COFF: Implement /pdbaltpath flag.

I needed to revert r330223 because we were embedding an absolute PDB path in the .rdata section, which ended up being laid out before the .idata section and affecting its RVAs. This flag will let us control the embedded path. Differential Revision: https://reviews.llvm.org/D45747 llvm-svn: 330232
llvm · Apr 17, 2018 · 94aa62e · 94aa62e
1 parent 5578901
commit 94aa62e
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Showing 4 changed files with 26 additions and 21 deletions.
diff --git a/lld/COFF/Config.h b/lld/COFF/Config.h
@@ -100,6 +100,7 @@ struct Configuration {
   bool ShowTiming = false;
   unsigned DebugTypes = static_cast<unsigned>(DebugType::None);
   std::vector<std::string> NatvisFiles;
+  llvm::SmallString<128> PDBAltPath;
   llvm::SmallString<128> PDBPath;
   std::vector<llvm::StringRef> Argv;
 

diff --git a/lld/COFF/Driver.cpp b/lld/COFF/Driver.cpp
@@ -936,6 +936,8 @@ void LinkerDriver::link(ArrayRef<const char *> ArgsArr) {
   if (ShouldCreatePDB) {
     if (auto *Arg = Args.getLastArg(OPT_pdb))
       Config->PDBPath = Arg->getValue();
+    if (auto *Arg = Args.getLastArg(OPT_pdbaltpath))
+      Config->PDBAltPath = Arg->getValue();
     if (Args.hasArg(OPT_natvis))
       Config->NatvisFiles = Args.getAllArgValues(OPT_natvis);
   }
@@ -1301,10 +1303,19 @@ void LinkerDriver::link(ArrayRef<const char *> ArgsArr) {
         getOutputPath((*Args.filtered(OPT_INPUT).begin())->getValue());
   }
 
-  // Put the PDB next to the image if no /pdb flag was passed.
-  if (ShouldCreatePDB && Config->PDBPath.empty()) {
-    Config->PDBPath = Config->OutputFile;
-    sys::path::replace_extension(Config->PDBPath, ".pdb");
+  if (ShouldCreatePDB) {
+    // Put the PDB next to the image if no /pdb flag was passed.
+    if (Config->PDBPath.empty()) {
+      Config->PDBPath = Config->OutputFile;
+      sys::path::replace_extension(Config->PDBPath, ".pdb");
+    }
+
+    // The embedded PDB path should be the absolute path to the PDB if no
+    // /pdbaltpath flag was passed.
+    if (Config->PDBAltPath.empty()) {
+      Config->PDBAltPath = Config->PDBPath;
+      sys::fs::make_absolute(Config->PDBAltPath);
+    }
   }
 
   // Set default image base if /base is not given.

diff --git a/lld/COFF/Writer.cpp b/lld/COFF/Writer.cpp
@@ -121,14 +121,8 @@ class DebugDirectoryChunk : public Chunk {
 
 class CVDebugRecordChunk : public Chunk {
 public:
-  CVDebugRecordChunk() {
-    PDBAbsPath = Config->PDBPath;
-    if (!PDBAbsPath.empty())
-      llvm::sys::fs::make_absolute(PDBAbsPath);
-  }
-
   size_t getSize() const override {
-    return sizeof(codeview::DebugInfo) + PDBAbsPath.size() + 1;
+    return sizeof(codeview::DebugInfo) + Config->PDBAltPath.size() + 1;
   }
 
   void writeTo(uint8_t *B) const override {
@@ -138,12 +132,11 @@ class CVDebugRecordChunk : public Chunk {
 
     // variable sized field (PDB Path)
     char *P = reinterpret_cast<char *>(B + OutputSectionOff + sizeof(*BuildId));
-    if (!PDBAbsPath.empty())
-      memcpy(P, PDBAbsPath.data(), PDBAbsPath.size());
-    P[PDBAbsPath.size()] = '\0';
+    if (!Config->PDBAltPath.empty())
+      memcpy(P, Config->PDBAltPath.data(), Config->PDBAltPath.size());
+    P[Config->PDBAltPath.size()] = '\0';
   }
 
-  SmallString<128> PDBAbsPath;
   mutable codeview::DebugInfo *BuildId = nullptr;
 };
 

diff --git a/lld/test/COFF/rsds.test b/lld/test/COFF/rsds.test
@@ -1,16 +1,16 @@
 # RUN: yaml2obj %s > %t.obj
 
 # RUN: rm -f %t.dll %t.pdb
-# RUN: lld-link /debug /dll /out:%t.dll /entry:DllMain %t.obj
+# RUN: lld-link /debug /pdbaltpath:test1.pdb /dll /out:%t.dll /entry:DllMain %t.obj
 # RUN: llvm-readobj -coff-debug-directory %t.dll > %t.1.txt
-# RUN: lld-link /debug /dll /out:%t.dll /entry:DllMain %t.obj
+# RUN: lld-link /debug /pdbaltpath:test2.pdb /dll /out:%t.dll /entry:DllMain %t.obj
 # RUN: llvm-readobj -coff-debug-directory %t.dll > %t.2.txt
 # RUN: cat %t.1.txt %t.2.txt | FileCheck %s
 
 # RUN: rm -f %t.dll %t.pdb
-# RUN: lld-link /debug /pdb:%t.pdb /dll /out:%t.dll /entry:DllMain %t.obj
+# RUN: lld-link /debug /pdb:%t1.pdb /dll /out:%t.dll /entry:DllMain %t.obj
 # RUN: llvm-readobj -coff-debug-directory %t.dll > %t.3.txt
-# RUN: lld-link /debug /pdb:%t.pdb /dll /out:%t.dll /entry:DllMain %t.obj
+# RUN: lld-link /debug /pdb:%t2.pdb /dll /out:%t.dll /entry:DllMain %t.obj
 # RUN: llvm-readobj -coff-debug-directory %t.dll > %t.4.txt
 # RUN: cat %t.3.txt %t.4.txt | FileCheck %s
 
@@ -29,7 +29,7 @@
 # CHECK:       PDBSignature: 0x53445352
 # CHECK:       PDBGUID: [[GUID:\(([A-Za-z0-9]{2} ?){16}\)]]
 # CHECK:       PDBAge: 1
-# CHECK:       PDBFileName: {{.*}}.pdb
+# CHECK:       PDBFileName: {{.*}}1.pdb
 # CHECK:     }
 # CHECK:   }
 # CHECK: ]
@@ -48,7 +48,7 @@
 # CHECK:       PDBSignature: 0x53445352
 # CHECK:       PDBGUID: [[GUID]]
 # CHECK:       PDBAge: 2
-# CHECK:       PDBFileName: {{.*}}.pdb
+# CHECK:       PDBFileName: {{.*}}2.pdb
 # CHECK:     }
 # CHECK:   }
 # CHECK: ]