[libc] Add "include/" to the LLVM include directories

[jhuber6]

Summary:
Recent changes added an include path in the float128 type that used the
internal libc path to find the macro. This doesn't work once it's
installed because we need to search from the root of the install dir.
This patch adds "include/" to the include path so that our inclusion
of installed headers always match the internal use.

[llvmbot]

@llvm/pr-subscribers-libc

Author: Joseph Huber (jhuber6)

Changes

Summary:
Recent changes added an include path in the float128 type that used the
internal libc path to find the macro. This doesn't work once it's
installed because we need to search from the root of the install dir.
Move the include to the top-level math.h so we can find it.

---

Full diff: https://github.com/llvm/llvm-project/pull/83199.diff

3 Files Affected:

• (modified) libc/include/CMakeLists.txt (+1)
• (modified) libc/include/llvm-libc-types/float128.h (-2)
• (modified) libc/include/math.h.def (+1-1)

diff --git a/libc/include/CMakeLists.txt b/libc/include/CMakeLists.txt
index 9090b3bca01e0d..fc16ce0c27cbbd 100644
--- a/libc/include/CMakeLists.txt
+++ b/libc/include/CMakeLists.txt
@@ -99,6 +99,7 @@ add_gen_header(
   DEPENDS
     .llvm_libc_common_h
     .llvm-libc-macros.math_macros
+    .llvm-libc-macros.float_macros
     .llvm-libc-types.double_t
     .llvm-libc-types.float_t
     .llvm-libc-types.float128
diff --git a/libc/include/llvm-libc-types/float128.h b/libc/include/llvm-libc-types/float128.h
index 61a094fdb96b12..dedb8076ecf03e 100644
--- a/libc/include/llvm-libc-types/float128.h
+++ b/libc/include/llvm-libc-types/float128.h
@@ -9,8 +9,6 @@
 #ifndef __LLVM_LIBC_TYPES_FLOAT128_H__
 #define __LLVM_LIBC_TYPES_FLOAT128_H__
 
-#include <include/llvm-libc-macros/float-macros.h> // LDBL_MANT_DIG
-
 // Currently, C23 `_Float128` type is only defined as a built-in type in GCC 7
 // or later, and only for C.  For C++, or for clang, `__float128` is defined
 // instead, and only on x86-64 targets.
diff --git a/libc/include/math.h.def b/libc/include/math.h.def
index 927e2d6697c67d..b2252cbb6170d0 100644
--- a/libc/include/math.h.def
+++ b/libc/include/math.h.def
@@ -11,9 +11,9 @@
 
 #include <__llvm-libc-common.h>
 #include <llvm-libc-macros/math-macros.h>
+#include <llvm-libc-macros/float-macros.h>
 #include <llvm-libc-types/float128.h>
 
-
 %%public_api()
 
 #endif // LLVM_LIBC_MATH_H

[lntue]

I think we plan (and currently we do) to directly include many of those headers in llvm-libc-macros and llvm-libc-types directly in our internal implementations inside src folder, we should add libc/include in the include paths so that internal inclusions will match with installed headers as #include <llvm-libc-macros/*>. WDYT? @nickdesaulniers @michaelrj-google @gchatelet

[jhuber6]

I think we plan (and currently we do) to directly include many of those headers in llvm-libc-macros and llvm-libc-types directly in our internal implementations inside src folder, we should add libc/include in the include paths so that internal inclusions will match with installed headers as #include <llvm-libc-macros/*>. WDYT? @nickdesaulniers @michaelrj-google @gchatelet

We'd end up with include/include/... and you'd need to append include/ to the internal include path, but that would be one option. Generally it's easier just to use the include directory as the root, but it's only difficult in this scenario where we want to include something in the macros from the types.

[nickdesaulniers]

This should never have been <>. While you're here, please change this to "".

[jhuber6]

The other headers seem to use <> in stuff like math.h.def.

[nickdesaulniers]

Check my grep command. libc/include/llvm-libc-types/float128.h is the ONLY place where <> is used to include float-macros.h. Every other include uses "". Consistency is good.

[michaelrj-google]

all the #includes in /include/ for things in llvm-libc-types or llvm-libc-macros currently use <>. It may be worthwhile to change this, but that should probably be one cleanup patch.

[nickdesaulniers]

Filed: #83210

[nickdesaulniers]

Assuming the result builds (please wait for presubmit results), this looks like a nice cleanup! Thanks! 👏 🤹

[jhuber6]

Assuming the result builds (please wait for presubmit results), this looks like a nice cleanup! Thanks! 👏 🤹

I added it in a few more locations, hopefully it fixes the CI.