[libc] force GCC limits.h to not include_next limits.h

libc/src/__support/CPP/limits.h

@@ -13,8 +13,25 @@
 #include "src/__support/CPP/type_traits/is_signed.h"
 #include "src/__support/macros/attributes.h" // LIBC_INLINE
 
+// Coax GCC to NOT attempt to include_next limits.h from glibc. llvmlibc should
+// include this file rather than <limits.h> directy for this reason.
+#ifndef __clang__
+#define _LIBC_LIMITS_H_
+#endif
 #include <limits.h> // CHAR_BIT
 
+// GCC's limits.h only defines these for __STDC_VERSION__ >= 199901L, i.e. not
+// C++.
+#ifndef LLONG_MAX
+#define LLONG_MAX __LONG_LONG_MAX__
+#endif
+#ifndef LLONG_MIN
+#define LLONG_MIN (-LONG_MAX - 1LL)
+#endif
+#ifndef ULLONG_MAX
+#define ULLONG_MAX (~0ULL)
+#endif
+
 namespace LIBC_NAMESPACE {
 namespace cpp {
 

libc/src/__support/FPUtil/ManipulationFunctions.h

@@ -14,12 +14,12 @@
 #include "NormalFloat.h"
 
 #include "src/__support/CPP/bit.h"
+#include "src/__support/CPP/limits.h" // INT_MAX, INT_MIN
 #include "src/__support/CPP/type_traits.h"
 #include "src/__support/FPUtil/FEnvImpl.h"
 #include "src/__support/macros/attributes.h"
 #include "src/__support/macros/optimization.h" // LIBC_UNLIKELY
 
-#include <limits.h>
 #include <math.h>
 
 namespace LIBC_NAMESPACE {

libc/src/__support/math_extras.h

@@ -10,12 +10,11 @@
 #ifndef LLVM_LIBC_SRC___SUPPORT_MATH_EXTRAS_H
 #define LLVM_LIBC_SRC___SUPPORT_MATH_EXTRAS_H
 
+#include "src/__support/CPP/limits.h"        // CHAR_BIT
 #include "src/__support/CPP/type_traits.h"   // is_unsigned_v
 #include "src/__support/macros/attributes.h" // LIBC_INLINE
 #include "src/__support/macros/config.h"     // LIBC_HAS_BUILTIN
 
-#include <limits.h> // CHAR_BIT
-
 namespace LIBC_NAMESPACE {
 
 // Create a bitmask with the count right-most bits set to 1, and all other bits

libc/src/__support/str_to_integer.h

@@ -15,7 +15,6 @@
 #include "src/__support/ctype_utils.h"
 #include "src/__support/str_to_num_result.h"
 #include "src/errno/libc_errno.h" // For ERANGE
-#include <limits.h>
 
 namespace LIBC_NAMESPACE {
 namespace internal {

libc/src/__support/threads/linux/callonce.cpp

@@ -9,10 +9,10 @@
 #include "futex_word.h"
 
 #include "src/__support/CPP/atomic.h"
+#include "src/__support/CPP/limits.h"     // For INT_MAX.
 #include "src/__support/OSUtil/syscall.h" // For syscall functions.
 #include "src/__support/threads/callonce.h"
 
-#include <limits.h>
 #include <linux/futex.h>
 #include <sys/syscall.h> // For syscall numbers.
 

libc/src/threads/CMakeLists.txt

@@ -10,6 +10,7 @@ add_entrypoint_object(
     call_once.h
   DEPENDS
     libc.include.threads
+    libc.src.__support.CPP.limits
     libc.src.__support.threads.callonce
 )
 

libc/src/threads/linux/call_once.cpp

@@ -9,12 +9,12 @@
 #include "Futex.h"
 
 #include "src/__support/CPP/atomic.h"
+#include "src/__support/CPP/limits.h"     // For INT_MAX.
 #include "src/__support/OSUtil/syscall.h" // For syscall functions.
 #include "src/__support/common.h"
 #include "src/threads/call_once.h"
 #include "src/threads/linux/Futex.h"
 
-#include <limits.h>
 #include <linux/futex.h>
 #include <sys/syscall.h> // For syscall numbers.
 #include <threads.h>     // For call_once related type definition.

libc/src/time/CMakeLists.txt

@@ -10,6 +10,7 @@ add_object_library(
     time_utils.h
   DEPENDS
     libc.include.time
+    libc.src.__support.CPP.limits
     libc.src.errno.errno
 )
 

libc/src/time/mktime.cpp

@@ -10,8 +10,6 @@
 #include "src/__support/common.h"
 #include "src/time/time_utils.h"
 
-#include <limits.h>
-
 namespace LIBC_NAMESPACE {
 
 using LIBC_NAMESPACE::time_utils::TimeConstants;

libc/src/time/time_utils.cpp

@@ -7,10 +7,9 @@
 //===----------------------------------------------------------------------===//
 
 #include "src/time/time_utils.h"
+#include "src/__support/CPP/limits.h" // INT_MAX, INT_MIN
 #include "src/__support/common.h"
 
-#include <limits.h>
-
 namespace LIBC_NAMESPACE {
 namespace time_utils {
 

libc/test/src/math/ILogbTest.h

@@ -9,13 +9,12 @@
 #ifndef LLVM_LIBC_TEST_SRC_MATH_ILOGBTEST_H
 #define LLVM_LIBC_TEST_SRC_MATH_ILOGBTEST_H
 
+#include "src/__support/CPP/limits.h" // INT_MAX
 #include "src/__support/FPUtil/FPBits.h"
 #include "src/__support/FPUtil/ManipulationFunctions.h"
 #include "test/UnitTest/Test.h"
 #include <math.h>
 
-#include <limits.h>
-
 class LlvmLibcILogbTest : public LIBC_NAMESPACE::testing::Test {
 public:
   template <typename T> struct ILogbFunc {

libc/test/src/math/LdExpTest.h

@@ -9,12 +9,12 @@
 #ifndef LLVM_LIBC_TEST_SRC_MATH_LDEXPTEST_H
 #define LLVM_LIBC_TEST_SRC_MATH_LDEXPTEST_H
 
+#include "src/__support/CPP/limits.h" // INT_MAX
 #include "src/__support/FPUtil/FPBits.h"
 #include "src/__support/FPUtil/NormalFloat.h"
 #include "test/UnitTest/FPMatcher.h"
 #include "test/UnitTest/Test.h"
 
-#include <limits.h>
 #include <math.h>
 #include <stdint.h>
 

libc/test/src/math/smoke/ILogbTest.h

@@ -9,13 +9,12 @@
 #ifndef LLVM_LIBC_TEST_SRC_MATH_ILOGBTEST_H
 #define LLVM_LIBC_TEST_SRC_MATH_ILOGBTEST_H
 
+#include "src/__support/CPP/limits.h" // INT_MAX
 #include "src/__support/FPUtil/FPBits.h"
 #include "src/__support/FPUtil/ManipulationFunctions.h"
 #include "test/UnitTest/Test.h"
 #include <math.h>
 
-#include <limits.h>
-
 class LlvmLibcILogbTest : public LIBC_NAMESPACE::testing::Test {
 public:
   template <typename T> struct ILogbFunc {

libc/test/src/math/smoke/LdExpTest.h

@@ -9,12 +9,12 @@
 #ifndef LLVM_LIBC_TEST_SRC_MATH_LDEXPTEST_H
 #define LLVM_LIBC_TEST_SRC_MATH_LDEXPTEST_H
 
+#include "src/__support/CPP/limits.h" // INT_MAX
 #include "src/__support/FPUtil/FPBits.h"
 #include "src/__support/FPUtil/NormalFloat.h"
 #include "test/UnitTest/FPMatcher.h"
 #include "test/UnitTest/Test.h"
 
-#include <limits.h>
 #include <math.h>
 #include <stdint.h>
 

libc/test/src/stdlib/AtoiTest.h

@@ -6,11 +6,10 @@
 //
 //===----------------------------------------------------------------------===//
 
+#include "src/__support/CPP/limits.h" // INT_MAX, INT_MIN, LLONG_MAX, LLONG_MIN
 #include "src/__support/CPP/type_traits.h"
 #include "test/UnitTest/Test.h"
 
-#include <limits.h>
-
 using LIBC_NAMESPACE::cpp::is_same_v;
 
 template <typename ReturnT>

libc/test/src/stdlib/CMakeLists.txt

@@ -62,9 +62,9 @@ if(NOT LIBC_GPU_TARGET_ARCHITECTURE_IS_NVPTX)
     SRCS
       strtod_test.cpp
     DEPENDS
+      libc.src.__support.FPUtil.fenv_impl
       libc.src.errno.errno
       libc.src.stdlib.strtod
-      libc.src.__support.FPUtil.fenv_impl
   )
 endif()
 
@@ -75,9 +75,9 @@ add_fp_unittest(
   SRCS
     strtof_test.cpp
   DEPENDS
+    libc.src.__support.FPUtil.fenv_impl
     libc.src.errno.errno
     libc.src.stdlib.strtof
-    libc.src.__support.FPUtil.fenv_impl
 )
 
 add_header_library(
@@ -134,8 +134,8 @@ if(NOT LIBC_GPU_TARGET_ARCHITECTURE_IS_NVPTX)
     SRCS
       strtold_test.cpp
     DEPENDS
-      libc.src.errno.errno
       libc.src.__support.uint128
+      libc.src.errno.errno
       libc.src.stdlib.strtold
   )
 endif()

libc/test/src/stdlib/StrtolTest.h

@@ -12,7 +12,6 @@
 #include "src/errno/libc_errno.h"
 #include "test/UnitTest/Test.h"
 
-#include <limits.h>
 #include <stddef.h>
 
 using LIBC_NAMESPACE::cpp::is_signed_v;

libc/test/src/stdlib/atof_test.cpp

@@ -13,7 +13,6 @@
 #include "test/UnitTest/ErrnoSetterMatcher.h"
 #include "test/UnitTest/Test.h"
 
-#include <limits.h>
 #include <stddef.h>
 
 using LIBC_NAMESPACE::testing::ErrnoSetterMatcher::Succeeds;

libc/test/src/stdlib/strtod_test.cpp

@@ -14,7 +14,6 @@
 #include "test/UnitTest/RoundingModeUtils.h"
 #include "test/UnitTest/Test.h"
 
-#include <limits.h>
 #include <stddef.h>
 
 using LIBC_NAMESPACE::fputil::testing::ForceRoundingModeTest;

libc/test/src/stdlib/strtof_test.cpp

@@ -14,7 +14,6 @@
 #include "test/UnitTest/RoundingModeUtils.h"
 #include "test/UnitTest/Test.h"
 
-#include <limits.h>
 #include <stddef.h>
 
 using LIBC_NAMESPACE::fputil::testing::ForceRoundingModeTest;

libc/test/src/stdlib/strtold_test.cpp

@@ -13,7 +13,6 @@
 
 #include "test/UnitTest/Test.h"
 
-#include <limits.h>
 #include <stddef.h>
 
 #if defined(LIBC_LONG_DOUBLE_IS_FLOAT64)

libc/test/src/time/CMakeLists.txt

@@ -70,6 +70,7 @@ add_libc_unittest(
   HDRS
     TmMatcher.h
   DEPENDS
+    libc.src.__support.CPP.limits
     libc.src.time.gmtime
 )
 
@@ -97,6 +98,7 @@ add_libc_unittest(
   CXX_STANDARD
     20
   DEPENDS
+    libc.src.__support.CPP.limits
     libc.src.time.mktime
 )
 
@@ -124,8 +126,9 @@ add_libc_unittest(
     time_test.cpp
   DEPENDS
     libc.include.time
-    libc.src.time.time
+    libc.src.__support.CPP.limits
     libc.src.errno.errno
+    libc.src.time.time
 )
 
 add_libc_test(
@@ -136,6 +139,6 @@ add_libc_test(
     clock_test.cpp
   DEPENDS
     libc.include.time
-    libc.src.time.clock
     libc.src.errno.errno
+    libc.src.time.clock
 )

libc/test/src/time/clock_test.cpp

@@ -9,7 +9,6 @@
 #include "src/time/clock.h"
 #include "test/UnitTest/Test.h"
 
-#include <limits.h>
 #include <time.h>
 
 TEST(LlvmLibcClockTest, SmokeTest) {

libc/test/src/time/gmtime_test.cpp

@@ -6,15 +6,14 @@
 //
 //===----------------------------------------------------------------------===//
 
+#include "src/__support/CPP/limits.h" // INT_MAX, INT_MIN
 #include "src/errno/libc_errno.h"
 #include "src/time/gmtime.h"
 #include "src/time/time_utils.h"
 #include "test/UnitTest/ErrnoSetterMatcher.h"
 #include "test/UnitTest/Test.h"
 #include "test/src/time/TmMatcher.h"
 
-#include <limits.h>
-
 using LIBC_NAMESPACE::testing::ErrnoSetterMatcher::Fails;
 using LIBC_NAMESPACE::testing::ErrnoSetterMatcher::Succeeds;
 using LIBC_NAMESPACE::time_utils::TimeConstants;

libc/test/src/time/mktime_test.cpp

@@ -6,15 +6,14 @@
 //
 //===----------------------------------------------------------------------===//
 
+#include "src/__support/CPP/limits.h" // INT_MAX
 #include "src/time/mktime.h"
 #include "src/time/time_utils.h"
 #include "test/UnitTest/ErrnoSetterMatcher.h"
 #include "test/UnitTest/Test.h"
 #include "test/src/time/TmHelper.h"
 #include "test/src/time/TmMatcher.h"
 
-#include <limits.h>
-
 using LIBC_NAMESPACE::testing::ErrnoSetterMatcher::Fails;
 using LIBC_NAMESPACE::testing::ErrnoSetterMatcher::Succeeds;
 using LIBC_NAMESPACE::time_utils::Month;

libc/test/src/time/time_test.cpp

@@ -9,7 +9,6 @@
 #include "src/time/time_func.h"
 #include "test/UnitTest/Test.h"
 
-#include <limits.h>
 #include <time.h>
 
 TEST(LlvmLibcTimeTest, SmokeTest) {