[libc] Temporary math macros fix

[michaelrj-google]

Downstream's having some issues due to math-macros.h issues. These will
be fixed properly soon.

See #87683 for tracking this tech debt.

[llvmbot]

@llvm/pr-subscribers-libc

Author: Michael Jones (michaelrj-google)

Changes

Downstream's having some issues due to math-macros.h issues. These will
be fixed properly soon.

---

Full diff: https://github.com/llvm/llvm-project/pull/87681.diff

2 Files Affected:

• (modified) libc/include/llvm-libc-macros/math-macros.h (+9)
• (modified) utils/bazel/llvm-project-overlay/libc/BUILD.bazel (+1-2)

diff --git a/libc/include/llvm-libc-macros/math-macros.h b/libc/include/llvm-libc-macros/math-macros.h
index 1497e32044e975..99fb3dbf0a9b4e 100644
--- a/libc/include/llvm-libc-macros/math-macros.h
+++ b/libc/include/llvm-libc-macros/math-macros.h
@@ -9,6 +9,9 @@
 #ifndef LLVM_LIBC_MACROS_MATH_MACROS_H
 #define LLVM_LIBC_MACROS_MATH_MACROS_H
 
+// TODO: Remove this. This is a temporary fix for a downstream problem.
+#ifdef LLVM_LIBC_FULLBUILD
+
 #include "limits-macros.h"
 
 #define FP_NAN 0
@@ -79,4 +82,10 @@ template <typename T> inline constexpr bool isnan(T x) {
 
 #endif
 
+#else
+
+#include <math.h>
+
+#endif // LLVM_LIBC_FULLBUILD
+
 #endif // LLVM_LIBC_MACROS_MATH_MACROS_H
diff --git a/utils/bazel/llvm-project-overlay/libc/BUILD.bazel b/utils/bazel/llvm-project-overlay/libc/BUILD.bazel
index 9dfe4c48184e3e..c06253b19558c8 100644
--- a/utils/bazel/llvm-project-overlay/libc/BUILD.bazel
+++ b/utils/bazel/llvm-project-overlay/libc/BUILD.bazel
@@ -68,7 +68,6 @@ libc_support_library(
     name = "llvm_libc_macros_math_macros",
     hdrs = ["include/llvm-libc-macros/math-macros.h"],
     deps = [":llvm_libc_macros_limits_macros"],
-    defines = ["__FP_LOGBNAN_MIN"],
 )
 
 libc_support_library(
@@ -1000,8 +999,8 @@ libc_support_library(
 
 libc_support_library(
     name = "__support_osutil_quick_exit",
-    hdrs = ["src/__support/OSUtil/quick_exit.h"],
     srcs = ["src/__support/OSUtil/linux/quick_exit.cpp"],
+    hdrs = ["src/__support/OSUtil/quick_exit.h"],
     deps = [
         ":__support_osutil_syscall",
     ],

[nickdesaulniers]

Please link to #87683 in the comment and commit message. Please wait for @lntue 's feedback before landing.

[lntue]

Can you change the flag to LIBC_FULL_BUILD and add the change to libc/cmake/modules/LLVMLibCCompileOptionRules.cmake in https://github.com/llvm/llvm-project/pull/87598/files#diff-25513d7d596301fa3039e5ad6bab76159cd5bd330a5890773e10cf5507045ca0

After this, if there is any regression on the full build bots, I will fix it forward.

[nickdesaulniers]

oh, right, we don't define LIBC_FULL_BUILD yet until (#87598, #87017)

[michaelrj-google]

I will land this after the presubmits finish.