It is possible to use python

>>> currentProgram.getImageBase()
>>> bytearray(getBytes(toAddr(0x4c00), 0x2a10))
>>> getCurrentProgram().getCodeManager().getCodeUnitBefore(toAddr(0xa0010004))
addiu sp,sp,-0x38
>>> function = currentProgram.getFunctionManager().getFunctionContaining(toAddr(0x005259c0))
>>> import as decomp
>>> decomp = decomp.DecompInterface()
>>> decomp.openProgram(currentProgram)
>>> results = decomp.decompileFunction(function, 10, None)
>>> dec = results.getDecompiledFunction()
>>> print(dec.getC())

void FUN_005259c0(int param_1,int *param_2,int param_3)

  bool bVar1;
  undefined *puVar2;
  int iVar3;
  int iVar4;

  iVar4 = 0;
  while( true ) {
    puVar2 = PTR_strlen_0058eb64;
    bVar1 = param_3 <= iVar4;
    iVar4 = iVar4 + 1;
    if (bVar1) break;
    *param_2 = param_1;
    iVar3 = (*(code *)puVar2)(param_1);
    param_1 = param_1 + iVar3 + 1;
    param_2 = param_2 + 1;
>>> [_ for _ in currentProgram.getFunctionManager().getFunctionsNoStubs(True)]
[FUN_c14001f0, FUN_c14002c8, FUN_c1400434, FUN_c14004a8, FUN_c14005d8,
FUN_c1400760, FUN_c14007f0, FUN_c1400818, FUN_c1400c40, FUN_c1400ec8,
FUN_c1401004, FUN_c1401080, FUN_c14010ac, FUN_c1401118, FUN_c140114c,
FUN_c14011d0, FUN_c1401240, FUN_c14012b0, FUN_c1401318, FUN_c140139c,
FUN_c1401450, FUN_c1401500, FUN_c1401594, FUN_c14017e8, FUN_c140196c,
FUN_c140199c, FUN_c1401b6c, FUN_c1401d2c, FUN_c1401f90, FUN_c1401fb4,
FUN_c1401fd8, FUN_c1401ffc, FUN_c1402020, FUN_c1402050, FUN_c1402074,
FUN_c140209c, FUN_c14020c4, FUN_c1402108, FUN_c1402148, FUN_c14021b8,
FUN_c1402228, FUN_c14022c0, FUN_c1402340, FUN_c14024ac, FUN_c140253c,
FUN_c1402548, FUN_c1402554, FUN_c1402560, FUN_c140256c, FUN_c1402578,
FUN_c1402584, FUN_c1402590, FUN_c140259c, FUN_c14025a8, FUN_c14025b4,
FUN_c14025c0, FUN_c14025cc, FUN_c14025d8, FUN_c14025e4, FUN_c14025f0,
FUN_c14025fc, FUN_c1402608, FUN_c1402614, FUN_c1402620, FUN_c140262c,
FUN_c1402638, FUN_c1402644, FUN_c1402974]
>>> [_ for _ in currentProgram.getListing().getInstructions(f.getBody(), True)]
[addiu sp,sp,-0x40, sw ra,0x3c(sp), sw s8,0x38(sp), move s8,sp, sw a0,0x40(s8),
sw a1,0x44(s8), sw a2,0x48(s8), sw zero,0x10(s8), lw v0,0x44(s8), bne
v0,zero,0xc140022c, _nop, li v0,-0x16, sw v0,0x30(s8), b 0xc14002ac, _nop, lw
v1,0x40(s8), lw v0,0x48(s8), addu v0,v1,v0, sltiu v0,v0,0x201, bne
v0,zero,0xc1400254, _nop, li v0,-0x16, sw v0,0x30(s8), b 0xc14002ac, _nop, addiu
v0,s8,0x18, move a0,v0, clear a1, li a2,0x18, jal 0xc14025e4, _nop, lw
v0,0x44(s8), sw v0,0x18(s8), lw v0,0x40(s8), addiu v0,v0,0x200, sw v0,0x1c(s8),
lw v0,0x48(s8), sw v0,0x20(s8), li v0,0x9, sw v0,0x24(s8), addiu v0,s8,0x18,
move a0,v0, jal 0xc14024ac, _nop, sw v0,0x10(s8), lw v0,0x10(s8), sw
v0,0x30(s8), lw v0,0x30(s8), move sp,s8, lw ra,0x3c(sp), lw s8,0x38(sp), addiu
sp,sp,0x40, jr ra, _nop]
>>> function = currentProgram.getFunctionManager().getFunctionContaining(toAddr(0x005259c0))
>>> list(currentProgram.getReferenceManager().getReferencesTo(function.getEntryPoint()))
[From: 00525a78 To: 005259c0 Type: UNCONDITIONAL_CALL Op: 0 DEFAULT, From: 00525a90 To: 005259c0 Type: UNCONDITIONAL_CALL Op: 0 DEFAULT, From: 00525aa8 To: 005259c0 Type: UNCONDITIONAL_CALL Op: 0 DEFAULT, From: 00525ac0 To: 005259c0 Type: UNCONDITIONAL_CALL Op: 0 DEFAULT, From: 00525ad8 To: 005259c0 Type: UNCONDITIONAL_CALL Op: 0 DEFAULT]
>>> [(getInstructionAt(_.getFromAddress()).getMnemonicString(), getFunctionContaining(_.getFromAddress()),_.getReferenceType()) for _ in currentProgram.getReferenceManager().getReferencesTo(function.getEntryPoint())]
[(u'jal', http_get_code_text, UNCONDITIONAL_CALL), (u'jal', http_get_code_text, UNCONDITIONAL_CALL), (u'jal', http_get_code_text, UNCONDITIONAL_CALL), (u'jal', http_get_code_text, UNCONDITIONAL_CALL), (u'jal', http_get_code_text, UNCONDITIONAL_CALL)]
>>> v = jarray.zeros(0x100, "b")
>>> createMemoryBlock("syscall", toAddr("OTHER:0x00000000"), v, True)
>>> lookup = getCurrentProgram().getSymbolTable().getSymbol("LOOKUP_TABLE").getObject()
>>> [hex(lookup.getUnsignedInt(_*4)) for _ in range(lookup.getLength()/4)]
['0x0L', '0x77073096L', '0xee0e612cL', '0x990951baL', '0x76dc419L',
'0x706af48fL', '0xe963a535L', '0x9e6495a3L', '0xedb8832L', '0x79dcb8a4L',
'0xe0d5e91eL', '0x97d2d988L', '0x9b64c2bL', '0x7eb17cbdL', '0xe7b82d07L',
'0x90bf1d91L', '0x1db71064L', '0x6ab020f2L', '0xf3b97148L', '0x84be41deL',
'0x1adad47dL', '0x6ddde4ebL', '0xf4d4b551L', '0x83d385c7L', '0x136c9856L',
'0x646ba8c0L', '0xfd62f97aL', '0x8a65c9ecL', '0x14015c4fL', '0x63066cd9L',
'0xfa0f3d63L', '0x8d080df5L', '0x3b6e20c8L', '0x4c69105eL', '0xd56041e4L',
'0xa2677172L', '0x3c03e4d1L', '0x4b04d447L', '0xd20d85fdL', '0xa50ab56bL',
'0x35b5a8faL', '0x42b2986cL', '0xdbbbc9d6L', '0xacbcf940L', '0x32d86ce3L',
'0x45df5c75L', '0xdcd60dcfL', '0xabd13d59L', '0x26d930acL', '0x51de003aL',
'0xc8d75180L', '0xbfd06116L', '0x21b4f4b5L', '0x56b3c423L', '0xcfba9599L',
'0xb8bda50fL', '0x2802b89eL', '0x5f058808L', '0xc60cd9b2L', '0xb10be924L',
'0x2f6f7c87L', '0x58684c11L', '0xc1611dabL', '0xb6662d3dL', '0x76dc4190L',
'0x1db7106L', '0x98d220bcL', '0xefd5102aL', '0x71b18589L', '0x6b6b51fL',
'0x9fbfe4a5L', '0xe8b8d433L', '0x7807c9a2L', '0xf00f934L', '0x9609a88eL',
'0xe10e9818L', '0x7f6a0dbbL', '0x86d3d2dL', '0x91646c97L', '0xe6635c01L',
'0x6b6b51f4L', '0x1c6c6162L', '0x856530d8L', '0xf262004eL', '0x6c0695edL',
'0x1b01a57bL', '0x8208f4c1L', '0xf50fc457L', '0x65b0d9c6L', '0x12b7e950L',
'0x8bbeb8eaL', '0xfcb9887cL', '0x62dd1ddfL', '0x15da2d49L', '0x8cd37cf3L',
'0xfbd44c65L', '0x4db26158L', '0x3ab551ceL', '0xa3bc0074L', '0xd4bb30e2L',
'0x4adfa541L', '0x3dd895d7L', '0xa4d1c46dL', '0xd3d6f4fbL', '0x4369e96aL',
'0x346ed9fcL', '0xad678846L', '0xda60b8d0L', '0x44042d73L', '0x33031de5L',
'0xaa0a4c5fL', '0xdd0d7cc9L', '0x5005713cL', '0x270241aaL', '0xbe0b1010L',
'0xc90c2086L', '0x5768b525L', '0x206f85b3L', '0xb966d409L', '0xce61e49fL',
'0x5edef90eL', '0x29d9c998L', '0xb0d09822L', '0xc7d7a8b4L', '0x59b33d17L',
'0x2eb40d81L', '0xb7bd5c3bL', '0xc0ba6cadL', '0xedb88320L', '0x9abfb3b6L',
'0x3b6e20cL', '0x74b1d29aL', '0xead54739L', '0x9dd277afL', '0x4db2615L',
'0x73dc1683L', '0xe3630b12L', '0x94643b84L', '0xd6d6a3eL', '0x7a6a5aa8L',
'0xe40ecf0bL', '0x9309ff9dL', '0xa00ae27L', '0x7d079eb1L', '0xf00f9344L',
'0x8708a3d2L', '0x1e01f268L', '0x6906c2feL', '0xf762575dL', '0x806567cbL',
'0x196c3671L', '0x6e6b06e7L', '0xfed41b76L', '0x89d32be0L', '0x10da7a5aL',
'0x67dd4accL', '0xf9b9df6fL', '0x8ebeeff9L', '0x17b7be43L', '0x60b08ed5L',
'0xd6d6a3e8L', '0xa1d1937eL', '0x38d8c2c4L', '0x4fdff252L', '0xd1bb67f1L',
'0xa6bc5767L', '0x3fb506ddL', '0x48b2364bL', '0xd80d2bdaL', '0xaf0a1b4cL',
'0x36034af6L', '0x41047a60L', '0xdf60efc3L', '0xa867df55L', '0x316e8eefL',
'0x4669be79L', '0xcb61b38cL', '0xbc66831aL', '0x256fd2a0L', '0x5268e236L',
'0xcc0c7795L', '0xbb0b4703L', '0x220216b9L', '0x5505262fL', '0xc5ba3bbeL',
'0xb2bd0b28L', '0x2bb45a92L', '0x5cb36a04L', '0xc2d7ffa7L', '0xb5d0cf31L',
'0x2cd99e8bL', '0x5bdeae1dL', '0x9b64c2b0L', '0xec63f226L', '0x756aa39cL',
'0x26d930aL', '0x9c0906a9L', '0xeb0e363fL', '0x72076785L', '0x5005713L',
'0x95bf4a82L', '0xe2b87a14L', '0x7bb12baeL', '0xcb61b38L', '0x92d28e9bL',
'0xe5d5be0dL', '0x7cdcefb7L', '0xbdbdf21L', '0x86d3d2d4L', '0xf1d4e242L',
'0x68ddb3f8L', '0x1fda836eL', '0x81be16cdL', '0xf6b9265bL', '0x6fb077e1L',
'0x18b74777L', '0x88085ae6L', '0xff0f6a70L', '0x66063bcaL', '0x11010b5cL',
'0x8f659effL', '0xf862ae69L', '0x616bffd3L', '0x166ccf45L', '0xa00ae278L',
'0xd70dd2eeL', '0x4e048354L', '0x3903b3c2L', '0xa7672661L', '0xd06016f7L',
'0x4969474dL', '0x3e6e77dbL', '0xaed16a4aL', '0xd9d65adcL', '0x40df0b66L',
'0x37d83bf0L', '0xa9bcae53L', '0xdebb9ec5L', '0x47b2cf7fL', '0x30b5ffe9L',
'0xbdbdf21cL', '0xcabac28aL', '0x53b39330L', '0x24b4a3a6L', '0xbad03605L',
'0xcdd70693L', '0x54de5729L', '0x23d967bfL', '0xb3667a2eL', '0xc4614ab8L',
'0x5d681b02L', '0x2a6f2b94L', '0xb40bbe37L', '0xc30c8ea1L', '0x5a05df1bL',

Script to obtain local variables from a function (taken from this issue)

from import DecompileOptions
from import DecompInterface
from ghidra.util.task import ConsoleTaskMonitor

func = getFunctionContaining(currentAddress)

print "Analyzing variables for function '%s'@%s" % (, currentAddress)

options = DecompileOptions()
monitor = ConsoleTaskMonitor()
ifc = DecompInterface()
res = ifc.decompileFunction(func, 60, monitor)
high_func = res.getHighFunction()
lsm = high_func.getLocalSymbolMap()
symbols = lsm.getSymbols()

for i, symbol in enumerate(symbols):
    print("\nSymbol {}:".format(i+1))
    print("  name:         {}".format(
    print("  dataType:     {}".format(symbol.dataType))
    hs = symbol.getHighVariable()  # note important part here
        instances = hs.getInstances()  # note important part here
    for instance in instances:
        print("\n  instance:     {}".format(instance))
        print("   type:         {}".format(type(instance)))
        print("   uniqueID:     {}".format(instance.uniqueId))
        print("   PCAddress:    {}".format(instance.getPCAddress()))
        for desc in instance.getDescendants():
            print("    Descendant:   {}".format(desc))

with the following output

Analyzing variables for function 'CheckImplicitLoad'

Symbol 1:
  name:         bVar1
  dataType:     byte

  instance:     (register, 0x8, 1)
   type:         <type 'ghidra.program.model.pcode.VarnodeAST'>
   uniqueID:     193
   PCAddress:    10004886
   Descendant:   (unique, 0x10000018, 4) INT_ZEXT (register, 0x8, 1)

  instance:     (register, 0x8, 1)
   type:         <type 'ghidra.program.model.pcode.VarnodeAST'>
   uniqueID:     22
   PCAddress:    1000486e
   Descendant:   (register, 0x8, 1) MULTIEQUAL (register, 0x8, 1) , (register, 0x8, 1) , (register, 0x8, 1)
   Descendant:   (register, 0x8, 1) MULTIEQUAL (register, 0x8, 1) , (register, 0x8, 1) , (register, 0x8, 1)

  instance:     (register, 0x8, 1)
   type:         <type 'ghidra.program.model.pcode.VarnodeAST'>
   uniqueID:     114
   PCAddress:    10004884
   Descendant:   (register, 0x8, 1) MULTIEQUAL (register, 0x8, 1) , (register, 0x8, 1) , (register, 0x8, 1)

Symbol 2:
  name:         param_1
  dataType:     uint

  instance:     (register, 0x0, 4)
   type:         <type 'ghidra.program.model.pcode.VarnodeAST'>
   uniqueID:     186
   PCAddress:    10004886
   Descendant:   (unique, 0x10000014, 4) INT_AND (register, 0x0, 4) , (const, 0xffffff00, 4)

  instance:     (register, 0x0, 4)
   type:         <type 'ghidra.program.model.pcode.VarnodeAST'>
   uniqueID:     184
   PCAddress:    1000487f
   Descendant:   (register, 0x0, 4) MULTIEQUAL (stack, 0x4, 4) , (stack, 0x4, 4) , (register, 0x0, 4)

  instance:     (stack, 0x4, 4)
   type:         <type 'ghidra.program.model.pcode.VarnodeAST'>
   uniqueID:     141
   PCAddress:    NO ADDRESS
   Descendant:   (register, 0x206, 1) INT_NOTEQUAL (stack, 0x4, 4) , (const, 0x0, 4)
   Descendant:   (unique, 0x41f80, 4) INT_AND (stack, 0x4, 4) , (const, 0xffff0000, 4)
   Descendant:   (register, 0x0, 4) INT_AND (stack, 0x4, 4) , (const, 0xffff, 4)
   Descendant:   (register, 0x0, 4) MULTIEQUAL (stack, 0x4, 4) , (stack, 0x4, 4) , (register, 0x0, 4)
   Descendant:   (register, 0x0, 4) MULTIEQUAL (stack, 0x4, 4) , (stack, 0x4, 4) , (register, 0x0, 4)

It's also possible to take a look at the all the analyzers available:

>>> from ghidra.util.classfinder import ClassSearcher
>>> from import Analyzer
>>> print '\n'.join(["%80s\t%s.%s"% (, _.__class__.__module__, _.__class__.__name__) for _ in ClassSearcher.getInstances(Analyzer)])
                                           Apple Single/Double Header Annotation
                                                          COFF Header Annotation
                                                  COFF Archive Header Annotation
                                                           Condense Filler Bytes
                                                           ELF Header Annotation
                                                           Function Start Search
                                                Function Start Search After Data
                                                           Function Start Search
                                                Function Start Search After Code
                                                        Mach-O Header Annotation
                                                           PEF Header Annotation
                                                            PE Header Annotation
                                                          AARCH64 ELF PLT Thunks
                                                        ARM Pre-Pattern Analyzer
                                                             Apply Data Archives
                                                 ARM Constant Reference Analyzer
                                                                      ARM Symbol
                                                     CLI Metadata Token Analyzer
                                               Basic Constant Reference Analyzer
                                                                  Data Reference
                                                              Call Convention ID
                                                         Decompiler Parameter ID
                                                      Decompiler Switch Analysis
                                                               DWARF Line Number
                                                   ELF Scalar Operand References
                                                                  Embedded Media
                                            Non-Returning Functions - Discovered
                                                                   Demangler GNU
                                               HCS12 Constant Reference Analyzer
                                                        HCS12 Calling Convention
                                                             Demangler Microsoft
                                                MIPS Constant Reference Analyzer
                                                 MIPS UnAlligned Instruction Fix
                                                                     MIPS Symbol
                                               68000 Constant Reference Analyzer
                                                 Non-Returning Functions - Known
                                                               Objective-C Class
                                                             Objective-C Message
                                                             Objective-C 2 Class
                                                Objective-C 2 Decompiler Message
                                                           Objective-C 2 Message
                                                            PPC64 ELF Call Stubs
                                                                       PDB MSDIA
                                                                   PDB Universal
                                                         PEF Indirect Addressing
                                                                       PEF Debug
                                                         PIC-12C5xx or PIC-16C5x
                                              PIC-16 Constant Reference Analyzer
                                                                  DInit Analyzer
                                                               PIC Switch Tables
                                             PowerPC Constant Reference Analyzer
                                               RISCV Constant Reference Analyzer
                                                       Scalar Operand References
                                               Segmented X86 Calling Conventions
                                               Sparc Constant Reference Analyzer
                                                 x86 Constant Reference Analyzer
                                                           Create Address Tables
                                                            Call-Fixup Installer
                                                            Call-Fixup Installer
                                                        Disassemble Entry Points
                                                           Subroutine References
                                                       External Entry References
                                                           Subroutine References
                                                             Shared Return Calls
                                                             Shared Return Calls
                                                       X86 Function Callee Purge
                                                                   ASCII Strings
                                            Variadic Function Signature Override
                                                          GCC Exception Handlers
                                               Windows x86 PE Exception Handling
                                     WindowsPE x86 Propagate External Parameters
                                                    Windows x86 PE RTTI Analyzer
                                                   Aggressive Instruction Finder
                                               ARM Aggressive Instruction Finder
                                                                     Function ID    ghidra.feature.fid.analyzer.FidAnalyzer
                                       Android Boot or Recovery Image Annotation
                                               Android DEX Condense Filler Bytes
                                                  Android DEX Exception Handlers
                                                       Android DEX Header Format
                                                         Android DEX Data Markup
                                                  Android DEX Instruction Markup
                                                 Android DEX Switch Table Markup
                                                      Android ODEX Header Format
                                        Binary Property List (BPLIST) Annotation    ghidra.file.formats.bplist.BinaryPropertyListAnalyzer
                                                                   Ext4 Analyzer    ghidra.file.formats.ext4.Ext4Analyzer
                                                               Ext4 Analyzer NEW    ghidra.file.formats.ext4.NewExt4Analyzer
                                                           Apple 8900 Annotation    ghidra.file.formats.ios.apple8900.Apple8900Analyzer
                                                                             DMG    ghidra.file.formats.ios.dmg.DmgAnalyzer
                                                           DYLD Cache Annotation    ghidra.file.formats.ios.dyldcache.DyldCacheAnalyzer
                               iOS Analyzer for iBoot, LLB, iBSS, and iBEC files    ghidra.file.formats.ios.generic.iOS_Analyzer
                                                      Apple iOS ARM Symbol Fixup    ghidra.file.formats.ios.generic.iOS_FixupArmSymbolsAnalyzer
                                                     iOS Kext STUB Section Fixup    ghidra.file.formats.ios.generic.iOS_KextStubFixupAnalyzer
                                                iBoot Image (iBootIm) Annotation    ghidra.file.formats.ios.ibootim.iBootImAnalyzer
                                                                 IMG2 Annotation    ghidra.file.formats.ios.img2.Img2Analyzer
                                                                 IMG3 Annotation    ghidra.file.formats.ios.img3.Img3Analyzer
                                                  ISO9660 File Format Annotation    ghidra.file.formats.iso9660.ISO9660Analyzer
                                                     LZSS Compression Annotation    ghidra.file.formats.lzss.LzssAnalyzer
       YAFFS2 Image Annotation (used in Android System and Userdata image files)    ghidra.file.formats.yaffs2.YAFFS2Analyzer
                                                             Java Class Analyzer    ghidra.javaclass.analyzers.JavaAnalyzer
                                                             JVM Switch Analyzer    ghidra.javaclass.analyzers.JvmSwitchAnalyzer
                                                                       CFStrings    ghidra.macosx.analyzers.CFStringAnalyzer
                                                   Mach-O Constructor/Destructor    ghidra.macosx.analyzers.MachoConstructorDestructorAnalyzer
                                                                            Test    ghidra.macosx.analyzers.TestAnalyzer


From this issue some indication on how to debug the decompiler

$ cd Ghidra/Feature/Decompiler/src/decompile/cpp
$ make decomp_dbg
$ export SLEIGHHOME=~/git/ghidra/
$ ./decomp_dbg