[libc] Add vsscanf function #101402
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[libc] Add vsscanf function #101402
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Summary: Adds support for the `vsscanf` function similar to `sscanf`. Based off of llvm#97529.
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@llvm/pr-subscribers-libc Author: Joseph Huber (jhuber6) ChangesSummary: Full diff: https://github.com/llvm/llvm-project/pull/101402.diff 10 Files Affected:
diff --git a/libc/config/gpu/entrypoints.txt b/libc/config/gpu/entrypoints.txt
index 04a42c3019495..6035af5c0ebb0 100644
--- a/libc/config/gpu/entrypoints.txt
+++ b/libc/config/gpu/entrypoints.txt
@@ -188,6 +188,7 @@ set(TARGET_LIBC_ENTRYPOINTS
libc.src.stdio.vsnprintf
libc.src.stdio.vsprintf
libc.src.stdio.sscanf
+ libc.src.stdio.vsscanf
libc.src.stdio.feof
libc.src.stdio.ferror
libc.src.stdio.fflush
diff --git a/libc/config/linux/riscv/entrypoints.txt b/libc/config/linux/riscv/entrypoints.txt
index 084f899c2b957..aa8edc188eeee 100644
--- a/libc/config/linux/riscv/entrypoints.txt
+++ b/libc/config/linux/riscv/entrypoints.txt
@@ -217,6 +217,7 @@ set(TARGET_LIBC_ENTRYPOINTS
libc.src.stdio.snprintf
libc.src.stdio.sprintf
libc.src.stdio.sscanf
+ libc.src.stdio.vsscanf
libc.src.stdio.vfprintf
libc.src.stdio.vprintf
libc.src.stdio.vsnprintf
diff --git a/libc/config/linux/x86_64/entrypoints.txt b/libc/config/linux/x86_64/entrypoints.txt
index dbd9cf07d6b7e..c9b22b5b1c701 100644
--- a/libc/config/linux/x86_64/entrypoints.txt
+++ b/libc/config/linux/x86_64/entrypoints.txt
@@ -217,6 +217,7 @@ set(TARGET_LIBC_ENTRYPOINTS
libc.src.stdio.snprintf
libc.src.stdio.sprintf
libc.src.stdio.sscanf
+ libc.src.stdio.vsscanf
libc.src.stdio.vfprintf
libc.src.stdio.vprintf
libc.src.stdio.vsnprintf
diff --git a/libc/newhdrgen/yaml/stdio.yaml b/libc/newhdrgen/yaml/stdio.yaml
index 687a6d696cad6..660087e20b0cc 100644
--- a/libc/newhdrgen/yaml/stdio.yaml
+++ b/libc/newhdrgen/yaml/stdio.yaml
@@ -105,6 +105,14 @@ functions:
- type: const char *__restrict
- type: const char *__restrict
- type: ...
+ - name: vsscanf
+ standards:
+ - stdc
+ return_type: int
+ arguments:
+ - type: const char *__restrict
+ - type: const char *__restrict
+ - type: va_list
- name: scanf
standards:
- stdc
diff --git a/libc/spec/stdc.td b/libc/spec/stdc.td
index 6aaf05ffd9f65..20d32615a5083 100644
--- a/libc/spec/stdc.td
+++ b/libc/spec/stdc.td
@@ -917,6 +917,13 @@ def StdC : StandardSpec<"stdc"> {
ArgSpec<ConstCharRestrictedPtr>,
ArgSpec<VarArgType>]
>,
+ FunctionSpec<
+ "vsscanf",
+ RetValSpec<IntType>,
+ [ArgSpec<ConstCharRestrictedPtr>,
+ ArgSpec<ConstCharRestrictedPtr>,
+ ArgSpec<VaListType>]
+ >,
FunctionSpec<
"scanf",
RetValSpec<IntType>,
diff --git a/libc/src/stdio/CMakeLists.txt b/libc/src/stdio/CMakeLists.txt
index 2d528a903cc2f..94f92351e92fa 100644
--- a/libc/src/stdio/CMakeLists.txt
+++ b/libc/src/stdio/CMakeLists.txt
@@ -121,6 +121,18 @@ add_entrypoint_object(
libc.src.stdio.scanf_core.scanf_main
)
+add_entrypoint_object(
+ vsscanf
+ SRCS
+ vsscanf.cpp
+ HDRS
+ vsscanf.h
+ DEPENDS
+ libc.src.__support.arg_list
+ libc.src.stdio.scanf_core.reader
+ libc.src.stdio.scanf_core.scanf_main
+)
+
add_entrypoint_object(
fscanf
SRCS
diff --git a/libc/src/stdio/vsscanf.cpp b/libc/src/stdio/vsscanf.cpp
new file mode 100644
index 0000000000000..fcf0b88885f17
--- /dev/null
+++ b/libc/src/stdio/vsscanf.cpp
@@ -0,0 +1,33 @@
+//===-- Implementation of vsscanf -------------------------------*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "src/stdio/vsscanf.h"
+
+#include "src/__support/CPP/limits.h"
+#include "src/__support/arg_list.h"
+#include "src/stdio/scanf_core/reader.h"
+#include "src/stdio/scanf_core/scanf_main.h"
+
+#include <stdarg.h>
+#include <stdio.h>
+
+namespace LIBC_NAMESPACE_DECL {
+
+LLVM_LIBC_FUNCTION(int, vsscanf,
+ (const char *buffer, const char *format, va_list vlist)) {
+ internal::ArgList args(vlist);
+ scanf_core::ReadBuffer rb{const_cast<char *>(buffer),
+ cpp::numeric_limits<size_t>::max()};
+ scanf_core::Reader reader(&rb);
+ int ret_val = scanf_core::scanf_main(&reader, format, args);
+ // This is done to avoid including stdio.h in the internals. On most systems
+ // EOF is -1, so this will be transformed into just "return ret_val".
+ return (ret_val == -1) ? EOF : ret_val;
+}
+
+} // namespace LIBC_NAMESPACE_DECL
diff --git a/libc/src/stdio/vsscanf.h b/libc/src/stdio/vsscanf.h
new file mode 100644
index 0000000000000..992c44d3d95b9
--- /dev/null
+++ b/libc/src/stdio/vsscanf.h
@@ -0,0 +1,20 @@
+//===-- Implementation header of vsscanf ------------------------*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LIBC_SRC_STDIO_VSSCANF_H
+#define LLVM_LIBC_SRC_STDIO_VSSCANF_H
+
+#include <stdarg.h>
+
+namespace LIBC_NAMESPACE {
+
+int vsscanf(const char *s, const char *format, va_list vlist);
+
+} // namespace LIBC_NAMESPACE
+
+#endif // LLVM_LIBC_SRC_STDIO_VSSCANF_H
diff --git a/libc/test/src/stdio/CMakeLists.txt b/libc/test/src/stdio/CMakeLists.txt
index 10ec890b043a7..4ac83ec2dd600 100644
--- a/libc/test/src/stdio/CMakeLists.txt
+++ b/libc/test/src/stdio/CMakeLists.txt
@@ -282,6 +282,20 @@ add_libc_test(
${sscanf_test_copts}
)
+add_libc_test(
+ vsscanf_test
+ SUITE
+ libc_stdio_unittests
+ SRCS
+ vsscanf_test.cpp
+ DEPENDS
+ libc.src.stdio.vsscanf
+ LINK_LIBRARIES
+ LibcFPTestHelpers
+ COMPILE_OPTIONS
+ ${sscanf_test_copts}
+)
+
add_libc_test(
puts_test
HERMETIC_TEST_ONLY # writes to libc's stdout
diff --git a/libc/test/src/stdio/vsscanf_test.cpp b/libc/test/src/stdio/vsscanf_test.cpp
new file mode 100644
index 0000000000000..4194e10f0602c
--- /dev/null
+++ b/libc/test/src/stdio/vsscanf_test.cpp
@@ -0,0 +1,159 @@
+//===-- Unittests for sscanf ----------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "src/stdio/vsscanf.h"
+
+#include "test/UnitTest/Test.h"
+
+int call_vsscanf(const char *__restrict buffer, const char *__restrict format,
+ ...) {
+ va_list vlist;
+ va_start(vlist, format);
+ int ret = LIBC_NAMESPACE::vsscanf(buffer, format, vlist);
+ va_end(vlist);
+ return ret;
+}
+
+TEST(LlvmLibcVSScanfTest, SimpleStringConv) {
+ int ret_val;
+ char buffer[10];
+ char buffer2[10];
+ ret_val = call_vsscanf("abc123", "abc %s", buffer);
+ ASSERT_EQ(ret_val, 1);
+ ASSERT_STREQ(buffer, "123");
+
+ ret_val = call_vsscanf("abc123", "%3s %3s", buffer, buffer2);
+ ASSERT_EQ(ret_val, 2);
+ ASSERT_STREQ(buffer, "abc");
+ ASSERT_STREQ(buffer2, "123");
+
+ ret_val = call_vsscanf("abc 123", "%3s%3s", buffer, buffer2);
+ ASSERT_EQ(ret_val, 2);
+ ASSERT_STREQ(buffer, "abc");
+ ASSERT_STREQ(buffer2, "123");
+}
+
+TEST(LlvmLibcVSScanfTest, IntConvSimple) {
+ int ret_val;
+ int result = 0;
+ ret_val = call_vsscanf("123", "%d", &result);
+ EXPECT_EQ(ret_val, 1);
+ EXPECT_EQ(result, 123);
+
+ ret_val = call_vsscanf("456", "%i", &result);
+ EXPECT_EQ(ret_val, 1);
+ EXPECT_EQ(result, 456);
+
+ ret_val = call_vsscanf("789", "%x", &result);
+ EXPECT_EQ(ret_val, 1);
+ EXPECT_EQ(result, 0x789);
+
+ ret_val = call_vsscanf("012", "%o", &result);
+ EXPECT_EQ(ret_val, 1);
+ EXPECT_EQ(result, 012);
+
+ ret_val = call_vsscanf("345", "%u", &result);
+ EXPECT_EQ(ret_val, 1);
+ EXPECT_EQ(result, 345);
+
+ // 288 characters
+ ret_val = call_vsscanf("10000000000000000000000000000000"
+ "00000000000000000000000000000000"
+ "00000000000000000000000000000000"
+ "00000000000000000000000000000000"
+ "00000000000000000000000000000000"
+ "00000000000000000000000000000000"
+ "00000000000000000000000000000000"
+ "00000000000000000000000000000000"
+ "00000000000000000000000000000000",
+ "%d", &result);
+ EXPECT_EQ(ret_val, 1);
+ EXPECT_EQ(result, int(LIBC_NAMESPACE::cpp::numeric_limits<intmax_t>::max()));
+
+ ret_val = call_vsscanf("Not an integer", "%d", &result);
+ EXPECT_EQ(ret_val, 0);
+}
+
+TEST(LlvmLibcVSScanfTest, IntConvLengthModifier) {
+ int ret_val;
+ uintmax_t max_result = 0;
+ int int_result = 0;
+ char char_result = 0;
+
+ ret_val = call_vsscanf("123", "%ju", &max_result);
+ EXPECT_EQ(ret_val, 1);
+ EXPECT_EQ(max_result, uintmax_t(123));
+
+ // Check overflow handling
+ ret_val =
+ call_vsscanf("999999999999999999999999999999999999", "%ju", &max_result);
+ EXPECT_EQ(ret_val, 1);
+ EXPECT_EQ(max_result, LIBC_NAMESPACE::cpp::numeric_limits<uintmax_t>::max());
+
+ // Because this is unsigned, any out of range value should return the maximum,
+ // even with a negative sign.
+ ret_val =
+ call_vsscanf("-999999999999999999999999999999999999", "%ju", &max_result);
+ EXPECT_EQ(ret_val, 1);
+ EXPECT_EQ(max_result, LIBC_NAMESPACE::cpp::numeric_limits<uintmax_t>::max());
+
+ ret_val = call_vsscanf("-18446744073709551616", "%ju", &max_result);
+ EXPECT_EQ(ret_val, 1);
+ EXPECT_EQ(max_result, LIBC_NAMESPACE::cpp::numeric_limits<uintmax_t>::max());
+
+ // But any number below the maximum should have the - sign applied.
+ ret_val = call_vsscanf("-1", "%ju", &max_result);
+ EXPECT_EQ(ret_val, 1);
+ EXPECT_EQ(max_result, uintmax_t(-1));
+
+ ret_val = call_vsscanf("-1", "%u", &int_result);
+ EXPECT_EQ(ret_val, 1);
+ EXPECT_EQ(int_result, -1);
+
+ max_result = 0xff00ff00ff00ff00;
+ char_result = 0x6f;
+
+ // Overflows for sizes larger than the maximum are handled by casting.
+ ret_val = call_vsscanf("8589967360", "%d", &int_result);
+ EXPECT_EQ(ret_val, 1);
+ EXPECT_EQ(int_result, int(8589967360)); // 2^33 + 2^15
+
+ // Check that the adjacent values weren't touched by the overflow.
+ ASSERT_EQ(max_result, uintmax_t(0xff00ff00ff00ff00));
+ ASSERT_EQ(char_result, char(0x6f));
+
+ ret_val = call_vsscanf("-8589967360", "%d", &int_result);
+ EXPECT_EQ(ret_val, 1);
+ EXPECT_EQ(int_result, int(-8589967360));
+ ASSERT_EQ(max_result, uintmax_t(0xff00ff00ff00ff00));
+ ASSERT_EQ(char_result, char(0x6f));
+
+ ret_val = call_vsscanf("25", "%hhd", &char_result);
+ EXPECT_EQ(ret_val, 1);
+ EXPECT_EQ(char_result, char(25));
+}
+
+TEST(LlvmLibcVSScanfTest, IntConvBaseSelection) {
+ int ret_val;
+ int result = 0;
+ ret_val = call_vsscanf("0xabc123", "%i", &result);
+ EXPECT_EQ(ret_val, 1);
+ EXPECT_EQ(result, 0xabc123);
+
+ ret_val = call_vsscanf("0456", "%i", &result);
+ EXPECT_EQ(ret_val, 1);
+ EXPECT_EQ(result, 0456);
+
+ ret_val = call_vsscanf("0999", "%i", &result);
+ EXPECT_EQ(ret_val, 1);
+ EXPECT_EQ(result, 0);
+
+ ret_val = call_vsscanf("123abc456", "%i", &result);
+ EXPECT_EQ(ret_val, 1);
+ EXPECT_EQ(result, 123);
+}
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SchrodingerZhu
approved these changes
Jul 31, 2024
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Summary:
Adds support for the
vsscanffunction similar tosscanf.Based off of #97529.