[libc] clean up ctype negative handling

The ctype functions will sometimes be passed negative numbers, such as
EOF. Some of the previous implementations didn't handle these properly.
Additionally, the tests did not check any negative numbers. These
problems have been fixed.

This patch fixes https://github.com/llvm/llvm-project/issues/62000

Reviewed By: lntue

Differential Revision: https://reviews.llvm.org/D147813

libc/src/ctype/isblank.cpp

@@ -15,8 +15,7 @@ namespace __llvm_libc {
 // TODO: Currently restricted to default locale.
 // These should be extended using locale information.
 LLVM_LIBC_FUNCTION(int, isblank, (int c)) {
-  const unsigned char ch = static_cast<unsigned char>(c);
-  return static_cast<int>(ch == ' ' || ch == '\t');
+  return static_cast<int>(c == ' ' || c == '\t');
 }
 
 } // namespace __llvm_libc

libc/src/ctype/iscntrl.cpp

@@ -15,7 +15,7 @@ namespace __llvm_libc {
 // TODO: Currently restricted to default locale.
 // These should be extended using locale information.
 LLVM_LIBC_FUNCTION(int, iscntrl, (int c)) {
-  const unsigned char ch = static_cast<unsigned char>(c);
+  const unsigned ch = static_cast<unsigned>(c);
   return static_cast<int>(ch < 0x20 || ch == 0x7f);
 }
 

libc/test/src/ctype/CMakeLists.txt

@@ -1,7 +1,7 @@
 add_libc_testsuite(libc_ctype_unittests)
 
 add_libc_unittest(
-  isalnum
+  isalnum_test
   SUITE
     libc_ctype_unittests
   SRCS
@@ -11,7 +11,7 @@ add_libc_unittest(
 )
 
 add_libc_unittest(
-  isalpha
+  isalpha_test
   SUITE
     libc_ctype_unittests
   SRCS
@@ -21,7 +21,7 @@ add_libc_unittest(
 )
 
 add_libc_unittest(
-  isascii
+  isascii_test
   SUITE
     libc_ctype_unittests
   SRCS
@@ -31,7 +31,7 @@ add_libc_unittest(
 )
 
 add_libc_unittest(
-  isblank
+  isblank_test
   SUITE
     libc_ctype_unittests
   SRCS
@@ -41,7 +41,7 @@ add_libc_unittest(
 )
 
 add_libc_unittest(
-  iscntrl
+  iscntrl_test
   SUITE
     libc_ctype_unittests
   SRCS
@@ -51,7 +51,7 @@ add_libc_unittest(
 )
 
 add_libc_unittest(
-  isdigit
+  isdigit_test
   SUITE
     libc_ctype_unittests
   SRCS
@@ -61,7 +61,7 @@ add_libc_unittest(
 )
 
 add_libc_unittest(
-  isgraph
+  isgraph_test
   SUITE
     libc_ctype_unittests
   SRCS
@@ -71,7 +71,7 @@ add_libc_unittest(
 )
 
 add_libc_unittest(
-  islower
+  islower_test
   SUITE
     libc_ctype_unittests
   SRCS
@@ -81,7 +81,7 @@ add_libc_unittest(
 )
 
 add_libc_unittest(
-  isprint
+  isprint_test
   SUITE
     libc_ctype_unittests
   SRCS
@@ -91,7 +91,7 @@ add_libc_unittest(
 )
 
 add_libc_unittest(
-  ispunct
+  ispunct_test
   SUITE
     libc_ctype_unittests
   SRCS
@@ -101,7 +101,7 @@ add_libc_unittest(
 )
 
 add_libc_unittest(
-  isspace
+  isspace_test
   SUITE
     libc_ctype_unittests
   SRCS
@@ -111,7 +111,7 @@ add_libc_unittest(
 )
 
 add_libc_unittest(
-  isupper
+  isupper_test
   SUITE
     libc_ctype_unittests
   SRCS
@@ -121,7 +121,7 @@ add_libc_unittest(
 )
 
 add_libc_unittest(
-  isxdigit
+  isxdigit_test
   SUITE
     libc_ctype_unittests
   SRCS
@@ -131,7 +131,7 @@ add_libc_unittest(
 )
 
 add_libc_unittest(
-  toascii
+  toascii_test
   SUITE
     libc_ctype_unittests
   SRCS
@@ -141,7 +141,7 @@ add_libc_unittest(
 )
 
 add_libc_unittest(
-  tolower
+  tolower_test
   SUITE
     libc_ctype_unittests
   SRCS
@@ -151,7 +151,7 @@ add_libc_unittest(
 )
 
 add_libc_unittest(
-  toupper
+  toupper_test
   SUITE
     libc_ctype_unittests
   SRCS

libc/test/src/ctype/isalnum_test.cpp

@@ -13,7 +13,7 @@
 TEST(LlvmLibcIsAlNum, DefaultLocale) {
   // Loops through all characters, verifying that numbers and letters
   // return non-zero integer and everything else returns a zero.
-  for (int c = 0; c < 255; ++c) {
+  for (int c = -255; c < 255; ++c) {
     if (('a' <= c && c <= 'z') || ('A' <= c && c <= 'Z') ||
         ('0' <= c && c <= '9'))
       EXPECT_NE(__llvm_libc::isalnum(c), 0);

libc/test/src/ctype/isalpha_test.cpp

@@ -13,7 +13,7 @@
 TEST(LlvmLibcIsAlpha, DefaultLocale) {
   // Loops through all characters, verifying that letters return a
   // non-zero integer and everything else returns zero.
-  for (int ch = 0; ch < 255; ++ch) {
+  for (int ch = -255; ch < 255; ++ch) {
     if (('a' <= ch && ch <= 'z') || ('A' <= ch && ch <= 'Z'))
       EXPECT_NE(__llvm_libc::isalpha(ch), 0);
     else

libc/test/src/ctype/isascii_test.cpp

@@ -14,8 +14,8 @@ TEST(LlvmLibcIsAscii, DefaultLocale) {
   // Loops through all characters, verifying that ascii characters
   //    (which are all 7 bit unsigned integers)
   // return a non-zero integer and everything else returns zero.
-  for (int ch = 0; ch < 255; ++ch) {
-    if (ch <= 0x7f)
+  for (int ch = -255; ch < 255; ++ch) {
+    if (0 <= ch && ch <= 0x7f)
       EXPECT_NE(__llvm_libc::isascii(ch), 0);
     else
       EXPECT_EQ(__llvm_libc::isascii(ch), 0);

libc/test/src/ctype/isblank_test.cpp

@@ -12,7 +12,7 @@
 TEST(LlvmLibcIsBlank, DefaultLocale) {
   // Loops through all characters, verifying that space and horizontal tab
   // return a non-zero integer and everything else returns zero.
-  for (int ch = 0; ch < 255; ++ch) {
+  for (int ch = -255; ch < 255; ++ch) {
     if (ch == ' ' || ch == '\t')
       EXPECT_NE(__llvm_libc::isblank(ch), 0);
     else

libc/test/src/ctype/iscntrl_test.cpp

@@ -12,7 +12,7 @@
 TEST(LlvmLibcIsCntrl, DefaultLocale) {
   // Loops through all characters, verifying that control characters
   // return a non-zero integer, all others return zero.
-  for (int ch = 0; ch < 255; ++ch) {
+  for (int ch = -255; ch < 255; ++ch) {
     if ((0 <= ch && ch <= 0x1f /*US*/) || ch == 0x7f /*DEL*/)
       EXPECT_NE(__llvm_libc::iscntrl(ch), 0);
     else

libc/test/src/ctype/isdigit_test.cpp

@@ -13,7 +13,7 @@
 TEST(LlvmLibcIsDigit, DefaultLocale) {
   // Loops through all characters, verifying that numbers return a
   // non-zero integer and everything else returns zero.
-  for (int ch = 0; ch < 255; ++ch) {
+  for (int ch = -255; ch < 255; ++ch) {
     if ('0' <= ch && ch <= '9')
       EXPECT_NE(__llvm_libc::isdigit(ch), 0);
     else

libc/test/src/ctype/isgraph_test.cpp

@@ -12,7 +12,7 @@
 TEST(LlvmLibcIsGraph, DefaultLocale) {
   // Loops through all characters, verifying that graphical characters
   // return a non-zero integer, everything else returns zero.
-  for (int ch = 0; ch < 255; ++ch) {
+  for (int ch = -255; ch < 255; ++ch) {
     if ('!' <= ch && ch <= '~') // A-Z, a-z, 0-9, punctuation.
       EXPECT_NE(__llvm_libc::isgraph(ch), 0);
     else

libc/test/src/ctype/islower_test.cpp

@@ -12,7 +12,7 @@
 TEST(LlvmLibcIsLower, DefaultLocale) {
   // Loops through all characters, verifying that lowercase letters
   // return a non-zero integer and everything else returns zero.
-  for (int ch = 0; ch < 255; ++ch) {
+  for (int ch = -255; ch < 255; ++ch) {
     if ('a' <= ch && ch <= 'z')
       EXPECT_NE(__llvm_libc::islower(ch), 0);
     else

libc/test/src/ctype/isprint_test.cpp

@@ -10,7 +10,7 @@
 #include "test/UnitTest/Test.h"
 
 TEST(LlvmLibcIsPrint, DefaultLocale) {
-  for (int ch = 0; ch < 255; ++ch) {
+  for (int ch = -255; ch < 255; ++ch) {
     if (' ' <= ch && ch <= '~') // A-Z, a-z, 0-9, punctuation, space.
       EXPECT_NE(__llvm_libc::isprint(ch), 0);
     else

libc/test/src/ctype/ispunct_test.cpp

@@ -25,7 +25,7 @@ static inline int is_punctuation_character(int c) {
 TEST(LlvmLibcIsPunct, DefaultLocale) {
   // Loops through all characters, verifying that punctuation characters
   // return a non-zero integer, and everything else returns zero.
-  for (int ch = 0; ch < 255; ++ch) {
+  for (int ch = -255; ch < 255; ++ch) {
     if (is_punctuation_character(ch))
       EXPECT_NE(__llvm_libc::ispunct(ch), 0);
     else

libc/test/src/ctype/isspace_test.cpp

@@ -19,7 +19,7 @@ TEST(LlvmLibcIsSpace, DefaultLocale) {
   //    0x0b     |   vertical tab
   //    0x0d     |   carriage return
   //    0x20     |   space
-  for (int ch = 0; ch < 255; ++ch) {
+  for (int ch = -255; ch < 255; ++ch) {
     if (ch == 0x20 || (0x09 <= ch && ch <= 0x0d))
       EXPECT_NE(__llvm_libc::isspace(ch), 0);
     else

libc/test/src/ctype/isupper_test.cpp

@@ -12,7 +12,7 @@
 TEST(LlvmLibcIsUpper, DefaultLocale) {
   // Loops through all characters, verifying that uppercase letters
   // return a non-zero integer and everything else returns zero.
-  for (int ch = 0; ch < 255; ++ch) {
+  for (int ch = -255; ch < 255; ++ch) {
     if ('A' <= ch && ch <= 'Z')
       EXPECT_NE(__llvm_libc::isupper(ch), 0);
     else

libc/test/src/ctype/isxdigit_test.cpp

@@ -10,7 +10,7 @@
 #include "test/UnitTest/Test.h"
 
 TEST(LlvmLibcIsXDigit, DefaultLocale) {
-  for (int ch = 0; ch < 255; ++ch) {
+  for (int ch = -255; ch < 255; ++ch) {
     if (('0' <= ch && ch <= '9') || ('a' <= ch && ch <= 'f') ||
         ('A' <= ch && ch <= 'F'))
       EXPECT_NE(__llvm_libc::isxdigit(ch), 0);

libc/test/src/ctype/toascii_test.cpp

@@ -15,8 +15,8 @@ TEST(LlvmLibcToAscii, DefaultLocale) {
   //    (which are all 7 bit unsigned integers)
   // return themself, and that all other characters return themself
   // mod 128 (which is equivalent to & 0x7f)
-  for (int ch = 0; ch < 255; ++ch) {
-    if (ch <= 0x7f)
+  for (int ch = -255; ch < 255; ++ch) {
+    if (0 <= ch && ch <= 0x7f)
       EXPECT_EQ(__llvm_libc::toascii(ch), ch);
     else
       EXPECT_EQ(__llvm_libc::toascii(ch), ch & 0x7f);

libc/test/src/ctype/tolower_test.cpp

@@ -10,7 +10,7 @@
 #include "test/UnitTest/Test.h"
 
 TEST(LlvmLibcToLower, DefaultLocale) {
-  for (int ch = 0; ch < 255; ++ch) {
+  for (int ch = -255; ch < 255; ++ch) {
     // This follows pattern 'A' + 32 = 'a'.
     if ('A' <= ch && ch <= 'Z')
       EXPECT_EQ(__llvm_libc::tolower(ch), ch + 32);

libc/test/src/ctype/toupper_test.cpp

@@ -10,7 +10,7 @@
 #include "test/UnitTest/Test.h"
 
 TEST(LlvmLibcToUpper, DefaultLocale) {
-  for (int ch = 0; ch < 255; ++ch) {
+  for (int ch = -255; ch < 255; ++ch) {
     // This follows pattern 'a' - 32 = 'A'.
     if ('a' <= ch && ch <= 'z')
       EXPECT_EQ(__llvm_libc::toupper(ch), ch - 32);