8l: pe changes

Dll names and function names padded to even size.
Refactoring of imports writing code.

R=rsc
CC=golang-dev
https://golang.org/cl/3804042

diff --git a/src/cmd/ld/pe.c b/src/cmd/ld/pe.c
index 82c6941f251dcb226f5cf67a3b4091249a95a327..661d3071855a332b45a7d9bd7d1d75c35740eaf9 100644 (file)
--- a/src/cmd/ld/pe.c
+++ b/src/cmd/ld/pe.c
@@ -48,21 +48,20 @@ static IMAGE_SECTION_HEADER sh[16];
 typedef struct Imp Imp;
 struct Imp {
        Sym* s;
-       long va;
-       long vb;
+       uvlong off;
        Imp* next;
 };
 
 typedef struct Dll Dll;
 struct Dll {
        char* name;
-       int count;
+       uvlong nameoff;
+       uvlong thunkoff;
        Imp* ms;
        Dll* next;
 };
 
 static Dll* dr;
-static int ndll, nimp, nsize;
 
 static IMAGE_SECTION_HEADER*
 addpesection(char *name, int sectsize, int filesize, Segment *s)
@@ -136,9 +135,15 @@ pewrite(void)
 static void
 strput(char *s)
 {
-       while(*s)
+       int n;
+
+       for(n=0; *s; n++)
                cput(*s++);
        cput('\0');
+       n++;
+       // string must be padded to even size
+       if(n%2)
+               cput('\0');
 }
 
 static Dll* 
@@ -146,50 +151,33 @@ initdynimport(void)
 {
        Imp *m;
        Dll *d;
-       Sym *s;
+       Sym *s, *dynamic;
        int i;
-       Sym *dynamic;
 
        dr = nil;
-       ndll = 0;
-       nimp = 0;
-       nsize = 0;
        
        for(i=0; i<NHASH; i++)
        for(s = hash[i]; s != S; s = s->hash) {
                if(!s->reachable || !s->dynimpname)
                        continue;
-               nimp++;
                for(d = dr; d != nil; d = d->next) {
                        if(strcmp(d->name,s->dynimplib) == 0) {
                                m = mal(sizeof *m);
-                               m->s = s;
-                               m->next = d->ms;
-                               d->ms = m;
-                               d->count++;
-                               nsize += strlen(s->dynimpname)+2+1;
                                break;
                        }
                }
                if(d == nil) {
                        d = mal(sizeof *d);
                        d->name = s->dynimplib;
-                       d->count = 1;
                        d->next = dr;
                        dr = d;
                        m = mal(sizeof *m);
-                       m->s = s;
-                       m->next = 0;
-                       d->ms = m;
-                       ndll++;
-                       nsize += strlen(s->dynimpname)+2+1;
-                       nsize += strlen(s->dynimplib)+1;
                }
+               m->s = s;
+               m->next = d->ms;
+               d->ms = m;
        }
        
-       nsize += 20*ndll + 20;
-       nsize += 4*nimp + 4*ndll;
-       
        dynamic = lookup(".windynamic", 0);
        dynamic->reachable = 1;
        dynamic->type = SWINDOWS;
@@ -211,83 +199,84 @@ static void
 addimports(vlong fileoff, IMAGE_SECTION_HEADER *datsect)
 {
        IMAGE_SECTION_HEADER *isect;
-       uint32 va;
-       int noff, aoff, o, last_fn, last_name_off, iat_off;
+       uvlong n, oftbase, ftbase;
        Imp *m;
        Dll *d;
        Sym* dynamic;
        
-       isect = addpesection(".idata", nsize, nsize, 0);
-       isect->Characteristics = IMAGE_SCN_CNT_INITIALIZED_DATA|
-               IMAGE_SCN_MEM_READ|IMAGE_SCN_MEM_WRITE;
-       va = isect->VirtualAddress;
-       oh.DataDirectory[IMAGE_DIRECTORY_ENTRY_IMPORT].VirtualAddress = va;
-       oh.DataDirectory[IMAGE_DIRECTORY_ENTRY_IMPORT].Size = isect->VirtualSize;
-
-       seek(cout, fileoff, 0);
-
        dynamic = lookup(".windynamic", 0);
-       iat_off = dynamic->value - PEBASE; // FirstThunk allocated in .data
-       oh.DataDirectory[IMAGE_DIRECTORY_ENTRY_IAT].VirtualAddress = iat_off;
-       oh.DataDirectory[IMAGE_DIRECTORY_ENTRY_IAT].Size = dynamic->size;
 
-       noff = va + 20*ndll + 20;
-       aoff = noff + 4*nimp + 4*ndll;
-       last_fn = 0;
-       last_name_off = aoff;
+       // skip import descriptor table (will write it later)
+       n = 0;
+       for(d = dr; d != nil; d = d->next)
+               n++;
+       seek(cout, fileoff + sizeof(IMAGE_IMPORT_DESCRIPTOR) * (n + 1), 0);
+
+       // write dll names
        for(d = dr; d != nil; d = d->next) {
-               lputl(noff);
-               lputl(0);
-               lputl(0);
-               lputl(last_name_off);
-               lputl(iat_off);
-               last_fn = d->count;
-               noff += 4*last_fn + 4;
-               aoff += 4*last_fn + 4;
-               iat_off += 4*last_fn + 4;
-               last_name_off += strlen(d->name)+1;
+               d->nameoff = cpos() - fileoff;
+               strput(d->name);
        }
-       lputl(0); //end
-       lputl(0);
-       lputl(0);
-       lputl(0);
-       lputl(0);
-       
-       // put OriginalFirstThunk
-       o = last_name_off;
+
+       // write function names
        for(d = dr; d != nil; d = d->next) {
                for(m = d->ms; m != nil; m = m->next) {
-                       lputl(o);
-                       o += 2 + strlen(m->s->dynimpname) + 1;
+                       m->off = nextsectoff + cpos() - fileoff;
+                       wputl(0); // hint
+                       strput(m->s->dynimpname);
                }
-               lputl(0);
        }
-       // put names
+       
+       // write OriginalFirstThunks
+       oftbase = cpos() - fileoff;
+       n = cpos();
        for(d = dr; d != nil; d = d->next) {
-               strput(d->name);
+               d->thunkoff = cpos() - n;
+               for(m = d->ms; m != nil; m = m->next)
+                       lputl(m->off);
+               lputl(0);
        }
-       // put hint+name
+
+       // add pe section and pad it at the end
+       n = cpos() - fileoff;
+       isect = addpesection(".idata", n, n, 0);
+       isect->Characteristics = IMAGE_SCN_CNT_INITIALIZED_DATA|
+               IMAGE_SCN_MEM_READ|IMAGE_SCN_MEM_WRITE;
+       strnput("", isect->SizeOfRawData - n);
+       cflush();
+
+       // write FirstThunks (allocated in .data section)
+       ftbase = dynamic->value - datsect->VirtualAddress - PEBASE;
+       seek(cout, datsect->PointerToRawData + ftbase, 0);
        for(d = dr; d != nil; d = d->next) {
-               for(m = d->ms; m != nil; m = m->next) {
-                       wputl(0);
-                       strput(m->s->dynimpname);
-               }
+               for(m = d->ms; m != nil; m = m->next)
+                       lputl(m->off);
+               lputl(0);
        }
-       
-       strnput("", isect->SizeOfRawData - nsize);
        cflush();
 
-       // put FirstThunk
-       o = last_name_off;
-       seek(cout, datsect->PointerToRawData + dynamic->value - PEBASE - datsect->VirtualAddress, 0);
+       // finally write import descriptor table
+       seek(cout, fileoff, 0);
        for(d = dr; d != nil; d = d->next) {
-               for(m = d->ms; m != nil; m = m->next) {
-                       lputl(o);
-                       o += 2 + strlen(m->s->dynimpname) + 1;
-               }
+               lputl(isect->VirtualAddress + oftbase + d->thunkoff);
+               lputl(0);
                lputl(0);
+               lputl(isect->VirtualAddress + d->nameoff);
+               lputl(datsect->VirtualAddress + ftbase + d->thunkoff);
        }
+       lputl(0); //end
+       lputl(0);
+       lputl(0);
+       lputl(0);
+       lputl(0);
        cflush();
+       
+       // update data directory
+       oh.DataDirectory[IMAGE_DIRECTORY_ENTRY_IMPORT].VirtualAddress = isect->VirtualAddress;
+       oh.DataDirectory[IMAGE_DIRECTORY_ENTRY_IMPORT].Size = isect->VirtualSize;
+       oh.DataDirectory[IMAGE_DIRECTORY_ENTRY_IAT].VirtualAddress = dynamic->value - PEBASE;
+       oh.DataDirectory[IMAGE_DIRECTORY_ENTRY_IAT].Size = dynamic->size;
+
        seek(cout, 0, 2);
 }