINE-1]]:50}:"\"..\\Output\\.\\case-insensitive-include.h\""
 
 #include "apath\..\.\case-insensitive-include.h"
 #include "apath\..\.\Case-Insensitive-Include.h" // expected-warning {{non-portable path}}
 // CHECK: fix-it:"{{.*}}":{[[@LINE-1]]:10-[[@LINE-1]]:49}:"\"apath\\..\\.\\case-insensitive-include.h\""
+#include "apath\\..\\.\\Case-Insensitive-Include.h" // expected-warning {{non-portable path}}
+// CHECK: fix-it:"{{.*}}":{[[@LINE-1]]:10-[[@LINE-1]]:52}:"\"apath\\\\..\\\\.\\\\case-insensitive-include.h\""
 #include "APath\..\.\case-insensitive-include.h" // For the sake of efficiency, this case is not diagnosed. :-(

diff  --git a/llvm/lib/Support/Path.cpp b/llvm/lib/Support/Path.cpp
index 0a4d5818703b..775629074f6c 100644
--- a/llvm/lib/Support/Path.cpp
+++ b/llvm/lib/Support/Path.cpp
@@ -540,15 +540,9 @@ void native(SmallVectorImpl<char> &Path, Style style) {
       Path = PathHome;
     }
   } else {
-    for (auto PI = Path.begin(), PE = Path.end(); PI < PE; ++PI) {
-      if (*PI == '\\') {
-        auto PN = PI + 1;
-        if (PN < PE && *PN == '\\')
-          ++PI; // increment once, the for loop will move over the escaped slash
-        else
-          *PI = '/';
-      }
-    }
+    for (auto PI = Path.begin(), PE = Path.end(); PI < PE; ++PI)
+      if (*PI == '\\')
+        *PI = '/';
   }
 }
 

diff  --git a/llvm/unittests/Support/Path.cpp b/llvm/unittests/Support/Path.cpp
index d80edbe19d12..a577f1b744bc 100644
--- a/llvm/unittests/Support/Path.cpp
+++ b/llvm/unittests/Support/Path.cpp
@@ -1182,7 +1182,7 @@ TEST(Support, NormalizePath) {
   Tests.emplace_back("a", "a", "a");
   Tests.emplace_back("a/b", "a\\b", "a/b");
   Tests.emplace_back("a\\b", "a\\b", "a/b");
-  Tests.emplace_back("a\\\\b", "a\\\\b", "a\\\\b");
+  Tests.emplace_back("a\\\\b", "a\\\\b", "a//b");
   Tests.emplace_back("\\a", "\\a", "/a");
   Tests.emplace_back("a\\", "a\\", "a/");
   Tests.emplace_back("a\\t", "a\\t", "a/t");