[ELF] Fix GCC8 warnings about "fall through", NFCI

hahnjo · hahnjo · commit ffd66b23e66b · 2019-03-13T10:38:17.000Z
Add break statements in Object/ELF.cpp since the code should consider the generic tags for Hexagon, MIPS, and PPC. Add a test (copied from llvm-readobj) to show that this works correctly (earlier versions of this patch would have asserted). The warnings in X86ELFObjectWriter.cpp are actually false-positives since the nested switch() handles all possible values and returns in all cases. Make this explicit by adding llvm_unreachable's. Differential Revision: https://reviews.llvm.org/D58837 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@356037 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Object/ELF.cpp b/lib/Object/ELF.cpp
@@ -438,20 +438,23 @@ std::string ELFFile<ELFT>::getDynamicTagAsString(unsigned Arch,
 #include "llvm/BinaryFormat/DynamicTags.def"
 #undef HEXAGON_DYNAMIC_TAG
     }
+    break;
 
   case ELF::EM_MIPS:
     switch (Type) {
 #define MIPS_DYNAMIC_TAG(name, value) DYNAMIC_STRINGIFY_ENUM(name, value)
 #include "llvm/BinaryFormat/DynamicTags.def"
 #undef MIPS_DYNAMIC_TAG
     }
+    break;
 
   case ELF::EM_PPC64:
     switch (Type) {
 #define PPC64_DYNAMIC_TAG(name, value) DYNAMIC_STRINGIFY_ENUM(name, value)
 #include "llvm/BinaryFormat/DynamicTags.def"
 #undef PPC64_DYNAMIC_TAG
     }
+    break;
   }
 #undef DYNAMIC_TAG
   switch (Type) {
diff --git a/lib/Target/X86/MCTargetDesc/X86ELFObjectWriter.cpp b/lib/Target/X86/MCTargetDesc/X86ELFObjectWriter.cpp
@@ -113,6 +113,7 @@ static unsigned getRelocType64(MCContext &Ctx, SMLoc Loc,
     case RT64_8:
       return IsPCRel ? ELF::R_X86_64_PC8 : ELF::R_X86_64_8;
     }
+    llvm_unreachable("unexpected relocation type!");
   case MCSymbolRefExpr::VK_GOT:
     switch (Type) {
     case RT64_64:
@@ -124,6 +125,7 @@ static unsigned getRelocType64(MCContext &Ctx, SMLoc Loc,
     case RT64_8:
       llvm_unreachable("Unimplemented");
     }
+    llvm_unreachable("unexpected relocation type!");
   case MCSymbolRefExpr::VK_GOTOFF:
     assert(Type == RT64_64);
     assert(!IsPCRel);
@@ -140,6 +142,7 @@ static unsigned getRelocType64(MCContext &Ctx, SMLoc Loc,
     case RT64_8:
       llvm_unreachable("Unimplemented");
     }
+    llvm_unreachable("unexpected relocation type!");
   case MCSymbolRefExpr::VK_DTPOFF:
     assert(!IsPCRel);
     switch (Type) {
@@ -152,6 +155,7 @@ static unsigned getRelocType64(MCContext &Ctx, SMLoc Loc,
     case RT64_8:
       llvm_unreachable("Unimplemented");
     }
+    llvm_unreachable("unexpected relocation type!");
   case MCSymbolRefExpr::VK_SIZE:
     assert(!IsPCRel);
     switch (Type) {
@@ -164,6 +168,7 @@ static unsigned getRelocType64(MCContext &Ctx, SMLoc Loc,
     case RT64_8:
       llvm_unreachable("Unimplemented");
     }
+    llvm_unreachable("unexpected relocation type!");
   case MCSymbolRefExpr::VK_TLSCALL:
     return ELF::R_X86_64_TLSDESC_CALL;
   case MCSymbolRefExpr::VK_TLSDESC:
@@ -196,6 +201,7 @@ static unsigned getRelocType64(MCContext &Ctx, SMLoc Loc,
     case X86::reloc_riprel_4byte_movq_load:
       return ELF::R_X86_64_REX_GOTPCRELX;
     }
+    llvm_unreachable("unexpected relocation type!");
   }
 }
 
@@ -233,6 +239,7 @@ static unsigned getRelocType32(MCContext &Ctx,
     case RT32_8:
       return IsPCRel ? ELF::R_386_PC8 : ELF::R_386_8;
     }
+    llvm_unreachable("unexpected relocation type!");
   case MCSymbolRefExpr::VK_GOT:
     assert(Type == RT32_32);
     if (IsPCRel)
diff --git a/test/tools/llvm-objdump/elf-dynamic-section-machine-specific.test b/test/tools/llvm-objdump/elf-dynamic-section-machine-specific.test
@@ -0,0 +1,77 @@
+# Test that hexagon machine-specific tags can be dumped.
+# RUN: yaml2obj --docnum=1 -o %t.hex \
+# RUN:          %S/../llvm-readobj/Inputs/elf-dynamic-tags-machine-specific.yaml
+# RUN: llvm-objdump -p %t.hex | FileCheck %s --check-prefix=HEXAGON
+
+# HEXAGON:      Dynamic Section:
+# HEXAGON-NEXT:   HASH                 0x0000000000001000
+# HEXAGON-NEXT:   HEXAGON_SYMSZ        0x0000000000000010
+# HEXAGON-NEXT:   HEXAGON_VER          0x0000000000001000
+# HEXAGON-NEXT:   HEXAGON_PLT          0x0000000000001000
+# HEXAGON-NEXT:   <unknown:>0x1234abcd 0x0000000000000001
+
+
+# Test that MIPS machine-specific tags can be dumped.
+# RUN: yaml2obj --docnum=2 -o %t.mips \
+# RUN:          %S/../llvm-readobj/Inputs/elf-dynamic-tags-machine-specific.yaml
+# RUN: llvm-objdump -p %t.mips | FileCheck %s --check-prefix=MIPS
+
+# MIPS:      Dynamic Section:
+# MIPS-NEXT:   HASH                 0x0000000000001000
+# MIPS-NEXT:   MIPS_RLD_VERSION     0x0000000012345678
+# MIPS-NEXT:   MIPS_TIME_STAMP      0x0000000011223344
+# MIPS-NEXT:   MIPS_ICHECKSUM       0x0000000011112222
+# MIPS-NEXT:   MIPS_IVERSION        0x0000000000000001
+# MIPS-NEXT:   MIPS_FLAGS           0x0000000011111111
+# MIPS-NEXT:   MIPS_BASE_ADDRESS    0x0000000087654321
+# MIPS-NEXT:   MIPS_MSYM            0x0000000000001000
+# MIPS-NEXT:   MIPS_CONFLICT        0x0000000000001000
+# MIPS-NEXT:   MIPS_LIBLIST         0x0000000000001000
+# MIPS-NEXT:   MIPS_LOCAL_GOTNO     0x0000000000000001
+# MIPS-NEXT:   MIPS_CONFLICTNO      0x0000000000000001
+# MIPS-NEXT:   MIPS_LIBLISTNO       0x0000000000000001
+# MIPS-NEXT:   MIPS_SYMTABNO        0x0000000000000001
+# MIPS-NEXT:   MIPS_UNREFEXTNO      0x0000000000000000
+# MIPS-NEXT:   MIPS_GOTSYM          0x0000000000000000
+# MIPS-NEXT:   MIPS_HIPAGENO        0x0000000088776655
+# MIPS-NEXT:   MIPS_RLD_MAP         0x0000000000001000
+# MIPS-NEXT:   MIPS_DELTA_CLASS     0x0000000000001000
+# MIPS-NEXT:   MIPS_DELTA_CLASS_NO  0x0000000000000001
+# MIPS-NEXT:   MIPS_DELTA_INSTANCE  0x0000000000001000
+# MIPS-NEXT:   MIPS_DELTA_INSTANCE_NO0x0000000000000001
+# MIPS-NEXT:   MIPS_DELTA_RELOC     0x0000000000001000
+# MIPS-NEXT:   MIPS_DELTA_RELOC_NO  0x0000000000000001
+# MIPS-NEXT:   MIPS_DELTA_SYM       0x0000000000001000
+# MIPS-NEXT:   MIPS_DELTA_SYM_NO    0x0000000000000001
+# MIPS-NEXT:   MIPS_DELTA_CLASSSYM  0x0000000000001000
+# MIPS-NEXT:   MIPS_DELTA_CLASSSYM_NO0x0000000000000001
+# MIPS-NEXT:   MIPS_CXX_FLAGS       0x0000000088887777
+# MIPS-NEXT:   MIPS_PIXIE_INIT      0x0000000000001000
+# MIPS-NEXT:   MIPS_LOCALPAGE_GOTIDX0x0000000000000001
+# MIPS-NEXT:   MIPS_LOCAL_GOTIDX    0x0000000000000001
+# MIPS-NEXT:   MIPS_HIDDEN_GOTIDX   0x0000000000000001
+# MIPS-NEXT:   MIPS_PROTECTED_GOTIDX0x0000000000000001
+# MIPS-NEXT:   MIPS_OPTIONS         0x0000000000001000
+# MIPS-NEXT:   MIPS_INTERFACE       0x0000000000001000
+# MIPS-NEXT:   MIPS_DYNSTR_ALIGN    0x0000000088888888
+# MIPS-NEXT:   MIPS_INTERFACE_SIZE  0x0000000000000010
+# MIPS-NEXT:   MIPS_RLD_TEXT_RESOLVE_ADDR0x0000000000000008
+# MIPS-NEXT:   MIPS_PERF_SUFFIX     0x0000000000000000
+# MIPS-NEXT:   MIPS_COMPACT_SIZE    0x0000000000000010
+# MIPS-NEXT:   MIPS_GP_VALUE        0x0000000000000001
+# MIPS-NEXT:   MIPS_AUX_DYNAMIC     0x0000000000001000
+# MIPS-NEXT:   MIPS_PLTGOT          0x0000000000001000
+# MIPS-NEXT:   MIPS_RWPLT           0x0000000000001000
+# MIPS-NEXT:   MIPS_RLD_MAP_REL     0x0000000000001000
+# MIPS-NEXT:   <unknown:>0x1234abcd 0x0000000000000001
+
+
+# Test that PPC64 machine-specific tags can be dumped.
+# RUN: yaml2obj --docnum=3 -o %t.ppc \
+# RUN:          %S/../llvm-readobj/Inputs/elf-dynamic-tags-machine-specific.yaml
+# RUN: llvm-objdump -p %t.ppc | FileCheck %s --check-prefix=PPC
+
+# PPC:      Dynamic Section:
+# PPC-NEXT:   HASH                 0x0000000000001000
+# PPC-NEXT:   PPC64_GLINK          0x0000000000001000
+# PPC-NEXT:   <unknown:>0x1234abcd 0x0000000000000001
diff --git a/test/tools/llvm-readobj/Inputs/elf-dynamic-tags-machine-specific.yaml b/test/tools/llvm-readobj/Inputs/elf-dynamic-tags-machine-specific.yaml
@@ -0,0 +1,202 @@
+# Used by llvm-readobj/elf-dynamic-tags-machine-specific.test and
+# llvm-objdump/elf-dynamic-section-machine-specific.test.
+
+# First document: Hexagon
+--- !ELF
+FileHeader:
+  Class:   ELFCLASS64
+  Data:    ELFDATA2LSB
+  Type:    ET_EXEC
+  Machine: EM_HEXAGON
+Sections:
+  - Name:    .dynstr
+    Type:    SHT_STRTAB
+    Address: 0x1000
+    Size:    0x10
+    Content: "004400550066007700"
+  - Name:    .dynamic
+    Type:    SHT_DYNAMIC
+    Address: 0x1010
+    Entries:
+      - Tag:   DT_HASH
+        Value: 0x1000
+      - Tag:   DT_HEXAGON_SYMSZ
+        Value: 0x10
+      - Tag:   DT_HEXAGON_VER
+        Value: 0x1000
+      - Tag:   DT_HEXAGON_PLT
+        Value: 0x1000
+      - Tag:   0x1234abcd
+        Value: 0x1
+      - Tag:   DT_NULL
+        Value: 0
+ProgramHeaders:
+  - Type: PT_LOAD
+    VAddr: 0x1000
+    Sections:
+      - Section: .dynstr
+      - Section: .dynamic
+  - Type: PT_DYNAMIC
+    VAddr: 0x1010
+    Sections:
+      - Section: .dynamic
+
+# Second document: MIPS
+--- !ELF
+FileHeader:
+  Class:   ELFCLASS64
+  Data:    ELFDATA2LSB
+  Type:    ET_EXEC
+  Machine: EM_MIPS
+Sections:
+  - Name:    .dynstr
+    Type:    SHT_STRTAB
+    Address: 0x1000
+    Size:    0x10
+    Content: "004400550066007700"
+  - Name:    .dynamic
+    Type:    SHT_DYNAMIC
+    Address: 0x1010
+    Entries:
+      - Tag:   DT_HASH
+        Value: 0x1000
+      - Tag:   DT_MIPS_RLD_VERSION
+        Value: 0x12345678
+      - Tag:   DT_MIPS_TIME_STAMP
+        Value: 0x11223344
+      - Tag:   DT_MIPS_ICHECKSUM
+        Value: 0x11112222
+      - Tag:   DT_MIPS_IVERSION
+        Value: 0x1
+      - Tag:   DT_MIPS_FLAGS
+        Value: 0x11111111
+      - Tag:   DT_MIPS_BASE_ADDRESS
+        Value: 0x87654321
+      - Tag:   DT_MIPS_MSYM
+        Value: 0x1000
+      - Tag:   DT_MIPS_CONFLICT
+        Value: 0x1000
+      - Tag:   DT_MIPS_LIBLIST
+        Value: 0x1000
+      - Tag:   DT_MIPS_LOCAL_GOTNO
+        Value: 0x1
+      - Tag:   DT_MIPS_CONFLICTNO
+        Value: 0x1
+      - Tag:   DT_MIPS_LIBLISTNO
+        Value: 0x1
+      - Tag:   DT_MIPS_SYMTABNO
+        Value: 0x1
+      - Tag:   DT_MIPS_UNREFEXTNO
+        Value: 0x0
+      - Tag:   DT_MIPS_GOTSYM
+        Value: 0x0
+      - Tag:   DT_MIPS_HIPAGENO
+        Value: 0x88776655
+      - Tag:   DT_MIPS_RLD_MAP
+        Value: 0x1000
+      - Tag:   DT_MIPS_DELTA_CLASS
+        Value: 0x1000
+      - Tag:   DT_MIPS_DELTA_CLASS_NO
+        Value: 0x1
+      - Tag:   DT_MIPS_DELTA_INSTANCE
+        Value: 0x1000
+      - Tag:   DT_MIPS_DELTA_INSTANCE_NO
+        Value: 0x1
+      - Tag:   DT_MIPS_DELTA_RELOC
+        Value: 0x1000
+      - Tag:   DT_MIPS_DELTA_RELOC_NO
+        Value: 0x1
+      - Tag:   DT_MIPS_DELTA_SYM
+        Value: 0x1000
+      - Tag:   DT_MIPS_DELTA_SYM_NO
+        Value: 0x1
+      - Tag:   DT_MIPS_DELTA_CLASSSYM
+        Value: 0x1000
+      - Tag:   DT_MIPS_DELTA_CLASSSYM_NO
+        Value: 0x1
+      - Tag:   DT_MIPS_CXX_FLAGS
+        Value: 0x88887777
+      - Tag:   DT_MIPS_PIXIE_INIT
+        Value: 0x1000
+      - Tag:   DT_MIPS_LOCALPAGE_GOTIDX
+        Value: 0x1
+      - Tag:   DT_MIPS_LOCAL_GOTIDX
+        Value: 0x1
+      - Tag:   DT_MIPS_HIDDEN_GOTIDX
+        Value: 0x1
+      - Tag:   DT_MIPS_PROTECTED_GOTIDX
+        Value: 0x1
+      - Tag:   DT_MIPS_OPTIONS
+        Value: 0x1000
+      - Tag:   DT_MIPS_INTERFACE
+        Value: 0x1000
+      - Tag:   DT_MIPS_DYNSTR_ALIGN
+        Value: 0x88888888
+      - Tag:   DT_MIPS_INTERFACE_SIZE
+        Value: 0x10
+      - Tag:   DT_MIPS_RLD_TEXT_RESOLVE_ADDR
+        Value: 0x8
+      - Tag:   DT_MIPS_PERF_SUFFIX
+        Value: 0x0
+      - Tag:   DT_MIPS_COMPACT_SIZE
+        Value: 0x10
+      - Tag:   DT_MIPS_GP_VALUE
+        Value: 0x1
+      - Tag:   DT_MIPS_AUX_DYNAMIC
+        Value: 0x1000
+      - Tag:   DT_MIPS_PLTGOT
+        Value: 0x1000
+      - Tag:   DT_MIPS_RWPLT
+        Value: 0x1000
+      - Tag:   DT_MIPS_RLD_MAP_REL
+        Value: 0x1000
+      - Tag:   0x1234abcd
+        Value: 0x1
+      - Tag:   DT_NULL
+        Value: 0
+ProgramHeaders:
+  - Type: PT_LOAD
+    VAddr: 0x1000
+    Sections:
+      - Section: .dynstr
+      - Section: .dynamic
+  - Type: PT_DYNAMIC
+    VAddr: 0x1010
+    Sections:
+      - Section: .dynamic
+
+# Third document: PPC64
+--- !ELF
+FileHeader:
+  Class:   ELFCLASS64
+  Data:    ELFDATA2LSB
+  Type:    ET_EXEC
+  Machine: EM_PPC64
+Sections:
+  - Name:    .dynstr
+    Type:    SHT_STRTAB
+    Address: 0x1000
+    Size:    0x10
+    Content: "004400550066007700"
+  - Name:    .dynamic
+    Type:    SHT_DYNAMIC
+    Address: 0x1010
+    Entries:
+      - Tag:   DT_HASH
+        Value: 0x1000
+      - Tag:   DT_PPC64_GLINK
+        Value: 0x1000
+      - Tag:   0x1234abcd
+        Value: 0x1
+      - Tag:   DT_NULL
+        Value: 0
+ProgramHeaders:
+  - Type: PT_LOAD
+    VAddr: 0x1000
+    Sections:
+      - Section: .dynstr
+      - Section: .dynamic
+  - Type: PT_DYNAMIC
+    VAddr: 0x1010
+    Sections:
+      - Section: .dynamic
diff --git a/test/tools/llvm-readobj/elf-dynamic-tags-machine-specific.test b/test/tools/llvm-readobj/elf-dynamic-tags-machine-specific.test

Original file line number	Diff line number	Diff line change
`@@ -438,20 +438,23 @@ std::string ELFFile<ELFT>::getDynamicTagAsString(unsigned Arch,`
`438`	`438`	`#include "llvm/BinaryFormat/DynamicTags.def"`
`439`	`439`	`#undef HEXAGON_DYNAMIC_TAG`
`440`	`440`	`}`
	`441`	`+ break;`
`441`	`442`
`442`	`443`	`case ELF::EM_MIPS:`
`443`	`444`	`switch (Type) {`
`444`	`445`	`#define MIPS_DYNAMIC_TAG(name, value) DYNAMIC_STRINGIFY_ENUM(name, value)`
`445`	`446`	`#include "llvm/BinaryFormat/DynamicTags.def"`
`446`	`447`	`#undef MIPS_DYNAMIC_TAG`
`447`	`448`	`}`
	`449`	`+ break;`
`448`	`450`
`449`	`451`	`case ELF::EM_PPC64:`
`450`	`452`	`switch (Type) {`
`451`	`453`	`#define PPC64_DYNAMIC_TAG(name, value) DYNAMIC_STRINGIFY_ENUM(name, value)`
`452`	`454`	`#include "llvm/BinaryFormat/DynamicTags.def"`
`453`	`455`	`#undef PPC64_DYNAMIC_TAG`
`454`	`456`	`}`
	`457`	`+ break;`
`455`	`458`	`}`
`456`	`459`	`#undef DYNAMIC_TAG`
`457`	`460`	`switch (Type) {`
Original file line number	Diff line number	Diff line change
`@@ -113,6 +113,7 @@ static unsigned getRelocType64(MCContext &Ctx, SMLoc Loc,`
`113`	`113`	`case RT64_8:`
`114`	`114`	`return IsPCRel ? ELF::R_X86_64_PC8 : ELF::R_X86_64_8;`
`115`	`115`	`}`
	`116`	`+ llvm_unreachable("unexpected relocation type!");`
`116`	`117`	`case MCSymbolRefExpr::VK_GOT:`
`117`	`118`	`switch (Type) {`
`118`	`119`	`case RT64_64:`
`@@ -124,6 +125,7 @@ static unsigned getRelocType64(MCContext &Ctx, SMLoc Loc,`
`124`	`125`	`case RT64_8:`
`125`	`126`	`llvm_unreachable("Unimplemented");`
`126`	`127`	`}`
	`128`	`+ llvm_unreachable("unexpected relocation type!");`
`127`	`129`	`case MCSymbolRefExpr::VK_GOTOFF:`
`128`	`130`	`assert(Type == RT64_64);`
`129`	`131`	`assert(!IsPCRel);`
`@@ -140,6 +142,7 @@ static unsigned getRelocType64(MCContext &Ctx, SMLoc Loc,`
`140`	`142`	`case RT64_8:`
`141`	`143`	`llvm_unreachable("Unimplemented");`
`142`	`144`	`}`
	`145`	`+ llvm_unreachable("unexpected relocation type!");`
`143`	`146`	`case MCSymbolRefExpr::VK_DTPOFF:`
`144`	`147`	`assert(!IsPCRel);`
`145`	`148`	`switch (Type) {`
`@@ -152,6 +155,7 @@ static unsigned getRelocType64(MCContext &Ctx, SMLoc Loc,`
`152`	`155`	`case RT64_8:`
`153`	`156`	`llvm_unreachable("Unimplemented");`
`154`	`157`	`}`
	`158`	`+ llvm_unreachable("unexpected relocation type!");`
`155`	`159`	`case MCSymbolRefExpr::VK_SIZE:`
`156`	`160`	`assert(!IsPCRel);`
`157`	`161`	`switch (Type) {`
`@@ -164,6 +168,7 @@ static unsigned getRelocType64(MCContext &Ctx, SMLoc Loc,`
`164`	`168`	`case RT64_8:`
`165`	`169`	`llvm_unreachable("Unimplemented");`
`166`	`170`	`}`
	`171`	`+ llvm_unreachable("unexpected relocation type!");`
`167`	`172`	`case MCSymbolRefExpr::VK_TLSCALL:`
`168`	`173`	`return ELF::R_X86_64_TLSDESC_CALL;`
`169`	`174`	`case MCSymbolRefExpr::VK_TLSDESC:`
`@@ -196,6 +201,7 @@ static unsigned getRelocType64(MCContext &Ctx, SMLoc Loc,`
`196`	`201`	`case X86::reloc_riprel_4byte_movq_load:`
`197`	`202`	`return ELF::R_X86_64_REX_GOTPCRELX;`
`198`	`203`	`}`
	`204`	`+ llvm_unreachable("unexpected relocation type!");`
`199`	`205`	`}`
`200`	`206`	`}`
`201`	`207`
`@@ -233,6 +239,7 @@ static unsigned getRelocType32(MCContext &Ctx,`
`233`	`239`	`case RT32_8:`
`234`	`240`	`return IsPCRel ? ELF::R_386_PC8 : ELF::R_386_8;`
`235`	`241`	`}`
	`242`	`+ llvm_unreachable("unexpected relocation type!");`
`236`	`243`	`case MCSymbolRefExpr::VK_GOT:`
`237`	`244`	`assert(Type == RT32_32);`
`238`	`245`	`if (IsPCRel)`