From 2ab910a35f7d45dd3c0d4874629168841b621ac2 Mon Sep 17 00:00:00 2001
From: Nikita Nemkin <nikita@nemkin.ru>
Date: Wed, 5 Feb 2025 21:44:20 +0500
Subject: [PATCH] SystemTools: Improve repeated slash handling in
ConvertToUnixSlashes
Collapse repeated slashes, but preserve exactly two leading slashes.
POSIX reserves exactly two leading slashes for implementation-defined
behavior. On Windows and Cygwin they mark UNC paths.
Improve test coverage of ConvertToUnixSlashes.
Issue: cmake/cmake#9182
---
SystemTools.cxx | 45 +++++++++++++--------------------------------
testSystemTools.cxx | 14 ++++++++++++++
2 files changed, 27 insertions(+), 32 deletions(-)
diff --git a/SystemTools.cxx b/SystemTools.cxx
index 39846c0..dcf2b66 100644
--- a/SystemTools.cxx
+++ b/SystemTools.cxx
@@ -2087,38 +2087,21 @@ void SystemTools::ConvertToUnixSlashes(std::string& path)
}
char const* pathCString = path.c_str();
- bool hasDoubleSlash = false;
#ifdef __VMS
ConvertVMSToUnix(path);
#else
- char const* pos0 = pathCString;
- for (std::string::size_type pos = 0; *pos0; ++pos) {
- if (*pos0 == '\\') {
- path[pos] = '/';
- }
-
- // Also, reuse the loop to check for slash followed by another slash
- if (!hasDoubleSlash && *(pos0 + 1) == '/' && *(pos0 + 2) == '/') {
-# ifdef _WIN32
- // However, on windows if the first characters are both slashes,
- // then keep them that way, so that network paths can be handled.
- if (pos > 0) {
- hasDoubleSlash = true;
- }
-# else
- hasDoubleSlash = true;
-# endif
- }
-
- pos0++;
- }
-
- if (hasDoubleSlash) {
- SystemTools::ReplaceString(path, "//", "/");
- }
+ // replace backslashes
+ std::replace(path.begin(), path.end(), '\\', '/');
+
+ // collapse repeated slashes, except exactly two leading slashes are
+ // meaningful and must be preserved.
+ bool hasDoubleSlash = path[0] == '/' && path[1] == '/' && path[2] != '/';
+ auto uniqueEnd = std::unique(
+ path.begin() + hasDoubleSlash, path.end(),
+ [](char c1, char c2) -> bool { return c1 == '/' && c1 == c2; });
+ path.erase(uniqueEnd, path.end());
#endif
- // remove any trailing slash
// if there is a tilda ~ then replace it with HOME
pathCString = path.c_str();
if (pathCString[0] == '~' &&
@@ -2140,13 +2123,11 @@ void SystemTools::ConvertToUnixSlashes(std::string& path)
}
}
#endif
- // remove trailing slash if the path is more than
- // a single /
- pathCString = path.c_str();
+ // remove trailing slash, but preserve the root slash and the slash
+ // after windows drive letter (c:/).
size_t size = path.size();
if (size > 1 && path.back() == '/') {
- // if it is c:/ then do not remove the trailing slash
- if (!((size == 3 && pathCString[1] == ':'))) {
+ if (!(size == 3 && path[1] == ':') && path[size - 2] != '/') {
path.resize(size - 1);
}
}
diff --git a/testSystemTools.cxx b/testSystemTools.cxx
index 055ffd1..0704458 100644
--- a/testSystemTools.cxx
+++ b/testSystemTools.cxx
@@ -53,6 +53,20 @@ static char const* toUnixPaths[][2] = {
{ "\\\\usr\\local\\bin\\passwd", "//usr/local/bin/passwd" },
{ "\\\\usr\\lo cal\\bin\\pa sswd", "//usr/lo cal/bin/pa sswd" },
{ "\\\\usr\\lo\\ cal\\bin\\pa\\ sswd", "//usr/lo/ cal/bin/pa/ sswd" },
+ { "\\", "/" },
+ { "/", "/" },
+ { "\\\\", "//" },
+ { "//", "//" },
+ { "\\\\\\", "/" },
+ { "///", "/" },
+ { "C:\\", "C:/" },
+ { "C:\\\\", "C:/" },
+ { "C:\\\\\\", "C:/" },
+ { "\\\\UNC\\path", "//UNC/path" },
+ { "//UNC/path", "//UNC/path" },
+ { "\\\\\\triple\\\\back\\\\\\slash\\\\\\", "/triple/back/slash" },
+ { "///triple//back///slash///", "/triple/back/slash" },
+ { "///////ex treme/////////", "/ex treme" },
{ nullptr, nullptr }
};
--
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