[LLDB][MIPS] Getting correct flags for MIPS

[nitesh.jain]

Summary

As per the discussions, updated signature for "ConvertMmapFlagsToPlatform" method to take "ArchSpec" as additional parameter.

[ovyalov]

source/Plugins/Platform/Linux/PlatformLinux.cpp

940

Please add spaces around equal sign.

941

We may need a special care for remote debugging scenario - i.e. use HostInfoBase::GetArchitecture() if IsHost() otherwise get archspec from remote target via GetRemoteSystemArchitecture

[tberghammer]

source/Plugins/Platform/Linux/PlatformLinux.cpp

941

We should use GetSystemArchitecture() what do this (with some additional caching)

[clayborg]

We probably need to pass in an architecture:

virtual uint64_t
Platform:: ConvertMmapFlagsToPlatform (const ArchSpec &arch, unsigned flags);

Then have all callers specify an architecture.

source/Plugins/Platform/Linux/PlatformLinux.cpp

941

You can't just get the Host for its architecture. We might need to change this function to take an "const ArchSpec &arch" as an argument and have the caller specify the right architecture using the current target.

[labath]

source/Target/Platform.cpp

1512

Wouldn't this be better in PlatformLinux? What are the odds of this constant being correct on non-linux platforms?

[emaste]

source/Target/Platform.cpp

1512

Yes, this is incorrect on FreeBSD.

/usr/include/sys/mman.h
84:#define MAP_ANON 0x1000 /* allocated from memory, swap space */
86:#define MAP_ANONYMOUS MAP_ANON /* For compatibility. */

[clayborg]

Looks good.

[ovyalov]

LGTM

include/lldb/Target/Platform.h

         Unlink(const FileSpec &file_spec);
 
         virtual uint64_t
-        ConvertMmapFlagsToPlatform(unsigned flags);
+        ConvertMmapFlagsToPlatform(const ArchSpec &arch, unsigned flags);
 
         virtual bool
         GetSupportsRSync ()

source/Plugins/Platform/Linux/PlatformLinux.h

                              NativeProcessProtocolSP &process_sp) override;
 
         uint64_t
-        ConvertMmapFlagsToPlatform(unsigned flags) override;
+        ConvertMmapFlagsToPlatform(const ArchSpec &arch, unsigned flags) override;
 
     private:
         DISALLOW_COPY_AND_ASSIGN (PlatformLinux);

source/Plugins/Platform/Linux/PlatformLinux.cpp

 }
 
 uint64_t
-PlatformLinux::ConvertMmapFlagsToPlatform(unsigned flags)
+PlatformLinux::ConvertMmapFlagsToPlatform(const ArchSpec &arch, unsigned flags)
 {
     uint64_t flags_platform = 0;
+    uint64_t map_anon = MAP_ANON;
+
+    // To get correct flags for MIPS Architecture
+    if (arch.GetTriple ().getArch () == llvm::Triple::mips64
+       || arch.GetTriple ().getArch () == llvm::Triple::mips64el 
+       || arch.GetTriple ().getArch () == llvm::Triple::mips 
+       || arch.GetTriple ().getArch () == llvm::Triple::mipsel)
+           map_anon = 0x800;
+
     if (flags & eMmapFlagsPrivate)
         flags_platform |= MAP_PRIVATE;
     if (flags & eMmapFlagsAnon)
-        flags_platform |= MAP_ANON;
+        flags_platform |= map_anon;
     return flags_platform;
 }

source/Plugins/Process/Utility/InferiorCallPOSIX.cpp

                 prot_arg |= PROT_WRITE;
             }
 
-            flags_arg = process->GetTarget().GetPlatform()->ConvertMmapFlagsToPlatform(flags);
+            const ArchSpec arch =  process->GetTarget().GetArchitecture();
+            flags_arg = process->GetTarget().GetPlatform()->ConvertMmapFlagsToPlatform(arch,flags);
 
             AddressRange mmap_range;
             if (sc.GetAddressRange(range_scope, 0, use_inline_block_range, mmap_range))

source/Target/Platform.cpp

 }
 
 uint64_t
-Platform::ConvertMmapFlagsToPlatform(unsigned flags)
+Platform::ConvertMmapFlagsToPlatform(const ArchSpec &arch, unsigned flags)
 {
+    uint64_t map_anon = MAP_ANON;
     uint64_t flags_platform = 0;
+
+    if (arch.GetTriple ().getArch () == llvm::Triple::mips64 
+       || arch.GetTriple ().getArch () == llvm::Triple::mips64el 
+       || arch.GetTriple ().getArch () == llvm::Triple::mips 
+       || arch.GetTriple ().getArch () == llvm::Triple::mipsel)
+           map_anon = 0x800;
+
     if (flags & eMmapFlagsPrivate)
         flags_platform |= MAP_PRIVATE;
     if (flags & eMmapFlagsAnon)
-        flags_platform |= MAP_ANON;
+        flags_platform |= map_anon;
     return flags_platform;
 }