@@ -85,126 +85,140 @@ func (r loadCmdReader) WriteAt(offset int64, data interface{}) error {
8585}
8686
8787// machoCombineDwarf merges dwarf info generated by dsymutil into a macho executable.
88+ // machoCombineDwarf returns true and skips merging if the input executable is for iOS.
89+ //
8890// With internal linking, DWARF is embedded into the executable, this lets us do the
8991// same for external linking.
9092// inexe is the path to the executable with no DWARF. It must have enough room in the macho
9193// header to add the DWARF sections. (Use ld's -headerpad option)
9294// dsym is the path to the macho file containing DWARF from dsymutil.
9395// outexe is the path where the combined executable should be saved.
94- func machoCombineDwarf (inexe , dsym , outexe string , buildmode BuildMode ) error {
96+ func machoCombineDwarf (inexe , dsym , outexe string , buildmode BuildMode ) ( bool , error ) {
9597 exef , err := os .Open (inexe )
9698 if err != nil {
97- return err
99+ return false , err
100+ }
101+ exem , err := macho .NewFile (exef )
102+ if err != nil {
103+ return false , err
104+ }
105+ cmdOffset := unsafe .Sizeof (exem .FileHeader )
106+ is64bit := exem .Magic == macho .Magic64
107+ if is64bit {
108+ // mach_header_64 has one extra uint32.
109+ cmdOffset += unsafe .Sizeof (exem .Magic )
110+ }
111+ // Check for LC_VERSION_MIN_IPHONEOS.
112+ reader := loadCmdReader {next : int64 (cmdOffset ), f : exef , order : exem .ByteOrder }
113+ for i := uint32 (0 ); i < exem .Ncmd ; i ++ {
114+ cmd , err := reader .Next ()
115+ if err != nil {
116+ return false , err
117+ }
118+ if cmd .Cmd == LC_VERSION_MIN_IPHONEOS {
119+ // The executable is for iOS, which doesn't support unmapped
120+ // segments such as our __DWARF segment. Skip combining.
121+ return true , nil
122+ }
98123 }
99124 dwarff , err := os .Open (dsym )
100125 if err != nil {
101- return err
126+ return false , err
102127 }
103128 outf , err := os .Create (outexe )
104129 if err != nil {
105- return err
130+ return false , err
106131 }
107132 outf .Chmod (0755 )
108133
109- exem , err := macho .NewFile (exef )
110- if err != nil {
111- return err
112- }
113134 dwarfm , err := macho .NewFile (dwarff )
114135 if err != nil {
115- return err
136+ return false , err
116137 }
117138
118139 // The string table needs to be the last thing in the file
119140 // for code signing to work. So we'll need to move the
120141 // linkedit section, but all the others can be copied directly.
121142 linkseg = exem .Segment ("__LINKEDIT" )
122143 if linkseg == nil {
123- return fmt .Errorf ("missing __LINKEDIT segment" )
144+ return false , fmt .Errorf ("missing __LINKEDIT segment" )
124145 }
125146
126147 if _ , err = exef .Seek (0 , 0 ); err != nil {
127- return err
148+ return false , err
128149 }
129150 if _ , err := io .CopyN (outf , exef , int64 (linkseg .Offset )); err != nil {
130- return err
151+ return false , err
131152 }
132153
133154 realdwarf = dwarfm .Segment ("__DWARF" )
134155 if realdwarf == nil {
135- return fmt .Errorf ("missing __DWARF segment" )
156+ return false , fmt .Errorf ("missing __DWARF segment" )
136157 }
137158
138159 // Now copy the dwarf data into the output.
139160 // Kernel requires all loaded segments to be page-aligned in the file,
140161 // even though we mark this one as being 0 bytes of virtual address space.
141162 dwarfstart = machoCalcStart (realdwarf .Offset , linkseg .Offset , pageAlign )
142163 if _ , err = outf .Seek (dwarfstart , 0 ); err != nil {
143- return err
164+ return false , err
144165 }
145166 dwarfaddr = int64 ((linkseg .Addr + linkseg .Memsz + 1 << pageAlign - 1 ) &^ (1 << pageAlign - 1 ))
146167
147168 if _ , err = dwarff .Seek (int64 (realdwarf .Offset ), 0 ); err != nil {
148- return err
169+ return false , err
149170 }
150171 if _ , err := io .CopyN (outf , dwarff , int64 (realdwarf .Filesz )); err != nil {
151- return err
172+ return false , err
152173 }
153174
154175 // And finally the linkedit section.
155176 if _ , err = exef .Seek (int64 (linkseg .Offset ), 0 ); err != nil {
156- return err
177+ return false , err
157178 }
158179 linkstart = machoCalcStart (linkseg .Offset , uint64 (dwarfstart )+ realdwarf .Filesz , pageAlign )
159180 linkoffset = uint32 (linkstart - int64 (linkseg .Offset ))
160181 if _ , err = outf .Seek (linkstart , 0 ); err != nil {
161- return err
182+ return false , err
162183 }
163184 if _ , err := io .Copy (outf , exef ); err != nil {
164- return err
185+ return false , err
165186 }
166187
167188 // Now we need to update the headers.
168- cmdOffset := unsafe .Sizeof (exem .FileHeader )
169- is64bit := exem .Magic == macho .Magic64
170- if is64bit {
171- // mach_header_64 has one extra uint32.
172- cmdOffset += unsafe .Sizeof (exem .Magic )
173- }
174-
175189 textsect := exem .Section ("__text" )
176190 if linkseg == nil {
177- return fmt .Errorf ("missing __text section" )
191+ return false , fmt .Errorf ("missing __text section" )
178192 }
179193
180194 dwarfCmdOffset := int64 (cmdOffset ) + int64 (exem .FileHeader .Cmdsz )
181195 availablePadding := int64 (textsect .Offset ) - dwarfCmdOffset
182196 if availablePadding < int64 (realdwarf .Len ) {
183- return fmt .Errorf ("No room to add dwarf info. Need at least %d padding bytes, found %d" , realdwarf .Len , availablePadding )
197+ return false , fmt .Errorf ("No room to add dwarf info. Need at least %d padding bytes, found %d" , realdwarf .Len , availablePadding )
184198 }
185199 // First, copy the dwarf load command into the header
186200 if _ , err = outf .Seek (dwarfCmdOffset , 0 ); err != nil {
187- return err
201+ return false , err
188202 }
189203 if _ , err := io .CopyN (outf , bytes .NewReader (realdwarf .Raw ()), int64 (realdwarf .Len )); err != nil {
190- return err
204+ return false , err
191205 }
192206
193207 if _ , err = outf .Seek (int64 (unsafe .Offsetof (exem .FileHeader .Ncmd )), 0 ); err != nil {
194- return err
208+ return false , err
195209 }
196210 if err = binary .Write (outf , exem .ByteOrder , exem .Ncmd + 1 ); err != nil {
197- return err
211+ return false , err
198212 }
199213 if err = binary .Write (outf , exem .ByteOrder , exem .Cmdsz + realdwarf .Len ); err != nil {
200- return err
214+ return false , err
201215 }
202216
203- reader : =loadCmdReader {next : int64 (cmdOffset ), f : outf , order : exem .ByteOrder }
217+ reader = loadCmdReader {next : int64 (cmdOffset ), f : outf , order : exem .ByteOrder }
204218 for i := uint32 (0 ); i < exem .Ncmd ; i ++ {
205219 cmd , err := reader .Next ()
206220 if err != nil {
207- return err
221+ return false , err
208222 }
209223 switch cmd .Cmd {
210224 case macho .LoadCmdSegment64 :
@@ -227,10 +241,10 @@ func machoCombineDwarf(inexe, dsym, outexe string, buildmode BuildMode) error {
227241 err = fmt .Errorf ("Unknown load command 0x%x (%s)\n " , int (cmd .Cmd ), cmd .Cmd )
228242 }
229243 if err != nil {
230- return err
244+ return false , err
231245 }
232246 }
233- return machoUpdateDwarfHeader (& reader , buildmode )
247+ return false , machoUpdateDwarfHeader (& reader , buildmode )
234248}
235249
236250// machoUpdateSegment updates the load command for a moved segment.
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