Disable calls to *_finite and other glibc-only functions on Musl.

[efriedma]

Summary

Non-GNU environments don't have __finite_*, so treat them as unavailable.

[dalias]

I'm reasonably happy as long as this is fixed, but I would really rather see the logic reversed: rather than special casing each !glibc, all of these nonstandard functions should be enabled only if(T.isGlibc) to begin with.

You can also possibly remove the exception for musl in the logic for marking the *64() functions unavailable. In musl these are just compat symbols and generating references to them is purely-worse behavior. When _LARGEFILE_SOURCE is defined musl's headers redirect them all at the preprocessor level anyway.

[efriedma]

It looks like this is still an issue on trunk. Was there any other discussion of this?

[efriedma]

Address review comments, add test.

[spatel]

LGTM

lib/Analysis/TargetLibraryInfo.cpp

416–417 ↗

(On Diff #172702)

Change this comment to better match the code?

// The following functions are only available on GNU/Linux.
// Linux variants without glibc (eg: bionic, musl) may have some subset.

llvm/trunk/lib/Analysis/TargetLibraryInfo.cpp

static void initialize(TargetLibraryInfoImpl &TLI, const Triple &T,
   // http://svn.freebsd.org/base/head/lib/libc/string/flsl.c
   // http://svn.freebsd.org/base/head/lib/libc/string/flsll.c
   if (!T.isOSFreeBSD()) {
     TLI.setUnavailable(LibFunc_fls);
     TLI.setUnavailable(LibFunc_flsl);
     TLI.setUnavailable(LibFunc_flsll);
   }
 
-  // The following functions are available on Linux,
-  // but Android uses bionic instead of glibc.
-  if (!T.isOSLinux() || T.isAndroid()) {
+  // The following functions are only available on GNU/Linux (using glibc).
+  // Linux variants without glibc (eg: bionic, musl) may have some subset.
+  if (!T.isOSLinux() || !T.isGNUEnvironment()) {
     TLI.setUnavailable(LibFunc_dunder_strdup);
     TLI.setUnavailable(LibFunc_dunder_strtok_r);
     TLI.setUnavailable(LibFunc_dunder_isoc99_scanf);
     TLI.setUnavailable(LibFunc_dunder_isoc99_sscanf);
     TLI.setUnavailable(LibFunc_under_IO_getc);
     TLI.setUnavailable(LibFunc_under_IO_putc);
-    // But, Android has memalign.
-    if (!T.isAndroid())
+    // But, Android and musl have memalign.
+    if (!T.isAndroid() && !T.isMusl())
       TLI.setUnavailable(LibFunc_memalign);
     TLI.setUnavailable(LibFunc_fopen64);
     TLI.setUnavailable(LibFunc_fseeko64);
     TLI.setUnavailable(LibFunc_fstat64);
     TLI.setUnavailable(LibFunc_fstatvfs64);
     TLI.setUnavailable(LibFunc_ftello64);
     TLI.setUnavailable(LibFunc_lstat64);
     TLI.setUnavailable(LibFunc_open64);

llvm/trunk/test/Transforms/ConstProp/calls-math-finite.ll

 ; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
 ; RUN: opt < %s -constprop -S | FileCheck %s
+; RUN: opt < %s -constprop -S -mtriple=unknown-unknown-linux-musl | FileCheck -check-prefix=MUSL %s
 
 ; Test to verify constant folding can occur when math routines are mapped
 ; to the __<func>_finite versions of functions due to __FINITE_MATH_ONLY__
 ; being enabled on headers on Linux. All calls should constant fold away
 ; in this test.
 
 target triple = "unknown-unknown-linux-gnu"
 

 ; CHECK-NEXT:    store float 0x403415E5C0000000, float* [[SLOTF]]
 ; CHECK-NEXT:    store float 8.000000e+00, float* [[SLOTF]]
 ; CHECK-NEXT:    store float 0x3FF193EA80000000, float* [[SLOTF]]
 ; CHECK-NEXT:    store float 0x3FDE8927A0000000, float* [[SLOTF]]
 ; CHECK-NEXT:    store float 8.100000e+01, float* [[SLOTF]]
 ; CHECK-NEXT:    store float 0x40240926E0000000, float* [[SLOTF]]
 ; CHECK-NEXT:    ret void
 ;
+; MUSL-LABEL: @T(
+; MUSL-NEXT:    [[SLOT:%.*]] = alloca double
+; MUSL-NEXT:    [[SLOTF:%.*]] = alloca float
+; MUSL-NEXT:    call
+; MUSL-NEXT:    store
+; MUSL-NEXT:    call
+; MUSL-NEXT:    store
+; MUSL-NEXT:    call
+; MUSL-NEXT:    store
+; MUSL-NEXT:    call
+; MUSL-NEXT:    store
+; MUSL-NEXT:    call
+; MUSL-NEXT:    store
+; MUSL-NEXT:    call
+; MUSL-NEXT:    store
+; MUSL-NEXT:    call
+; MUSL-NEXT:    store
+; MUSL-NEXT:    call
+; MUSL-NEXT:    store
+; MUSL-NEXT:    call
+; MUSL-NEXT:    store
+; MUSL-NEXT:    call
+; MUSL-NEXT:    store
+; MUSL-NEXT:    call
+; MUSL-NEXT:    store
+; MUSL-NEXT:    call
+; MUSL-NEXT:    store
+; MUSL-NEXT:    call
+; MUSL-NEXT:    store
+; MUSL-NEXT:    call
+; MUSL-NEXT:    store
+; MUSL-NEXT:    call
+; MUSL-NEXT:    store
+; MUSL-NEXT:    call
+; MUSL-NEXT:    store
+; MUSL-NEXT:    call
+; MUSL-NEXT:    store
+; MUSL-NEXT:    call
+; MUSL-NEXT:    store
+; MUSL-NEXT:    call
+; MUSL-NEXT:    store
+
   %slot = alloca double
   %slotf = alloca float
 
   %ACOS = call fast double @__acos_finite(double 1.000000e+00)
   store double %ACOS, double* %slot
   %ASIN = call fast double @__asin_finite(double 1.000000e+00)
   store double %ASIN, double* %slot
   %ATAN2 = call fast double @__atan2_finite(double 3.000000e+00, double 4.000000e+00)

llvm/trunk/test/Transforms/InferFunctionAttrs/annotate.ll

 ; RUN: opt < %s -mtriple=x86_64-- -inferattrs -S | FileCheck %s
 ; RUN: opt < %s -mtriple=x86_64-- -passes=inferattrs -S | FileCheck %s
 ; RUN: opt < %s -mtriple=x86_64-apple-macosx10.8.0 -inferattrs -S | FileCheck -check-prefix=CHECK -check-prefix=CHECK-DARWIN %s
-; RUN: opt < %s -mtriple=x86_64-unknown-linux -inferattrs -S | FileCheck -check-prefix=CHECK -check-prefix=CHECK-LINUX %s
+; RUN: opt < %s -mtriple=x86_64-unknown-linux-gnu -inferattrs -S | FileCheck -check-prefix=CHECK -check-prefix=CHECK-LINUX %s
 ; RUN: opt < %s -mtriple=nvptx -inferattrs -S | FileCheck -check-prefix=CHECK-NVPTX %s
 
 ; operator new routines
 declare i8* @_Znwj(i64)
 ; CHECK: declare noalias nonnull i8* @_Znwj(i64)
 declare i8* @_Znwm(i64)
 ; CHECK: declare noalias nonnull i8* @_Znwm(i64)