[libc] Templatize strtointeger implementation. (#165884)

* Removes the copy-pasta implementation of wcstointeger,
  and migrate the wcsto* family of functions to use a template
  version of strtointeger.
* Fixes the out-of-bound read in the original implementation(s)
  when the entire input string consists of whitespaces
  (then the sign check can access OOB memory)

The code is currently slightly peppered with "if constexpr" statements
to distinguish between char and wchar_t. We can probably
simplify it in subsequent changes by:
* using overrides, so that internal::isalnum() is overriden for
  both char and wchar_t (since C++ luckily allows us to reuse names).
* this wouldn't help for direct comparison with literals -
for this as a somewhat ugly workaround like is_char_literal(c, '0',
L'0')

5 files changed, 12 insertions, 12 deletions

diff --git a/libc/src/wchar/CMakeLists.txt b/libc/src/wchar/CMakeLists.txt
index adde382bf095..ba27cd77f6ba 100644
--- a/libc/src/wchar/CMakeLists.txt
+++ b/libc/src/wchar/CMakeLists.txt
@@ -63,7 +63,7 @@ add_entrypoint_object(
     wcstol.h
   DEPENDS
     libc.src.errno.errno
-    libc.src.__support.wcs_to_integer
+    libc.src.__support.str_to_integer
 )
 
 add_entrypoint_object(
@@ -74,7 +74,7 @@ add_entrypoint_object(
     wcstoll.h
   DEPENDS
     libc.src.errno.errno
-    libc.src.__support.wcs_to_integer
+    libc.src.__support.str_to_integer
 )
 
 add_entrypoint_object(
@@ -85,7 +85,7 @@ add_entrypoint_object(
     wcstoul.h
   DEPENDS
     libc.src.errno.errno
-    libc.src.__support.wcs_to_integer
+    libc.src.__support.str_to_integer
 )
 
 add_entrypoint_object(
@@ -96,7 +96,7 @@ add_entrypoint_object(
     wcstoull.h
   DEPENDS
     libc.src.errno.errno
-    libc.src.__support.wcs_to_integer
+    libc.src.__support.str_to_integer
 )
 
 add_entrypoint_object(
diff --git a/libc/src/wchar/wcstol.cpp b/libc/src/wchar/wcstol.cpp
index a05718f706df..a56b5f91272c 100644
--- a/libc/src/wchar/wcstol.cpp
+++ b/libc/src/wchar/wcstol.cpp
@@ -10,14 +10,14 @@
 #include "src/__support/common.h"
 #include "src/__support/libc_errno.h"
 #include "src/__support/macros/config.h"
-#include "src/__support/wcs_to_integer.h"
+#include "src/__support/str_to_integer.h"
 
 namespace LIBC_NAMESPACE_DECL {
 
 LLVM_LIBC_FUNCTION(long, wcstol,
                    (const wchar_t *__restrict str, wchar_t **__restrict str_end,
                     int base)) {
-  auto result = internal::wcstointeger<long>(str, base);
+  auto result = internal::strtointeger<long>(str, base);
   if (result.has_error())
     libc_errno = result.error;
 
diff --git a/libc/src/wchar/wcstoll.cpp b/libc/src/wchar/wcstoll.cpp
index de1299d681cd..6229d24172b5 100644
--- a/libc/src/wchar/wcstoll.cpp
+++ b/libc/src/wchar/wcstoll.cpp
@@ -10,14 +10,14 @@
 #include "src/__support/common.h"
 #include "src/__support/libc_errno.h"
 #include "src/__support/macros/config.h"
-#include "src/__support/wcs_to_integer.h"
+#include "src/__support/str_to_integer.h"
 
 namespace LIBC_NAMESPACE_DECL {
 
 LLVM_LIBC_FUNCTION(long long, wcstoll,
                    (const wchar_t *__restrict str, wchar_t **__restrict str_end,
                     int base)) {
-  auto result = internal::wcstointeger<long long>(str, base);
+  auto result = internal::strtointeger<long long>(str, base);
   if (result.has_error())
     libc_errno = result.error;
 
diff --git a/libc/src/wchar/wcstoul.cpp b/libc/src/wchar/wcstoul.cpp
index 79b8c9b5c9fa..c5639bee1d64 100644
--- a/libc/src/wchar/wcstoul.cpp
+++ b/libc/src/wchar/wcstoul.cpp
@@ -10,14 +10,14 @@
 #include "src/__support/common.h"
 #include "src/__support/libc_errno.h"
 #include "src/__support/macros/config.h"
-#include "src/__support/wcs_to_integer.h"
+#include "src/__support/str_to_integer.h"
 
 namespace LIBC_NAMESPACE_DECL {
 
 LLVM_LIBC_FUNCTION(unsigned long, wcstoul,
                    (const wchar_t *__restrict str, wchar_t **__restrict str_end,
                     int base)) {
-  auto result = internal::wcstointeger<unsigned long>(str, base);
+  auto result = internal::strtointeger<unsigned long>(str, base);
   if (result.has_error())
     libc_errno = result.error;
 
diff --git a/libc/src/wchar/wcstoull.cpp b/libc/src/wchar/wcstoull.cpp
index 768e03c4bd18..2ab24e9b2b2a 100644
--- a/libc/src/wchar/wcstoull.cpp
+++ b/libc/src/wchar/wcstoull.cpp
@@ -10,14 +10,14 @@
 #include "src/__support/common.h"
 #include "src/__support/libc_errno.h"
 #include "src/__support/macros/config.h"
-#include "src/__support/wcs_to_integer.h"
+#include "src/__support/str_to_integer.h"
 
 namespace LIBC_NAMESPACE_DECL {
 
 LLVM_LIBC_FUNCTION(unsigned long long, wcstoull,
                    (const wchar_t *__restrict str, wchar_t **__restrict str_end,
                     int base)) {
-  auto result = internal::wcstointeger<unsigned long long>(str, base);
+  auto result = internal::strtointeger<unsigned long long>(str, base);
   if (result.has_error())
     libc_errno = result.error;