Centralize elf soname provide addition, comment

- Remember DT_SONAME in the elfInfo struct if encountered and
  only add it after everything else has been processed. This doesn't
  change any actual functionality for now, but gives us a single
  place where to control the addition.
- Additionally document what the related DT_DEBUG test is for and
  clean up the processDynamic() loop and switch-case a bit.
(cherry picked from commit 8e3ce7417a20dd8bca4676c0a598fc4932d22eef)

diff --git a/tools/elfdeps.c b/tools/elfdeps.c
index 2a8fea3..ab8ca90 100644 (file)
--- a/tools/elfdeps.c
+++ b/tools/elfdeps.c
@@ -24,7 +24,7 @@ typedef struct elfInfo_s {
     int gotDEBUG;
     int gotHASH;
     int gotGNUHASH;
-    int gotSONAME;
+    char *soname;
     const char *marker;                /* elf class marker or NULL */
 
     ARGV_t requires;
@@ -152,7 +152,6 @@ static void processDynamic(Elf_Scn *scn, GElf_Shdr *shdr, elfInfo *ei)
     Elf_Data *data = NULL;
     while ((data = elf_getdata(scn, data)) != NULL) {
        for (int i = 0; i < (shdr->sh_size / shdr->sh_entsize); i++) {
-           ARGV_t *deptype = NULL;
            const char *s = NULL;
            GElf_Dyn dyn_mem, *dyn;
 
@@ -171,22 +170,17 @@ static void processDynamic(Elf_Scn *scn, GElf_Shdr *shdr, elfInfo *ei)
                ei->gotDEBUG = 1;
                break;
            case DT_SONAME:
-               ei->gotSONAME = 1;
                s = elf_strptr(ei->elf, shdr->sh_link, dyn->d_un.d_val);
-               deptype = &ei->provides;
+               if (s)
+                   ei->soname = rstrdup(s);
                break;
            case DT_NEEDED:
                if (ei->isExec) {
                    s = elf_strptr(ei->elf, shdr->sh_link, dyn->d_un.d_val);
-                   deptype = &ei->requires;
+                   if (s)
+                       addDep(&ei->requires, s, NULL, ei->marker);
                }
                break;
-           default:
-               break;
-           }
-
-           if (s && deptype) {
-               addDep(deptype, s, NULL, ei->marker);
            }
        }
     }
@@ -254,10 +248,18 @@ static int processFile(const char *fn, int dtype)
        argvAdd(&ei->requires, "rtld(GNU_HASH)");
     }
 
-    /* For DSO's, provide the basename of the file if DT_SONAME not found. */
-    if (ei->isDSO && !ei->gotDEBUG && !ei->gotSONAME && fake_soname) {
-       const char *bn = strrchr(fn, '/');
-       addDep(&ei->provides, bn ? bn + 1 : fn, NULL, ei->marker);
+    /*
+     * For DSOs, add DT_SONAME as provide. If its missing, we can fake
+     * it from the basename if requested. The bizarre looking DT_DEBUG
+     * check is used to avoid adding basename provides for PIE executables.
+     */
+    if (ei->isDSO && !ei->gotDEBUG) {
+       if (!ei->soname && fake_soname) {
+           const char *bn = strrchr(fn, '/');
+           ei->soname = rstrdup(bn ? bn + 1 : fn);
+       }
+       if (ei->soname)
+           addDep(&ei->provides, ei->soname, NULL, ei->marker);
     }
 
     rc = 0;
@@ -271,6 +273,7 @@ exit:
     if (ei) {
        argvFree(ei->provides);
        argvFree(ei->requires);
+       free(ei->soname);
        if (ei->elf) elf_end(ei->elf);
        rfree(ei);
     }