ld: Add -I option to set ELF interpreter.

R=rsc
CC=golang-dev
https://golang.org/cl/4080049

src/cmd/5l/asm.c

@@ -448,7 +448,9 @@ asmb(void)
 			sh->type = SHT_PROGBITS;
 			sh->flags = SHF_ALLOC;
 			sh->addralign = 1;
-			elfinterp(sh, startva, linuxdynld);
+			if(interpreter == nil)
+				interpreter = linuxdynld;
+			elfinterp(sh, startva, interpreter);
 
 			ph = newElfPhdr();
 			ph->type = PT_INTERP;

src/cmd/5l/doc.go

@@ -23,6 +23,8 @@ Options new in this version:
 -F
 	Force use of software floating point.
 	Also implied by setting GOARM=5 in the environment.
+-I interpreter
+	Set the ELF dynamic linker to use.
 -L dir1 -L dir2
 	Search for libraries (package files) in dir1, dir2, etc.
 	The default is the single location $GOROOT/pkg/$GOOS_arm.

src/cmd/5l/l.h

@@ -332,6 +332,7 @@ EXTERN	Oprang	thumboprange[ALAST];
 EXTERN	char*	outfile;
 EXTERN	int32	pc;
 EXTERN	uchar	repop[ALAST];
+EXTERN	char*	interpreter;
 EXTERN	char*	rpath;
 EXTERN	uint32	stroffset;
 EXTERN	int32	symsize;

src/cmd/5l/obj.c

@@ -61,7 +61,7 @@ linkername[] =
 void
 usage(void)
 {
-	fprint(2, "usage: 5l [-E entry] [-H head] [-L dir] [-T text] [-D data] [-R rnd] [-r path] [-o out] main.5\n");
+	fprint(2, "usage: 5l [-E entry] [-H head] [-I interpreter] [-L dir] [-T text] [-D data] [-R rnd] [-r path] [-o out] main.5\n");
 	errorexit();
 }
 
@@ -100,6 +100,9 @@ main(int argc, char *argv[])
 	case 'E':
 		INITENTRY = EARGF(usage());
 		break;
+	case 'I':
+		interpreter = EARGF(usage());
+		break;
 	case 'L':
 		Lflag(EARGF(usage()));
 		break;

src/cmd/6l/asm.c

@@ -915,14 +915,17 @@ asmb(void)
 			sh->type = SHT_PROGBITS;
 			sh->flags = SHF_ALLOC;
 			sh->addralign = 1;
+			if(interpreter == nil) {
 				switch(HEADTYPE) {
 				case 7:
-				elfinterp(sh, startva, linuxdynld);
+					interpreter = linuxdynld;
 					break;
 				case 9:
-				elfinterp(sh, startva, freebsddynld);
+					interpreter = freebsddynld;
 					break;
 				}
+			}
+			elfinterp(sh, startva, interpreter);
 
 			ph = newElfPhdr();
 			ph->type = PT_INTERP;

src/cmd/6l/doc.go

@@ -32,6 +32,8 @@ Options new in this version:
 	Write Apple Mach-O binaries (default when $GOOS is darwin)
 -H7
 	Write Linux ELF binaries (default when $GOOS is linux)
+-I interpreter
+	Set the ELF dynamic linker to use.
 -L dir1 -L dir2
 	Search for libraries (package files) in dir1, dir2, etc.
 	The default is the single location $GOROOT/pkg/$GOOS_amd64.

src/cmd/6l/l.h

@@ -352,6 +352,7 @@ EXTERN	int	nerrors;
 EXTERN	char*	noname;
 EXTERN	char*	outfile;
 EXTERN	vlong	pc;
+EXTERN	char*	interpreter;
 EXTERN	char*	rpath;
 EXTERN	int32	spsize;
 EXTERN	Sym*	symlist;

src/cmd/6l/obj.c

@@ -58,7 +58,7 @@ char*	paramspace	= "FP";
 void
 usage(void)
 {
-	fprint(2, "usage: 6l [-options] [-E entry] [-H head] [-L dir] [-T text] [-R rnd] [-r path] [-o out] main.6\n");
+	fprint(2, "usage: 6l [-options] [-E entry] [-H head] [-I interpreter] [-L dir] [-T text] [-R rnd] [-r path] [-o out] main.6\n");
 	exits("usage");
 }
 
@@ -96,6 +96,9 @@ main(int argc, char *argv[])
 	case 'H':
 		HEADTYPE = atolwhex(EARGF(usage()));
 		break;
+	case 'I':
+		interpreter = EARGF(usage());
+		break;
 	case 'L':
 		Lflag(EARGF(usage()));
 		break;

src/cmd/8l/asm.c

@@ -936,14 +936,17 @@ asmb(void)
 			sh->type = SHT_PROGBITS;
 			sh->flags = SHF_ALLOC;
 			sh->addralign = 1;
+			if(interpreter == nil) {
 				switch(HEADTYPE) {
 				case 7:
-				elfinterp(sh, startva, linuxdynld);
+					interpreter = linuxdynld;
 					break;
 				case 9:
-				elfinterp(sh, startva, freebsddynld);
+					interpreter = freebsddynld;
 					break;
 				}
+			}
+			elfinterp(sh, startva, interpreter);
 
 			ph = newElfPhdr();
 			ph->type = PT_INTERP;

src/cmd/8l/doc.go

@@ -29,6 +29,8 @@ Options new in this version:
 	Write Apple Mach-O binaries (default when $GOOS is darwin)
 -H7
 	Write Linux ELF binaries (default when $GOOS is linux)
+-I interpreter
+	Set the ELF dynamic linker to use.
 -L dir1 -L dir2
 	Search for libraries (package files) in dir1, dir2, etc.
 	The default is the single location $GOROOT/pkg/$GOOS_386.

src/cmd/8l/l.h

@@ -315,6 +315,7 @@ EXTERN	int	maxop;
 EXTERN	int	nerrors;
 EXTERN	char*	noname;
 EXTERN	int32	pc;
+EXTERN	char*	interpreter;
 EXTERN	char*	rpath;
 EXTERN	int32	spsize;
 EXTERN	Sym*	symlist;

src/cmd/8l/obj.c

@@ -64,7 +64,7 @@ char	*thestring 	= "386";
 void
 usage(void)
 {
-	fprint(2, "usage: 8l [-options] [-E entry] [-H head] [-L dir] [-T text] [-R rnd] [-r path] [-o out] main.8\n");
+	fprint(2, "usage: 8l [-options] [-E entry] [-H head] [-I interpreter] [-L dir] [-T text] [-R rnd] [-r path] [-o out] main.8\n");
 	exits("usage");
 }
 
@@ -102,6 +102,9 @@ main(int argc, char *argv[])
 	case 'H':
 		HEADTYPE = atolwhex(EARGF(usage()));
 		break;
+	case 'I':
+		interpreter = EARGF(usage());
+		break;
 	case 'L':
 		Lflag(EARGF(usage()));
 		break;