[libcxx] Implement parsing of root_name for paths on windows
Differential Revision: https://reviews.llvm.org/D91176
GitOrigin-RevId: 929f0bcc24e246ea02ab57df8009a6fd5751d45c
diff --git a/src/filesystem/operations.cpp b/src/filesystem/operations.cpp
index 674f191..88a039f 100644
--- a/src/filesystem/operations.cpp
+++ b/src/filesystem/operations.cpp
@@ -64,6 +64,10 @@
return false;
}
+bool isDriveLetter(path::value_type C) {
+ return (C >= 'a' && C <= 'z') || (C >= 'A' && C <= 'Z');
+}
+
namespace parser {
using string_view_t = path::__string_view;
@@ -120,6 +124,12 @@
switch (State) {
case PS_BeforeBegin: {
+ PosPtr TkEnd = consumeRootName(Start, End);
+ if (TkEnd)
+ return makeState(PS_InRootName, Start, TkEnd);
+ }
+ _LIBCPP_FALLTHROUGH();
+ case PS_InRootName: {
PosPtr TkEnd = consumeSeparator(Start, End);
if (TkEnd)
return makeState(PS_InRootDir, Start, TkEnd);
@@ -142,7 +152,6 @@
case PS_InTrailingSep:
return makeState(PS_AtEnd);
- case PS_InRootName:
case PS_AtEnd:
_LIBCPP_UNREACHABLE();
}
@@ -160,9 +169,15 @@
if (PosPtr SepEnd = consumeSeparator(RStart, REnd)) {
if (SepEnd == REnd)
return makeState(PS_InRootDir, Path.data(), RStart + 1);
+ PosPtr TkStart = consumeRootName(SepEnd, REnd);
+ if (TkStart == REnd)
+ return makeState(PS_InRootDir, RStart, RStart + 1);
return makeState(PS_InTrailingSep, SepEnd + 1, RStart + 1);
} else {
- PosPtr TkStart = consumeName(RStart, REnd);
+ PosPtr TkStart = consumeRootName(RStart, REnd);
+ if (TkStart == REnd)
+ return makeState(PS_InRootName, TkStart + 1, RStart + 1);
+ TkStart = consumeName(RStart, REnd);
return makeState(PS_InFilenames, TkStart + 1, RStart + 1);
}
}
@@ -173,11 +188,17 @@
PosPtr SepEnd = consumeSeparator(RStart, REnd);
if (SepEnd == REnd)
return makeState(PS_InRootDir, Path.data(), RStart + 1);
- PosPtr TkEnd = consumeName(SepEnd, REnd);
- return makeState(PS_InFilenames, TkEnd + 1, SepEnd + 1);
+ PosPtr TkStart = consumeRootName(SepEnd ? SepEnd : RStart, REnd);
+ if (TkStart == REnd) {
+ if (SepEnd)
+ return makeState(PS_InRootDir, SepEnd + 1, RStart + 1);
+ return makeState(PS_InRootName, TkStart + 1, RStart + 1);
+ }
+ TkStart = consumeName(SepEnd, REnd);
+ return makeState(PS_InFilenames, TkStart + 1, SepEnd + 1);
}
case PS_InRootDir:
- // return makeState(PS_InRootName, Path.data(), RStart + 1);
+ return makeState(PS_InRootName, Path.data(), RStart + 1);
case PS_InRootName:
case PS_BeforeBegin:
_LIBCPP_UNREACHABLE();
@@ -284,7 +305,7 @@
}
PosPtr consumeSeparator(PosPtr P, PosPtr End) const noexcept {
- if (P == End || !isSeparator(*P))
+ if (P == nullptr || P == End || !isSeparator(*P))
return nullptr;
const int Inc = P < End ? 1 : -1;
P += Inc;
@@ -293,15 +314,72 @@
return P;
}
+ // Consume exactly N separators, or return nullptr.
+ PosPtr consumeNSeparators(PosPtr P, PosPtr End, int N) const noexcept {
+ PosPtr Ret = consumeSeparator(P, End);
+ if (Ret == nullptr)
+ return nullptr;
+ if (P < End) {
+ if (Ret == P + N)
+ return Ret;
+ } else {
+ if (Ret == P - N)
+ return Ret;
+ }
+ return nullptr;
+ }
+
PosPtr consumeName(PosPtr P, PosPtr End) const noexcept {
- if (P == End || isSeparator(*P))
+ PosPtr Start = P;
+ if (P == nullptr || P == End || isSeparator(*P))
return nullptr;
const int Inc = P < End ? 1 : -1;
P += Inc;
while (P != End && !isSeparator(*P))
P += Inc;
+ if (P == End && Inc < 0) {
+ // Iterating backwards and consumed all the rest of the input.
+ // Check if the start of the string would have been considered
+ // a root name.
+ PosPtr RootEnd = consumeRootName(End + 1, Start);
+ if (RootEnd)
+ return RootEnd - 1;
+ }
return P;
}
+
+ PosPtr consumeDriveLetter(PosPtr P, PosPtr End) const noexcept {
+ if (P == End)
+ return nullptr;
+ if (P < End) {
+ if (P + 1 == End || !isDriveLetter(P[0]) || P[1] != ':')
+ return nullptr;
+ return P + 2;
+ } else {
+ if (P - 1 == End || !isDriveLetter(P[-1]) || P[0] != ':')
+ return nullptr;
+ return P - 2;
+ }
+ }
+
+ PosPtr consumeNetworkRoot(PosPtr P, PosPtr End) const noexcept {
+ if (P == End)
+ return nullptr;
+ if (P < End)
+ return consumeName(consumeNSeparators(P, End, 2), End);
+ else
+ return consumeNSeparators(consumeName(P, End), End, 2);
+ }
+
+ PosPtr consumeRootName(PosPtr P, PosPtr End) const noexcept {
+#if defined(_LIBCPP_WIN32API)
+ if (PosPtr Ret = consumeDriveLetter(P, End))
+ return Ret;
+ if (PosPtr Ret = consumeNetworkRoot(P, End))
+ return Ret;
+#endif
+ return nullptr;
+ }
};
string_view_pair separate_filename(string_view_t const& s) {
