From e438dd3c9b406ba36fbd98c25514b4a335f21b41 Mon Sep 17 00:00:00 2001
From: AnotherTest <ali.mpfard@gmail.com>
Date: Tue, 16 Feb 2021 12:50:48 +0330
Subject: [PATCH] LibC: Teach scanf how to read "%lu" and "%llu" (unsigned
 long{, long})

This makes the gcc port work again.
---
 Userland/Libraries/LibC/scanf.cpp | 38 +++++++++++++++++++++++++++++++
 Userland/Tests/LibC/scanf.cpp     |  5 ++++
 2 files changed, 43 insertions(+)

diff --git a/Userland/Libraries/LibC/scanf.cpp b/Userland/Libraries/LibC/scanf.cpp
index e1b30f6f69..bb51aad92d 100644
--- a/Userland/Libraries/LibC/scanf.cpp
+++ b/Userland/Libraries/LibC/scanf.cpp
@@ -163,6 +163,40 @@ struct read_element_concrete<unsigned, ApT, kind> {
     }
 };
 
+template<typename ApT, ReadKind kind>
+struct read_element_concrete<unsigned long long, ApT, kind> {
+    bool operator()(GenericLexer& lexer, va_list* ap)
+    {
+        lexer.ignore_while(isspace);
+
+        auto* ptr = va_arg(*ap, ApT*);
+        unsigned long long value = 0;
+        char* endptr = nullptr;
+        auto nptr = lexer.remaining().characters_without_null_termination();
+        if constexpr (kind == ReadKind::Normal)
+            value = strtoull(nptr, &endptr, 10);
+        if constexpr (kind == ReadKind::Octal)
+            value = strtoull(nptr, &endptr, 8);
+        if constexpr (kind == ReadKind::Hex)
+            value = strtoull(nptr, &endptr, 16);
+        if constexpr (kind == ReadKind::Infer)
+            value = strtoull(nptr, &endptr, 0);
+
+        if (!endptr)
+            return false;
+
+        if (endptr == nptr)
+            return false;
+
+        auto diff = endptr - nptr;
+        ASSERT(diff > 0);
+        lexer.ignore((size_t)diff);
+
+        *ptr = value;
+        return true;
+    }
+};
+
 template<typename ApT, ReadKind kind>
 struct read_element_concrete<float, ApT, kind> {
     bool operator()(GenericLexer& lexer, va_list* ap)
@@ -211,12 +245,16 @@ struct read_element {
         case Long:
             if constexpr (IsSame<T, int>::value)
                 return read_element_concrete<T, long, kind> {}(input_lexer, ap);
+            if constexpr (IsSame<T, unsigned>::value)
+                return read_element_concrete<T, unsigned, kind> {}(input_lexer, ap);
             if constexpr (IsSame<T, float>::value)
                 return read_element_concrete<T, double, kind> {}(input_lexer, ap);
             return false;
         case LongLong:
             if constexpr (IsSame<T, int>::value)
                 return read_element_concrete<T, long long, kind> {}(input_lexer, ap);
+            if constexpr (IsSame<T, unsigned>::value)
+                return read_element_concrete<T, unsigned long long, kind> {}(input_lexer, ap);
             if constexpr (IsSame<T, float>::value)
                 return read_element_concrete<T, double, kind> {}(input_lexer, ap);
             return false;
diff --git a/Userland/Tests/LibC/scanf.cpp b/Userland/Tests/LibC/scanf.cpp
index 4da0d92856..da358ddac2 100644
--- a/Userland/Tests/LibC/scanf.cpp
+++ b/Userland/Tests/LibC/scanf.cpp
@@ -31,6 +31,7 @@
 
 typedef long double longdouble;
 typedef long long longlong;
+typedef unsigned long unsignedlong;
 typedef char charstar[32];
 
 template<typename T>
@@ -143,6 +144,7 @@ DECL_WITH_TYPE(longlong);
 DECL_WITH_TYPE(float);
 DECL_WITH_TYPE(double);
 DECL_WITH_TYPE(longdouble);
+DECL_WITH_TYPE(unsignedlong);
 
 #undef DECL_WITH_TYPE
 
@@ -179,6 +181,9 @@ const TestSuite test_suites[] {
     { "%u.%u.%u", "3.19", 2, 3, { unsignedarg0, unsignedarg1, unsignedarg2 }, { to_value_t(3u), to_value_t(19u) } },
     // Failing test case from previous impl:
     { "SSH-%d.%d-%[^\n]\n", "SSH-2.0-OpenSSH_8.2p1 Ubuntu-4ubuntu0.1\n", 3, 3, { intarg0, intarg1, charstararg0 }, { to_value_t(2), to_value_t(0), str_to_value_t("OpenSSH_8.2p1 Ubuntu-4ubuntu0.1") } },
+    // GCC failure tests
+    { "%d.%d.%d", "10.2.0", 3, 3, { intarg0, intarg1, intarg2 }, { to_value_t(10), to_value_t(2), to_value_t(0) } },
+    { "%lu", "3054       ", 1, 1, { unsignedlongarg0 }, { to_value_t(3054ul) } },
 };
 
 bool g_any_failed = false;