[llvm] 01a92f0 - [llvm-exegesis] Use mmap2 when mmap is unavailable to fix riscv32 build

[Fangrui Song via llvm-commits]

Author: Khem Raj
Date: 2023-08-25T10:43:00-07:00
New Revision: 01a92f06f23585f15b3e83b7c378d0df2d91e06b

URL: https://github.com/llvm/llvm-project/commit/01a92f06f23585f15b3e83b7c378d0df2d91e06b
DIFF: https://github.com/llvm/llvm-project/commit/01a92f06f23585f15b3e83b7c378d0df2d91e06b.diff

LOG: [llvm-exegesis] Use mmap2 when mmap is unavailable to fix riscv32 build

Some 32-bit architectures don't have mmap and define mmap2 instead.
E.g. on riscv32 we may get

```
| /mnt/b/yoe/master/build/tmp/work-shared/llvm-project-source-17.0.0-r0/git/llvm/tools/llvm-exegesis/lib/X86/Target.cpp:1116:19: error: use of undeclared identifier 'SYS_mmap'
|  1116 |   generateSyscall(SYS_mmap, MmapCode);
|       |                   ^
| /mnt/b/yoe/master/build/tmp/work-shared/llvm-project-source-17.0.0-r0/git/llvm/tools/llvm-exegesis/lib/X86/Target.cpp:1134:19: error: use of undeclared identifier 'SYS_mmap'
|  1134 |   generateSyscall(SYS_mmap, GeneratedCode);                                                                                                                                       |       |                   ^
| 1 warning and 2 errors generated.
```

Co-Authored-By: Fangrui Song <i at maskray.me>
Differential Revision: https://reviews.llvm.org/D158375

Added: 
    

Modified: 
    llvm/tools/llvm-exegesis/lib/X86/Target.cpp
    llvm/unittests/tools/llvm-exegesis/X86/TargetTest.cpp

Removed: 
    


################################################################################
diff  --git a/llvm/tools/llvm-exegesis/lib/X86/Target.cpp b/llvm/tools/llvm-exegesis/lib/X86/Target.cpp
index d41fa44f9258d5..ac99e98cc851f3 100644
--- a/llvm/tools/llvm-exegesis/lib/X86/Target.cpp
+++ b/llvm/tools/llvm-exegesis/lib/X86/Target.cpp
@@ -1087,11 +1087,11 @@ ExegesisX86Target::generateExitSyscall(unsigned ExitCode) const {
 #define MAP_FIXED_NOREPLACE MAP_FIXED
 #endif
 
-// 32 bit ARM doesn't have mmap and uses mmap2 instead. The only 
diff erence
-// between the two syscalls is that mmap2's offset parameter is in terms 4096
-// byte offsets rather than individual bytes, so for our purposes they are
-// effectively the same as all ofsets here are set to 0.
-#ifdef __arm__
+// Some 32-bit architectures don't have mmap and define mmap2 instead. The only
+// 
diff erence between the two syscalls is that mmap2's offset parameter is in
+// terms 4096 byte offsets rather than individual bytes, so for our purposes
+// they are effectively the same as all ofsets here are set to 0.
+#if defined(SYS_mmap2) && !defined(SYS_mmap)
 #define SYS_mmap SYS_mmap2
 #endif
 

diff  --git a/llvm/unittests/tools/llvm-exegesis/X86/TargetTest.cpp b/llvm/unittests/tools/llvm-exegesis/X86/TargetTest.cpp
index aa5d525f24eb7e..c001c693cc1461 100644
--- a/llvm/unittests/tools/llvm-exegesis/X86/TargetTest.cpp
+++ b/llvm/unittests/tools/llvm-exegesis/X86/TargetTest.cpp
@@ -635,11 +635,11 @@ TEST_F(X86Core2TargetTest, GenerateExitSyscallTest) {
 #define MAP_FIXED_NOREPLACE MAP_FIXED
 #endif
 
-// 32 bit ARM doesn't have mmap and uses mmap2 instead. The only 
diff erence
-// between the two syscalls is that mmap2's offset parameter is in terms 4096
-// byte offsets rather than individual bytes, so for our purposes they are
-// effectively the same as all ofsets here are set to 0.
-#ifdef __arm__
+// Some 32-bit architectures don't have mmap and define mmap2 instead. The only
+// 
diff erence between the two syscalls is that mmap2's offset parameter is in
+// terms 4096 byte offsets rather than individual bytes, so for our purposes
+// they are effectively the same as all ofsets here are set to 0.
+#if defined(SYS_mmap2) && !defined(SYS_mmap)
 #define SYS_mmap SYS_mmap2
 #endif